CLI


Line plots across dimensions of each concept
Tables

Table of contents



us-gaap:CommonStockValue
us-gaap:StatementEquityComponents
us-gaap:SharesOutstanding

us-gaap:CommonStockSharesOutstanding
us-gaap:SubsequentEventType

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic
dei:LegalEntity

us-gaap:EarningsPerShareDiluted
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare
dei:LegalEntity

us-gaap:Revenues
dei:LegalEntity
dei:LegalEntity, us-gaap:ProductOrService
us-gaap:ProductOrService
us-gaap:StatementBusinessSegments

us-gaap:CostOfGoodsAndServicesSold
dei:LegalEntity
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

us-gaap:OperatingCostsAndExpenses
dei:LegalEntity

us-gaap:CostsAndExpenses
dei:LegalEntity

us-gaap:GeneralAndAdministrativeExpense
dei:LegalEntity

us-gaap:InterestExpense
dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation

us-gaap:IncomeLossFromContinuingOperations
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
dei:LegalEntity

us-gaap:ProfitLoss
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest
dei:LegalEntity

us-gaap:NetIncomeLoss
dei:LegalEntity

us-gaap:ComprehensiveIncomeNetOfTax
dei:LegalEntity

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic
dei:LegalEntity

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted
dei:LegalEntity

us-gaap:Assets
dei:LegalEntity
us-gaap:StatementBusinessSegments

us-gaap:Liabilities
dei:LegalEntity

us-gaap:LiabilitiesAndStockholdersEquity
dei:LegalEntity

us-gaap:StockholdersEquity
us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:CashAndCashEquivalentsAtCarryingValue
dei:LegalEntity
us-gaap:DisposalGroupClassification
us-gaap:Land
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
dei:LegalEntity
us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StatementBusinessSegments

us-gaap:Goodwill

us-gaap:LongTermDebt
us-gaap:DebtInstrument
us-gaap:LongtermDebtType

us-gaap:MinorityInterest
us-gaap:StatementEquityComponents

us-gaap:StockholdersEquity
us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:AdditionalPaidInCapital

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:MinorityInterest
us-gaap:StatementEquityComponents

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetIncomeLoss
dei:LegalEntity

us-gaap:ProfitLoss
dei:LegalEntity

us-gaap:DepreciationDepletionAndAmortization
dei:LegalEntity

us-gaap:ShareBasedCompensation
dei:LegalEntity

us-gaap:AmortizationOfFinancingCosts

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:PaymentsForRepurchaseOfCommonStock
dei:LegalEntity

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity

cli:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

cli:AmortizationOfDebtDiscountAndMarkToMarket
dei:LegalEntity

cli:AmortizationOfDeferredStockUnits
dei:LegalEntity
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:TaxPeriod
cli:AnnualPercentageOfCostForPhaseIn
us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
cli:AnnualReturnOnEquityValueBaseReturn
us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
cli:AnnualReturnOnEquityValueCapitalBaseReturn
us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:StatementScenario, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty

cli:BuildingsAndImprovementsNetOfAccumulatedDepreciation
us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification, us-gaap:PropertyPlantAndEquipmentByType

cli:CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses

cli:CommonStockDividendsAndCommonUnitDistributionsPerShare
us-gaap:SubsequentEventType

cli:CommonUnits

cli:CommonUnitsConversionOfVestedLtipUnitsToCommonStock

cli:CommonUnitsRedeemedForCommonShares

cli:CommonUnitsVestedLtipUnits

cli:ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestJointVenturePartnersNonredeemable
dei:LegalEntity

cli:ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestOperatingPartnershipsNonredeemable

cli:ComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNoncontrollingInterest
dei:LegalEntity

cli:CostsOfRealEstateServices
dei:LegalEntity
us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
cli:DebtInstrumentExtensionFeePercentage
us-gaap:CreditFacility
cli:DebtInstrumentNumberOfExtensionOptions
us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrument

cli:DeferredStockUnitsConverted

cli:DeferredStockUnitsSharesEarned

cli:DepreciationAmortizationOnDiscontinuedOperations
us-gaap:DisposalGroupClassification
cli:DisposalGroupIncludingDiscontinuedOperationLandNetValue
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupClassification
cli:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cli:DistributionsInExcessOfCumulativeEarningsFromJvs
dei:LegalEntity

cli:EquityMethodInvestmentAmortizationOfBasisDifference
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty
cli:EstimatedCostOfProject
us-gaap:DisposalGroupClassification
cli:GainLossOnDispositionOfLandDiscontinuedOperations
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cli:GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses
us-gaap:DisposalGroupClassification

cli:GainLossOnSaleOfRealizedAndUnrealizedPropertyPlantEquipment
dei:LegalEntity

cli:ImpairmentOfLandAndOther
dei:LegalEntity
us-gaap:StatementGeographical
us-gaap:StatementGeographical, us-gaap:DisposalGroupClassification

cli:IncomeLossFromContinuingOperationsBasic
dei:LegalEntity

cli:IncomeLossFromContinuingOperationsDiluted

cli:IncomeLossFromContinuingOperationsDilutedEarningsPerShare
dei:LegalEntity

cli:IncomeLossFromDiscontinuedOperationsAvailableToCommonShareholders
dei:LegalEntity

cli:IncreaseDecreaseImpairmentOfLandAndOt

cli:IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits
dei:LegalEntity

cli:IncreaseDecreaseInUnbilledRentReceivables
dei:LegalEntity

cli:InvestmentIncomeLossNonoperating
dei:LegalEntity

cli:LeasingPersonnelCosts

cli:LongTermIncentivePlanIssuanceOfUnits

cli:LongTermIncentivePlanUnitsForfeited

cli:LongTermIncentivePlanVested

cli:ManagementLeasingDevelopmentAndOtherServicesFees
us-gaap:StatementEquityComponents
cli:MinorityInterestDecreaseFromNoncontrollingInterest

cli:MinorityInterestIncreaseDecreaseFromRedemptions
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

cli:NoncontrollingInterestInDiscontinuedOperations
us-gaap:PartnerTypeOfPartnersCapitalAccount
cli:NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance
us-gaap:StatementEquityComponents

cli:NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemable
dei:LegalEntity
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership
dei:LegalEntity

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership

cli:NonoperatingIncomeExpenseIncludingEquityMethodInvestments
dei:LegalEntity
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cli:NumberOfDisposalGroups
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:DisposalGroupClassification
us-gaap:StatementGeographical, us-gaap:DisposalGroupClassification
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:DisposalGroupClassification
cli:NumberOfPropertiesSold

cli:OperatingAndInterestExpenses
us-gaap:StatementBusinessSegments

cli:OperatingLeaseExpenseIncludingSubleaseRentals
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty
cli:PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:TaxPeriod
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty
cli:PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:TaxPeriod
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty
cli:PaymentsInLieuOfPropertyTaxes

cli:PaymentsToDevelopPropertyAndOtherRelatedCosts
dei:LegalEntity
us-gaap:TitleOfIndividual, us-gaap:PlanName
cli:PercentageOfAward
us-gaap:Range, us-gaap:AwardType, us-gaap:PlanName, us-gaap:Vesting
cli:PercentageOfSharesVested
us-gaap:ConsolidatedEntities, us-gaap:Range, us-gaap:RelatedPartyTransaction
cli:PreferredUnitsContributionToObtainEquityUnits
us-gaap:ConsolidatedEntities, us-gaap:PreferredUnitsByName
cli:ProRataDistributionPercent
us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:PreferredUnitsByName
us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:StatementEquityComponents
us-gaap:NonrecurringAdjustment
cli:ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary

cli:PropertyNetBookValue
us-gaap:PropertyPlantAndEquipmentByType

cli:RealEstateDevelopmentCostsIncurred
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:RealEstatePropertyOwnedAndInvestmentInterest
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty
cli:RealEstatePropertyOwnedAndInvestmentInterestArea

cli:RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations
dei:LegalEntity

cli:RealizedGainsLossOnDispositionOfAssetsNet
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents
cli:RedeemableNoncontrollingInterestDecreaseFromDistribution
us-gaap:PreferredUnitsByName, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

cli:RedeemableNoncontrollingInterestRedemptionValueAdjustment
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
cli:RedemptionOfCommonUnits
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:DisposalGroupClassification
cli:RedemptionOfCommonUnitsShares
us-gaap:ConsolidatedEntities, us-gaap:RelatedPartyTransaction
cli:RightOfFirstRefusalToInvestInPreferredUnitsAmount

cli:SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
dei:LegalEntity
us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:AwardType
cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnvestedInPeriod
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:Vesting
cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsSharesToBeVestedAndExpectedToVestExercisableNumber
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:Vesting
cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger
us-gaap:PartnerTypeOfPartnersCapitalAccount
cli:StockBasedCompensationAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
cli:StockIssuedDuringPeriodSharesLongTermIncentivePlanVested
us-gaap:StatementEquityComponents
cli:StockIssuedDuringPeriodValueLongTermIncentivePlanUnitsForfeited
us-gaap:PlanName
cli:TotalStockholderReturnPercent

cli:UnrealizedGainLossOnDispositionOfRentalProperty
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cli:WriteOffOfUnamortizedDeferredFinancingCosts
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings

us-gaap:AmortizationOfFinancingCostsAndDiscounts
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
dei:LegalEntity

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations
dei:LegalEntity

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
dei:LegalEntity

us-gaap:CommonStockDividendsPerShareDeclared
dei:LegalEntity

us-gaap:DeferredCompensationArrangementWithIndividualExercisePrice

us-gaap:DepreciationAndAmortization
dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation
us-gaap:DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation
us-gaap:DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet

us-gaap:DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax
dei:LegalEntity

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax
dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization
dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationInterestExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue

us-gaap:DividendsCommonStock
us-gaap:StatementEquityComponents
dei:LegalEntity
us-gaap:DividendsCommonStockCash
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementEquityComponents
us-gaap:SubsequentEventType

us-gaap:EmployeeBenefitsAndShareBasedCompensation

us-gaap:EquityMethodInvestmentDividendsOrDistributions
dei:LegalEntity

us-gaap:ExtinguishmentOfDebtGainLossNetOfTax

us-gaap:GainLossOnDispositionOfAssets
dei:LegalEntity

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax
dei:LegalEntity

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare
dei:LegalEntity

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare
dei:LegalEntity

us-gaap:IncomeLossFromEquityMethodInvestments
dei:LegalEntity
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInInterestPayableNet
dei:LegalEntity

us-gaap:IncreaseDecreaseInLeasingReceivables
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherOperatingAssets
dei:LegalEntity

us-gaap:InterestCostsCapitalized
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:InterestPaid
us-gaap:DisposalGroupClassification
us-gaap:CreditFacility
us-gaap:LineOfCreditFacilityCommitmentFeePercentage
us-gaap:CreditFacility, us-gaap:DebtInstrument
us-gaap:CreditRatingMoodys, us-gaap:CreditRatingStandardPoors, us-gaap:CreditFacility

us-gaap:MinorityInterestPeriodIncreaseDecrease
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
dei:LegalEntity
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:NetIncomeLossAttributableToNonredeemableNoncontrollingInterest
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents
us-gaap:PreferredUnitsByName, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable
dei:LegalEntity

us-gaap:NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax
dei:LegalEntity

us-gaap:PaymentsOfCapitalDistribution
dei:LegalEntity

us-gaap:PaymentsOfFinancingCosts
dei:LegalEntity

us-gaap:PaymentsToAcquireAndDevelopRealEstate
dei:LegalEntity
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:BusinessAcquisition

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired
dei:LegalEntity

us-gaap:PaymentsToAcquireInterestInJointVenture
dei:LegalEntity

us-gaap:ProceedsFromCollectionOfLoansReceivable
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfSecuredDebt
dei:LegalEntity

us-gaap:ProceedsFromPaymentsToMinorityShareholders
dei:LegalEntity

us-gaap:ProceedsFromSaleOfBuildings
dei:LegalEntity
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, us-gaap:SubsequentEventType
us-gaap:DisposalGroupClassification
us-gaap:ProceedsFromSaleOfLandHeldforinvestment
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:ProceedsFromUnsecuredLinesOfCredit
dei:LegalEntity

us-gaap:RealEstateTaxExpense
dei:LegalEntity

us-gaap:RepaymentsOfLinesOfCredit
dei:LegalEntity

us-gaap:RepaymentsOfSecuredDebt
dei:LegalEntity

us-gaap:RestrictedStockExpense

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
us-gaap:RelatedPartyTransactionsByRelatedParty, us-gaap:SubsequentEventType
us-gaap:TitleOfIndividual, us-gaap:AwardType
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StockDividendsShares
us-gaap:StatementEquityComponents
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StockIssuedDuringPeriodSharesConversionOfUnits

us-gaap:StockIssuedDuringPeriodValueDividendReinvestmentPlan
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensationForfeited
dei:LegalEntity
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:StatementEquityComponents

us-gaap:StockOptionPlanExpense
us-gaap:AwardType
us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents
us-gaap:TemporaryEquityStockIssuedDuringPeriodValueNewIssues
us-gaap:PreferredUnitsByName, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:UnrealizedGainLossOnInvestments
us-gaap:DisposalGroupClassification
us-gaap:StatementGeographical
us-gaap:StatementGeographical, us-gaap:DisposalGroupClassification
dei:LegalEntity
us-gaap:WeightedAverageLimitedPartnershipUnitsOutstanding
dei:LegalEntity
us-gaap:WeightedAverageLimitedPartnershipUnitsOutstandingDiluted

cli:AccumulatedAmortizationLeasingAndFinancingCosts
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty
cli:AmountToFund
us-gaap:DisposalGroupClassification
cli:AreaOfRealEstatePropertySold
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableTotalBelowMarketLiability
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableUnearnedRentsDeferredRentalIncome
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesNet
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupMortgagesLoansPayableNet
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:AssetsHeldForSaleNotPartOfDisposalGroupTotalIntangiblesNet
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification
cli:BuildingsAndImprovementsAvailableForSale
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification

cli:CommonUnitsOutstanding
us-gaap:SubsequentEventType

cli:ConsolidatedJointVenturesMortgages

cli:ConsolidatedJointVenturesOtherLiabilities

cli:ConsolidatedJointVenturesRealEstateAssets
us-gaap:CreditFacility
cli:DebtLoansPayableAndOtherObligationsNet

cli:DeferredCostsGross

cli:DeferredStockUnitsOutstanding

cli:DevelopmentAndConstructionInProgressIncludingLand

cli:GeneralPartnerOwnershipPercentage

cli:LandAndLeasehold
dei:LegalEntity

cli:LongLivedAssets
us-gaap:StatementBusinessSegments

cli:LongTermIncentivePlanUnitsOutstanding
us-gaap:SubsequentEventType

cli:MortgagePropertyCarryingValue
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty

cli:NetInvestmentInRentalPropertyAndRentalPropertyHeldForSale
dei:LegalEntity
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:DisposalGroupClassification
cli:NumberOfRealEstatePropertiesHeldForSale
us-gaap:StatementGeographical, us-gaap:DisposalGroupClassification
us-gaap:StatementGeographical, us-gaap:DisposalGroupClassification, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty
cli:NumberOfTenants

cli:NumberOfUnitsInRealEstatePropertyInOperations
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:RentalPropertyHeldForSaleNet
dei:LegalEntity
us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification

cli:RentsReceivedInAdvanceAndSecurityDeposits
dei:LegalEntity
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cli:ResidualOwnershipInterest
us-gaap:CreditFacility
cli:UnamortizedDeferredFinancingCosts
us-gaap:LongtermDebtType
us-gaap:DisposalGroupClassification
cli:UnrealizedGainLossOnInvestmentsHeldForSale
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent
dei:LegalEntity

us-gaap:AccountsReceivableNet
dei:LegalEntity

us-gaap:DebtInstrumentCarryingAmount
us-gaap:CreditFacility
us-gaap:CreditFacility, us-gaap:DebtInstrument
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, us-gaap:SubsequentEventType
us-gaap:LongtermDebtType

us-gaap:DebtInstrumentFairValue
us-gaap:LongtermDebtType
us-gaap:DebtInstrumentUnamortizedDiscount

us-gaap:DeferredCosts

us-gaap:DeferredCostsLeasingGross

us-gaap:DeferredFinanceCostsGross

us-gaap:DeferredRentReceivablesNet
dei:LegalEntity

us-gaap:DividendsPayableCurrentAndNoncurrent
dei:LegalEntity

us-gaap:DueFromJointVentures
us-gaap:AwardType
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
us-gaap:PlanName

us-gaap:EscrowDeposit

us-gaap:FiniteLivedIntangibleAssetAcquiredInPlaceLeases

us-gaap:FixturesAndEquipmentGross
dei:LegalEntity
dei:LegalEntity
us-gaap:GeneralPartnersCapitalAccount
dei:LegalEntity
us-gaap:GeneralPartnersCapitalAccountUnitsOutstanding

us-gaap:InterestPayableCurrentAndNoncurrent
dei:LegalEntity

us-gaap:InvestmentBuildingAndBuildingImprovements
dei:LegalEntity

us-gaap:LandAndLandImprovements
us-gaap:DisposalGroupClassification
us-gaap:LandAvailableForSale

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
dei:LegalEntity
us-gaap:LimitedPartnersCapitalAccount
dei:LegalEntity
us-gaap:LimitedPartnersCapitalAccountUnitsOutstanding

us-gaap:LineOfCredit
dei:LegalEntity
us-gaap:CreditFacility, us-gaap:DebtInstrument
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:LongtermDebtType

us-gaap:LoansAndLeasesReceivableNetReportedAmount
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

us-gaap:LongtermDebtWeightedAverageInterestRate
us-gaap:DebtInstrument

us-gaap:MinorityInterestInJointVentures

us-gaap:MinorityInterestInOperatingPartnerships
us-gaap:Ownership
us-gaap:MinorityInterestOwnershipPercentageByNoncontrollingOwners
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty
us-gaap:MortgageLoansOnRealEstate
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:NumberOfRealEstateProperties
us-gaap:FairValueByAssetClass
us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty
us-gaap:PropertyPlantAndEquipmentByType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:DisposalGroupClassification
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:DisposalGroupClassification
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:DisposalGroupClassification
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:OperatingLeaseLiability
us-gaap:AdjustmentsForNewAccountingPronouncements

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivable

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivableCurrent

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivableInFourYears

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivableRemainderOfFiscalYear

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivableThereafter

us-gaap:OtherAssets
dei:LegalEntity
us-gaap:DisposalGroupClassification
dei:LegalEntity
us-gaap:PartnersCapital
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnersCapitalAccountUnits
dei:LegalEntity
us-gaap:PartnersCapitalAttributableToNoncontrollingInterest
dei:LegalEntity
us-gaap:PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:PrepaidExpenseAndOtherAssets

us-gaap:RealEstateInvestmentPropertyAccumulatedDepreciation
dei:LegalEntity
us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupClassification, us-gaap:LongLivedAssetsHeldForSaleByAssetType

us-gaap:RealEstateInvestmentPropertyAtCost
dei:LegalEntity

us-gaap:RealEstateInvestmentPropertyNet
dei:LegalEntity

us-gaap:RedeemableNoncontrollingInterestEquityFairValue
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents
us-gaap:PreferredUnitsByName, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:RestrictedCashAndCashEquivalents
dei:LegalEntity

us-gaap:SecuredDebt
dei:LegalEntity

us-gaap:SecurityDeposit

us-gaap:SeniorNotes
dei:LegalEntity

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
dei:LegalEntity, us-gaap:AwardType
us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
us-gaap:Range, us-gaap:RelatedPartyTransactionsByRelatedParty, us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
us-gaap:PlanName

us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions

us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions
us-gaap:PlanName

us-gaap:SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1
us-gaap:PlanName
us-gaap:Range, us-gaap:RelatedPartyTransactionsByRelatedParty, us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:SharesIssuedPricePerShare

us-gaap:TenantImprovements
dei:LegalEntity

Tables

  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:CommonStockValue █████▅▅▅▄▄▂▂▂▁0.9060.9060.9060.9060.9060.9030.9030.9030.9020.9010.8990.8990.8990.898
 us-gaap:SharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock█████▅▅▅▅▄▂▂▂▁90.59790.59690.59590.55290.55390.32690.3290.30790.28690.13689.91489.91489.91489.845
us-gaap:CommonStockSharesOutstanding █████▅▅▅▅▄▂▂▂▁90.59672390.59607990.59517690.55196790.55335790.32578390.32030690.3072890.28626890.13627889.91411389.91357689.91391989.844752
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁100.213100.183NA100.56100.523100.943NA100.712100.598100.604NA100.727100.37100.637
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁90.62990.616NA90.58490.53390.498NA90.46890.3390.263NA90.02390.01189.955
us-gaap:EarningsPerShareBasic ▂▁▁▁▁█▃▂▂▃▂▃▁▃-0.41-0.47-0.64-0.65-0.432.670.45-0.05-0.050.45-0.010.39-0.440.11
us-gaap:EarningsPerShareDiluted ▂▁▁▁▁█▃▂▂▃▂▃▁▃-0.41-0.47-0.64-0.65-0.432.660.45-0.05-0.050.45-0.010.39-0.440.11
us-gaap:IncomeLossFromContinuingOperationsPerBasicShare ▁▁▄▁▁█▃▂▂▃-5.1e-07-4.1e-075.3e-07-6.4e-07-4.5000000000000003e-072.5899999999999998e-063.7e-07-1.2e-07-1.3e-074.2e-07NANANANA
 us-gaap:IncomeLossFromContinuingOperationsPerBasicShare dei:LegalEntity cli:MackCaliRealtyLp▁▁▄▁▁█▃▂▂▃-5.1e-07-4.1e-075.3e-07-6.4e-07-4.5000000000000003e-072.5899999999999998e-063.7e-07-1.2e-07-1.3e-074.2e-07NANANANA
us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare ▁▂▄▁▁█▃▂▂▃-5.1e-07-4.1e-075.3e-07-6.4e-07-4.5000000000000003e-072.58e-063.7e-07-1.2e-07-1.3e-074.2e-07NANANANA
 us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare dei:LegalEntity cli:MackCaliRealtyLp▁▂▄▁▁█▃▂▂▃-5.1e-07-4.1e-075.3e-07-6.4e-07-4.5000000000000003e-072.58e-063.7e-07-1.2e-07-1.3e-074.2e-07NANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:Revenues ▁▂▂▆▅▆▆▆▅▆▇██▇72.6582.05786.673131.884130.461134.249132.936132.114126.589138.967143.529160.018162.766149.887
us-gaap:CostOfGoodsAndServicesSold ▁█3.1133.853NANA4.0916.112NANANANANANANANA
us-gaap:OperatingCostsAndExpenses ▆▆▁█████▇█████15.63316.064-8.71827.23626.16124.96226.96227.10722.93925.61826.88426.31227.09227.091
us-gaap:CostsAndExpenses ▆▆▁██▇█▇▇▇▇██▇93.83389.452-4.908129.65128.815118.137136.456114.61107.688118.801120.131130.814134.818125.09
us-gaap:GeneralAndAdministrativeExpense █▆▇▂▇▂▃▁▃▇▄▃▂▁17.24215.81816.46112.05416.42712.59312.82811.6213.45516.08513.72613.1412.49111.592
us-gaap:InterestExpense ▃▃▁▆▆▇▆▃▁▂▅█▇▃20.61220.91818.8323.4523.51524.77423.58621.09418.99920.07522.4925.63424.94320.321
us-gaap:IncomeLossFromContinuingOperations ▁█-42.734-32.091NANA-22.479267.366NANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperations dei:LegalEntity cli:MackCaliRealtyLp▁█-42.734-32.091NANA-22.479267.366NANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest ▁▂▃▁▂█▃▂▂▃▂▃▁▃-42.734-32.09153.31-56.021-20.329275.59452.5231.6891.50150.6885.41144.703-39.12522.729
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity cli:MackCaliRealtyLp▁▂▃▁▂█▃▂▂▃▂▃▁▃-42.734-32.09153.31-56.021-20.329275.59452.5231.6891.50150.6885.41144.703-39.12522.729
us-gaap:ProfitLoss ▁▁▁▁▂█▃▂▂▃▂▃▁▃-32.934-37.844-55.408-56.021-20.329275.59452.5231.6891.50150.6885.41144.703-39.12522.729
 us-gaap:ProfitLoss dei:LegalEntity cli:MackCaliRealtyLp▁▁▁▁▂█▃▂▂▃▂▃▁▃-32.934-37.844-55.408-56.021-20.329275.59452.5231.6891.50150.6885.41144.703-39.12522.729
us-gaap:OtherComprehensiveIncomeLossNetOfTax ▄▄▄▄▁▁▁▅▆██▅▄▅0.0-0.016-0.205-0.878-4.624-4.451-4.9690.3541.7885.1454.6460.73-1.3531.227
 us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity cli:MackCaliRealtyLp▄▄▄▄▁▁▁▅▆██▅▄▅0.0-0.016-0.205-0.878-4.624-4.451-4.9690.3541.7885.1454.6460.73-1.3531.227
 us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity,us-gaap:PartnerTypeOfPartnersCapitalAccount cli:MackCaliRealtyLp,cli:LimitedPartnersCommonUnitholders▆▆▆▅▁▂▁▇█0.0-0.034-0.02-0.087-0.46-0.413-0.5050.0360.182NANANANANA
 us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity,us-gaap:StatementEquityComponents cli:MackCaliRealtyLp,us-gaap:AccumulatedOtherComprehensiveIncome▄▄▄▄▁▂▁▅▆██▅▄▅0.00.018-0.185-0.791-4.164-3.648-4.4640.3181.6064.6214.1630.654-1.2131.1
 us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:PartnerTypeOfPartnersCapitalAccount cli:GeneralPartnerCommonUnitholders▁█0.00.018NA-0.791-4.164-4.038NA0.3181.6064.621NANANANA
 us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedOtherComprehensiveIncome▄▄▄▄▁▂▁▅▆██▅▄▅0.00.018-0.185-0.791-4.164-3.648-4.4640.3181.6064.6214.1630.654-1.2131.1
 us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:NoncontrollingInterest▄▄▄▄▁▂▁▅▆██▅▃▅0.0-0.034-0.02-0.087-0.46-0.413-0.5050.0360.1820.5240.4830.076-0.140.127
us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest ▂▁▁▁▂█▃▂▂▃▂▃▁▃-32.934-37.86-55.613-56.899-24.953271.53347.5542.0433.28955.83310.05745.433-40.47823.956
 us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity cli:MackCaliRealtyLp▂▁▁▁▂█▃▂▂▃▂▃▁▃-32.934-37.86-55.613-56.899-24.953271.53347.5542.0433.28955.83310.05745.433-40.47823.956
us-gaap:NetIncomeLoss ▁▁▁▁▂█▃▂▂▃▂▃▁▃-34.887-39.924-54.652-55.928-22.054244.49543.804-1.478-1.25143.0362.58238.054-37.3319.879
 us-gaap:NetIncomeLoss dei:LegalEntity cli:MackCaliRealtyLp▁▁▁▁▂█▃▂▂▃▂▃▁▃-38.576-44.139-60.475-62.087-24.488272.17548.757-1.645-1.39347.9192.88142.467-41.62622.174
us-gaap:ComprehensiveIncomeNetOfTax ▂▁▁▁▂█▃▂▂▃▂▃▁▃-34.887-39.906-54.837-56.719-26.218240.84739.34-1.160.35547.6576.74538.708-38.54320.979
 us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity cli:MackCaliRealtyLp▂▁▁▁▂█▃▂▂▃▂▃▁▃-38.576-44.155-60.68-62.965-29.112268.11443.788-1.2910.39553.0647.52743.197-42.97923.401
us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic ▂▁▁▁▁█▃▂▂▃▂▃▁▃-37.123-42.728-57.601-58.953-38.813241.34341.178-4.144-4.6340.282-0.2335.326-39.88110.019
 us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic dei:LegalEntity cli:MackCaliRealtyLp▂▁▁▁▁█▃▂▂▃▂▃▁▃-41.049-47.239-63.738-65.446-43.097268.66645.834-4.613-5.15644.852-0.25739.423-44.47111.176
us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted ▂▁▁▁▁█▃▂▂▃▂▃▁▃-41.049-47.239-63.738-65.446-43.097268.66645.834-4.613-5.15644.852-0.25739.423-44.47111.176
 us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted dei:LegalEntity cli:MackCaliRealtyLp▂▁▁▁▁█▃▂▂▃▂▃▁▃-41.049-47.239-63.738-65.446-43.097268.66645.834-4.613-5.15644.852-0.25739.423-44.47111.176
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
 COGS Ratio dei:LegalEntity cli:MackCaliRealtyLp▁▂▂▆▆▆▆▆▅▆▇█72.6582.05786.673131.884130.461134.249132.936132.114126.589138.967143.529160.018NANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:Assets ▅▅▅█▅▅▃▃▁▁▂▂▃▂5360.0125285.5325292.7985720.9355327.7125274.2845060.6445046.1944858.2844815.6064957.8854995.5195076.4944914.227
us-gaap:Liabilities ▆▄▄█▂▂▃▃▁▁▃▄▅▂3257.5613146.893089.9413429.9572955.2922951.9223033.0043062.1132896.7532889.3693076.9543106.1753211.8422986.651
us-gaap:LiabilitiesAndStockholdersEquity ▅▅▅█▅▅▃▃▁▁▂▂▃▂5360.0125285.5325292.7985720.9355327.7125274.2845060.6445046.1944858.2844815.6064957.8854995.5195076.4944914.227
us-gaap:StockholdersEquity ▁▂▃▅▇█▃▃▃▄▃▃▃▄1399.0331434.1431493.6991569.2611645.5871704.0181486.6581467.0441487.2471508.0911476.2951488.4661468.6691528.29
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:CashAndCashEquivalentsAtCarryingValue ▂▂▂▂▃▁▂▁▂▂▂▄▁█26.29525.26425.58934.76860.63812.06129.63310.82329.66425.30728.1888.78921.719168.316
 us-gaap:Land us-gaap:DisposalGroupClassification us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations▁▆█38.946.348.5NANANANANANANANANANANA
 us-gaap:Land us-gaap:PropertyPlantAndEquipmentByType cli:Development▅▅▇▄█▁▁▁▄▄▄84.085.596.671.2108.849.649.649.671.772.677.0NANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:PropertyPlantAndEquipmentGross ▆▄▃▁▄▁▁▄▆█▇974.942915.333852.812786.693917.836792.967792.969914.1951004.8181065.7841019.403NANANA
us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures ▁▁▁▂▂▂▃▃▄▄▄▃▇█200.409202.574209.091213.499215.957212.961232.75230.614247.607249.513252.626238.44315.11325.15
us-gaap:Goodwill ██▁███████████2.9452.9452.92.9452.9452.9452.9452.9452.9452.9452.9452.9452.9452.945
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:LongTermDebt ▆▄▃█▂▂▃▃▁▁▃▄▅▃2990.4652877.1212808.5183169.552705.8962701.3452792.6512821.7932660.5172630.6142809.5682856.6762968.6992751.244
us-gaap:MinorityInterest ▂▂▃▆▇█▄▄▁▁▁▁▁▂194.463198.017205.776221.598230.461239.149210.523209.622190.069192.82192.428191.808189.957196.572
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:StockholdersEquity ▁▂▃▅▇█▃▃▃▄▃▃▃▄1399.0331434.1431493.6991569.2611645.5871704.0181486.6581467.0441487.2471508.0911476.2951488.4661468.6691528.29
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest ▁▂▃▅▇█▃▃▃▃▃▃▂▄1593.4961632.161699.4751790.8591876.0481943.1671697.1811676.6661677.3161700.9111668.7231680.2741658.6261724.862
us-gaap:CommonStockValue █████▅▅▅▄▄▂▂▂▁0.9060.9060.9060.9060.9060.9030.9030.9030.9020.9010.8990.8990.8990.898
us-gaap:AdditionalPaidInCapital ▁▁▁▂▂▅▆▇▇▇▇▇▇█2533.6862533.9092535.442538.0462539.5472553.6522561.5032563.1652564.1532567.32565.1362566.0692566.9972570.093
us-gaap:RetainedEarningsAccumulatedDeficit ▁▂▃▅▇█▂▂▂▃▂▂▂▃-1135.559-1100.672-1042.629-969.858-895.824-855.659-1084.518-1110.258-1090.724-1071.42-1096.429-1081.028-1101.099-1045.786
us-gaap:MinorityInterest ▂▂▃▆▇█▄▄▁▁▁▁▁▂194.463198.017205.776221.598230.461239.149210.523209.622190.069192.82192.428191.808189.957196.572
us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders ▁████▇██▇████▆-0.792.272.2882.362.3611.6962.2622.3642.1362.262.3342.3342.3141.647
 us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders dei:LegalEntity cli:MackCaliRealtyLp▁████████████▆-0.7920.38920.40720.46620.47219.76120.32620.4220.18920.28720.31720.31720.29715.128
 us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders dei:LegalEntity,us-gaap:PartnerTypeOfPartnersCapitalAccount cli:MackCaliRealtyLp,cli:GeneralPartnerCommonUnitholders▁████████0.018.11918.11918.10618.11118.06518.06418.05618.053NANANANANA
 us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders dei:LegalEntity,us-gaap:PartnerTypeOfPartnersCapitalAccount cli:MackCaliRealtyLp,cli:LimitedPartnersCommonUnitholders▁████▇██▇-0.792.272.2882.362.3611.6962.2622.3642.136NANANANANA
 us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:PartnerTypeOfPartnersCapitalAccount cli:GeneralPartnerCommonUnitholders▁█0.018.119NA18.10618.11118.065NA18.05618.05318.027NANANANA
 us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:StatementEquityComponents us-gaap:NoncontrollingInterest▁████▇██▇████▆-0.792.272.2882.362.3611.6962.2622.3642.1362.262.3342.3342.3141.647
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▆▁▇▃▆▅▆▃█▄█▇▇24.59143.66310.93552.08722.78346.03740.81644.32125.03756.89933.52858.8552.44951.313
us-gaap:NetCashProvidedByUsedInInvestingActivities ▅▆█▁▆▇▆▄▅█▆█▄▂-111.082-83.098120.006-512.759-52.2128.888-0.636-215.404-95.662143.548-22.68127.457-227.953-422.53
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cli:MackCaliRealtyLp▅▆█▁▆▇▆▄▅█▆█▄▂-111.082-83.098120.006-512.759-52.2128.888-0.636-215.404-95.662143.548-22.68127.457-227.953-422.53
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▃▂▇▄▂▃▄▄▁▂▂▃█85.80339.394-144.178436.54575.335-91.857-21.568150.2462.273-208.282-57.978-134.93127.478511.566
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▆▁▇▃▆▅▆▃█▄█▇▇24.59143.66310.93552.08722.78346.03740.81644.32125.03756.89933.52858.8552.44951.313
us-gaap:NetIncomeLoss ▁▁▁▁▂█▃▂▂▃▂▃▁▃-34.887-39.924-54.652-55.928-22.054244.49543.804-1.478-1.25143.0362.58238.054-37.3319.879
 us-gaap:NetIncomeLoss dei:LegalEntity cli:MackCaliRealtyLp▁▁▁▁▂█▃▂▂▃▂▃▁▃-38.576-44.139-60.475-62.087-24.488272.17548.757-1.645-1.39347.9192.88142.467-41.62622.174
us-gaap:ProfitLoss ▁▁▁▁▂█▃▂▂▃▂▃▁▃-32.934-37.844-55.408-56.021-20.329275.59452.5231.6891.50150.6885.41144.703-39.12522.729
 us-gaap:ProfitLoss dei:LegalEntity cli:MackCaliRealtyLp▁▁▁▁▂█▃▂▂▃▂▃▁▃-32.934-37.844-55.408-56.021-20.329275.59452.5231.6891.50150.6885.41144.703-39.12522.729
us-gaap:DepreciationDepletionAndAmortization ▅▆▁▇▇▇▇▇▆▆▇▇█▇26.54132.904-16.01548.33648.5347.29445.3945.06740.33839.48945.61750.66856.05146.338
us-gaap:ShareBasedCompensation ▁█2.4392.53NA1.982.1911.88NA1.770.6572.532NA2.1692.0461.053
us-gaap:AmortizationOfFinancingCosts ▂▁▃▂▃▄█▅▃▂▃▃▃▂1.061.0241.1471.1211.1681.1891.4851.3021.1451.0961.151.1841.1751.103
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▅▆█▁▆▇▆▄▅█▆█▄▂-111.082-83.098120.006-512.759-52.2128.888-0.636-215.404-95.662143.548-22.68127.457-227.953-422.53
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cli:MackCaliRealtyLp▅▆█▁▆▇▆▄▅█▆█▄▂-111.082-83.098120.006-512.759-52.2128.888-0.636-215.404-95.662143.548-22.68127.457-227.953-422.53
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▃▂▇▄▂▃▄▄▁▂▂▃█85.80339.394-144.178436.54575.335-91.857-21.568150.2462.273-208.282-57.978-134.93127.478511.566
us-gaap:PaymentsForRepurchaseOfCommonStock ▁█0.02.141NANANANANANANANANANANANA
 us-gaap:PaymentsForRepurchaseOfCommonStock dei:LegalEntity cli:MackCaliRealtyLp▁█0.02.141NANANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31

None

us-gaap:CommonStockValue

us-gaap:CommonStockValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value906000.0906000.0906000.0906000.0906000.0903000.0903000.0903000.0902000.0901000.0899000.0899000.0899000.0898000.0897000.0897000.0897000.0896000.0896000.0893000.0892000.0891000.0891000.0891000.0890000.0886000.0882000.0880000.0880000.0879000.0875000.0878000.0878000.0878000.0878000.0871000.0871000.0869000.0796000.0789000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:SharesOutstanding us-gaap:StatementEquityComponents

us-gaap:SharesOutstanding

us-gaap:CommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312012-12-312011-12-31
Value909090909090909090908989898989898989898989898989888787
Percentage of SharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:CommonStockSharesOutstanding

us-gaap:CommonStockSharesOutstanding


None
Period End2020-06-302020-03-312020-01-032019-12-312019-09-302019-06-302019-03-312019-01-032018-12-312018-09-302018-06-302018-03-312018-01-032017-12-312017-09-302017-06-302017-03-312017-01-052016-12-312016-09-302016-06-302016-03-312016-01-062015-12-312015-09-302015-06-302015-05-112015-03-312015-03-102015-01-062014-12-312014-12-092014-10-032014-09-302014-07-032014-06-302014-04-032014-03-312014-01-062013-12-312013-10-032013-09-302013-07-032013-06-302013-04-032013-03-312013-01-042012-12-312012-10-032012-09-302012-07-052012-06-302012-04-042012-03-312012-01-052011-12-312011-10-052011-09-302011-07-062011-06-302011-03-312011-01-052010-12-312009-12-31
Value90909090909090909090909089898989898989898989898989898989888889888889888888888788878887888787878787878787878787878787878786797978
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStockSharesOutstanding us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


None
Period End2020-07-132020-04-022020-01-032019-10-042019-07-022019-04-022019-01-032018-10-022018-07-032018-04-132018-01-032017-10-032017-07-062017-04-052017-01-052016-10-052016-07-062016-04-052016-01-062015-10-052015-01-06
Value909090909090909090908989898989898989898988
Percentage of CommonStockSharesOutstanding0.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.0100.0

None

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value10010010010010010010010010010010010010010010010010010010099999999100100100999996929292
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value9090909090909090909089898989898989888888878787878787878682797978
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-0.41-0.47-0.64-0.65-0.432.670.45-0.05-0.050.45-0.010.39-0.440.110.17-0.10.540.69-0.35-1.420.4-0.03-0.10.020.58-0.17-0.620.050.260.13-0.110.160.110.290.180.240.20.190.090.160.240.18
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EarningsPerShareBasic dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-0.41-0.47-0.64-0.65-0.432.670.45-0.05-0.050.45-0.010.39-0.440.110.17-0.10.540.69-0.35-1.420.4-0.03
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-0.41-0.47-0.64-0.65-0.432.660.45-0.05-0.050.45-0.010.39-0.440.110.17-0.10.540.69-0.35-1.420.4-0.03-0.10.020.58-0.17-0.620.050.260.13-0.110.160.110.290.180.240.20.190.090.160.240.18
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EarningsPerShareDiluted dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-0.41-0.47-0.64-0.65-0.432.660.45-0.05-0.050.45-0.010.39-0.440.110.17-0.10.540.69-0.35-1.420.4-0.03
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-0.51-0.410.53-0.64-0.452.590.37-0.12-0.130.42-0.10.020.58-0.17-0.6-0.44-0.120.11-0.050.160.120.250.180.240.20.190.090.160.190.18
Percentage of IncomeLossFromContinuingOperationsPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.51-0.410.53-0.64-0.452.590.37-0.12-0.130.42
Percentage of IncomeLossFromContinuingOperationsPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-0.51-0.410.53-0.64-0.452.580.37-0.12-0.130.42-0.10.020.58-0.17-0.6-0.44-0.120.11-0.050.160.120.250.180.240.20.190.090.160.190.18
Percentage of IncomeLossFromContinuingOperationsPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.51-0.410.53-0.64-0.452.580.37-0.12-0.130.42
Percentage of IncomeLossFromContinuingOperationsPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:Revenues

us-gaap:Revenues


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value728286131130134132132126138143160162149
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value728286131130134132132126138143160162149
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues cli:MackCaliRealtyLp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues dei:LegalEntity, us-gaap:ProductOrService

cli:MackCaliRealtyLp, cli:RealEstateServices


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.7552.9933.093.4113.533.8423.9274.4324.0744.6615.1495.7485.7676.465
Percentage of Revenues3.83.63.62.62.72.93.03.43.23.43.63.63.54.3
Percentage of Revenues3.83.63.62.62.72.93.03.43.23.43.63.63.54.3
Percentage of Revenues cli:MackCaliRealtyLp cli:RealEstateServices100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:MackCaliRealtyLp, srt:Hotel


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.7721.6254.1393.3252.0940.283
Percentage of Revenues1.12.04.82.51.60.2
Percentage of Revenues1.12.04.82.51.60.2
Percentage of Revenues cli:MackCaliRealtyLp srt:Hotel100.0100.0100.0100.0100.0100.0

cli:MackCaliRealtyLp, us-gaap:Parking


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3.0345.2655.5875.7665.5634.9415.5345.4995.7575.3275.2235.766
Percentage of Revenues4.26.46.44.44.33.74.24.24.53.83.63.6
Percentage of Revenues4.26.46.44.44.33.74.24.24.53.83.63.6
Percentage of Revenues cli:MackCaliRealtyLp us-gaap:Parking100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:MackCaliRealtyLp, us-gaap:RealEstateOther


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1.2971.7241.8982.6662.492.1682.6052.2882.8733.2863.4263.476
Percentage of Revenues1.82.12.22.01.91.62.01.72.32.42.42.2
Percentage of Revenues1.82.12.22.01.91.62.01.72.32.42.42.2
Percentage of Revenues cli:MackCaliRealtyLp us-gaap:RealEstateOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues us-gaap:ProductOrService

cli:RealEstateServices


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.7552.9933.093.4113.533.8423.9274.4324.0744.6615.1495.7485.7676.465
Percentage of Revenues3.83.63.62.62.72.93.03.43.23.43.63.63.54.3
Percentage of Revenues3.83.63.62.62.72.93.03.43.23.43.63.63.54.3
Percentage of Revenues cli:RealEstateServices100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

srt:Hotel


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.7721.6254.1393.3252.0940.283
Percentage of Revenues1.12.04.82.51.60.2
Percentage of Revenues1.12.04.82.51.60.2
Percentage of Revenues srt:Hotel100.0100.0100.0100.0100.0100.0

us-gaap:Parking


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3.0345.2655.5875.7665.5634.9415.5345.4995.7575.3275.2235.766
Percentage of Revenues4.26.46.44.44.33.74.24.24.53.83.63.6
Percentage of Revenues4.26.46.44.44.33.74.24.24.53.83.63.6
Percentage of Revenues us-gaap:Parking100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RealEstateOther


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1.2971.7241.8982.6662.492.1682.6052.2882.8733.2863.4263.476
Percentage of Revenues1.82.12.22.01.91.62.01.72.32.42.42.2
Percentage of Revenues1.82.12.22.01.91.62.01.72.32.42.42.2
Percentage of Revenues us-gaap:RealEstateOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues us-gaap:StatementBusinessSegments

cli:MultipleFamilyRealEstateAndServicesSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value3842434644363430242324242317
Percentage of Revenues52.652.250.035.234.327.125.723.419.617.217.315.414.711.6
Percentage of Revenues52.652.250.035.234.327.125.723.419.617.217.315.414.711.6
Percentage of Revenues cli:MultipleFamilyRealEstateAndServicesSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:RealEstateCommercialAndOtherSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value3439-89.43784859898100101115118133138131
Percentage of Revenues47.848.2-103.264.265.473.074.476.180.482.982.583.784.888.0
Percentage of Revenues47.848.2-103.264.265.473.074.476.180.482.982.583.784.888.0
Percentage of Revenues cli:RealEstateCommercialAndOtherSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CorporateAndOther


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.344-0.3390.4660.7260.381-0.17-0.1890.6830.016-0.0770.2951.450.9040.661
Percentage of Revenues-0.5-0.40.50.60.3-0.1-0.10.50.0-0.10.20.90.60.4
Percentage of Revenues-0.5-0.40.50.60.3-0.1-0.10.50.0-0.10.20.90.60.4
Percentage of Revenues us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostOfGoodsAndServicesSold


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value3.1133.8534.0916.112
Percentage of CostOfGoodsAndServicesSold100.0100.0100.0100.0
Percentage of Revenues4.34.73.14.6

us-gaap:CostOfGoodsAndServicesSold dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3.1133.853-7.9157.8897.456109.0059.997.555129.34711
Percentage of CostOfGoodsAndServicesSold100.0100.00.00.0182.3171.00.00.00.00.00.00.0
Percentage of Revenues4.34.7-9.16.05.77.86.87.66.09.06.57.2
Percentage of Revenues cli:MackCaliRealtyLp4.34.7-9.16.05.77.86.87.66.09.06.57.2

us-gaap:CostOfGoodsAndServicesSold us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:Building89


None
Period End2020-03-312019-09-302019-06-302019-03-312018-12-31
Value779.68.5445.7
Percentage of CostOfGoodsAndServicesSold2016.60.0207.8719.90.0
Percentage of Revenues94.77.36.532.84.3
Percentage of Revenues cli:Building890.00.00.00.00.0

cli:TwentyFiveChristopherColumbus


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value3219537282263
Percentage of CostOfGoodsAndServicesSold1040.85071.40.00.0540.21035.7
Percentage of Revenues44.6238.143.721.716.947.2
Percentage of Revenues cli:TwentyFiveChristopherColumbus0.00.00.00.00.00.0

cli:TwoThirtyThreeCanoeBrook


None
Period End2020-03-312019-09-302019-06-302019-03-31
Value559.51022
Percentage of CostOfGoodsAndServicesSold1450.80.0259.1363.2
Percentage of Revenues68.17.28.116.5
Percentage of Revenues cli:TwoThirtyThreeCanoeBrook0.00.00.00.0

None

us-gaap:OperatingCostsAndExpenses

us-gaap:OperatingCostsAndExpenses


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1516-8.718272624262722252626272727252426292425282926272928252727282727263028283030272828
Percentage of OperatingCostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.519.6-10.120.720.118.620.320.518.118.418.716.416.618.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingCostsAndExpenses dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value1516-8.7182726242627222526262727272524262924
Percentage of OperatingCostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.519.6-10.120.720.118.620.320.518.118.418.716.416.618.10.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp21.519.6-10.120.720.118.620.320.518.118.418.716.416.618.10.00.00.00.00.00.0

None

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value9389-4.908129128118136114107118120130134125131129121125157285121126134125130156195177159139150129131127130122130136146145147137
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues129.2109.0-5.798.398.788.0102.686.885.185.583.781.782.883.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CostsAndExpenses dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value9389-4.908129128118136114107118120130134125131129121125157285121126
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues129.2109.0-5.798.398.788.0102.686.885.185.583.781.782.883.50.00.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp129.2109.0-5.798.398.788.0102.686.885.185.583.781.782.883.50.00.00.00.00.00.00.00.0

None

us-gaap:GeneralAndAdministrativeExpense

us-gaap:GeneralAndAdministrativeExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value171516121612121113161313121112141212121311112312132210121312121211109.0038.6839.2268.6298.9398.9928.6588.414
Percentage of GeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues23.719.319.09.112.69.49.68.810.611.69.68.27.77.70.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:GeneralAndAdministrativeExpense dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value17151612161212111316131312111214121212131111
Percentage of GeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.1100.0
Percentage of Revenues23.719.319.09.112.69.49.68.810.611.69.68.27.77.70.00.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp23.719.319.09.112.69.49.68.810.611.69.68.27.77.70.00.00.00.00.00.00.00.0

None

us-gaap:InterestExpense

us-gaap:InterestExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value202018232324232118202225242022242224242426272727282931303129293031303131313135363739
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.425.521.717.818.018.517.716.015.014.415.716.015.313.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:InterestExpense dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value20201823232423211820222524202224222424242627
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.425.521.717.818.018.517.716.015.014.415.716.015.313.60.00.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp28.425.521.717.818.018.517.716.015.014.415.716.015.313.60.00.00.00.00.00.00.00.0

us-gaap:InterestExpense us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation

us-gaap:InterestRateSwap, us-gaap:CashFlowHedging, us-gaap:DesignatedAsHedgingInstrument


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value2020232324211820
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.425.517.818.018.516.015.014.4
Percentage of Revenues us-gaap:InterestRateSwap us-gaap:CashFlowHedging us-gaap:DesignatedAsHedgingInstrument0.00.00.00.00.00.00.00.0

None

us-gaap:IncomeLossFromContinuingOperations

us-gaap:IncomeLossFromContinuingOperations


None
Period End2020-06-302020-03-312019-06-302019-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-42.734-32.091-22.47926715-8.5414862-31.718-126.89235-2.521-9.241.98251-15.298-52.779-38.894-10.5699.889-6.796141122162017156.6271314
Percentage of IncomeLossFromContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-58.8-39.1-17.2199.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperations dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-312016-12-312016-09-302015-12-312015-09-30
Value-42.734-32.091-22.47926716-9.54-35.513-142.422
Percentage of IncomeLossFromContinuingOperations100.0100.0100.0100.0111.7111.7112.0112.2
Percentage of Revenues-58.8-39.1-17.2199.20.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-58.8-39.1-17.2199.20.00.00.00.0

None

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-42.734-32.09153-56.021-20.329275521.6891.501505.41144-39.1252216-9.6055468-35.975-142.14139-3.325-10.4132.08557-17.628-60.202-46.046-12.08611-4.464151225182420188.232151717
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-58.8-39.161.5-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-42.734-32.09153-56.021-20.329275521.6891.501505.41144-39.1252216-9.6055468-35.975-142.141
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-58.8-39.161.5-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-58.8-39.161.5-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.0

None

us-gaap:ProfitLoss

us-gaap:ProfitLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-32.934-37.844-55.408-56.021-20.329275521.6891.501505.41144-39.1252216-9.6055468-35.975-142.14139-3.325-10.4132.08557-17.628-61.773.4392613-10.585161129182420188.232152217
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-45.3-46.1-63.9-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProfitLoss dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-32.934-37.844-55.408-56.021-20.329275521.6891.501505.41144-39.1252216-9.6055468-35.975-142.14139-3.325
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-45.3-46.1-63.9-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-45.3-46.1-63.9-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.00.00.0

None

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0-16000.0-205000.0-878000.0-4624000.0-4451000.0-4969000.0354000.01788000.05145000.04646000.0730000.0-1353000.01227000.09744000.01725000.0-2913000.0-6340000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.0-0.0-0.2-0.7-3.5-3.3-3.70.31.43.73.20.5-0.80.80.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value0-16000.0-205000.0-878000.0-4624000.0-4451000.0-4969000.0354000.01788000.05145000.04646000.0730000.0-1353000.01227000.09744000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.0-0.0-0.2-0.7-3.5-3.3-3.70.31.43.73.20.5-0.80.80.0
Percentage of Revenues cli:MackCaliRealtyLp0.0-0.0-0.2-0.7-3.5-3.3-3.70.31.43.73.20.5-0.80.80.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0-34000.0-20000.0-87000.0-460000.0-413000.0-505000.036000.0182000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.0212.59.89.99.99.310.210.210.2
Percentage of Revenues0.0-0.0-0.0-0.1-0.4-0.3-0.40.00.1
Percentage of Revenues cli:MackCaliRealtyLp cli:LimitedPartnersCommonUnitholders0.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity, us-gaap:StatementEquityComponents

cli:MackCaliRealtyLp, us-gaap:AccumulatedOtherComprehensiveIncome


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value018000.0-185000.0-791000.0-4164000.0-3648000.0-4464000.0318000.01606000.04621000.04163000.0654000.0-1213000.01100000.08724000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.0-112.590.290.190.182.089.889.889.889.889.689.689.789.689.5
Percentage of Revenues0.00.0-0.2-0.6-3.2-2.7-3.40.21.33.32.90.4-0.70.70.0
Percentage of Revenues cli:MackCaliRealtyLp us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value018000.0-791000.0-4164000.0-4038000.0318000.01606000.04621000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.0-112.590.190.190.789.889.889.8
Percentage of Revenues0.00.0-0.6-3.2-3.00.21.33.3
Percentage of Revenues cli:GeneralPartnerCommonUnitholders0.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value018000.0-185000.0-791000.0-4164000.0-3648000.0-4464000.0318000.01606000.04621000.04163000.0654000.0-1213000.01100000.08724000.01544000.0-2608000.0-5675000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.0-112.590.290.190.182.089.889.889.889.889.689.689.789.689.589.589.589.5
Percentage of Revenues0.00.0-0.2-0.6-3.2-2.7-3.40.21.33.32.90.4-0.70.70.00.00.00.0
Percentage of Revenues us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0-34000.0-20000.0-87000.0-460000.0-413000.0-505000.036000.0182000.0524000.0483000.076000.0-140000.0127000.01020000.0181000.0-305000.0-665000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.0212.59.89.99.99.310.210.210.210.210.410.410.310.410.510.510.510.5
Percentage of Revenues0.0-0.0-0.0-0.1-0.4-0.3-0.40.00.10.40.30.0-0.10.10.00.00.00.0
Percentage of Revenues us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-32.934-37.86-55.613-56.899-24.953271472.0433.289551045-40.4782326-7.885162-35.975-142.14139-3.325
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-45.3-46.1-64.2-43.1-19.1202.335.81.52.640.27.028.4-24.916.00.00.00.00.00.00.00.00.0

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-32.934-37.86-55.613-56.899-24.953271472.0433.289551045-40.4782326-7.885162-35.975-142.141
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-45.3-46.1-64.2-43.1-19.1202.335.81.52.640.27.028.4-24.916.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-45.3-46.1-64.2-43.1-19.1202.335.81.52.640.27.028.4-24.916.00.00.00.00.00.00.0

None

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-34.887-39.924-54.652-55.928-22.05424443-1.478-1.251432.58238-37.331915-8.5414862-31.718-126.89235-2.521-9.241.98251-15.298-54.1794.6432311-9.227141025162017156.627131814
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-48.0-48.7-63.1-42.4-16.9182.133.0-1.1-1.031.01.823.8-22.913.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-38.576-44.139-60.475-62.087-24.48827248-1.645-1.393472.88142-41.6262216-9.545469-35.513-142.42239-2.835
Percentage of NetIncomeLoss110.6110.6110.7111.0111.0111.3111.3111.3111.4111.3111.6111.6111.5111.5111.7111.7111.7111.7112.0112.2112.4112.5
Percentage of Revenues-53.1-53.8-69.8-47.1-18.8202.736.7-1.2-1.134.52.026.5-25.614.80.00.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-53.1-53.8-69.8-47.1-18.8202.736.7-1.2-1.134.52.026.5-25.614.80.00.00.00.00.00.00.00.0

None

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-34.887-39.906-54.837-56.719-26.21824039-1.160.355476.74538-38.5432023-6.9974555-31.718-126.89235-2.521
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-48.0-48.6-63.3-43.0-20.1179.429.6-0.90.334.34.724.2-23.714.00.00.00.00.00.00.00.00.0

us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-38.576-44.155-60.68-62.965-29.11226843-1.2910.395537.52743-42.9792326-7.8155163-35.513-142.422
Percentage of ComprehensiveIncomeNetOfTax110.6110.6110.7111.0111.0111.3111.3111.3111.3111.3111.6111.6111.5111.5111.7111.7111.7113.0112.0112.2
Percentage of Revenues-53.1-53.8-70.0-47.7-22.3199.732.9-1.00.338.25.227.0-26.415.60.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-53.1-53.8-70.0-47.7-22.3199.732.9-1.00.338.25.227.0-26.415.60.00.00.00.00.00.0

None

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-37.123-42.728-57.601-58.953-38.81324141-4.144-4.6340-0.2335-39.8811015-8.5414862
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-51.1-52.1-66.5-44.7-29.8179.831.0-3.1-3.729.0-0.222.1-24.56.70.00.00.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-41.049-47.239-63.738-65.446-43.09726845-4.613-5.15644-0.25739-44.4711116-9.545469
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic110.6110.6110.7111.0111.0111.3111.3111.3111.4111.3111.7111.6111.5111.5111.7111.7111.7111.7
Percentage of Revenues-56.5-57.6-73.5-49.6-33.0200.134.5-3.5-4.132.3-0.224.6-27.37.50.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-56.5-57.6-73.5-49.6-33.0200.134.5-3.5-4.132.3-0.224.6-27.37.50.00.00.00.0

None

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-41.049-47.239-63.738-65.446-43.09726845-4.613-5.15644-0.25739-44.4711116-9.545469-35.513-142.42239-2.835-10.3922.2357-17.306-61.5335.2772613-10.511161129182319187.7131521
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-56.5-57.6-73.5-49.6-33.0200.134.5-3.5-4.132.3-0.224.6-27.37.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-31
Value-41.049-47.239-63.738-65.446-43.09726845-4.613-5.15644-0.25739-44.47111-9.545469
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-56.5-57.6-73.5-49.6-33.0200.134.5-3.5-4.132.3-0.224.6-27.37.50.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-56.5-57.6-73.5-49.6-33.0200.134.5-3.5-4.132.3-0.224.6-27.37.50.00.00.0

None

us-gaap:Assets

us-gaap:Assets


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value5360528552925720532752745060504648584815495749955076491442964435421342284063400141534198419243574354435445154609463845854526426942704299429543094326433043624721
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value53605285529257205327527450605046485848154957499550764914429644354053
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.8
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.8
Percentage of Assets cli:MackCaliRealtyLp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:StatementBusinessSegments

cli:MultipleFamilyRealEstateAndServicesSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value323931623079333228982440226022462036197919371287
Percentage of Assets60.459.858.258.254.446.344.744.541.941.139.130.0
Percentage of Assets60.459.858.258.254.446.344.744.541.941.139.130.0
Percentage of Assets cli:MultipleFamilyRealEstateAndServicesSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:RealEstateCommercialAndOtherSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value21122091217823272369250926872734275127642915312534143760334433943165313631673197338436273636386137963891388639974382
Percentage of Assets39.439.641.240.744.547.653.154.256.657.458.862.667.376.577.876.575.174.277.979.981.586.486.788.687.289.486.186.796.8
Percentage of Assets39.439.641.240.744.547.653.154.256.657.458.862.667.376.577.876.575.174.277.979.981.586.486.788.687.289.486.186.796.8
Percentage of Assets cli:RealEstateCommercialAndOtherSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CorporateAndOther


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value8.3373235615932411265707210417547445223151802413531842859131216
Percentage of Assets0.20.60.71.11.16.12.21.31.41.52.13.51.11.11.30.53.51.85.37.74.00.61.30.30.30.4
Percentage of Assets0.20.60.71.11.16.12.21.31.41.52.13.51.11.11.30.53.51.85.37.74.00.61.30.30.30.4
Percentage of Assets us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:Liabilities

us-gaap:Liabilities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3257314630893429295529513033306228962889307631063211298625702721247824952379227022642334231024522438248325962598260225472457219121632160214121312104208523182578
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets60.859.558.460.055.556.059.960.759.660.062.162.263.360.859.861.458.859.058.656.754.555.655.156.356.057.057.556.456.155.654.351.350.750.249.949.548.648.153.154.6

us-gaap:Liabilities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value32573146308934292955295130333062289628893076310632112986257027212370
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.6
Percentage of Assets60.859.558.460.055.556.059.960.759.660.062.162.263.360.859.861.458.3
Percentage of Assets cli:MackCaliRealtyLp60.859.558.460.055.556.059.960.759.660.062.162.263.360.859.861.458.5

None

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value5360528552925720532752745060504648584815495749955076491442964435421342284063400141534198419243574354435445154609463845854526426942704299429543094326433043624721
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value53605285529257205327527450605046485848154957499550764914429644354053
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.8
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.8
Percentage of Assets cli:MackCaliRealtyLp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1399143414931569164517041486146714871508147614881468152815271515153314991455149516331610162416441653160716421720174017411766182318481876188918981938195717581831
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets26.127.128.227.430.932.329.429.130.631.329.829.828.931.135.534.236.435.535.837.439.338.338.837.738.036.936.437.337.538.039.042.743.343.744.044.044.845.240.338.8

us-gaap:StockholdersEquity us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value13991434149315691645170414861467148715081476
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets26.127.128.227.430.932.329.429.130.631.329.8
Percentage of Assets cli:GeneralPartnerCommonUnitholders0.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value2625253460122910292528882116831212911637301919291058058221308177245821192020151810211051402742912124
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.50.50.61.10.20.60.20.60.50.61.80.43.40.70.50.72.80.90.80.50.50.72.41.91.34.96.73.80.51.30.50.50.50.50.40.40.20.50.00.00.06.20.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312013-12-31
Value26252534601229102925288821168312129116373029221
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.50.50.61.10.20.60.20.60.50.61.80.43.40.70.50.72.80.90.80.74.9
Percentage of Assets cli:MackCaliRealtyLp0.50.50.50.61.10.20.60.20.60.50.61.80.43.40.70.50.00.00.90.00.00.0

None

us-gaap:Land us-gaap:DisposalGroupClassification

us-gaap:Land

us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations


None
Period End2020-06-302020-03-312019-12-31
Value384648
Percentage of Land100.0100.0100.0
Percentage of Assets0.70.90.9
Percentage of Assets us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations0.00.00.0

us-gaap:Land us-gaap:PropertyPlantAndEquipmentByType

cli:Development


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value84859671108494949717277
Percentage of Land215.9184.7199.20.00.00.00.00.00.00.00.0
Percentage of Assets1.61.61.81.22.00.91.01.01.51.51.6
Percentage of Assets cli:Development0.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value974915852786917792792914100410651019
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets18.217.316.113.817.215.015.718.120.722.120.6

None

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value200202209213215212232230247249252238315325320319315303303299284262247239265179181131135158132656463323132333435
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.73.84.03.74.14.04.64.65.15.25.14.86.26.67.47.27.57.27.57.56.86.25.95.56.14.14.02.92.93.52.91.51.51.50.70.70.80.80.80.8

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value200202209213215212232230247249252238315325320319303
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.73.84.03.74.14.04.64.65.15.25.14.86.26.67.47.27.5
Percentage of Assets cli:MackCaliRealtyLp3.73.84.03.74.14.04.64.65.15.25.14.86.26.67.47.27.5

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:VariableInterestEntityNotPrimaryBeneficiary


None
Period End2020-06-302020-03-31
Value112113
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures56.256.2
Percentage of Assets2.12.2
Percentage of Assets us-gaap:VariableInterestEntityNotPrimaryBeneficiary0.00.0

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty

cli:UnconsolidatedJointVentureOtherProperty


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value200202209213216212232230247249252238315325320319303
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.73.84.03.74.14.04.64.65.15.25.14.86.26.67.47.27.5
Percentage of Assets cli:UnconsolidatedJointVentureOtherProperty0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:CrystalHouseApartmentsInvestorsLLC


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value2828282828292929293030303130303028
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures14.214.113.813.513.313.812.712.711.912.112.113.09.89.59.69.59.3
Percentage of Assets0.50.50.50.50.50.60.60.60.60.60.60.60.60.60.70.70.7
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:CrystalHouseApartmentsInvestorsLLC0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:MarbellaIi


None
Period End2020-03-312019-12-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value35351515151616
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures17.617.06.66.86.56.56.5
Percentage of Assets0.70.70.30.30.30.30.3
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:MarbellaIi0.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:MetropolitanAt40Park


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value4.1724.3687.2577.3467.4817.6017.6796.4726.6036.7596.834
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures2.12.23.53.43.53.63.32.82.72.72.7
Percentage of Assets0.10.10.10.10.10.10.20.10.10.10.1
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:MetropolitanAt40Park0.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:PiNorthRiverwalk


None
Period End2020-06-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value35353535292723201816
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures17.917.016.616.413.911.710.18.17.26.7
Percentage of Assets0.70.70.60.70.60.50.50.40.40.3
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:PiNorthRiverwalk0.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:RiverparkAtHarrison


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value0.890.9561.0151.0321.0751.2041.2721.3431.3921.5041.604
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures0.40.50.50.50.50.60.50.60.60.60.6
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:RiverparkAtHarrison0.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:RivertraceAtPortImperial


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value7.0217.197.4637.5417.7327.9448.1128.3118.4818.6628.864
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures3.53.53.63.53.63.73.53.63.43.53.5
Percentage of Assets0.10.10.10.10.10.20.20.20.20.20.2
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:RivertraceAtPortImperial0.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:StationHouse


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value3435353636373738383940
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures17.217.417.117.016.917.416.216.615.715.915.9
Percentage of Assets0.60.70.70.60.70.70.70.80.80.80.8
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:StationHouse0.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:UrbyAtHarborside


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value7778798082838587899294
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures38.538.838.237.838.039.236.738.036.337.137.4
Percentage of Assets1.41.51.51.41.51.61.71.71.91.91.9
Percentage of Assets cli:UnconsolidatedJointVentureMultipleFamilyProperties cli:UrbyAtHarborside0.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureOfficeBuildings, cli:OfficesAtCrystalLake


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value3.5953.5413.5213.5073.4713.4873.4423.4253.3893.3953.369
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures1.81.71.71.61.61.61.51.51.41.41.3
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.1
Percentage of Assets cli:UnconsolidatedJointVentureOfficeBuildings cli:OfficesAtCrystalLake0.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureOfficeBuildings, cli:TwelveVreelandAssociatesLLC


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value4.1043.9573.8467.37.1767.0647.0196.8916.7716.7926.7346.5546.3686.3156.2376.1575.89
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures2.02.01.83.43.33.33.03.02.72.72.72.72.01.91.91.91.9
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1
Percentage of Assets cli:UnconsolidatedJointVentureOfficeBuildings cli:TwelveVreelandAssociatesLLC0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cli:UnconsolidatedJointVentureOtherProperty, cli:OtherJointVentures


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value0.5690.5290.7290.080.8970.5511.321.1361.9231.3561.5950.981.7950.8791.0050.8113.506
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures0.30.30.30.00.40.30.60.50.80.50.60.40.60.30.30.31.2
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.1
Percentage of Assets cli:UnconsolidatedJointVentureOtherProperty cli:OtherJointVentures0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures us-gaap:StatementBusinessSegments

cli:MultipleFamilyRealEstateAndServicesSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value192195201202204202218216232234237238
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures96.296.396.594.994.994.994.094.193.894.093.974.5
Percentage of Assets3.63.73.83.53.83.84.34.34.84.94.85.6
Percentage of Assets cli:MultipleFamilyRealEstateAndServicesSegment5.96.26.66.17.18.39.79.711.411.912.218.5

cli:RealEstateCommercialAndOtherSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value7.6997.4987.367101010131315141514858381807878767677798182116535369
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures3.83.73.55.14.95.05.95.86.15.96.06.127.125.625.525.224.825.725.125.627.430.233.034.243.929.729.352.8
Percentage of Assets0.10.10.10.20.20.20.30.30.30.30.30.31.71.71.91.81.91.81.91.91.91.91.91.92.71.21.21.5
Percentage of Assets cli:RealEstateCommercialAndOtherSegment0.40.40.30.50.40.40.50.50.50.50.50.52.52.22.42.42.52.52.42.42.32.22.22.13.11.41.41.6

None

us-gaap:Goodwill

us-gaap:Goodwill


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value2945000.02945000.02900000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.02945000.0
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1

None

us-gaap:LongTermDebt

us-gaap:LongTermDebt


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value29902877280831692705270127922821266026302809285629682751234024742274228121542043203421072088223822082232236223682369229622041970192919401914188618692089
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets55.854.453.155.450.851.255.255.954.854.656.757.258.556.054.555.854.053.953.051.149.050.249.851.450.751.352.351.451.150.148.746.145.245.144.643.843.247.9

us-gaap:LongTermDebt us-gaap:DebtInstrument

cli:FixedRateDebtAndOtherObligations


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value233123322298282825492519249322962166216624432632259320981875221220202089186218651895192719282043204320812282228922907572127
Percentage of LongTermDebt78.081.181.989.394.293.389.381.481.482.487.092.187.476.380.289.488.891.686.491.393.191.592.391.392.693.396.696.696.733.096.5
Percentage of Assets43.544.143.449.447.947.849.345.544.645.049.352.751.142.743.749.948.049.445.846.645.645.946.046.946.947.850.649.749.416.547.0
Percentage of Assets cli:FixedRateDebtAndOtherObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cli:RevolvingCreditFacilityAndOtherVariableRateMortgageDebt


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value658545509340156181314525494464382224375652481261254197292177139179159195164150807978153877
Percentage of LongTermDebt22.018.918.110.75.86.711.318.618.617.613.67.912.623.720.610.611.28.713.68.76.98.57.78.77.46.73.43.43.367.03.5
Percentage of Assets12.310.39.66.02.93.46.210.410.29.67.74.57.413.311.25.96.04.77.24.43.44.33.84.53.83.51.81.71.733.61.7
Percentage of Assets cli:RevolvingCreditFacilityAndOtherVariableRateMortgageDebt0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:LongTermDebt us-gaap:LongtermDebtType

us-gaap:UnsecuredDebt


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value572571571571570570570570569569569818818817817951106410641263
Percentage of LongTermDebt19.119.920.318.021.121.120.420.221.421.620.328.727.629.734.938.446.846.758.6
Percentage of Assets10.710.810.810.010.710.811.311.311.711.811.516.416.116.619.021.425.325.231.1
Percentage of Assets us-gaap:UnsecuredDebt0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:MinorityInterest

us-gaap:MinorityInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value194198205221230239210209190192192191189196199198200233228235255254257259262263276290294295301254258262264280283288285311
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.63.73.93.94.34.54.24.23.94.03.93.83.74.04.64.54.85.55.65.96.26.16.16.06.06.16.16.36.36.46.76.06.06.16.26.56.66.76.56.6

us-gaap:MinorityInterest us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-31
Value194198205221230239210209190192192191189196199198200233228235255254257259262276
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.63.73.93.94.34.54.24.23.94.03.93.83.74.04.64.54.85.55.65.96.26.16.16.06.06.1
Percentage of Assets us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1399143414931569164517041486146714871508147614881468152815271515153314991455149516331610162416441653160716421720174017411766182318481876188918981938195717581831
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets26.127.128.227.430.932.329.429.130.631.329.829.828.931.135.534.236.435.535.837.439.338.338.837.738.036.936.437.337.538.039.042.743.343.744.044.044.845.240.338.8

us-gaap:StockholdersEquity us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value13991434149315691645170414861467148715081476
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets26.127.128.227.430.932.329.429.130.631.329.8
Percentage of Assets cli:GeneralPartnerCommonUnitholders0.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value159316321699179018761943169716761677170016681680165817241726171317341732168317301889186418821904191518711918201020352037206820782106213921542178222222452043214319592100
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets29.730.932.131.335.236.833.533.234.535.333.733.632.735.140.238.641.241.041.443.345.544.444.943.744.043.042.543.643.944.445.748.749.349.850.150.551.451.946.945.40.00.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value253325332535253825392553256125632564256725652566256625702576257425732571257025652562256125602556255425462539253625352533253025382538253725362521251825142292227519051886
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest159.0155.2149.2141.7135.4131.4150.9152.9152.9150.9153.7152.7154.8149.0149.2150.2148.3148.4152.7148.2135.6137.4136.0134.3133.4136.1132.4126.2124.6124.3122.3122.2120.5118.6117.7115.7113.3112.0112.2106.297.289.8
Percentage of Assets47.347.947.944.447.748.450.650.852.853.351.751.450.652.360.058.161.160.863.364.161.761.061.158.758.758.556.255.054.755.255.959.559.459.059.058.558.258.152.648.20.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value0.9060.9060.9060.9060.9060.9030.9030.9030.9020.9010.8990.8990.8990.8980.8970.8970.8970.8960.8960.8930.8920.8910.8910.8910.890.8860.8820.880.880.8790.8750.8780.8780.8780.8780.8710.8710.8690.7960.7890.6640.656
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest0.10.10.10.10.00.00.10.10.10.10.10.10.10.10.10.10.10.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value194198205221230239210209190192192191189196199198200233228235255254257259262263276290294295301254258262264280283288285311414457
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest12.212.112.112.412.312.312.412.511.311.311.511.411.511.411.611.611.613.513.513.613.613.613.713.613.714.114.414.414.514.514.612.212.312.312.312.912.812.814.014.521.221.8
Percentage of Assets3.63.73.93.94.34.54.24.23.94.03.93.83.74.04.64.54.85.55.65.96.26.16.16.06.06.16.16.36.36.46.76.06.06.16.26.56.66.76.56.60.00.0
Percentage of Assets us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value-1135.559-1100.672-1042.629-969.858-895.824-855.659-1084.518-1110.258-1090.724-1071.42-1096.429-1081.028-1101.099-1045.786-1052.184-1053.91-1031.922-1066.867-1115.612-1070.456-930.167-952.183-936.293-913.389-902.036-939.837-897.849-817.387-795.7-792.446-764.522-715.903-690.664-661.246-647.498-624.11-605.396-583.556-560.165-470.047-386.587-269.521
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-71.3-67.4-61.4-54.2-47.8-44.0-63.9-66.2-65.0-63.0-65.7-64.3-66.4-60.6-60.9-61.5-59.5-61.6-66.3-61.8-49.2-51.1-49.7-48.0-47.1-50.2-46.8-40.7-39.1-38.9-37.0-34.4-32.8-30.9-30.1-28.6-27.2-26.0-27.4-21.9-19.7-12.8
Percentage of Assets-21.2-20.8-19.7-17.0-16.8-16.2-21.4-22.0-22.5-22.2-22.1-21.6-21.7-21.3-24.5-23.8-24.5-25.2-27.5-26.7-22.4-22.7-22.3-21.0-20.7-21.6-19.9-17.7-17.2-17.3-16.9-16.8-16.2-15.4-15.1-14.5-14.0-13.5-12.8-10.00.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:CommonStockValue

us-gaap:CommonStockValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value906000.0906000.0906000.0906000.0906000.0903000.0903000.0903000.0902000.0901000.0899000.0899000.0899000.0898000.0897000.0897000.0897000.0896000.0896000.0893000.0892000.0891000.0891000.0891000.0890000.0886000.0882000.0880000.0880000.0879000.0875000.0878000.0878000.0878000.0878000.0871000.0871000.0869000.0796000.0789000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:AdditionalPaidInCapital

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value2533253325352538253925532561256325642567256525662566257025762574257325712570256525622561256025562554254625392536253525332530253825382537253625212518251422922275
Percentage of AdditionalPaidInCapital100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets47.347.947.944.447.748.450.650.852.853.351.751.450.652.360.058.161.160.863.364.161.761.061.158.758.758.556.255.054.755.255.959.559.459.059.058.558.258.152.648.2

None

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value-1135600000.0-1100700000.0-1042600000.0-969860000.0-895820000.0-855660000.0-1084500000.0-1110300000.0-1090700000.0-1071400000.0-1096400000.0-1081000000.0-1101100000.0-1045800000.0-1052200000.0-1053900000.0-1031900000.0-1066900000.0-1115600000.0-1070500000.0-930170000.0-952180000.0-936290000.0-913390000.0-902040000.0-939840000.0-897850000.0-817390000.0-795700000.0-792450000.0-764520000.0-715900000.0-690660000.0-661250000.0-647500000.0-624110000.0-605400000.0-583560000.0-560160000.0-470050000.0
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-21.2-20.8-19.7-17.0-16.8-16.2-21.4-22.0-22.5-22.2-22.1-21.6-21.7-21.3-24.5-23.8-24.5-25.2-27.5-26.7-22.4-22.7-22.3-21.0-20.7-21.6-19.9-17.7-17.2-17.3-16.9-16.8-16.2-15.4-15.1-14.5-14.0-13.5-12.8-10.0

None

us-gaap:MinorityInterest

us-gaap:MinorityInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value194198205221230239210209190192192191189196199198200233228235255254257259262263276290294295301254258262264280283288285311
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.63.73.93.94.34.54.24.23.94.03.93.83.74.04.64.54.85.55.65.96.26.16.16.06.06.16.16.36.36.46.76.06.06.16.26.56.66.76.56.6

us-gaap:MinorityInterest us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-31
Value194198205221230239210209190192192191189196199198200233228235255254257259262276
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.63.73.93.94.34.54.24.23.94.03.93.83.74.04.64.54.85.55.65.96.26.16.16.06.06.1
Percentage of Assets us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value-0.792.272.2882.362.3611.6962.2622.3642.1362.262.3342.3342.3141.6471.6721.6731.6731.6011.5781.6191.6521.6561.6631.6641.6743.4553.5593.5963.6015.4375.4645.485.485.4845.48928-5.763-5.795
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value-0.792020202019202020202020201515
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0898.2891.9867.2867.11165.2898.6863.8945.2897.7870.5870.5877.1918.5904.7
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets cli:MackCaliRealtyLp0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0.01818181818181818
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders-0.0798.2791.9767.2767.11065.2798.6763.8845.2
Percentage of Assets0.00.00.00.00.00.00.00.00.0
Percentage of Assets cli:MackCaliRealtyLp cli:GeneralPartnerCommonUnitholders0.00.00.00.00.00.00.00.00.0

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-0.792.272.2882.362.3611.6962.2622.3642.136
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.0
Percentage of Assets cli:MackCaliRealtyLp cli:LimitedPartnersCommonUnitholders0.00.00.00.00.00.00.00.00.0

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.018181818181818
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders-0.0798.2767.2767.11065.2763.8845.2797.7
Percentage of Assets0.00.00.00.00.00.00.00.0
Percentage of Assets cli:GeneralPartnerCommonUnitholders0.00.00.00.00.00.00.00.0

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value-0.792.272.2882.362.3611.6962.2622.3642.1362.262.3342.3342.3141.6471.6721.6731.6731.6011.5781.6191.6521.6561.6631.6641.6743.4553.5593.5963.6015.4375.4645.485.485.4845.48928-5.763-5.795
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value24431052224640442556335852514330572755385549713679568146873679237941
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues33.853.212.639.517.534.330.733.519.840.923.436.832.234.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2443105222464044255633585251
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues33.853.212.639.517.534.330.733.519.840.923.436.832.234.2
Percentage of Revenues cli:MackCaliRealtyLp33.853.212.639.517.534.330.733.519.840.923.436.832.234.2

None

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-111.082-83.098120-512.759-52.2128-0.636-215.404-95.662143-22.68127-227.953-422.53-15.5756920-24.216-101.78112675-128.778-130.43-28.544-20.315-53.067-27.572-21.004-26.82-18.781-42.747-15.352-17.498-13.428
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-152.9-101.3138.5-388.8-40.021.5-0.5-163.0-75.6103.3-15.879.7-140.0-281.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-111.082-83.098120-512.759-52.2128-0.636-215.404-95.662143-22.68127-227.953-422.53
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-152.9-101.3138.5-388.8-40.021.5-0.5-163.0-75.6103.3-15.879.7-140.0-281.9
Percentage of Revenues cli:MackCaliRealtyLp-152.9-101.3138.5-388.8-40.021.5-0.5-163.0-75.6103.3-15.879.7-140.0-281.9

None

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value8539-144.17843675-91.857-21.56815062-208.282-57.978-134.93127511-104.158-75.232-56.117-166.226-40.321-34.928234595-5.727-60.564-3.811-49.242-28.081-53.308-28.612-120.296-43.218-195.1-44.605
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues118.148.0-166.3331.057.7-68.4-16.2113.749.2-149.9-40.4-84.316.9341.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value8539-144.17843675-91.857-21.56815062-208.282-57.978-134.93127511
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues118.148.0-166.3331.057.7-68.4-16.2113.749.2-149.9-40.4-84.316.9341.3
Percentage of Revenues cli:MackCaliRealtyLp118.148.0-166.3331.057.7-68.4-16.2113.749.2-149.9-40.4-84.316.9341.3

None

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value24431052224640442556335852514330572755385549713679568146873679237941
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues33.853.212.639.517.534.330.733.519.840.923.436.832.234.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2443105222464044255633585251
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues33.853.212.639.517.534.330.733.519.840.923.436.832.234.2
Percentage of Revenues cli:MackCaliRealtyLp33.853.212.639.517.534.330.733.519.840.923.436.832.234.2

None

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-34.887-39.924-54.652-55.928-22.05424443-1.478-1.251432.58238-37.331915-8.5414862-31.718-126.89235-2.521-9.241.98251-15.298-54.1794.6432311-9.227141025162017156.627131814
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-48.0-48.7-63.1-42.4-16.9182.133.0-1.1-1.031.01.823.8-22.913.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-38.576-44.139-60.475-62.087-24.48827248-1.645-1.393472.88142-41.6262216-9.545469-35.513-142.42239-2.835
Percentage of NetIncomeLoss110.6110.6110.7111.0111.0111.3111.3111.3111.4111.3111.6111.6111.5111.5111.7111.7111.7111.7112.0112.2112.4112.5
Percentage of Revenues-53.1-53.8-69.8-47.1-18.8202.736.7-1.2-1.134.52.026.5-25.614.80.00.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-53.1-53.8-69.8-47.1-18.8202.736.7-1.2-1.134.52.026.5-25.614.80.00.00.00.00.00.00.00.0

None

us-gaap:ProfitLoss

us-gaap:ProfitLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-32.934-37.844-55.408-56.021-20.329275521.6891.501505.41144-39.1252216-9.6055468-35.975-142.14139-3.325-10.4132.08557-17.628-61.773.4392613-10.585161129182420188.232152217
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-45.3-46.1-63.9-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProfitLoss dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-32.934-37.844-55.408-56.021-20.329275521.6891.501505.41144-39.1252216-9.6055468-35.975-142.14139-3.325
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-45.3-46.1-63.9-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.00.00.0
Percentage of Revenues cli:MackCaliRealtyLp-45.3-46.1-63.9-42.5-15.6205.339.51.31.236.53.827.9-24.015.20.00.00.00.00.00.00.00.0

None

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2632-16.015484847454540394550564651474343434442414142444548404746454748474848484847474748
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationDepletionAndAmortization dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value2632-16.01548484745454039455056465147434343
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2.4392.531.982.1911.881.770.6572.5322.1692.0461.0532.0461.4680.7850.7190.6950.4920.3134.6580.8761.024.543-0.0640.7641.0810.6061.7970.7030.7010.9342.1640.7990.7970.7972.3550.7290.7280.716
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShareBasedCompensation dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-31
Value2.4392.531.982.1911.881.770.6572.5322.1692.0461.0532.0461.4680.785
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:AmortizationOfFinancingCosts

us-gaap:AmortizationOfFinancingCosts


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1060000.01024000.01147000.01121000.01168000.01189000.01485000.01302000.01145000.01096000.01150000.01184000.01175000.01103000.0999000.01234000.01180000.01169000.0944000.0945000.0948000.0953000.0968000.0778000.0759000.0769000.0793000.0954000.0809000.0773000.0724000.0673000.0661000.0611000.0618000.0584000.0584000.0584000.0635000.0646000.0660000.0
Percentage of AmortizationOfFinancingCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-111.082-83.098120-512.759-52.2128-0.636-215.404-95.662143-22.68127-227.953-422.53-15.5756920-24.216-101.78112675-128.778-130.43-28.544-20.315-53.067-27.572-21.004-26.82-18.781-42.747-15.352-17.498-13.428
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-152.9-101.3138.5-388.8-40.021.5-0.5-163.0-75.6103.3-15.879.7-140.0-281.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-111.082-83.098120-512.759-52.2128-0.636-215.404-95.662143-22.68127-227.953-422.53
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-152.9-101.3138.5-388.8-40.021.5-0.5-163.0-75.6103.3-15.879.7-140.0-281.9
Percentage of Revenues cli:MackCaliRealtyLp-152.9-101.3138.5-388.8-40.021.5-0.5-163.0-75.6103.3-15.879.7-140.0-281.9

None

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value8539-144.17843675-91.857-21.56815062-208.282-57.978-134.93127511-104.158-75.232-56.117-166.226-40.321-34.928234595-5.727-60.564-3.811-49.242-28.081-53.308-28.612-120.296-43.218-195.1-44.605
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues118.148.0-166.3331.057.7-68.4-16.2113.749.2-149.9-40.4-84.316.9341.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value8539-144.17843675-91.857-21.56815062-208.282-57.978-134.93127511
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues118.148.0-166.3331.057.7-68.4-16.2113.749.2-149.9-40.4-84.316.9341.3
Percentage of Revenues cli:MackCaliRealtyLp118.148.0-166.3331.057.7-68.4-16.2113.749.2-149.9-40.4-84.316.9341.3

None

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:PaymentsForRepurchaseOfCommonStock


None
Period End2020-06-302020-03-31
Value02141000.0
Percentage of PaymentsForRepurchaseOfCommonStock0.0100.0

us-gaap:PaymentsForRepurchaseOfCommonStock dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-31
Value02141000.0
Percentage of PaymentsForRepurchaseOfCommonStock0.0100.0

None

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312014-12-312013-12-31
Value12109.89.51111109.8109.75.31413
Percentage of DeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value4041415478324930516067129772258572
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value4041415478324930516067129772258572
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue

cli:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2439000.02530000.02110000.01980000.02191000.01880000.01935000.01770000.0657000.02532000.02179000.02169000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2439000.02530000.02110000.01980000.02191000.01880000.01935000.01770000.0657000.02532000.02179000.02169000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value334000.0430000.0137000.07000.0218000.0265000.0261000.0202000.0434000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue13.717.06.50.49.914.113.511.466.1

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value2105000.02100000.01973000.01973000.01973000.01615000.01674000.01568000.0223000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue86.383.093.599.690.185.986.588.633.9

cli:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value334000.0430000.0137000.07000.0218000.0265000.0261000.0202000.0433000.0517000.0849000.0840000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue13.717.06.50.49.914.113.511.465.920.439.038.7

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2105000.02100000.01973000.01973000.01973000.01615000.01674000.01568000.0223000.02015000.01330000.01329000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue86.383.093.599.690.185.986.588.633.979.661.061.3

cli:AmortizationOfDebtDiscountAndMarkToMarket

cli:AmortizationOfDebtDiscountAndMarkToMarket


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value-237000.0-237000.0-238000.0-237000.0-237000.0-237000.0-237000.0-237000.0-237000.0-237000.0-201000.0-164000.0-163000.0241000.0269000.0
Percentage of AmortizationOfDebtDiscountAndMarkToMarket100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:AmortizationOfDebtDiscountAndMarkToMarket dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value-237000.0-237000.0-238000.0-237000.0-237000.0-237000.0-237000.0-237000.0-237000.0-237000.0-201000.0-164000.0-163000.0241000.0269000.0
Percentage of AmortizationOfDebtDiscountAndMarkToMarket100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:AmortizationOfDeferredStockUnits

cli:AmortizationOfDeferredStockUnits


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value57000.082000.081000.081000.027000.0130000.0129000.0127000.0126000.0125000.0124000.0122000.0121000.0115000.087000.087000.097000.0101000.0100000.0100000.099000.098000.098000.096000.096000.0117000.0
Percentage of AmortizationOfDeferredStockUnits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:AmortizationOfDeferredStockUnits dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value57000.082000.081000.081000.027000.0130000.0129000.0127000.0126000.0125000.0124000.0122000.0121000.0115000.087000.087000.097000.0101000.0100000.0
Percentage of AmortizationOfDeferredStockUnits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:AnnualPercentageOfCostForPhaseIn us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:TaxPeriod

cli:AnnualPercentageOfCostForPhaseIn

cli:PortImperialSouthOneThirdGarageDevelopment, cli:TaxYearFive


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value00.950000.950000.950000.9500
Percentage of AnnualPercentageOfCostForPhaseIn0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.0

cli:PortImperialSouthOneThirdGarageDevelopment, cli:TaxYearFour


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value00.950000.950000.950000.9500
Percentage of AnnualPercentageOfCostForPhaseIn0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.0

cli:PortImperialSouthOneThirdGarageDevelopment, cli:TaxYearOne


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value00.01-0.0100.0100000000000
Percentage of AnnualPercentageOfCostForPhaseIn0.01.10.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cli:PortImperialSouthOneThirdGarageDevelopment, cli:TaxYearThree


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value00.950000.950000.950000.9500
Percentage of AnnualPercentageOfCostForPhaseIn0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.0

cli:PortImperialSouthOneThirdGarageDevelopment, cli:TaxYearTwo


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value00.950000.950000.950000.9500
Percentage of AnnualPercentageOfCostForPhaseIn0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.0

cli:AnnualReturnOnEquityValueBaseReturn us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty

cli:AnnualReturnOnEquityValueBaseReturn

cli:RockpointGroupL.l.c., cli:CashFlowFromCapitalEventsDistributionThree, cli:InvestmentAgreement, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.95
Percentage of AnnualReturnOnEquityValueBaseReturn0.0100.0

cli:RockpointGroupL.l.c., cli:CashFlowFromOperations, cli:InvestmentAgreement, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.05
Percentage of AnnualReturnOnEquityValueBaseReturn0.05.3

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionThree, cli:InvestmentAgreement, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.05
Percentage of AnnualReturnOnEquityValueBaseReturn0.05.3

cli:RoselandResidentialTrust, cli:CashFlowFromOperations, cli:InvestmentAgreement, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.95
Percentage of AnnualReturnOnEquityValueBaseReturn0.0100.0

cli:AnnualReturnOnEquityValueBaseReturn us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransactionsByRelatedParty

cli:RockpointGroupL.l.c., cli:CashFlowFromCapitalEventsDistributionThree, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.0464
Percentage of AnnualReturnOnEquityValueBaseReturn0.04.9

cli:RockpointGroupL.l.c., cli:CashFlowFromOperations, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.0464
Percentage of AnnualReturnOnEquityValueBaseReturn0.04.9

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionThree, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.9536
Percentage of AnnualReturnOnEquityValueBaseReturn0.0100.4

cli:RoselandResidentialTrust, cli:CashFlowFromOperations, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.9536
Percentage of AnnualReturnOnEquityValueBaseReturn0.0100.4

cli:AnnualReturnOnEquityValueCapitalBaseReturn us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty

cli:AnnualReturnOnEquityValueCapitalBaseReturn

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionFour, cli:InvestmentAgreement, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.95
Percentage of AnnualReturnOnEquityValueCapitalBaseReturn0.0100.0

cli:AnnualReturnOnEquityValueCapitalBaseReturn us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:RelatedPartyTransactionsByRelatedParty

cli:RockpointGroupL.l.c., cli:CashFlowFromCapitalEventsDistributionFour, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.0464
Percentage of AnnualReturnOnEquityValueCapitalBaseReturn0.04.9

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionFour, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.9536
Percentage of AnnualReturnOnEquityValueCapitalBaseReturn0.0100.4

cli:AnnualReturnOnEquityValueCapitalBaseReturn us-gaap:StatementScenario, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty

cli:CashFlowFromCapitalEventsDistributionFour, cli:InvestmentAgreement, cli:RoselandResidentialL.p.


None
Period End2020-06-302020-03-31
Value00.05
Percentage of AnnualReturnOnEquityValueCapitalBaseReturn0.05.3

cli:BuildingsAndImprovementsNetOfAccumulatedDepreciation

cli:BuildingsAndImprovementsNetOfAccumulatedDepreciation


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-16.5166-7.20.1-43.6207-15.8166.5197
Percentage of BuildingsAndImprovementsNetOfAccumulatedDepreciation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:BuildingsAndImprovementsNetOfAccumulatedDepreciation us-gaap:DisposalGroupClassification

us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations


None
Period End2020-06-302020-03-31
Value-25.639
Percentage of BuildingsAndImprovementsNetOfAccumulatedDepreciation155.223.7

cli:BuildingsAndImprovementsNetOfAccumulatedDepreciation us-gaap:DisposalGroupClassification, us-gaap:PropertyPlantAndEquipmentByType

us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations, cli:Development


None
Period End2020-06-302020-03-31
Value-4.95.6
Percentage of BuildingsAndImprovementsNetOfAccumulatedDepreciation29.73.4

cli:CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses

cli:CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value400000.0500000.0500000.0500000.0600000.0600000.0600000.0600000.0600000.0600000.0400000.0600000.0600000.0600000.0700000.0700000.0800000.0600000.0700000.0900000.01200000.01300000.0400000.01000000.0900000.0900000.0700000.01900000.0900000.0900000.01062000.0765000.0770000.01000000.0851000.0969000.0909000.0
Percentage of CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:CommonStockDividendsAndCommonUnitDistributionsPerShare

cli:CommonStockDividendsAndCommonUnitDistributionsPerShare


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-05-112015-03-102014-12-092014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-04-152013-06-302013-03-312012-12-312011-12-31
Value0.20.20.20.20.20.2000.20.200.050.150.15000.150.150.150.150.150.150.150.150.150.30.30.30.45-0.150.450.450.45
Percentage of CommonStockDividendsAndCommonUnitDistributionsPerShare100.0100.0100.0100.0100.0100.00.00.0100.0100.00.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:CommonStockDividendsAndCommonUnitDistributionsPerShare us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


None
Period End2020-07-01
Value0.2
Percentage of CommonStockDividendsAndCommonUnitDistributionsPerShare0.0

cli:CommonUnits

cli:CommonUnits


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value9.5849.567-0.1059.9769.9910-0.0051010100.011101010-0.003101010-0.076101111-0.062111111-0.031111212-0.004121212-0.056121212-0.0471313
Percentage of CommonUnits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:CommonUnitsConversionOfVestedLtipUnitsToCommonStock

cli:CommonUnitsConversionOfVestedLtipUnitsToCommonStock


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value742.03688.09220.09218.0
Percentage of CommonUnitsConversionOfVestedLtipUnitsToCommonStock100.0100.0100.0100.0

cli:CommonUnitsRedeemedForCommonShares

cli:CommonUnitsRedeemedForCommonShares


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value97727.003000.033011.05000.012500.024294.03061.0
Percentage of CommonUnitsRedeemedForCommonShares100.00.0100.0100.0100.0100.0100.0100.0

cli:CommonUnitsVestedLtipUnits

cli:CommonUnitsVestedLtipUnits


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value67148.0614.000-9220.077426.000
Percentage of CommonUnitsVestedLtipUnits100.0100.00.00.0100.0100.00.00.0

cli:ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestJointVenturePartnersNonredeemable

cli:ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestJointVenturePartnersNonredeemable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-829000.0-176000.0-1404000.0-405000.0-847000.0-1248000.0-640000.0-451000.0-95000.0-30000.0-153000.0-447000.0-181000.0-237000.0-191000.0-65000.0311000.0-706000.0-462000.0281000.0-373000.0-490000.0
Percentage of ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestJointVenturePartnersNonredeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestJointVenturePartnersNonredeemable dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-829000.0-176000.0-1404000.0-405000.0-847000.0-1248000.0-640000.0-451000.0-95000.0-30000.0-153000.0-447000.0-181000.0-237000.0-191000.0-65000.0311000.0-706000.0-462000.0281000.0
Percentage of ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestJointVenturePartnersNonredeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestOperatingPartnershipsNonredeemable

cli:ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestOperatingPartnershipsNonredeemable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-3.689-4.249-5.843-6.246-2.894274.448-0.1310.045.4070.7824.489-4.4362.4222.794-0.8185.3577.284-3.795-15.534.383-0.314
Percentage of ComprehensiveIncomeLossNetOfTaxAttributableToNoncontrollingInterestOperatingPartnershipsNonredeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:ComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNoncontrollingInterest

cli:ComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.4716.4716.4716.4715.0064.6674.4063.7852.9892.7992.6832.6832.6820.792
Percentage of ComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:ComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNoncontrollingInterest dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.4716.4716.4715.0064.6674.4063.7852.9892.7992.6832.6832.6820.792
Percentage of ComprehensiveIncomeLossNetOfTaxAttributableToRedeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:CostsOfRealEstateServices

cli:CostsOfRealEstateServices


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value3.0853.7213.7683.9053.9794.2664.2234.44.364.9365.0186.2075.8996.276.8426.3616.2116.8466.0636.6736.2086.6395.9236.9336.5716.7096.9075.5525.3044.9522.2040.5360.5010.504
Percentage of CostsOfRealEstateServices100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:CostsOfRealEstateServices dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value3.0853.7213.7683.9053.9794.2664.2234.44.364.9365.0186.2075.8996.276.8426.3616.2116.8466.0636.673
Percentage of CostsOfRealEstateServices100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:DebtInstrumentExtensionFeePercentage us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

cli:DebtInstrumentExtensionFeePercentage

us-gaap:SecuredDebt, cli:Charlotte, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-31
Value00.0025
Percentage of DebtInstrumentExtensionFeePercentage0.0100.0

us-gaap:SecuredDebt, cli:EmeryAtOverlookRidge, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-31
Value00.0025
Percentage of DebtInstrumentExtensionFeePercentage0.0100.0

us-gaap:SecuredDebt, cli:PortImperialSouthNine, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-312019-12-31
Value00.00150
Percentage of DebtInstrumentExtensionFeePercentage0.060.00.0

us-gaap:SecuredDebt, cli:ShortHillsPortfolio, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-31
Value00.003
Percentage of DebtInstrumentExtensionFeePercentage0.0120.0

cli:DebtInstrumentNumberOfExtensionOptions us-gaap:CreditFacility

cli:DebtInstrumentNumberOfExtensionOptions

cli:TwentySeventeenUnsecuredRevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value02.00002.00002.00002.0
Percentage of DebtInstrumentNumberOfExtensionOptions0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

cli:DebtInstrumentNumberOfExtensionOptions us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:SecuredDebt, cli:Charlotte, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-31
Value01.0
Percentage of DebtInstrumentNumberOfExtensionOptions0.050.0

us-gaap:SecuredDebt, cli:EmeryAtOverlookRidge, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-31
Value01.0
Percentage of DebtInstrumentNumberOfExtensionOptions0.050.0

us-gaap:SecuredDebt, cli:PortImperialSouthNine, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-312019-12-31
Value01.00
Percentage of DebtInstrumentNumberOfExtensionOptions0.050.00.0

us-gaap:SecuredDebt, cli:ShortHillsResidential, us-gaap:ConstructionLoans


None
Period End2020-06-302020-03-31
Value01.0
Percentage of DebtInstrumentNumberOfExtensionOptions0.050.0

cli:DebtInstrumentNumberOfExtensionOptions us-gaap:DebtInstrument

cli:TwentySeventeenTermLoan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value02.00002.00002.00002.0
Percentage of DebtInstrumentNumberOfExtensionOptions0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

cli:TwentySixteenTermLoan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value02.00002.00002.00002.0
Percentage of DebtInstrumentNumberOfExtensionOptions0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

cli:DeferredStockUnitsConverted

cli:DeferredStockUnitsConverted


None
Period End2020-06-122019-06-12
Value61277.0193950.0
Percentage of DeferredStockUnitsConverted100.0100.0

cli:DeferredStockUnitsSharesEarned

cli:DeferredStockUnitsSharesEarned


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value3907.05804.03570.03724.01173.05870.06702.06331.06168.07420.05726.05181.04556.04265.03025.03390.03486.04373.04423.05015.05262.05002.05031.04985.04538.05707.06060.05960.05218.05154.04777.04665.04154.04238.04266.04235.03188.03197.03152.03100.0
Percentage of DeferredStockUnitsSharesEarned100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:DepreciationAmortizationOnDiscontinuedOperations

cli:DepreciationAmortizationOnDiscontinuedOperations


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-302010-03-31
Value1.4531.45317160.0221.7690.2340.2972.6490.0130.0130.4152.2590.4160.4220.4410.3020.107
Percentage of DepreciationAmortizationOnDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:DisposalGroupIncludingDiscontinuedOperationLandNetValue us-gaap:DisposalGroupClassification

cli:DisposalGroupIncludingDiscontinuedOperationLandNetValue

us-gaap:DisposalGroupNotDiscontinuedOperations


None
Period End2020-06-302020-03-31
Value0.011
Percentage of DisposalGroupIncludingDiscontinuedOperationLandNetValue0.0100.0

cli:DisposalGroupIncludingDiscontinuedOperationLandNetValue us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:CapitalOfficeParkLand


None
Period End2020-06-302020-03-31
Value0.08.21
Percentage of DisposalGroupIncludingDiscontinuedOperationLandNetValue0.073.4

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:TwoThirtyAndTwoFiftyHalfMileRoad


None
Period End2020-06-302020-03-31
Value0.02.969
Percentage of DisposalGroupIncludingDiscontinuedOperationLandNetValue0.026.6

cli:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue us-gaap:DisposalGroupClassification

cli:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue

us-gaap:DisposalGroupNotDiscontinuedOperations


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.0173430.04028519190.0164642698.27142
Percentage of DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue0.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0

cli:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:OneBridgePlaza


None
Period End2020-06-302020-03-31
Value0.017
Percentage of DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue0.0100.0

cli:DistributionsInExcessOfCumulativeEarningsFromJvs

cli:DistributionsInExcessOfCumulativeEarningsFromJvs


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value1.4794.3963.721.3752.0361.5661.8461.9013.2354.5711.1781.531.481.6891.325171.4181.7712.1162.3440.8881.097-0.402350.3810.4563.2360.317191.2330.5190.040.00.9880.182.209-0.298-0.631-2.848
Percentage of DistributionsInExcessOfCumulativeEarningsFromJvs100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

cli:DistributionsInExcessOfCumulativeEarningsFromJvs dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value1.4794.3963.721.3752.0361.5661.8461.9013.2354.5711.1781.531.481.6891.325171.4181.7712.116
Percentage of DistributionsInExcessOfCumulativeEarningsFromJvs100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:EquityMethodInvestmentAmortizationOfBasisDifference

cli:EquityMethodInvestmentAmortizationOfBasisDifference


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value143000.0152000.0154000.0156000.0156000.0172000.094000.0230000.0289000.0289000.0-46000.0289000.0289000.0259000.0
Percentage of EquityMethodInvestmentAmortizationOfBasisDifference100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:EstimatedCostOfProject us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:EstimatedCostOfProject

cli:Building89


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1420.00.00.01420.0
Percentage of EstimatedCostOfProject100.00.00.00.0100.00.0

cli:HarborsideFinancialCenterPlazaFive


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.01700.00.00.01700.00.00.01700.00.00.01700.00.00.01700.00.00.01700.00.00.01700.0
Percentage of EstimatedCostOfProject0.0119.60.00.00.0119.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cli:HarborsideFinancialCenterPlazaFoura


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.0490.00.00.0490.00.00.0490.00.00.0490.00.00.0490.00.00.0490.00.00.0490.0
Percentage of EstimatedCostOfProject0.034.60.00.00.034.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cli:TwentyFiveChristopherColumbus


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0469-1.00.0-0.1470
Percentage of EstimatedCostOfProject0.0328.60.00.00.0329.3

cli:TwoThirtyThreeCanoeBrook


None
Period End2020-03-312019-09-302019-06-302019-03-31
Value990.00.099
Percentage of EstimatedCostOfProject69.60.00.069.7

cli:GainLossOnDispositionOfLandDiscontinuedOperations us-gaap:DisposalGroupClassification

cli:GainLossOnDispositionOfLandDiscontinuedOperations

us-gaap:DisposalGroupNotDiscontinuedOperations


None
Period End2020-06-302020-03-31
Value0.04.813
Percentage of GainLossOnDispositionOfLandDiscontinuedOperations0.0100.0

cli:GainLossOnDispositionOfLandDiscontinuedOperations us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:CapitalOfficeParkLand


None
Period End2020-06-302020-03-31
Value0.00.764
Percentage of GainLossOnDispositionOfLandDiscontinuedOperations0.015.9

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:TwoThirtyAndTwoFiftyHalfMileRoad


None
Period End2020-06-302020-03-31
Value0.04.049
Percentage of GainLossOnDispositionOfLandDiscontinuedOperations0.084.1

cli:GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses

cli:GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses


None
Period End2020-06-302020-03-31
Value0.0-7.915
Percentage of GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses0.0100.0

cli:GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses us-gaap:DisposalGroupClassification

us-gaap:DisposalGroupNotDiscontinuedOperations


None
Period End2020-06-302020-03-31
Value-11.929-27.746
Percentage of GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses0.0350.5

cli:GainLossOnSaleOfRealizedAndUnrealizedPropertyPlantEquipment

cli:GainLossOnSaleOfRealizedAndUnrealizedPropertyPlantEquipment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.04.813-0.0440.2960.27
Percentage of GainLossOnSaleOfRealizedAndUnrealizedPropertyPlantEquipment0.0100.0100.0100.0100.0

cli:GainLossOnSaleOfRealizedAndUnrealizedPropertyPlantEquipment dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.04.813-0.0440.2960.27
Percentage of GainLossOnSaleOfRealizedAndUnrealizedPropertyPlantEquipment0.0100.0100.0100.0100.0

cli:ImpairmentOfLandAndOther

cli:ImpairmentOfLandAndOther


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-30
Value165.263236.3452.499
Percentage of ImpairmentOfLandAndOther100.0100.0100.0100.0100.0

cli:ImpairmentOfLandAndOther dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-30
Value165.263236.3452.499
Percentage of ImpairmentOfLandAndOther100.0100.0100.0100.0100.0

cli:ImpairmentOfLandAndOther us-gaap:StatementGeographical

cli:ParsippanyMadisonShortHillsEdisonRedBankAndFlorhanPark


None
Period End2020-03-31
Value5.3
Percentage of ImpairmentOfLandAndOther100.7

cli:ImpairmentOfLandAndOther us-gaap:StatementGeographical, us-gaap:DisposalGroupClassification

cli:ParsippanyMadisonShortHillsEdisonRedBankAndFlorhamPark, us-gaap:SegmentDiscontinuedOperations


None
Period End2020-06-30
Value16
Percentage of ImpairmentOfLandAndOther99.7

cli:ParsippanyMadisonShortHillsEdisonRedBankAndFlorhanPark, us-gaap:SegmentDiscontinuedOperations


None
Period End2020-03-31
Value5.3
Percentage of ImpairmentOfLandAndOther100.7

cli:IncomeLossFromContinuingOperationsBasic

cli:IncomeLossFromContinuingOperationsBasic


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-45.986-37.524-40.75233
Percentage of IncomeLossFromContinuingOperationsBasic100.0100.0100.0100.0

cli:IncomeLossFromContinuingOperationsBasic dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-50.849-41.486-45.247260
Percentage of IncomeLossFromContinuingOperationsBasic110.6110.6111.0111.3

cli:IncomeLossFromContinuingOperationsDiluted

cli:IncomeLossFromContinuingOperationsDiluted


None
Period End2020-06-302020-03-312019-06-302019-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-50.849-41.486-45.247260-10.3922.2357-17.306-59.943-44.208-12.02411-7.741161225182319187.7131517
Percentage of IncomeLossFromContinuingOperationsDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:IncomeLossFromContinuingOperationsDilutedEarningsPerShare

cli:IncomeLossFromContinuingOperationsDilutedEarningsPerShare


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-45.986-37.524-40.75233
Percentage of IncomeLossFromContinuingOperationsDilutedEarningsPerShare100.0100.0100.0100.0

cli:IncomeLossFromContinuingOperationsDilutedEarningsPerShare dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-50.849-41.486-45.247260
Percentage of IncomeLossFromContinuingOperationsDilutedEarningsPerShare110.6110.6111.0111.3

cli:IncomeLossFromDiscontinuedOperationsAvailableToCommonShareholders

cli:IncomeLossFromDiscontinuedOperationsAvailableToCommonShareholders


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-30
Value8.863-5.2041.9377.391-1.443331.667-2.4310.224-1.1563.3532.929-0.0910.1650.1213.823
Percentage of IncomeLossFromDiscontinuedOperationsAvailableToCommonShareholders100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:IncomeLossFromDiscontinuedOperationsAvailableToCommonShareholders dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value9.8-5.7532.158.228
Percentage of IncomeLossFromDiscontinuedOperationsAvailableToCommonShareholders110.6110.5111.0111.3

cli:IncreaseDecreaseImpairmentOfLandAndOt

cli:IncreaseDecreaseImpairmentOfLandAndOt


None
Period End2020-06-30
Value2500000.0
Percentage of IncreaseDecreaseImpairmentOfLandAndOt100.0

cli:IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits

cli:IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2821000.0-5132000.01193000.07266000.01327000.0-7784000.03847000.0-117000.0-737000.0-2118000.0-1097000.0-6319000.01708000.03891000.0-1872000.0-866000.0-929000.0370000.02094000.0-1449000.01664000.0-4717000.04355000.0-1140000.0-1244000.0-3554000.07872000.0-3301000.0-3419000.0-3339000.05370000.0-2673000.0-405000.0606000.0794000.0-3326000.02248000.0-4575000.08164000.0-1074000.0-894000.0-3012000.0
Percentage of IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value2821000.0-5132000.01193000.07266000.01327000.0-7784000.03847000.0-117000.0-737000.0-2118000.0-1097000.0-6319000.01708000.03891000.0-1872000.0-866000.0-929000.0370000.02094000.0
Percentage of IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:IncreaseDecreaseInUnbilledRentReceivables

cli:IncreaseDecreaseInUnbilledRentReceivables


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-30
Value-1.9071.392-2.3372.9153.9552.7892.2951.727-0.2913.7880.0165.3432.9772.952.9153.1154.5762.1691.7770.784-0.454-0.347-0.3940.9260.6432.9081.6010.2881.8816.3354.050.8280.8540.7562.4250.861
Percentage of IncreaseDecreaseInUnbilledRentReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:IncreaseDecreaseInUnbilledRentReceivables dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value-1.9071.392-2.3372.9153.9552.7892.2951.727-0.2913.7880.0165.3432.9772.952.9153.1154.5762.1691.777
Percentage of IncreaseDecreaseInUnbilledRentReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:InvestmentIncomeLossNonoperating

cli:InvestmentIncomeLossNonoperating


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value7000.032000.0884000.0189000.0515000.0824000.0769000.0851000.0641000.01128000.01408000.0762000.0122000.0474000.0875000.01262000.0146000.0-669000.0231000.05000.0291000.0267000.0
Percentage of InvestmentIncomeLossNonoperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:InvestmentIncomeLossNonoperating dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value7000.032000.0884000.0189000.0515000.0824000.0769000.0851000.0641000.01128000.01408000.0762000.0122000.0474000.0875000.01262000.0146000.0-669000.0231000.05000.0
Percentage of InvestmentIncomeLossNonoperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:LeasingPersonnelCosts

cli:LeasingPersonnelCosts


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value663000.01038000.0443000.0534000.0542000.0742000.0
Percentage of LeasingPersonnelCosts100.0100.0100.0100.0100.0100.0

cli:LongTermIncentivePlanIssuanceOfUnits

cli:LongTermIncentivePlanIssuanceOfUnits


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value01287600.0000565620.000864020.0
Percentage of LongTermIncentivePlanIssuanceOfUnits0.0100.00.00.00.0100.00.00.0100.0

cli:LongTermIncentivePlanUnitsForfeited

cli:LongTermIncentivePlanUnitsForfeited


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value366920.015273.0000359750.059214.029427.0214050.0
Percentage of LongTermIncentivePlanUnitsForfeited100.0100.00.00.00.0100.0100.0100.0100.0

cli:LongTermIncentivePlanVested

cli:LongTermIncentivePlanVested


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value-67890.0-4302.0000-86644.000
Percentage of LongTermIncentivePlanVested100.0100.00.00.00.0100.00.00.0

cli:ManagementLeasingDevelopmentAndOtherServicesFees

cli:ManagementLeasingDevelopmentAndOtherServicesFees


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value500000.0600000.0600000.0500000.0300000.0500000.0600000.0600000.02200000.0700000.0700000.0700000.0900000.01000000.01000000.01100000.01300000.01400000.01600000.01100000.01900000.01400000.0504000.01600000.01700000.01300000.0
Percentage of ManagementLeasingDevelopmentAndOtherServicesFees100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:MinorityInterestDecreaseFromNoncontrollingInterest us-gaap:StatementEquityComponents

cli:MinorityInterestDecreaseFromNoncontrollingInterest

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302017-09-302017-06-302017-03-31
Value0.083-0.2160.00.308-9.418-22.735-0.0510.0011.0670.014
Percentage of MinorityInterestDecreaseFromNoncontrollingInterest100.0100.00.0100.0100.0100.0100.0100.0100.0100.0

cli:MinorityInterestIncreaseDecreaseFromRedemptions

cli:MinorityInterestIncreaseDecreaseFromRedemptions


None
Period End2020-03-312019-09-30
Value-2141000.0-65000.0
Percentage of MinorityInterestIncreaseDecreaseFromRedemptions100.0100.0

cli:MinorityInterestIncreaseDecreaseFromRedemptions dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-03-312019-09-30
Value-2141000.0-65000.0
Percentage of MinorityInterestIncreaseDecreaseFromRedemptions100.0100.0

cli:MinorityInterestIncreaseDecreaseFromRedemptions dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value-2141000.01410000.0-65000.0-623000.0-82000.0-203000.0-400000.0
Percentage of MinorityInterestIncreaseDecreaseFromRedemptions100.00.0100.00.00.00.00.0

cli:MinorityInterestIncreaseDecreaseFromRedemptions us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value-2141000.01410000.0-65000.0-623000.0-82000.08485000.0-400000.0-51000.0-3690000.05062000.000-2531000.0782000.0
Percentage of MinorityInterestIncreaseDecreaseFromRedemptions100.00.0100.00.00.00.00.00.00.00.00.00.00.00.0

cli:NoncontrollingInterestInDiscontinuedOperations

cli:NoncontrollingInterestInDiscontinuedOperations


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-302010-03-31
Value937000.0549000.0213000.0-837000.0-187000.05948000.04630000.0230000.0-748000.031000.0-160000.0466000.0153000.0-13000.024000.019000.0635000.033000.0
Percentage of NoncontrollingInterestInDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1611000.0742000.01426000.01778000.0-1563000.0937000.0287000.0560000.0
Percentage of NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance100.0100.0100.0100.0100.0100.0100.0100.0

cli:NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value1611000.0742000.0117000.01426000.01778000.0-1563000.0367000.0937000.0287000.0560000.0866000.0869000.02445000.0443000.0495000.0
Percentage of NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance100.0100.00.0100.0100.0100.00.0100.0100.0100.00.00.00.00.00.0

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value-1611000.0-742000.0-117000.0-1426000.0-1778000.01563000.0-367000.0-937000.0-287000.0-560000.0-866000.0-869000.0-2445000.0-443000.0-495000.0-351000.0-396000.0-118000.0150000.0
Percentage of NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance-100.0-100.00.0-100.0-100.0-100.00.0-100.0-100.0-100.00.00.00.00.00.00.00.00.00.0

cli:NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders

cli:NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders


None
Period End2020-06-30
Value790000.0
Percentage of NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders100.0

cli:NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-30
Value790000.0
Percentage of NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders100.0

cli:NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders


None
Period End2020-06-30
Value790000.0
Percentage of NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders100.0

cli:NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-30
Value790000.0
Percentage of NoncontrollingInterestIncreaseFromDistributionsToNoncontrollingInterestHolders100.0

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemable

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.4716.4716.4716.4715.0064.6674.4063.7852.9892.7992.6832.6832.6820.792
Percentage of NoncontrollingInterestRedemptionValueAdjustmentRedeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemable dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.4716.4716.4716.4715.0064.6674.4063.7852.9892.7992.6832.6832.6820.792
Percentage of NoncontrollingInterestRedemptionValueAdjustmentRedeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemable us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value2.2362.8043.025163.1522.6663.3792.754
Percentage of NoncontrollingInterestRedemptionValueAdjustmentRedeemable34.643.346.7334.867.570.4113.098.4

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemable us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value6.7086.7676.8056.8565.0244.0873.3733.1122.9992.9761.93
Percentage of NoncontrollingInterestRedemptionValueAdjustmentRedeemable103.7104.6105.2137.0107.6108.0112.8111.2111.8111.0243.7

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.2362.8042.9493.025163.1522.6262.6663.3792.7542.8122.7282.5519.86
Percentage of NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.4733.13.2633.359183.5092.9232.9683.7633.0673.1383.0442.84510
Percentage of NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership110.6110.6110.6111.0111.0111.3111.3111.3111.4111.4111.6111.6111.5111.5

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership

cli:NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value237000.0296000.0314000.0334000.01850000.0357000.0297000.0302000.0384000.0313000.0326000.0316000.0294000.01138000.0
Percentage of NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:NonoperatingIncomeExpenseIncludingEquityMethodInvestments

cli:NonoperatingIncomeExpenseIncludingEquityMethodInvestments


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-21.551-24.69694-58.255-21.97525956-15.815-17.430-17.98715-67.073-2.068-5.346-37.5362641-24.592-2.83112-30.333-26.966-27.44927-30.795
Percentage of NonoperatingIncomeExpenseIncludingEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:NonoperatingIncomeExpenseIncludingEquityMethodInvestments dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-21.551-24.69694-58.255-21.97525956-15.815-17.430-17.98715-67.073-2.068-5.346-37.5362641-24.592-2.83112-30.333
Percentage of NonoperatingIncomeExpenseIncludingEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:NumberOfDisposalGroups us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cli:NumberOfDisposalGroups

us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations, cli:SuburbanOfficePortfolio


None
Period End2020-06-302020-03-31
Value1.012.0
Percentage of NumberOfDisposalGroups100.0100.0

cli:NumberOfDisposalGroups us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cli:DisposalGroupOne


None
Period End2020-06-302020-03-31
Value3.04.0
Percentage of NumberOfDisposalGroups300.033.3

cli:NumberOfDisposalGroups us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:DisposalGroupClassification

srt:OfficeBuilding, us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations


None
Period End2020-06-302020-03-31
Value1.012.0
Percentage of NumberOfDisposalGroups100.0100.0

cli:NumberOfDisposalGroups us-gaap:StatementGeographical, us-gaap:DisposalGroupClassification

cli:ParsippanyMadisonShortHillsEdisonRedBankAndFlorhanPark, us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations


None
Period End2020-03-31
Value4.0
Percentage of NumberOfDisposalGroups33.3

cli:NumberOfPropertiesSold us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:DisposalGroupClassification

cli:NumberOfPropertiesSold

cli:SuburbanOfficePortfolio, cli:PropertiesDisposedOne, us-gaap:DisposalGroupNotDiscontinuedOperations


None
Period End2020-06-30
Value0
Percentage of NumberOfPropertiesSold0.0

cli:OperatingAndInterestExpenses

cli:OperatingAndInterestExpenses


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value707116919494888984969310310197101104101108105101105112120110113141115113117122113111115110113105113117125134137
Percentage of OperatingAndInterestExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:OperatingAndInterestExpenses us-gaap:StatementBusinessSegments

cli:MultipleFamilyRealEstateAndServicesSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2222212322211819161615161614
Percentage of OperatingAndInterestExpenses31.531.9136.526.323.822.521.221.619.116.716.916.216.215.0

cli:RealEstateCommercialAndOtherSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value1516-34.7013535414243435753616063666864656559647268697286747265707070
Percentage of OperatingAndInterestExpenses22.622.9-216.239.437.644.648.249.250.959.757.359.259.265.465.365.663.660.962.658.760.964.057.162.863.861.764.963.956.057.562.763.1

us-gaap:CorporateAndOther


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value3232283136302725252228232920252127382729412830474639414441363940
Percentage of OperatingAndInterestExpenses45.945.2179.734.238.532.930.729.229.923.630.523.029.321.124.920.424.532.225.026.129.225.127.240.237.734.737.538.337.332.337.935.5

cli:OperatingLeaseExpenseIncludingSubleaseRentals

cli:OperatingLeaseExpenseIncludingSubleaseRentals


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value0.686830001.40.640.640.6296510.60.6080.550.550.80.6260.5990.590.7330.5380.128
Percentage of OperatingLeaseExpenseIncludingSubleaseRentals100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues

cli:PortImperialSouthElevenDevelopment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value00.10000.10000.100
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues0.0100.00.00.00.0100.00.00.00.0100.00.00.0

cli:PortImperialSouthParcel89


None
Period End2020-03-31
Value0.1
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues100.0

cli:PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:TaxPeriod

cli:PortImperialSouthParcel89, cli:YearsElevenToEighteen


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.1250000.1250000.125
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues125.00.00.00.0125.00.00.00.0125.0

cli:PortImperialSouthParcel89, cli:YearsNineteenToTwentyFive


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.140000.140000.14
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues140.00.00.00.0140.00.00.00.0140.0

cli:PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost

cli:HarborsideFinancialCenterPlazaFive


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value00.020000.020000.020000.020000.020000.020000.020
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.0

cli:HarborsideFinancialCenterPlazaFoura


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value00.020000.020000.020000.020000.020000.020000.020
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.0

cli:MonacoTowers


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value00.1000.1
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost0.0500.00.00.0500.0

cli:PortImperialHotelDevelopment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value00.020000.020000.020000.0200
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.0

cli:PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty, us-gaap:TaxPeriod

cli:MarbellaIi, cli:YearsFiveToEight


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value00.12000.12
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost0.0600.00.00.0600.0

cli:MarbellaIi, cli:YearsNineToTen


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value00.14000.14
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost0.0700.00.00.0700.0

cli:MarbellaIi, cli:YearsOneToFour


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value00.1000.1
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost0.0500.00.00.0500.0

cli:PortImperialSouthParcel89, cli:YearsOneToTen


None
Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.11000.11000.11
Percentage of PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost550.00.00.0550.00.00.0550.0

cli:PaymentsInLieuOfPropertyTaxes us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:PaymentsInLieuOfPropertyTaxes

cli:HarborsideFinancialCenterPlazaFive


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value1.11.11.21.01.11.11.11.11.11.10.11.21.31.31.01.10.9170.8540.80.8540.8540.8540.80.8540.8540.8540.80.8540.8540.8540.80.854
Percentage of PaymentsInLieuOfPropertyTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:HarborsideFinancialCenterPlazaFoura


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-09-30
Value0.2640.2640.3340.2260.270.270.290.270.270.270.10.3450.3490.3490.3020.2790.2710.2470.2480.2470.2470.2470.2480.2470.2470.2470.2480.2470.2470.2470.247
Percentage of PaymentsInLieuOfPropertyTaxes24.024.027.822.624.524.526.424.524.524.5100.028.826.826.830.225.429.628.931.028.928.928.931.028.928.928.931.028.928.928.928.9

cli:MarbellaIi


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value0.30.20.50.2
Percentage of PaymentsInLieuOfPropertyTaxes27.318.245.518.2

cli:MarbellaTowerUrbanRenewalAssociatesLlc


None
Period End2020-03-312019-09-302019-06-302019-03-312018-12-31
Value0.30.30.50.20.522
Percentage of PaymentsInLieuOfPropertyTaxes27.330.045.518.247.5

cli:MonacoTowers


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value0.50.50.50.50.70.40.5350.6350.6160.6140.5375220.5580.548
Percentage of PaymentsInLieuOfPropertyTaxes45.545.541.750.063.636.448.657.756.055.8537.546.542.2

cli:OneOneOneRiverRealty


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.43520000.40.3520.3520.3520.30.3520.3520.3520.3050.3810.3070.3070.58320.306927
Percentage of PaymentsInLieuOfPropertyTaxes36.432000000.033.335.232.032.027.332.032.032.0305.031.823.623.658.327.9

cli:PortImperialHotelDevelopment


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value0.50.60.30.3
Percentage of PaymentsInLieuOfPropertyTaxes45.554.527.327.3

cli:PortImperialSouthElevenDevelopment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.30.30.30.20.20.3
Percentage of PaymentsInLieuOfPropertyTaxes27.327.325.020.018.227.3

cli:PaymentsToDevelopPropertyAndOtherRelatedCosts

cli:PaymentsToDevelopPropertyAndOtherRelatedCosts


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value7471166650384236
Percentage of PaymentsToDevelopPropertyAndOtherRelatedCosts100.0100.0100.0100.0100.0100.0100.0100.0

cli:PaymentsToDevelopPropertyAndOtherRelatedCosts dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value7471166650384236
Percentage of PaymentsToDevelopPropertyAndOtherRelatedCosts100.0100.0100.0100.0100.0100.0100.0100.0

cli:PercentageOfAward us-gaap:TitleOfIndividual, us-gaap:PlanName

cli:PercentageOfAward

cli:MessieurDebari, cli:TwoThousandNineteenLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value01.00001.0
Percentage of PercentageOfAward0.0100.00.00.00.0100.0

cli:PercentageOfSharesVested us-gaap:Range, us-gaap:AwardType, us-gaap:PlanName, us-gaap:Vesting

cli:PercentageOfSharesVested

srt:Maximum, us-gaap:PerformanceShares, cli:TwoThousandThirteenIncentiveStockPlan, cli:ShareBasedCompensationAwardThreeYearsPeriod


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312015-06-05
Value01.5001.51.5
Percentage of PercentageOfSharesVested0.0100.00.00.0100.0100.0

cli:PreferredUnitsContributionToObtainEquityUnits us-gaap:ConsolidatedEntities, us-gaap:Range, us-gaap:RelatedPartyTransaction

cli:PreferredUnitsContributionToObtainEquityUnits

cli:RockpointGroupL.l.c., srt:Maximum, cli:AddOnInvestmentAgreement


None
Period End2020-06-302020-03-31
Value0.0154
Percentage of PreferredUnitsContributionToObtainEquityUnits0.0100.0

cli:ProRataDistributionPercent us-gaap:ConsolidatedEntities, us-gaap:PreferredUnitsByName

cli:ProRataDistributionPercent

cli:RockpointGroupL.l.c., cli:PreferredUnits


None
Period End2020-06-302020-03-31
Value00.10947
Percentage of ProRataDistributionPercent0.0100.0

cli:ProRataDistributionPercent us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:PreferredUnitsByName

cli:RockpointGroupL.l.c., cli:CashFlowFromCapitalEventsDistributionFive, cli:PreferredUnits


None
Period End2020-06-302020-03-31
Value00.2189
Percentage of ProRataDistributionPercent0.0200.0

cli:RockpointGroupL.l.c., cli:CashFlowFromOperations, cli:PreferredUnits


None
Period End2020-06-302020-03-31
Value00.2189
Percentage of ProRataDistributionPercent0.0200.0

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionFive, cli:PreferredUnits


None
Period End2020-06-302020-03-31
Value00.0265
Percentage of ProRataDistributionPercent0.024.2

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionSix, cli:PreferredUnits


None
Period End2020-06-302020-03-31
Value00.01325
Percentage of ProRataDistributionPercent0.012.1

cli:RoselandResidentialTrust, cli:CashFlowFromOperations, cli:PreferredUnits


None
Period End2020-06-302020-03-31
Value00.0265
Percentage of ProRataDistributionPercent0.024.2

cli:ProRataDistributionPercent us-gaap:ConsolidatedEntities, us-gaap:StatementScenario, us-gaap:StatementEquityComponents

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionFive, cli:CommonUnits


None
Period End2020-06-302020-03-31
Value00.7546
Percentage of ProRataDistributionPercent0.0689.3

cli:RoselandResidentialTrust, cli:CashFlowFromCapitalEventsDistributionSix, cli:CommonUnits


None
Period End2020-06-302020-03-31
Value00.87728
Percentage of ProRataDistributionPercent0.0801.4

cli:RoselandResidentialTrust, cli:CashFlowFromOperations, cli:CommonUnits


None
Period End2020-06-302020-03-31
Value00.7546
Percentage of ProRataDistributionPercent0.0689.3

cli:ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary us-gaap:NonrecurringAdjustment

cli:ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary

us-gaap:AcquisitionRelatedCosts


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-9.19.128-0.7-267.2267
Percentage of ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary100.0100.0100.0100.0100.0100.0

cli:PropertyNetBookValue

cli:PropertyNetBookValue


None
Period End2020-06-302020-03-31
Value-896.9898
Percentage of PropertyNetBookValue100.0100.0

cli:PropertyNetBookValue us-gaap:PropertyPlantAndEquipmentByType

cli:PropertyLockUpsExpired


None
Period End2020-06-302020-03-312019-12-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-100.018002000.00.00.013000.0-100.0-100.01500-100.00.0-100.01700
Percentage of PropertyNetBookValue11.1200.40.00.00.00.00.00.00.00.00.00.00.00.00.0

cli:RealEstateDevelopmentCostsIncurred

cli:RealEstateDevelopmentCostsIncurred


None
Period End2020-06-302020-03-312019-12-312018-12-312018-09-302018-06-302018-03-312013-12-31
Value19290.061123177940.06
Percentage of RealEstateDevelopmentCostsIncurred100.0100.00.0100.0100.0100.0100.0100.0

cli:RealEstateDevelopmentCostsIncurred us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

cli:EmeryAtOverlookRidge


None
Period End2020-06-302020-03-31
Value1929
Percentage of RealEstateDevelopmentCostsIncurred100.0100.0

cli:RealEstatePropertyOwnedAndInvestmentInterest

cli:RealEstatePropertyOwnedAndInvestmentInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-30
Value071.0-5.01.01.074.0-3.0-3.03.0138.0-5.0-52.00214.0-15.0-6.0-4.0273.01.0-5.0-4.0283.01.03.00279.04.02.0-6.0279.02.0-1.00277.000
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.0

cli:RealEstatePropertyOwnedAndInvestmentInterest us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty

cli:MultipleFamilyProperties


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value022.0-3.01.01.022.03.003.018.0001.017.02.0-1.0-1.019.000-1.020.03.03.01.012.03.0
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.031.060.0100.0100.029.7-100.0-0.0100.013.0-0.0-0.00.07.9-13.316.725.07.00.0-0.025.07.1300.0100.00.04.375.0

cli:ParkingRetail


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value04.00004.00006.00006.001.005.0005.00005.0
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.05.6-0.00.00.05.4-0.0-0.00.04.3-0.0-0.00.02.8-0.0-16.7-0.01.8-0.0-0.01.80.00.00.01.8

cli:UnconsolidatedJointVentureMultipleFamilyProperties


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value07.00007.00-1.01.08.00008.000-2.012.000-1.014.03.03.007.00
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.09.9-0.00.00.09.5-0.033.333.35.8-0.0-0.00.03.7-0.0-0.050.04.40.0-0.025.04.9300.0100.00.02.50.0

cli:UnconsolidatedJointVentureOfficeBuildings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value02.00002.00004.00-1.005.000036.000036.0-1.07.08.022.01.0
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.02.8-0.00.00.02.7-0.0-0.00.02.9-0.01.90.02.3-0.0-0.0-0.013.20.0-0.0-0.012.7-100.0233.30.07.925.0

cli:UnconsolidatedJointVentureOfficeFlexBuildingsAndHotel


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value03.01.0002.00001.00001.0
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.04.2-20.00.00.02.7-0.0-0.00.00.7-0.0-0.00.00.5

cli:UnconsolidatedJointVentureParkingRetailBuildings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value01.00002.00002.00002.00002.00002.00002.0
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.01.4-0.00.00.02.7-0.0-0.00.01.4-0.0-0.00.00.9-0.0-0.0-0.00.70.0-0.0-0.00.70.00.00.00.7

srt:OfficeBuilding


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value041.0-3.00045.00
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.057.760.00.00.060.8-0.0

us-gaap:Land


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value01.00001.00001.0-1.0-1.003.00003.0003.00003.00
Percentage of RealEstatePropertyOwnedAndInvestmentInterest0.01.4-0.00.00.01.4-0.0-0.00.00.720.01.90.01.4-0.0-0.0-0.01.1-0.0-0.01.10.00.00.01.10.0

cli:RealEstatePropertyOwnedAndInvestmentInterestArea us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty

cli:RealEstatePropertyOwnedAndInvestmentInterestArea

cli:ParkingRetail


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.00.108-0.0070.00.00120.11380.00010.0-0.00010.13710.00.00.00.13710.0070.00840.00.12170.00.00.12150.00.00.00.1215
Percentage of RealEstatePropertyOwnedAndInvestmentInterestArea0.0100.0100.00.0100.0100.0100.00.0100.0100.00.00.00.0100.0100.0100.00.0100.00.00.0100.00.00.00.0100.0

cli:UnconsolidatedJointVentureOfficeBuildings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.00.20.00.00.00.20.00.00.00.50.0-0.90.01.40.00.00.05.60.00.00.05.6-0.40.92.22.90.3
Percentage of RealEstatePropertyOwnedAndInvestmentInterestArea0.0185.2-0.00.00.0175.70.00.0-0.0364.70.00.00.01021.20.00.00.04601.50.00.00.04609.10.00.00.02386.80.0

cli:UnconsolidatedJointVentureParkingRetailBuildings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.00.0510.00.00.00.08170.00.00.00.08170.00.00.00.08170.00.00.00.08170.00020.00.00.08150.00.00.00.0815
Percentage of RealEstatePropertyOwnedAndInvestmentInterestArea0.047.2-0.00.00.071.80.00.0-0.059.60.00.00.059.60.00.00.067.10.00.00.067.10.00.00.067.1

srt:OfficeBuilding


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value0.010-0.90.0-0.3110.0
Percentage of RealEstatePropertyOwnedAndInvestmentInterestArea0.09722.212857.10.0-25000.010456.90.0

cli:RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations

cli:RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-27.746112-35.0790.25526849-9.1021.01584.47631-38.9545.50641-17.05327580.018340.144
Percentage of RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0

cli:RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value-27.746112-35.0790.25526849-9.1021.01584.47631-38.9545.50641-17.05327580.0
Percentage of RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

cli:RealizedGainsLossOnDispositionOfAssetsNet

cli:RealizedGainsLossOnDispositionOfAssetsNet


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value0.0-7.9150.255268
Percentage of RealizedGainsLossOnDispositionOfAssetsNet0.0100.0100.0100.0

cli:RealizedGainsLossOnDispositionOfAssetsNet dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value0.0-7.9150.255268
Percentage of RealizedGainsLossOnDispositionOfAssetsNet0.0100.0100.0100.0

cli:RedeemableNoncontrollingInterestDecreaseFromDistribution us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents

cli:RedeemableNoncontrollingInterestDecreaseFromDistribution

cli:RockpointGroupL.l.c., cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value6.0166.0164.5514.212
Percentage of RedeemableNoncontrollingInterestDecreaseFromDistribution100.0100.0100.0100.0

cli:RedeemableNoncontrollingInterestDecreaseFromDistribution us-gaap:PreferredUnitsByName, us-gaap:StatementEquityComponents

cli:SeriesUnitsSeriesOnePreferredLimitedPartnershipUnits, cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.4550.4550.4550.4550.4550.4550.4550.4550.4550.4550.4550.4560.4550.265
Percentage of RedeemableNoncontrollingInterestDecreaseFromDistribution7.67.60.00.010.010.80.00.00.00.00.00.00.00.0

cli:RedeemableNoncontrollingInterestDecreaseFromDistribution us-gaap:StatementEquityComponents

cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.4716.4716.4716.4715.0064.6674.4063.7852.9892.7992.6832.6832.6820.792
Percentage of RedeemableNoncontrollingInterestDecreaseFromDistribution107.6107.60.00.0110.0110.80.00.00.00.00.00.00.00.0

cli:RedeemableNoncontrollingInterestRedemptionValueAdjustment

cli:RedeemableNoncontrollingInterestRedemptionValueAdjustment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-8.944-9.571-9.734-9.83-23.615-8.176-7.329-6.753-6.752-5.866-5.821-5.727-5.527-11.79
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:RedeemableNoncontrollingInterestRedemptionValueAdjustment dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-8.944-9.571-9.734-9.83-23.615-8.176-7.329-6.753-6.752-5.866-5.821-5.727-5.527-11.79
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:RedeemableNoncontrollingInterestRedemptionValueAdjustment dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-2.236-2.804-2.949-3.025-16.759-3.152-2.626-2.666-3.379
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment25.029.330.330.871.038.635.839.550.0

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-0.237-0.296-0.314-0.334-1.85-0.357-0.297-0.302-0.384
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment2.63.13.23.47.84.44.14.55.7

cli:MackCaliRealtyLp, us-gaap:OtherOwnershipInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-6.471-6.471-6.471-6.471-5.006-4.667-4.406-3.785-2.989
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment72.467.666.565.821.257.160.156.044.3

cli:RedeemableNoncontrollingInterestRedemptionValueAdjustment us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents

cli:RockpointGroupL.l.c., cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value2.4733.1183.736
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment-27.6-32.4-79.0-45.7

cli:RedeemableNoncontrollingInterestRedemptionValueAdjustment us-gaap:StatementEquityComponents

cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.4733.13.2633.814183.7363.0443.23.8893.1183.1383.0443.2511
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment-27.6-32.4-33.5-38.8-79.0-45.7-41.5-47.4-57.6-53.2-53.9-53.2-58.8-100.0

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-2.236-2.804-2.949-3.025-16.759-3.152-2.626-2.666-3.379-2.754-2.812-2.728-2.551-9.86
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment25.029.330.330.871.038.635.839.550.046.948.347.646.283.6

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-6.708-6.767-6.785-6.805-6.856-5.024-4.703-4.087-3.373-3.112-3.009-2.999-2.976-1.93
Percentage of RedeemableNoncontrollingInterestRedemptionValueAdjustment75.070.769.769.229.061.464.260.550.053.151.752.453.816.4

cli:RedemptionOfCommonUnits us-gaap:StatementEquityComponents

cli:RedemptionOfCommonUnits

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0-2141000.0-7769000.0-65000.00-4965000.0
Percentage of RedemptionOfCommonUnits0.0100.0100.0100.00.0100.0

cli:RedemptionOfCommonUnitsShares us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:DisposalGroupClassification

cli:RedemptionOfCommonUnitsShares

cli:FlexProperties, us-gaap:DisposalGroupNotDiscontinuedOperations


None
Period End2020-06-302020-03-312019-03-31
Value097727.0301640.0
Percentage of RedemptionOfCommonUnitsShares0.0100.0100.0

cli:RightOfFirstRefusalToInvestInPreferredUnitsAmount us-gaap:ConsolidatedEntities, us-gaap:RelatedPartyTransaction

cli:RightOfFirstRefusalToInvestInPreferredUnitsAmount

cli:RockpointGroupL.l.c., cli:AddOnInvestmentAgreement


None
Period End2020-06-302020-03-312019-06-30
Value0.0100100
Percentage of RightOfFirstRefusalToInvestInPreferredUnitsAmount0.0100.0100.0

cli:SegmentReportingInformationNetOperatingIncomeLossForReportableSegment

cli:SegmentReportingInformationNetOperatingIncomeLossForReportableSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value1.45310-62.1540363943424144485557525174474340474037304347274948605754536069
Percentage of SegmentReportingInformationNetOperatingIncomeLossForReportableSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:SegmentReportingInformationNetOperatingIncomeLossForReportableSegment dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value1.45310-62.154036394342414448555752517447434047
Percentage of SegmentReportingInformationNetOperatingIncomeLossForReportableSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cli:SegmentReportingInformationNetOperatingIncomeLossForReportableSegment us-gaap:StatementBusinessSegments

cli:MultipleFamilyRealEstateAndServicesSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value15192322211313107.6269.4757.5845.294.1242.297
Percentage of SegmentReportingInformationNetOperatingIncomeLossForReportableSegment1068.2193.5-38.154.259.934.831.424.218.221.515.69.67.24.4

cli:RealEstateCommercialAndOtherSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value1823-57.474950565757595760757871749570696677716670738071828392858687
Percentage of SegmentReportingInformationNetOperatingIncomeLossForReportableSegment1274.5229.892.5120.8139.3143.8131.1135.5142.2130.3125.3136.4137.2136.1143.8127.1149.3160.3163.6163.0174.2177.3226.5167.8169.4261.6164.9170.3153.2148.3159.3163.4

us-gaap:CorporateAndOther


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value-32.587-32.555-28.383-30.485-35.917-31.08-27.288-25.311-25.307-22.848-16.27-26.454-28.898-19.905-15.718-23.626-28.539-39.166-29.338-33.887-41.884-30.507-32.556-41.06-42.206-30.149-33.829-43.558-40.905
Percentage of SegmentReportingInformationNetOperatingIncomeLossForReportableSegment-2242.7-323.345.7-75.0-99.2-78.6-62.6-59.7-60.4-51.8-33.5-47.9-50.2-37.9-30.5-31.6-76.4-126.4-67.0-71.4-153.1-61.3-66.8-68.2-73.2-55.3-63.4-71.5-58.6

cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnvestedInPeriod dei:LegalEntity, us-gaap:AwardType

cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnvestedInPeriod

cli:MackCaliRealtyLp, cli:UnvestedLongTermIncentivePlanAwards


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-434810.03094300.0001826300.0-29427.0649980.01145800.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnvestedInPeriod100.0100.00.00.0100.0100.0100.0100.0

cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsSharesToBeVestedAndExpectedToVestExercisableNumber us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:Vesting

cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsSharesToBeVestedAndExpectedToVestExercisableNumber

cli:MichaelJ.DemarcoChiefExecutiveOfficer, cli:AoLtipUnitsAward, us-gaap:ShareBasedCompensationAwardTrancheOne


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0250000.0000250000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsSharesToBeVestedAndExpectedToVestExercisableNumber0.0100.00.00.00.0100.0

cli:MichaelJ.DemarcoChiefExecutiveOfficer, cli:AoLtipUnitsAward, us-gaap:ShareBasedCompensationAwardTrancheThree


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0125000.0000125000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsSharesToBeVestedAndExpectedToVestExercisableNumber0.050.00.00.00.050.0

cli:MichaelJ.DemarcoChiefExecutiveOfficer, cli:AoLtipUnitsAward, us-gaap:ShareBasedCompensationAwardTrancheTwo


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0250000.0000250000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsSharesToBeVestedAndExpectedToVestExercisableNumber0.0100.00.00.00.0100.0

cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:Vesting

cli:ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger

cli:MichaelJ.DemarcoChiefExecutiveOfficer, cli:AoLtipUnitsAward, us-gaap:ShareBasedCompensationAwardTrancheOne


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value025.000025.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger0.0100.00.00.00.0100.0

cli:MichaelJ.DemarcoChiefExecutiveOfficer, cli:AoLtipUnitsAward, us-gaap:ShareBasedCompensationAwardTrancheThree


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value031.000031.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger0.0124.00.00.00.0124.0

cli:MichaelJ.DemarcoChiefExecutiveOfficer, cli:AoLtipUnitsAward, us-gaap:ShareBasedCompensationAwardTrancheTwo


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value028.000028.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger0.0112.00.00.00.0112.0

cli:StockBasedCompensationAttributableToNoncontrollingInterest us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:StockBasedCompensationAttributableToNoncontrollingInterest

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value334000.0430000.07000.0218000.0265000.0202000.0434000.0517000.0
Percentage of StockBasedCompensationAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0

cli:StockBasedCompensationAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-31
Value2105000.02100000.01973000.01973000.01615000.01568000.0223000.02015000.01329000.01329000.0644000.0669000.0669000.0173000.0
Percentage of StockBasedCompensationAttributableToNoncontrollingInterest630.2488.428185.7905.0609.4776.251.4389.70.00.00.00.00.00.0

cli:StockIssuedDuringPeriodSharesLongTermIncentivePlanVested dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:StockIssuedDuringPeriodSharesLongTermIncentivePlanVested

cli:MackCaliRealtyLp, us-gaap:LimitedPartner


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-30
Value68000.04000.00-9000.077000.00
Percentage of StockIssuedDuringPeriodSharesLongTermIncentivePlanVested100.0100.00.0100.0100.00.0

cli:StockIssuedDuringPeriodValueLongTermIncentivePlanUnitsForfeited us-gaap:StatementEquityComponents

cli:StockIssuedDuringPeriodValueLongTermIncentivePlanUnitsForfeited

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value0201000.0002889000.0
Percentage of StockIssuedDuringPeriodValueLongTermIncentivePlanUnitsForfeited0.0100.00.00.0100.0

cli:TotalStockholderReturnPercent us-gaap:PlanName

cli:TotalStockholderReturnPercent

cli:TwoThousandEighteenOutperformancePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value00.360000.360000.36
Percentage of TotalStockholderReturnPercent0.0100.00.00.00.0100.00.00.00.0100.0

cli:TwoThousandNineteenOutperformancePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value00.360000.36
Percentage of TotalStockholderReturnPercent0.0100.00.00.00.0100.0

cli:TwoThousandSeventeenOutperformancePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00.360000.360000.360000.36
Percentage of TotalStockholderReturnPercent0.0100.00.00.00.0100.00.00.00.0100.00.00.00.00.0

cli:TwoThousandSixteenOutperformancePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00.50000.50000.50000.5
Percentage of TotalStockholderReturnPercent0.0138.90.00.00.0138.90.00.00.0138.90.00.00.00.0

cli:TwoThousandTwentyOutperformancePlan


None
Period End2020-06-302020-03-31
Value00.36
Percentage of TotalStockholderReturnPercent0.0100.0

cli:UnrealizedGainLossOnDispositionOfRentalProperty

cli:UnrealizedGainLossOnDispositionOfRentalProperty


None
Period End2020-06-302020-03-312019-06-302012-06-30
Value-11.929-45.068-5.802-1.634
Percentage of UnrealizedGainLossOnDispositionOfRentalProperty100.0100.0100.0100.0

cli:UnrealizedGainLossOnDispositionOfRentalProperty us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cli:DisposalGroupOne


None
Period End2020-06-302020-03-31
Value1145
Percentage of UnrealizedGainLossOnDispositionOfRentalProperty-99.8-100.1

cli:WriteOffOfUnamortizedDeferredFinancingCosts

cli:WriteOffOfUnamortizedDeferredFinancingCosts


None
Period End2020-06-302019-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value00105000.0161000.0000399000.0346000.00
Percentage of WriteOffOfUnamortizedDeferredFinancingCosts0.00.0100.0100.00.00.00.0100.0100.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-11000.0-19000.0-10000.0-11000.0-10000.0-13000.082000.0-28000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmortizationOfFinancingCostsAndDiscounts

us-gaap:AmortizationOfFinancingCostsAndDiscounts


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1060000.01024000.01147000.01121000.01168000.01189000.01485000.01302000.01145000.01096000.01150000.01184000.01175000.01103000.0999000.01234000.01180000.01169000.0944000.0945000.0948000.0953000.0968000.0778000.0759000.0769000.0793000.0797000.0809000.0773000.0724000.0673000.0661000.0611000.0618000.0584000.0584000.0584000.0635000.0645000.0661000.0715000.0
Percentage of AmortizationOfFinancingCostsAndDiscounts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmortizationOfFinancingCostsAndDiscounts dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value1060000.01024000.01147000.01121000.01168000.01189000.01485000.01302000.01145000.01096000.01150000.01184000.01175000.01103000.0999000.01234000.01180000.01169000.0944000.0
Percentage of AmortizationOfFinancingCostsAndDiscounts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.688-0.041-13.237-24.12745-16.93218-20.843-8.352-7.835-61.2951-148.026140
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.688-0.041-13.237-24.12745-16.93218-20.843-8.352-7.835-61.2951-148.026140
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-4.40656-14.571-60.451
Percentage of CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations100.0100.0100.0100.0

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-4.40656-14.571-60.451
Percentage of CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations100.0100.0100.0100.0

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value19272219
Percentage of CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations100.0100.0100.0100.0

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value19272219
Percentage of CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations100.0100.0100.0100.0

us-gaap:CommonStockDividendsPerShareDeclared

us-gaap:CommonStockDividendsPerShareDeclared


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.20.20.20.20.20.20.20.20.20.20.20.20.20.150.150.150.150.150.150.150.150.150.150.150.150.30.30.30.30.450.450.450.450.450.450.450.450.450.450.450.450.45
Percentage of CommonStockDividendsPerShareDeclared100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStockDividendsPerShareDeclared dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0.20.20.20.20.20.20.20.20.20.20.150.150.150.150.150.150.150.150.15
Percentage of CommonStockDividendsPerShareDeclared100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredCompensationArrangementWithIndividualExercisePrice

us-gaap:DeferredCompensationArrangementWithIndividualExercisePrice


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value17.31017.3117.3117.31017.3117.3117.31
Percentage of DeferredCompensationArrangementWithIndividualExercisePrice100.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:DepreciationAndAmortization

us-gaap:DepreciationAndAmortization


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2733-14.92494948464541414752574752484343434442404041444447464846474747474848484847474748
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAndAmortization dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value2733-14.9249494846454141475257475248434343444240
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation

us-gaap:DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet

us-gaap:InterestRateSwap, us-gaap:CashFlowHedging, us-gaap:DesignatedAsHedgingInstrument, us-gaap:InterestExpense


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value016000.0551000.01297000.01571000.0929000.0640000.080000.0
Percentage of DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet0.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation

us-gaap:DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet

us-gaap:InterestRateSwap, us-gaap:CashFlowHedging, us-gaap:DesignatedAsHedgingInstrument, cli:InterestAndOtherInvestmentIncomeLoss


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value00100000.0500000.01279000.047000.0-100000.0-74000.0
Percentage of DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet0.00.0100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax

us-gaap:DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax


None
Period End2020-06-302020-03-312019-06-302013-12-312013-09-302013-06-30
Value-11.929-27.746-5.802-1.5594713
Percentage of DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-30
Value-11.929-27.746-5.802
Percentage of DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-302010-03-31
Value21217.9528.228-0.0092.1641.3641.8971.0440.2430.318-0.1931.207-0.1040.1890.140.0110.231
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value21217.9528.228
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-30
Value1.4521.44517160.0221.7692.989
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value1.4521.4451716
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationInterestExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationInterestExpense


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-30
Value1.3071.3061.3071.2930.00.0020.0350.0810.00.0820.080.4280.4470.4470.4470.4470.134
Percentage of DisposalGroupIncludingDiscontinuedOperationInterestExpense100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-30
Value141617170.02.4721.1091.6772.3010.7050.6070.8783.3340.9590.8821.0890.498
Percentage of DisposalGroupIncludingDiscontinuedOperationOperatingExpense100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-30
Value39414343-0.0096.4052.7423.9529.3450.9610.9381.5289.41.7181.942.1170.945
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DividendsCommonStock

us-gaap:DividendsCommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value0.018181818181818181817171713131313131313131313131326262626393939393939393939
Percentage of DividendsCommonStock0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DividendsCommonStock us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value0.018181818181818181817171713131313131313131313131326262626393939393939393939
Percentage of DividendsCommonStock0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DividendsCommonStockCash dei:LegalEntity

us-gaap:DividendsCommonStockCash

cli:MackCaliRealtyLp


None
Period End2020-03-312019-12-312019-09-302019-06-302018-12-31
Value0.40.40.40.418
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0

us-gaap:DividendsCommonStockCash dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementEquityComponents

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders, cli:CommonUnits


None
Period End2020-03-312019-12-312019-09-302019-06-302018-12-31
Value1.91.92.02.02.0
Percentage of DividendsCommonStockCash475.0475.0500.0500.011.0

us-gaap:DividendsCommonStockCash us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


None
Period End2020-07-13
Value20
Percentage of DividendsCommonStockCash0.0

us-gaap:EmployeeBenefitsAndShareBasedCompensation

us-gaap:EmployeeBenefitsAndShareBasedCompensation


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value175000.0256000.053000.0212000.0189000.0319000.0151000.0237000.0225000.0273000.0234000.0246000.0233000.0342000.0283000.0254000.0254000.0237000.0970000.0000-77000.024000.027000.025000.026000.024000.029000.038000.07000.0000000000
Percentage of EmployeeBenefitsAndShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.0

us-gaap:EquityMethodInvestmentDividendsOrDistributions

us-gaap:EquityMethodInvestmentDividendsOrDistributions


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2.2030.8151.4032.1531.8141.5531.4464.2671.352.1191.6842.681.1382.6841.2872.4181.8410.5742.4990.4471.8830.8150.2397.2181.9451.8112.0171.7564.2590.4531.311.1861.3690.1250.8191.0111.1020.3691.9980.2110.0540.048
Percentage of EquityMethodInvestmentDividendsOrDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquityMethodInvestmentDividendsOrDistributions dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value2.2030.8151.4032.1531.8141.5531.4464.2671.352.1191.6842.681.1382.6841.2872.4181.8410.5742.499
Percentage of EquityMethodInvestmentDividendsOrDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ExtinguishmentOfDebtGainLossNetOfTax

us-gaap:ExtinguishmentOfDebtGainLossNetOfTax


None
Period End2020-06-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value0.0-0.153-0.0980.5881.311-0.4610.00.0-10.289-0.1820.00.0-0.239-23.658-19.30212
Percentage of ExtinguishmentOfDebtGainLossNetOfTax0.0100.0100.0100.0100.0100.00.00.0100.0100.00.00.0100.0100.0100.0100.0

us-gaap:GainLossOnDispositionOfAssets

us-gaap:GainLossOnDispositionOfAssets


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302013-06-302012-12-312012-09-302012-06-302012-03-312010-06-30
Value0.0-7.915112-35.0790.25526849-9.1021.01584.47631-38.9545.50641-17.05327580.018340.1440.00.26454-1.5594737-7.1650.012-1.6344.0124.447
Percentage of GainLossOnDispositionOfAssets0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GainLossOnDispositionOfAssets dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0.0-7.915112-35.0790.25526849-9.1021.01584.47631-38.9545.50641-17.05327580.018340.144
Percentage of GainLossOnDispositionOfAssets0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax


None
Period End2020-06-302020-03-312019-06-302019-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-302010-03-31
Value9.8-5.7532.158.228-1.56849381.897-6.1210.255-1.3163.8191.207-0.1040.1890.144.4580.231
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value9.8-5.7532.158.228
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTax100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-06-30
Value0.1-0.06-1.17-0.010.020.080.080.070.080.03-0.020.490.380.02-0.060.01-0.010.040.010.010.010.05
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.1-0.06-1.17-0.010.020.080.080.070.080.03
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-06-30
Value0.1-0.06-1.17-0.010.020.080.080.070.080.03-0.020.490.380.02-0.060.01-0.010.040.010.010.010.05
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.1-0.06-1.17-0.010.020.080.080.070.080.03
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments

us-gaap:IncomeLossFromEquityMethodInvestments


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-0.946-0.708-0.437-0.113-0.088-0.681-0.96-0.687-0.0521.572-1.199-1.533-3.298-0.051-0.83421-0.614-1.554-0.4493.135-2.329-3.529-0.363-1.2680.443-1.235-0.268-0.229-0.08-1.75-0.6622.4181.7330.60.8480.5390.736-0.1012.0630.4750.26-0.522
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-0.946-0.708-0.437-0.113-0.088-0.681-0.96-0.687-0.0521.572-1.199-1.533-3.298-0.051-0.83421-0.614-1.554-0.4493.135-2.329-3.529
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty

cli:UnconsolidatedJointVentureOtherProperty


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-0.946-0.708-0.437-0.113-0.088-0.681-0.96-0.687-0.0521.572-1.199-1.533-3.298-0.051-0.83421-0.614-1.554-0.4493.135
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:CrystalHouseApartmentsInvestorsLLC


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-0.181-0.159525-0.117-0.184-0.226-0.257-0.192-0.263-0.162-0.171-0.171-0.289-0.293-0.549-0.099-0.11-0.112-0.082-0.044
Percentage of IncomeLossFromEquityMethodInvestments19.122.5-120208.9103.5209.133.226.827.9505.8-10.314.311.28.8574.565.8-0.517.97.218.3-1.4

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:MetropolitanAt40Park


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.195-0.14332-0.135-0.121-0.077-0.093-0.131-0.156-0.075-0.077-0.081-0.068-0.085
Percentage of IncomeLossFromEquityMethodInvestments20.619.8-76104.8119.5137.511.39.719.1300.0-4.86.45.32.1166.7

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:PiNorthRiverwalk


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-31
Value-0.119-0.119210-0.079-0.062-0.07-0.038-0.051-0.0370.059-0.298-0.283-0.131
Percentage of IncomeLossFromEquityMethodInvestments12.616.8-48219.969.970.510.34.07.471.2-4.919.48.6256.9

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:RiverparkAtHarrison


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.066-0.058158-0.034-0.065-0.06-0.058-0.026-0.085-0.063-0.09-0.085-0.066-0.011
Percentage of IncomeLossFromEquityMethodInvestments7.08.2-36345.130.173.98.86.03.8163.5-4.07.55.52.021.6

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:RivertraceAtPortImperial


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.0350.098-136.6830.0470.0520.0380.0320.0330.0450.0440.0530.0520.0420.048
Percentage of IncomeLossFromEquityMethodInvestments-3.7-13.831277.6-41.6-59.1-5.6-3.3-4.8-86.52.8-4.4-3.4-1.3-94.1

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:StationHouse


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.672-0.4671484-0.392-0.538-0.556-0.653-0.531-0.484-0.428-0.521-0.447-0.449-0.375
Percentage of IncomeLossFromEquityMethodInvestments71.066.0-339588.1346.9611.481.668.077.3930.8-27.243.529.213.6735.3

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:UrbyAtHarborside


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.0260.017990-0.24-0.29-0.458-1.132-0.99-0.5741.721-1.182-2.053-2.976-0.145
Percentage of IncomeLossFromEquityMethodInvestments2.7-2.4-226678.9212.4329.567.3117.9144.11103.8109.598.6133.990.2284.3

cli:UnconsolidatedJointVentureOfficeBuildings, cli:OfficesAtCrystalLake


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.0540.02-64.9210.036-0.0160.0450.0160.037-0.0060.0260.0150.0290.0390.006
Percentage of IncomeLossFromEquityMethodInvestments-5.7-2.814856.1-31.918.2-6.6-1.7-5.411.51.7-1.3-1.9-1.2-11.8

cli:UnconsolidatedJointVentureOfficeBuildings, cli:TwelveVreelandAssociatesLLC


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value0.1470.111-285.1720.1250.1120.0450.1280.119-0.0210.0590.1790.1860.0540.0770.0810.0740.1080.0840.160.038
Percentage of IncomeLossFromEquityMethodInvestments-15.5-15.765256.8-110.6-127.3-6.6-13.3-17.340.43.8-14.9-12.1-1.6-151.0-9.70.3-17.6-5.4-35.61.2

cli:UnconsolidatedJointVentureOtherProperty, cli:HyattRegencyJerseyCity


None
Period End2020-06-302019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value-0.050.751.00.6381.0241.2260.310.9730.750.587
Percentage of IncomeLossFromEquityMethodInvestments5.3-663.7-1136.4-93.7-149.1-2357.719.7-63.5-22.7-1151.0

cli:UnconsolidatedJointVentureOtherProperty, cli:OtherJointVentures


None
Period End2020-06-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value0.127-19.879-0.0530.0450.0280.0370.0740.2770.11-0.2050.070.2740.080.1680.7450.2310.150.5370.082
Percentage of IncomeLossFromEquityMethodInvestments-13.44549.046.9-51.1-4.1-3.9-10.8-532.77.017.1-4.6-8.3-156.9-20.13.4-37.6-9.7-119.62.6

cli:UnconsolidatedJointVentureOtherProperty, cli:RiverwalkRetail


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value0.0-0.011-0.021-0.021-0.021-0.02-0.02-0.025-0.023-0.026-0.011
Percentage of IncomeLossFromEquityMethodInvestments-0.01.618.623.93.12.938.5-1.61.50.821.6

us-gaap:IncomeLossFromEquityMethodInvestments us-gaap:StatementBusinessSegments

cli:MultipleFamilyRealEstateAndServicesSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.569-0.5912.297-0.42-0.6-1.402-1.797-1.4-0.9611.712-1.39-2.591-3.28-0.464
Percentage of IncomeLossFromEquityMethodInvestments60.183.5-525.6371.7681.8205.9187.2203.81848.1108.9115.9169.099.5909.8

cli:RealEstateCommercialAndOtherSegment


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-0.377-0.117-2.7340.3070.5120.7210.8370.7130.909-0.140.1921.058-0.0180.4120.227221.405-1.9260.4935.1810.798-1.3681.0910.3281.8290.9881.1311.9192.8450.3850.8132.418
Percentage of IncomeLossFromEquityMethodInvestments39.916.5625.6-271.7-581.8-105.9-87.2-103.8-1748.1-8.9-16.0-69.00.5-807.8-27.2103.2-228.8123.9-109.8165.3-34.338.8-300.6-25.9412.9-80.0-422.0-838.0-3556.2-22.0-122.8100.0

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2.6464.384-14.074-0.7580.903153.8723.01-7.10114-5.2975.8291.852-11.396-1.879-7.223-3.063-2.371.6623.82-6.6818.1592.293-6.381-1.63321-13.0572.847-6.6779.797-9.872-2.1734.16.129-4.1010.17913-7.724-3.8-14.058115.887
Percentage of IncreaseDecreaseInAccountsPayableAndAccruedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value2.6464.384-14.074-0.7580.903153.8723.01-7.10114-5.2975.8291.852-11.396-1.879-7.223-3.063-2.371.662
Percentage of IncreaseDecreaseInAccountsPayableAndAccruedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInterestPayableNet

us-gaap:IncreaseDecreaseInInterestPayableNet


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-5540000.05473000.0-5363000.06917000.0-5787000.05301000.0-5260000.05859000.0-5668000.04667000.0-7257000.07781000.0-7341000.08113000.0-7862000.01696000.0-2707000.0-489000.0-2929000.01409000.03671000.02671000.02224000.0-1260000.02714000.0-5894000.05681000.0-5090000.06790000.0-5783000.08388000.0-7727000.011826000.0-11832000.012171000.0-10869000.011698000.0-10992000.08137000.0-16834000.013223000.0-14818000.0
Percentage of IncreaseDecreaseInInterestPayableNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInterestPayableNet dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value-5540000.05473000.0-5363000.06917000.0-5787000.05301000.0-5260000.05859000.0-5668000.04667000.0-7257000.07781000.0-7341000.08113000.0-7862000.01696000.0-2707000.0-489000.0-2929000.0
Percentage of IncreaseDecreaseInInterestPayableNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInLeasingReceivables

us-gaap:IncreaseDecreaseInLeasingReceivables


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value3582000.01673000.0-5082000.0-1225000.02273000.01830000.0-1824000.0838000.0-941000.0545000.0-793000.0-127000.0-1898000.0-13000.0-172000.04156000.0-3337000.0-1243000.01575000.0-2958000.02695000.0866000.0-2266000.0-414000.09000.02316000.0-247000.01170000.0-1097000.0-74000.01156000.0-920000.01092000.0737000.0-1462000.0-225000.0-2153000.0-1401000.0-2296000.03068000.0-422000.03956000.0
Percentage of IncreaseDecreaseInLeasingReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInLeasingReceivables dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value3582000.01673000.0-5082000.0-1225000.02273000.01830000.0-1824000.0838000.0-941000.0545000.0-793000.0-127000.0-1898000.0-13000.0-172000.04156000.0-3337000.0-1243000.01575000.0
Percentage of IncreaseDecreaseInLeasingReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingAssets

us-gaap:IncreaseDecreaseInOtherOperatingAssets


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.352-0.2912.8684.2947.8726.7749.444116.6111.8996.4674.2166.1862.84222-14.2976.14719-0.5338.5853.974104.85314-7.15315-2.961107.9978.862-5.29415-3.58810-3.84129.9268.5421.1054.149108.554
Percentage of IncreaseDecreaseInOtherOperatingAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingAssets dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0.352-0.2912.8684.2947.8726.7749.444116.6111.8996.4674.2166.1862.84222-14.2976.14719-0.533
Percentage of IncreaseDecreaseInOtherOperatingAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsCapitalized

us-gaap:InterestCostsCapitalized


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value5.9325.8565.014.8575.1614.2975.7736.9787.1877.1096.2854.7824.1764.9974.885.094.7854.5614.4734.3563.7813.6074.824.1573.3523.1412.6233.5143.2813.4672.9150.8910.3060.230.20560.12240.2030.550.5850.552
Percentage of InterestCostsCapitalized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsCapitalized us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:CorporateJointVenture


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.3350.3460.3490.3630.3420.2850.2540.2140.1820.1660.0470.00.01.0091.1181.166
Percentage of InterestCostsCapitalized5.65.97.07.56.66.64.43.12.52.30.70.00.020.222.922.9

us-gaap:InterestPaid

us-gaap:InterestPaid


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value31203320322131242219332034153227332830312725273025362536243621371843174017402652
Percentage of InterestPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestPaid us-gaap:DisposalGroupClassification

us-gaap:SegmentDiscontinuedOperations


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value1.2921.2780.6191.937
Percentage of InterestPaid4.16.11.98.8

us-gaap:LineOfCreditFacilityCommitmentFeePercentage us-gaap:CreditFacility

us-gaap:LineOfCreditFacilityCommitmentFeePercentage

cli:TwentySeventeenUnsecuredRevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00.00250000.00250000.00250000.0025
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

us-gaap:LineOfCreditFacilityCommitmentFeePercentage us-gaap:CreditFacility, us-gaap:DebtInstrument

cli:TwentySeventeenUnsecuredRevolvingCreditFacility, cli:FiftyAndFiftyFivePercentUnsecuredTermLoanLeverageRatio


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00.0030000.0030000.0030000.003
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0120.00.00.00.0120.00.00.00.0120.00.00.00.0120.0

cli:TwentySeventeenUnsecuredRevolvingCreditFacility, cli:FiftyFivePercentUnsecuredTermLoanLeverageRatio


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00.00350000.00350000.00350000.0035
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0140.00.00.00.0140.00.00.00.0140.00.00.00.0140.0

cli:TwentySeventeenUnsecuredRevolvingCreditFacility, cli:FortyFiveAndFiftyUnsecuredTermLoanPercentLeverageRatio


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00.00250000.00250000.00250000.0025
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

cli:TwentySeventeenUnsecuredRevolvingCreditFacility, cli:FortyFiveUnsecuredTermLoanPercentLeverageRatio


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00.0020000.0020000.0020000.002
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.080.00.00.00.080.00.00.00.080.00.00.00.080.0

us-gaap:LineOfCreditFacilityCommitmentFeePercentage us-gaap:CreditRatingMoodys, us-gaap:CreditRatingStandardPoors, us-gaap:CreditFacility

cli:MoodysA3RatingOrHigher, cli:StandardPoorsMinusRatingOrHigher, cli:TwentySeventeenUnsecuredRevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.001250000.001250
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.050.00.00.00.050.00.0

cli:MoodysA3RatingOrHigher, cli:StandardPoorsMinusRatingOrHigher, us-gaap:RevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.001250000.001250
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.050.00.00.00.050.00.0

cli:NoRatingsOrLessThanMoodysBaa3Rating, cli:NoRatingsOrLessThanStandardPoorsBBBMinus, cli:TwentySeventeenUnsecuredRevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.0030000.0030
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0120.00.00.00.0120.00.0

cli:NoRatingsOrLessThanMoodysBaa3Rating, cli:NoRatingsOrLessThanStandardPoorsBBBMinus, us-gaap:RevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.00350000.00350
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0140.00.00.00.0140.00.0

srt:MoodysBaa1Rating, srt:StandardPoorsBBBPlusRating, cli:TwentySeventeenUnsecuredRevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.00150000.00150
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.060.00.00.00.060.00.0

srt:MoodysBaa1Rating, srt:StandardPoorsBBBPlusRating, us-gaap:RevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.00150000.00150
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.060.00.00.00.060.00.0

srt:MoodysBaa2Rating, srt:StandardPoorsBBBRating, cli:TwentySeventeenUnsecuredRevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.0020000.0020
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.080.00.00.00.080.00.0

srt:MoodysBaa2Rating, srt:StandardPoorsBBBRating, us-gaap:RevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.0020000.0020
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.080.00.00.00.080.00.0

srt:MoodysBaa3Rating, srt:StandardPoorsBBBMinusRating, cli:TwentySeventeenUnsecuredRevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.00250000.00250
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0100.00.00.00.0100.00.0

srt:MoodysBaa3Rating, srt:StandardPoorsBBBMinusRating, us-gaap:RevolvingCreditFacility


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value00.0030000.0030
Percentage of LineOfCreditFacilityCommitmentFeePercentage0.0120.00.00.00.0120.00.0

us-gaap:MinorityInterestPeriodIncreaseDecrease

us-gaap:MinorityInterestPeriodIncreaseDecrease


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value-0.0830.216-0.060.0-0.3087.46-0.45322-4.807-0.0140.00.0-36.1270.9972.8770.0930.0640.094-0.021-0.145-0.29-0.322-0.531.2510.334-0.015540.00.00.026-0.214
Percentage of MinorityInterestPeriodIncreaseDecrease100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0

us-gaap:MinorityInterestPeriodIncreaseDecrease dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-06-302017-03-312016-12-31
Value-0.0830.216-0.060.0-0.3087.46-0.45322-4.807-0.0140.0
Percentage of MinorityInterestPeriodIncreaseDecrease100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.0

us-gaap:MinorityInterestPeriodIncreaseDecrease dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, us-gaap:OtherOwnershipInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-0.0830.216-0.060.0-0.3089.418
Percentage of MinorityInterestPeriodIncreaseDecrease100.0100.0100.00.0100.0126.2

us-gaap:MinorityInterestPeriodIncreaseDecrease us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value-0.0830.216-0.060.0-0.3089.418-0.45322-1.067-0.0140.00.0-36.5410.9972.8770.0930.0640.0940.0650.452-0.531.2510.334-0.015540.00.00.026-0.214
Percentage of MinorityInterestPeriodIncreaseDecrease100.0100.0100.00.0100.0126.2100.0100.022.2100.00.00.0101.1100.0100.0100.0100.0100.0-309.5-311.7100.0100.0100.0100.0100.00.00.0100.0100.0

us-gaap:NetCashProvidedByUsedInInvestingActivitiesContinuingOperations

us-gaap:NetCashProvidedByUsedInInvestingActivitiesContinuingOperations


None
Period End2020-06-302020-03-312019-06-302019-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-106.676-139.707-37.63989323143-226.524-421.311145-212.743-69.029-1.394-132.103-55.27517-52.423-15.5756920-24.216
Percentage of NetCashProvidedByUsedInInvestingActivitiesContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetCashProvidedByUsedInInvestingActivitiesContinuingOperations dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value-106.676-139.707-37.63989143-226.524-421.311145-250.689-31.083-1.394-132.103
Percentage of NetCashProvidedByUsedInInvestingActivitiesContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0117.845.0100.0100.0

us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations

us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations


None
Period End2020-06-302020-03-312019-06-302019-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value5.021160.36226-51.401585251-4.6833939254445403943305727
Percentage of NetCashProvidedByUsedInOperatingActivitiesContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-06-302019-03-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value5.021160.36226585251-4.68339392544
Percentage of NetCashProvidedByUsedInOperatingActivitiesContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossAttributableToNonredeemableNoncontrollingInterest us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:NetIncomeLossAttributableToNonredeemableNoncontrollingInterest

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value34395522-244.4951.4781.251-43.036
Percentage of NetIncomeLossAttributableToNonredeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossAttributableToNonredeemableNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-30
Value-1.953-2.080.093-1.725-31.099-3.167-2.752-7.652-6.6491.795-2.851.064
Percentage of NetIncomeLossAttributableToNonredeemableNoncontrollingInterest-5.6-5.20.2-7.812.7-214.3-220.017.80.00.00.00.0

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.4716.4716.4716.4715.0064.6674.4063.7852.9892.7992.6832.6832.6820.792
Percentage of NetIncomeLossAttributableToRedeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.4716.4716.4716.4715.0064.6674.4063.7852.9892.7992.6832.6832.6820.792
Percentage of NetIncomeLossAttributableToRedeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest us-gaap:ConsolidatedEntities, us-gaap:StatementEquityComponents

cli:RockpointGroupL.l.c., cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-6.016-6.016-4.551-4.212
Percentage of NetIncomeLossAttributableToRedeemableNoncontrollingInterest-93.0-93.0-90.9-90.3

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest us-gaap:PreferredUnitsByName, us-gaap:StatementEquityComponents

cli:SeriesUnitsSeriesOnePreferredLimitedPartnershipUnits, cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.455-0.455-0.455-0.455-0.455-0.455-0.455-0.455-0.455-0.455-0.455-0.456-0.455-0.265
Percentage of NetIncomeLossAttributableToRedeemableNoncontrollingInterest-7.0-7.0-7.0-7.0-9.1-9.7-10.3-12.0-15.2-16.3-17.0-17.0-17.0-33.5

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest us-gaap:StatementEquityComponents

cli:RedeemableNoncontrollingInterests


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-6.471-6.471-6.471-6.471-5.006-4.667-4.406-3.785-2.989-2.799-2.683-2.683-2.682-0.792
Percentage of NetIncomeLossAttributableToRedeemableNoncontrollingInterest-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0

us-gaap:NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest

us-gaap:NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-32.934-37.844-55.408-56.021-20.329275521.6891.501505.411
Percentage of NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-32.934-37.844-55.408-56.021-20.329275521.6891.501505.411
Percentage of NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-34.887-39.924-54.652-55.928-22.05424443-1.478-1.251
Percentage of NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest105.9105.598.699.8108.588.783.4-87.5-83.3

cli:MackCaliRealtyLp, cli:LimitedPartnersCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-3.689-4.215-5.823-6.159-2.434274.953-0.167-0.142
Percentage of NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest11.211.110.511.012.010.09.4-9.9-9.5

cli:MackCaliRealtyLp, us-gaap:OtherOwnershipInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value5.6426.2955.0676.0664.1593.4193.7663.3342.894
Percentage of NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest-17.1-16.6-9.1-10.8-20.51.27.2197.4192.8

us-gaap:NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value1.9532.08-0.756-0.0931.725318.7193.1672.7527.6522.829
Percentage of NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest-5.9-5.51.40.2-8.511.316.6187.5183.315.152.3

us-gaap:RetainedEarnings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-34.887-39.924-54.652-55.928-22.05424443-1.478-1.251432.582
Percentage of NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest105.9105.598.699.8108.588.783.4-87.5-83.384.947.7

us-gaap:NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable

us-gaap:NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value-829000.0-176000.0-1404000.0-405000.0-847000.0-1248000.0-640000.0-451000.0-95000.0-30000.0-153000.0-447000.0-181000.0-237000.0-191000.0-65000.0311000.0-706000.0-462000.0281000.0-373000.0-490000.0-21000.0-145000.0-290000.0-322000.0-237000.0-1838000.0-62000.0-62000.0-74000.0-85000.0-92000.0-79000.0
Percentage of NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-829000.0-176000.0-1404000.0-405000.0-847000.0-1248000.0-640000.0-451000.0-95000.0-30000.0-153000.0-447000.0-181000.0-237000.0-191000.0-65000.0311000.0-706000.0-462000.0281000.0-373000.0-490000.0
Percentage of NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable

us-gaap:NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value-4.626-3.6664.598-6.159-2.434274.953-0.167-0.1424.8830.2994.413-4.2962.2951.774-0.9995.6627.284-3.795-15.534.383-0.314-1.1520.2486.514-2.008-7.167-5.3141.0480.9730.0731.2070.8742.464
Percentage of NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value6470-60.373116116123-41.69119113125118128133121126129124126122119121123123125133134136134144143138146148148151149149149149150149152
Percentage of OperatingLeasesIncomeStatementLeaseRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value6470-60.373116116123-41.69119113125118128133121126129124126122119
Percentage of OperatingLeasesIncomeStatementLeaseRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0-16000.0-205000.0-878000.0-4624000.0-4061000.0-4969000.0354000.01788000.05145000.04646000.0730000.0-1353000.01227000.09744000.01725000.0-2913000.0-6340000.0
Percentage of OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0-16000.0-205000.0-878000.0-4624000.0-4061000.0-4969000.0354000.01788000.05145000.04646000.0730000.0-1353000.01227000.09744000.01725000.0-2913000.0-6340000.0
Percentage of OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfCapitalDistribution

us-gaap:PaymentsOfCapitalDistribution


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value262626262524242323222222171514151515151514141414292929294444444444444545454242424242
Percentage of PaymentsOfCapitalDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfCapitalDistribution dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value26262626252424232322222217151415151515
Percentage of PaymentsOfCapitalDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfFinancingCosts

us-gaap:PaymentsOfFinancingCosts


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-302012-12-312012-09-302011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.00.6565.3361.3664.2741.3632.5540.7670.00.2550.1790.566-0.1428.6272.3640.3943.2643.3922.90.00.0680.032.1260.823-0.032.8162.0760.04.9790.0080.00.0060.0640.01.1590.851
Percentage of PaymentsOfFinancingCosts0.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.00.0100.0100.00.0100.0100.0

us-gaap:PaymentsOfFinancingCosts dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0.00.6565.3361.3664.2741.3632.5540.7670.00.2550.1790.566-0.1428.6272.3640.3943.2643.3922.9
Percentage of PaymentsOfFinancingCosts0.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireAndDevelopRealEstate

us-gaap:PaymentsToAcquireAndDevelopRealEstate


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value4162-11.834382743363541552221232227421734341623191435271422271425-11.9142512212621261645161811
Percentage of PaymentsToAcquireAndDevelopRealEstate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireAndDevelopRealEstate dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value4162-11.83438274336354155222123222742173434
Percentage of PaymentsToAcquireAndDevelopRealEstate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireAndDevelopRealEstate us-gaap:MortgageLoansOnRealEstateDescriptionTypeOfProperty, us-gaap:BusinessAcquisition

cli:UnconsolidatedJointVentureMultipleFamilyProperties, cli:PortImperialNorthRetailLLC


None
Period End2020-03-12
Value13
Percentage of PaymentsToAcquireAndDevelopRealEstate0.0

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312014-09-302013-12-312013-09-30
Value0.14160.0954103222220.9531594.4890.365757.191234132.06118816947642.0159.187290.0
Percentage of PaymentsToAcquireBusinessesNetOfCashAcquired100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0.14160.0954103222220.9531594.4890.365757.191234132.0611881694764
Percentage of PaymentsToAcquireBusinessesNetOfCashAcquired100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireInterestInJointVenture

us-gaap:PaymentsToAcquireInterestInJointVenture


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.4280.1250.1520.6215.7952.4435.1313.3062.0861.266167.8574.7976.6254.6127.661167.2259.5591928209.75718371.889540.7350.977303.5740.0020.187320.1670.1330.090.1110.1210.1660.2740.393
Percentage of PaymentsToAcquireInterestInJointVenture100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireInterestInJointVenture dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value1.4280.1250.1520.6215.7952.4435.1313.3062.0861.266167.8574.7976.6254.6127.661167.2259.559
Percentage of PaymentsToAcquireInterestInJointVenture100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromCollectionOfLoansReceivable

us-gaap:ProceedsFromCollectionOfLoansReceivable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312014-09-302013-12-312013-09-30
Value0.1250.0830.1670.125460.1254.1251.6113.0293.337650.2790.2799.0620.1250.1250.1250.1250.50.05210.00.1250.125
Percentage of ProceedsFromCollectionOfLoansReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:ProceedsFromCollectionOfLoansReceivable dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0.1250.0830.1670.125460.1254.1251.6113.0293.337650.2790.2799.0620.1250.1250.1250.1250.5
Percentage of ProceedsFromCollectionOfLoansReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromIssuanceOfSecuredDebt

us-gaap:ProceedsFromIssuanceOfSecuredDebt


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value60120112443199121206148384111892392632831929774.5593.2961.7471.151010.215270.4250.8270.5450.4351.363
Percentage of ProceedsFromIssuanceOfSecuredDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromIssuanceOfSecuredDebt dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value60120112443199121206148384111892392632831929774.559
Percentage of ProceedsFromIssuanceOfSecuredDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromPaymentsToMinorityShareholders

us-gaap:ProceedsFromPaymentsToMinorityShareholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-83000.0216000.0-59000.00-308000.0-99000.0-603000.0-6990000.00-1000.0-3000.0-15000.000362000.0703000.0
Percentage of ProceedsFromPaymentsToMinorityShareholders100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0

us-gaap:ProceedsFromPaymentsToMinorityShareholders dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-83000.0216000.0-59000.00-308000.0-99000.0-603000.0-6990000.00-1000.0-3000.0-15000.000362000.0703000.0
Percentage of ProceedsFromPaymentsToMinorityShareholders100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0

us-gaap:ProceedsFromSaleOfBuildings

us-gaap:ProceedsFromSaleOfBuildings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-302012-12-31
Value9.5166.9391871.82130533078141.51243701930.04719882232940.00.468791.0720.084-0.43817019
Percentage of ProceedsFromSaleOfBuildings100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfBuildings dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value9.5166.9391871.82130533078141.51243701930.04719882232940.0
Percentage of ProceedsFromSaleOfBuildings100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0

us-gaap:ProceedsFromSaleOfBuildings us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, us-gaap:SubsequentEventType

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:OneHundredElevenRiverStreetHobokenNewJersey, us-gaap:SubsequentEvent


None
Period End2020-04-24
Value244
Percentage of ProceedsFromSaleOfBuildings0.0

us-gaap:ProceedsFromSaleOfLandHeldforinvestment us-gaap:DisposalGroupClassification

us-gaap:ProceedsFromSaleOfLandHeldforinvestment

us-gaap:DisposalGroupNotDiscontinuedOperations


None
Period End2020-06-302020-03-31
Value0.015
Percentage of ProceedsFromSaleOfLandHeldforinvestment0.0100.0

us-gaap:ProceedsFromSaleOfLandHeldforinvestment us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:CapitalOfficeParkLand


None
Period End2020-06-302020-03-31
Value0.08.974
Percentage of ProceedsFromSaleOfLandHeldforinvestment0.056.1

us-gaap:DisposalGroupNotDiscontinuedOperations, cli:TwoThirtyAndTwoFiftyHalfMileRoad


None
Period End2020-06-302020-03-31
Value0.07.018
Percentage of ProceedsFromSaleOfLandHeldforinvestment0.043.9

us-gaap:ProceedsFromUnsecuredLinesOfCredit

us-gaap:ProceedsFromUnsecuredLinesOfCredit


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value71693402081899233574932230294592753724382051501555073561528163700.00.01351531711179520780804792
Percentage of ProceedsFromUnsecuredLinesOfCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromUnsecuredLinesOfCredit dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value7169340208189923357493223029459275372438205150155
Percentage of ProceedsFromUnsecuredLinesOfCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RealEstateTaxExpense

us-gaap:RealEstateTaxExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1010-5.931161617121517181721212121202223191921222022232423202122232224222314242520242522
Percentage of RealEstateTaxExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RealEstateTaxExpense dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value1010-5.9311616171215171817212121212022231919
Percentage of RealEstateTaxExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfLinesOfCredit

us-gaap:RepaymentsOfLinesOfCredit


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value191212190.019420411343572811521935047118141822021535151151415840.00.0227612386028464526254304
Percentage of RepaymentsOfLinesOfCredit100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfLinesOfCredit dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value191212190.019420411343572811521935047118141822021535
Percentage of RepaymentsOfLinesOfCredit100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfSecuredDebt

us-gaap:RepaymentsOfSecuredDebt


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.1410.14574230251400.350.35277481051.6791.43161445389132.0562.02325382.356392.7938.532.7656.7772.64329172.3352.3392.3022.2222.0862.0742.1222.0542.0221.956
Percentage of RepaymentsOfSecuredDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfSecuredDebt dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0.1410.14574230251400.350.35277481051.6791.4316144538913
Percentage of RepaymentsOfSecuredDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestrictedStockExpense

us-gaap:RestrictedStockExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value2439000.02530000.02110000.01980000.02191000.01880000.01935000.01770000.0657000.02532000.02179000.02169000.02046000.01053000.01347000.02046000.01469000.0785000.0719000.0695000.0492000.0313000.03045000.0830000.0877000.03387000.0-15000.0755000.0981000.0845000.01671000.0579000.0579000.0814000.02053000.0690000.0690000.0691000.02252000.0626000.0626000.0
Percentage of RestrictedStockExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod


None
Period End2020-06-302019-12-312019-06-302019-03-312018-12-312018-09-302018-06-30
Value25614.0040185.0968.003872.0968.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod100.00.0100.0100.00.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue


None
Period End2020-06-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value21.082.0525.8320.1625.830024.1726.97
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue100.0100.0100.0100.0100.00.00.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod

cli:TwoThousandEighteenLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-31
Value06572.0003540.034475.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod0.0100.00.00.0100.0100.0

cli:TwoThousandNineteenLongTermIncentivePlan


None
Period End2020-06-302020-03-31
Value05693.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod0.086.6

cli:TwoThousandSeventeenLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value366920.03008.0001792.017922.01792.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod0.045.80.00.050.652.00.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross

cli:TwoThousandEighteenPerformanceBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0629250.0000629250.0-22676.00
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.0100.00.00.00.0100.0100.00.0

cli:TwoThousandEighteenTimeBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0186640.0000193220.0-11799.0-3540.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.029.70.00.00.030.752.00.0

cli:TwoThousandNineteenPerformanceBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value0392480.000392480.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.062.40.00.062.4

cli:TwoThousandNineteenTimeBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value0167450.000173150.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.026.60.00.027.5

cli:TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-366920.0388410.0000390650.0-13473.0-22839.0-57485.0464310.000
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.061.70.00.00.062.159.40.00.00.00.00.0

cli:TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-742.079672.000080434.0-4449.0-11802.0-9715.095488.000
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.012.70.00.00.012.819.60.00.00.00.00.0

cli:TwoThousandSixteenPerformanceBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value011155.000011155.0-6817.0-26030.0-121960.0487110.0000496780.0000499760.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.01.80.00.00.01.830.10.00.00.00.00.00.00.00.00.00.00.0

cli:TwoThousandSixteenTimeBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value075578.000-9220.088486.00-20280.0-24885.0153930.0000155770.0000157620.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.012.00.00.00.014.1-0.00.00.00.00.00.00.00.00.00.00.00.0

cli:TwoThousandTwentyPerformanceBasedVestingLongTermIncentivePlan


None
Period End2020-06-302020-03-31
Value01287600.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.0204.6

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross us-gaap:RelatedPartyTransactionsByRelatedParty, us-gaap:SubsequentEventType

cli:MagPartners2.0Llc, us-gaap:SubsequentEvent


None
Period End2020-07-26
Value157500.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross us-gaap:TitleOfIndividual, us-gaap:AwardType

cli:MichaelJ.DemarcoChiefExecutiveOfficer, cli:AoLtipUnitsAward


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0625000.0000625000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross0.099.30.00.00.099.3

us-gaap:StockDividendsShares dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:StockDividendsShares

cli:MackCaliRealtyLp, us-gaap:GeneralPartner


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value1000.01000.001000.001000.01000.01000.01000.0
Percentage of StockDividendsShares100.0100.00.0100.00.0100.0100.0100.0100.0

us-gaap:StockDividendsShares us-gaap:StatementEquityComponents

us-gaap:CommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value1000.01000.001000.001000.01000.01000.01000.0
Percentage of StockDividendsShares100.0100.00.0100.00.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodSharesConversionOfUnits dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:StockIssuedDuringPeriodSharesConversionOfUnits

cli:MackCaliRealtyLp, us-gaap:LimitedPartner


None
Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-98000.00-3000.0-24000.04000.0-25000.0-3000.0
Percentage of StockIssuedDuringPeriodSharesConversionOfUnits100.00.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueDividendReinvestmentPlan

us-gaap:StockIssuedDuringPeriodValueDividendReinvestmentPlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value11000.019000.08000.010000.011000.010000.013000.028000.09000.016000.05000.037000.048000.011000.02000.010000.06000.029000.013000.012000.016000.025000.032000.045000.052000.042000.063000.086000.073000.072000.047000.067000.048000.047000.046000.046000.0
Percentage of StockIssuedDuringPeriodValueDividendReinvestmentPlan100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueDividendReinvestmentPlan dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value11000.019000.08000.010000.011000.010000.013000.028000.09000.016000.05000.037000.048000.0
Percentage of StockIssuedDuringPeriodValueDividendReinvestmentPlan100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueDividendReinvestmentPlan dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-30
Value11000.019000.08000.010000.011000.010000.013000.0
Percentage of StockIssuedDuringPeriodValueDividendReinvestmentPlan100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueDividendReinvestmentPlan us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value11000.019000.08000.010000.011000.010000.013000.028000.09000.016000.05000.037000.048000.011000.02000.010000.06000.029000.013000.012000.016000.025000.032000.045000.052000.042000.063000.086000.073000.072000.047000.067000.048000.047000.046000.046000.0
Percentage of StockIssuedDuringPeriodValueDividendReinvestmentPlan100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value57000.082000.081000.081000.027000.0130000.0129000.0127000.0126000.0125000.0124000.0122000.0121000.0115000.087000.087000.097000.0101000.0100000.0100000.099000.098000.097000.097000.096000.0117000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross dei:LegalEntity

cli:MackCaliRealtyLp


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value57000.082000.081000.081000.027000.0130000.0129000.0127000.0126000.0125000.0124000.0122000.0121000.0115000.087000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:MackCaliRealtyLp, cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value57000.082000.081000.081000.027000.0130000.0129000.0127000.0126000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross us-gaap:PartnerTypeOfPartnersCapitalAccount

cli:GeneralPartnerCommonUnitholders


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value57000.082000.081000.027000.0130000.0127000.0126000.0125000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value57000.082000.081000.081000.025000.0130000.0129000.0127000.0126000.0125000.0124000.0122000.0121000.0115000.087000.087000.097000.0101000.0100000.0100000.099000.098000.097000.097000.096000.0117000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0100.0100.092.6100.0100.0100.0100.0100.0