CNP


Line plots across dimensions of each concept
Tables

Table of contents



us-gaap:CommonStockValue

us-gaap:CommonStockSharesOutstanding
us-gaap:StatementEquityComponents

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
dei:LegalEntity
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems, dei:LegalEntity

us-gaap:Revenues
dei:LegalEntity
us-gaap:MajorCustomers, dei:LegalEntity
us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, dei:LegalEntity
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems, dei:LegalEntity

us-gaap:CostOfGoodsAndServicesSold
dei:LegalEntity
us-gaap:StatementOperatingActivitiesSegment
us-gaap:StatementOperatingActivitiesSegment, dei:LegalEntity

us-gaap:CostsAndExpenses
dei:LegalEntity

us-gaap:OperatingIncomeLoss
dei:LegalEntity

us-gaap:InterestAndDebtExpense
dei:LegalEntity

us-gaap:OtherNonoperatingIncomeExpense
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperations
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, dei:LegalEntity

us-gaap:NonoperatingIncomeExpense
dei:LegalEntity

us-gaap:IncomeTaxExpenseBenefit
dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, dei:LegalEntity

us-gaap:IncomeTaxesPaidNet
dei:LegalEntity

us-gaap:ComprehensiveIncomeNetOfTax
dei:LegalEntity

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

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic
us-gaap:StatementOperatingActivitiesSegment
us-gaap:StatementOperatingActivitiesSegment
us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

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

us-gaap:LiabilitiesAndStockholdersEquity
dei:LegalEntity

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

us-gaap:AssetsCurrent
dei:LegalEntity

us-gaap:CashAndCashEquivalentsAtCarryingValue
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities, dei:LegalEntity

us-gaap:AccountsReceivableNetCurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities, dei:LegalEntity

us-gaap:InventoryRawMaterialsAndSupplies
dei:LegalEntity

us-gaap:PrepaidExpenseAndOtherAssetsCurrent
dei:LegalEntity

us-gaap:PropertyPlantAndEquipmentGross
dei:LegalEntity

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
dei:LegalEntity

us-gaap:PropertyPlantAndEquipmentNet
dei:LegalEntity

us-gaap:Goodwill
dei:LegalEntity
us-gaap:StatementBusinessSegments

us-gaap:FiniteLivedIntangibleAssetsNet
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:OtherAssetsNoncurrent
dei:LegalEntity

us-gaap:LiabilitiesCurrent
dei:LegalEntity

us-gaap:AccountsPayableCurrent
dei:LegalEntity

us-gaap:TaxesPayableCurrent
dei:LegalEntity

us-gaap:OtherLiabilitiesCurrent
dei:LegalEntity

us-gaap:LongTermDebtNoncurrent
dei:LegalEntity

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
dei:LegalEntity

us-gaap:OtherLiabilitiesNoncurrent
dei:LegalEntity

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

us-gaap:CommonStockValue

us-gaap:RetainedEarningsAccumulatedDeficit
dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity

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:StatementEquityComponents
us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:DepreciationDepletionAndAmortization
dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, dei:LegalEntity

us-gaap:IncreaseDecreaseInInventories
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfLongTermDebt
dei:LegalEntity

us-gaap:RepaymentsOfLongTermDebt
dei:LegalEntity
dei:LegalEntity
us-gaap:PaymentsOfDividends
dei:LegalEntity
us-gaap:PaymentsOfDividends

us-gaap:RepaymentsOfLongTermDebt
dei:LegalEntity
dei:LegalEntity
us-gaap:EffectiveIncomeTaxRateContinuingOperations
us-gaap:StatementOperatingActivitiesSegment
us-gaap:StatementOperatingActivitiesSegment, dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:Accountspayablerelatedtocapitalexpendituresdiscontinuedoperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:AmountOfAllowedEquityReturnNotRecognizedInPeriod
dei:LegalEntity

cnp:AmountOfAllowedEquityReturnRecognizedInPeriod
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:BasisDifferenceAccretionGain

cnp:ComprehensiveIncomeNetofTaxBeforePreferredStockDividend
us-gaap:StatementEquityComponents, dei:LegalEntity
cnp:ContributionFromParent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents
cnp:CostMethodInvestmentDividendsOrDistributions
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:DilutionLossEquityMethodInvestment
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationafterDisposalPipelineconstructionandrepaircharges
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DiscontinuedoperationCapitalizedfees
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:DisposalGroupIncludingDiscontinuedOperationOperationandMaintenanceExpense
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:DisposalGroupIncludingDiscontinuedOperationTaxesOtherthanIncomeTaxes
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents
cnp:Distributionpershareofcommonunits
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentGrossEquityInEarningsLosses
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentSummarizedFinancialInformationImpairmentofGoodwillandLongLivedAssets
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentSummarizedFinancialInformationOperatingIncomeLoss
us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
cnp:FairValueInputsPricePerMMBtu
us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

cnp:GainLossOnIndexedDebtSecurities

cnp:Goodwillimpairmentandlossfromreclassificationtoheldforsale
dei:LegalEntity
us-gaap:PartnerTypeOfPartnersCapitalAccount, dei:LegalEntity
cnp:IncentiveDistributionRightPercentage
dei:LegalEntity
cnp:IncreaseDecreaseInAccountsReceivablePayableAffiliates

cnp:IncreaseDecreaseInContractWithCustomerAssetOtherAccruedUnbilledReceivables
dei:LegalEntity

cnp:IncreaseDecreaseInterestAndTaxesAccrued
dei:LegalEntity

cnp:IncreaseDecreaseinAccountsReceivableonContractswithCustomers
dei:LegalEntity

cnp:IndexedDebtSecuritiesGainLoss
dei:LegalEntity
cnp:InterestIncomeExpenseNetRelatedParty

cnp:InterestIncomeonTransitionandSystemRestorationBonds
dei:LegalEntity
us-gaap:StatementBusinessSegments

cnp:InterestOnTransitionAndSystemRestorationBonds
dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:InventoryWritedowndiscontinuedoperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:Lossfromreclassificationtoheldforsale
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:Lossfromreclassificationtoheldforsaleincludingimpairment
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:PartnerTypeOfPartnersCapitalAccount, dei:LegalEntity
cnp:ManagementRightsOwnershipPercentage
us-gaap:IncomeStatementLocation, dei:LegalEntity
cnp:Netaffiliateservicechargesbillings

cnp:OtherRevenueExcludingAssessedTax
dei:LegalEntity
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems, dei:LegalEntity

cnp:Othercomprehensivelossfromunconsolidatedaffiliatesnetoftax
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
cnp:PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths
us-gaap:CreditFacility, dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType
cnp:PercentageReductionofDividendorDistributionAmount

cnp:SaleofUnitsPercentageTriggerRightofFirstRefusal
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:SubsequentEventType
cnp:Salespriceofoutstandingequityinterests
us-gaap:ConsolidatedEntities, us-gaap:SubsequentEventType, dei:LegalEntity
us-gaap:Range, us-gaap:EnvironmentalRemediationSite
cnp:SiteContingencyLossExposure
us-gaap:Range, us-gaap:EnvironmentalRemediationSite, dei:LegalEntity
us-gaap:LongtermDebtType
cnp:SubordinatedNoteCashExchangeablePercentageOfFairValue

cnp:TotaldistributionsreceivedfromEnable
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
cnp:VolumetricallyWeightedAveragePricePerMMBtu
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

us-gaap:AmortizationOfFinancingCosts
dei:LegalEntity

us-gaap:AmortizationOfIntangibleAssets
us-gaap:IncomeStatementLocation
us-gaap:StatementClassOfStock
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:CapitalExpenditureDiscontinuedOperations

us-gaap:CapitalExpendituresIncurredButNotYetPaid
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation
us-gaap:ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:IncomeStatementLocation
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:IncomeStatementLocation, dei:LegalEntity
us-gaap:StatementClassOfStock
us-gaap:CommonStockDividendsPerShareCashPaid
us-gaap:StatementClassOfStock, cnp:Period

us-gaap:CommonStockDividendsPerShareDeclared
us-gaap:StatementClassOfStock
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType, cnp:DividendsDistributionsChange

us-gaap:ContractWithCustomerLiabilityRevenueRecognized
dei:LegalEntity
us-gaap:AdjustmentsForNewAccountingPronouncements
us-gaap:CumulativeEffectOnRetainedEarningsBeforeTax1
us-gaap:AdjustmentsForNewAccountingPronouncements, dei:LegalEntity
us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:CreditFacility, us-gaap:VariableRate, dei:LegalEntity
us-gaap:DebtInstrumentBasisSpreadOnVariableRate1

us-gaap:DeferredIncomeTaxExpenseBenefit
dei:LegalEntity
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType, dei:LegalEntity
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanContributionsByEmployer
us-gaap:RetirementPlanType, dei:LegalEntity
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType, dei:LegalEntity
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType, dei:LegalEntity
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType, dei:LegalEntity
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType, dei:LegalEntity

us-gaap:DepreciationAndAmortizationDiscontinuedOperations
dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:IncomeStatementLocation
us-gaap:DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:IncomeStatementLocation, dei:LegalEntity

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeNonmonetaryNotionalAmountVolume
us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:Position
us-gaap:DerivativeInstrumentRisk, us-gaap:Position, dei:LegalEntity

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationAfterDisposalExpense
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation
dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherExpense
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType
us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType, cnp:DividendsDistributionsChange
us-gaap:StatementEquityComponents, dei:LegalEntity
us-gaap:DividendsCash
us-gaap:StatementClassOfStock
us-gaap:DividendsCommonStockCash
us-gaap:StatementClassOfStock, cnp:Period
us-gaap:StatementEquityComponents
us-gaap:StatementClassOfStock
us-gaap:DividendsPreferredStockCash
us-gaap:StatementClassOfStock, cnp:Period
us-gaap:StatementClassOfStock, us-gaap:StatementEquityComponents

us-gaap:EquityMethodInvestmentDividendsOrDistributions
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOtherThanTemporaryImpairment
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationCostOfSales
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationRevenue

us-gaap:FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss
dei:LegalEntity

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings
dei:LegalEntity

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements
dei:LegalEntity

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersIntoLevel3
dei:LegalEntity

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersOutOfLevel3
dei:LegalEntity

us-gaap:GoodwillImpairmentLoss
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:StatementOperatingActivitiesSegment
us-gaap:Range, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:IncentiveDistributionDistributionPerUnit

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity
dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:IncomeLossFromEquityMethodInvestments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables
dei:LegalEntity

us-gaap:IncreaseDecreaseInAccountsPayable
dei:LegalEntity

us-gaap:IncreaseDecreaseInContractWithCustomerLiability
dei:LegalEntity

us-gaap:IncreaseDecreaseInDerivativeAssetsAndLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable
dei:LegalEntity

us-gaap:IncreaseDecreaseInMarginDepositsOutstanding
dei:LegalEntity
dei:LegalEntity
us-gaap:IncreaseDecreaseInNotesPayableRelatedParties
dei:LegalEntity
us-gaap:IncreaseDecreaseInNotesReceivableRelatedParties

us-gaap:IncreaseDecreaseInOtherCurrentAssets
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherCurrentLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherNoncurrentAssets
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherNoncurrentLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInOverUnderEnergyRecovery
dei:LegalEntity

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities
dei:LegalEntity
us-gaap:AwardType
us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:InterestExpenseOther
dei:LegalEntity
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, dei:LegalEntity

us-gaap:InterestIncomeOther
dei:LegalEntity
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, dei:LegalEntity

us-gaap:InterestPaidNet
dei:LegalEntity

us-gaap:InventoryWriteDown
dei:LegalEntity

us-gaap:LeaseIncome

us-gaap:MarketableSecuritiesGainLoss

us-gaap:MarketableSecuritiesUnrealizedGainLossExcludingOtherThanTemporaryImpairments
us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:StatementEquityComponents
us-gaap:NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification
us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent
us-gaap:DerivativeInstrumentRisk
us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax
us-gaap:DerivativeInstrumentRisk, dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax

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

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax

us-gaap:OtherComprehensiveIncomeLossTaxPortionAttributableToParent1
dei:LegalEntity

us-gaap:OtherOperatingActivitiesCashFlowStatement
dei:LegalEntity

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
dei:LegalEntity

us-gaap:PaymentsOfDebtIssuanceCosts
dei:LegalEntity

us-gaap:PaymentsOfDividendsCommonStock

us-gaap:PaymentsOfDividendsPreferredStockAndPreferenceStock

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired

us-gaap:PaymentsToAcquireProductiveAssets
dei:LegalEntity

us-gaap:PensionContributions

us-gaap:PreferredStockDividendsAndOtherAdjustments

us-gaap:PreferredStockDividendsIncomeStatementImpact
us-gaap:StatementClassOfStock
us-gaap:StatementClassOfStock
us-gaap:PreferredStockDividendsPerShareCashPaid
us-gaap:StatementClassOfStock, cnp:Period
us-gaap:StatementClassOfStock
us-gaap:PreferredStockDividendsPerShareDeclared
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
dei:LegalEntity
us-gaap:ProceedsFromContributionsFromParent

us-gaap:ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfCommercialPaper
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfLinesOfCredit
us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:RegulatoryAgency, us-gaap:SubsequentEventType
us-gaap:PublicUtilitiesRequestedDebtCapitalStructurePercentage
us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:RegulatoryAgency, us-gaap:SubsequentEventType
us-gaap:PublicUtilitiesRequestedEquityCapitalStructurePercentage
us-gaap:PublicUtilitiesRegulatoryProceeding
us-gaap:PublicUtilitiesRequestedRateIncreaseDecreaseAmount
us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:RegulatoryAgency, us-gaap:SubsequentEventType
us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:RegulatoryAgency, us-gaap:SubsequentEventType
us-gaap:PublicUtilitiesRequestedReturnOnEquityPercentage

us-gaap:RegulatedOperatingRevenue
dei:LegalEntity
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty, dei:LegalEntity
us-gaap:IncomeStatementLocation, us-gaap:RelatedPartyTransactionsByRelatedParty, dei:LegalEntity
us-gaap:RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability
dei:LegalEntity
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation

us-gaap:TaxesExcludingIncomeAndExciseTaxes
dei:LegalEntity

us-gaap:UnregulatedOperatingRevenue
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:VariableInterestEntityOwnershipPercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, dei:LegalEntity

cnp:AccountsReceivableforContractswithCustomers
dei:LegalEntity

cnp:AccruedUnbilledRevenuesAllowanceforCreditLossesCurrent
dei:LegalEntity

cnp:AssetsNoncurrentOtherThanPropertyPlantAndEquipment
dei:LegalEntity
us-gaap:DerivativeInstrumentRisk
cnp:DerivativeFairValueOffsetsNet
us-gaap:DerivativeInstrumentRisk, dei:LegalEntity

cnp:DisposalGroupDiscontinuedOperationNontradingderivativeliabilities
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:DisposalGroupIncludingDiscontinuedOperationAccruedUnbilledRevenues
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:DisposalGroupIncludingDiscontinuedOperationNontradingderivativeassets
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentBasisDifference
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentSummarizedFinancialInformationAccumulatedOtherComprehensiveIncomeLoss
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentSummarizedFinancialInformationPreferredEquity
us-gaap:Range, dei:LegalEntity
cnp:Estimatedcapitalexpendituretocleanashponds
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
cnp:FairValueAssetsMeasuredOnRecurringBasisCorporateEquities
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, dei:LegalEntity
us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency, dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:FairValueOfDisposalGroup
dei:LegalEntity
cnp:GeneralMortgageBondsUsedAsCollateral

cnp:IndexedDebtCurrent

cnp:IndexedDebtSecuritiesDerivative

cnp:Lossonassetsheldforsale
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:BalanceSheetLocation, dei:LegalEntity
cnp:MoneyPoolInvestments
us-gaap:RelatedPartyTransaction, dei:LegalEntity
cnp:MoneyPoolInvestmentsWeightedAverageInterestRate
us-gaap:StatementBusinessSegments
cnp:NumberofStatesinwhichtheEntityPerformsGasDeliveryServices
us-gaap:StatementBusinessSegments, dei:LegalEntity

cnp:Performanceguaranteeobligationsoutstandingfaceamount
us-gaap:GuaranteeObligationsByNature, us-gaap:StatementBusinessSegments, dei:LegalEntity

cnp:TotalAssetsClassifiedasHeldForSaleCurrentandNoncurrent
dei:LegalEntity

cnp:TotalAssetsClassifiedasHeldForUseCurrentandNoncurrent
dei:LegalEntity

cnp:TransitionAndSystemRestorationBondsLongTermDebtCurrent
dei:LegalEntity

cnp:TransitionAndSystemRestorationBondsLongTermDebtNonCurrent
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementClassOfStock
cnp:VariableInterestEntityOwnershipShares
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementClassOfStock, dei:LegalEntity

dei:EntityCommonStockSharesOutstanding
dei:LegalEntity
us-gaap:AccountsAndNotesReceivableNet
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsPayableRelatedPartiesCurrent
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty, dei:LegalEntity
us-gaap:EnvironmentalRemediationSite
us-gaap:AccrualForEnvironmentalLossContingencies
us-gaap:EnvironmentalRemediationSite, dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax
dei:LegalEntity

us-gaap:AdditionalCollateralAggregateFairValue
dei:LegalEntity

us-gaap:AdditionalPaidInCapital
dei:LegalEntity

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent
dei:LegalEntity

us-gaap:AssetsFairValueDisclosure
dei:LegalEntity
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent
dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:CollateralAlreadyPostedAggregateFairValue

us-gaap:ContractWithCustomerAssetNetCurrent

us-gaap:ContractWithCustomerLiability
dei:LegalEntity
dei:LegalEntity
us-gaap:ContractWithCustomerLiabilityCurrent

us-gaap:CostMethodInvestments
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:DebtWeightedAverageInterestRate
us-gaap:CreditFacility, dei:LegalEntity

us-gaap:DeferredGainLossOnDiscontinuationOfFairValueHedge
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, cnp:HedgedItem
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, cnp:HedgedItem, dei:LegalEntity

us-gaap:DeferredIncomeTaxLiabilitiesNet
dei:LegalEntity
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsCurrentFiscalYear
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DerivativeAssetFairValueGrossLiability
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DerivativeAssets
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, cnp:HedgedItem
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, cnp:HedgedItem, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeAssetsLiabilitiesAtFairValueNet
us-gaap:DerivativeInstrumentRisk, dei:LegalEntity

us-gaap:DerivativeFairValueOfDerivativeAsset
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, dei:LegalEntity

us-gaap:DerivativeFairValueOfDerivativeLiability
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeFairValueOfDerivativeNet
us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeLiabilities
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, cnp:HedgedItem
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, cnp:HedgedItem, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DerivativeLiabilitiesCurrent

us-gaap:DerivativeLiabilitiesNoncurrent

us-gaap:DerivativeLiabilityFairValueGrossAsset
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship
us-gaap:DerivativeLiabilityNotionalAmount

us-gaap:DerivativeNetLiabilityPositionAggregateFairValue
dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayable
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent
dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationGoodwillCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationPensionPlanBenefitObligationCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity
dei:LegalEntity
us-gaap:DueFromRelatedPartiesCurrent
dei:LegalEntity
us-gaap:DueToRelatedPartiesCurrent

us-gaap:EnergyRelatedInventoryNaturalGasInStorage
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOwnershipPercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationMinorityInterest
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentUnderlyingEquityInNetAssets

us-gaap:EquityMethodInvestments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentsFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem
us-gaap:FairValueHedgeAssetsAtFairValue
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem, dei:LegalEntity
us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem
us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem, dei:LegalEntity
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem
us-gaap:FairValueHedgeLiabilitiesAtFairValue
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem, dei:LegalEntity
us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem
us-gaap:FairValueByMeasurementFrequency, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, cnp:HedgedItem, dei:LegalEntity

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
dei:LegalEntity

us-gaap:FinancialLiabilitiesFairValueDisclosure
dei:LegalEntity
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsGross
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:IncomeTaxesReceivable

us-gaap:InterestPayableCurrent
dei:LegalEntity
us-gaap:FinancialInstrument
us-gaap:InvestmentOwnedBalanceShares
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:InvestmentsFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, dei:LegalEntity
us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency, dei:LegalEntity

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent
dei:LegalEntity
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent
dei:LegalEntity

us-gaap:LiabilitiesOtherThanLongtermDebtNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:LineOfCredit
us-gaap:CreditFacility
us-gaap:CreditFacility, dei:LegalEntity

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebtFairValue
us-gaap:FairValueByMeasurementBasis, dei:LegalEntity

us-gaap:MarketableSecuritiesCurrent

us-gaap:OtherLongTermDebtCurrent
dei:LegalEntity

us-gaap:OtherLongTermDebtNoncurrent
dei:LegalEntity
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:PreferredStockLiquidationPreference
us-gaap:StatementClassOfStock
us-gaap:PreferredStockLiquidationPreferenceValue
us-gaap:StatementClassOfStock
us-gaap:PreferredStockParOrStatedValuePerShare
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:PreferredStockSharesIssued
us-gaap:StatementClassOfStock
us-gaap:PreferredStockSharesOutstanding
us-gaap:StatementEquityComponents
us-gaap:StatementClassOfStock
us-gaap:PreferredStockValue
dei:LegalEntity
us-gaap:PublicUtilitiesInventory

us-gaap:PurchaseObligationDueAfterFifthYear
dei:LegalEntity

us-gaap:PurchaseObligationDueInFifthYear
dei:LegalEntity

us-gaap:PurchaseObligationDueInFourthYear
dei:LegalEntity

us-gaap:PurchaseObligationDueInNextTwelveMonths
dei:LegalEntity

us-gaap:PurchaseObligationDueInSecondYear
dei:LegalEntity

us-gaap:PurchaseObligationDueInThirdYear
dei:LegalEntity

us-gaap:PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:RatioOfIndebtednessToNetCapital1
us-gaap:CreditFacility, dei:LegalEntity

us-gaap:RegulatoryAssetsNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities, dei:LegalEntity

us-gaap:RegulatoryLiabilityNoncurrent
dei:LegalEntity
us-gaap:BalanceSheetLocation
us-gaap:RestrictedCashAndCashEquivalents
us-gaap:BalanceSheetLocation, dei:LegalEntity

us-gaap:RevenueRemainingPerformanceObligation

us-gaap:UnbilledContractsReceivable
dei:LegalEntity

us-gaap:UnbilledReceivablesCurrent
dei:LegalEntity

Tables

  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:CommonStockValue ██████▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁555555444444444444444444444444444444444444NANANA
us-gaap:CommonStockSharesOutstanding ██████▄▄▄▄▄▄▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▁▁502502502502502501431431431431431431430430430430430430430430430429429429429428428428428427427427427426425425425424423421394391NANANA
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us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding 502NA505505503NA434431434NA434433433NA433430432NA430431431NA431431430NA430430429NA429429428NA428428427NA00395NA00349
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic 502NA502502501NA431431431NA431430430NA430430430NA430430429NA429429429NA428428427NA427427426NA425425425NA00393NA00347
us-gaap:EarningsPerShareBasic ▁▄▅▅▄▄▅▄▅█▅▅▅▄▅▄▅▃▃▄▅▅▅▄▅▄▅▄▅▅▄▅▅▄▇▄▅▅▅▄▅▄▅▄▄-2.440.250.480.330.280.180.35-0.170.383.010.390.310.450.230.42-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.280.280.350.290.290.20.290.270.310.240.19
us-gaap:EarningsPerShareDiluted ▁▄▅▅▅▄▅▄▅█▅▅▅▄▅▄▅▃▃▄▅▅▅▄▅▄▅▄▅▅▄▅▅▄▇▅▅▅▅▄▅▄▅▄▄-2.440.250.470.330.280.180.35-0.170.382.990.390.310.440.230.41-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.270.280.350.290.290.20.290.270.310.240.19
us-gaap:IncomeLossFromContinuingOperationsPerBasicShare -2.15NANANA0.23NANANANANANANANANANANANANANANANANANANANANANANANANA0.02NANA0.270.90.280.35NANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare -2.15NANANA0.23NANANANANANANANANANANANANANANANANANANANANANANANANA0.02NANA0.270.90.280.35NANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ▄█▄▄▅▇▁▁▄▆▁▁▂▄▃▂▃▃▂▂▅▅▃▃█▄▂▃▅▄▂▂▄▄▃▃▆▄▃▃▇▅▂▂▆214132302093205625393036138514492126263813471338171220811889157419841791163015322433237218071884316321841640189423882138170515252084214518811837258720981908175630232299157616402766
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 us-gaap:Revenues dei:LegalEntity cnp:HoustonElectric▁▂▇▄▂▄█▇▄▄▇▄▁634680859765686728897854755765843752638NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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 us-gaap:Revenues us-gaap:StatementBusinessSegments,us-gaap:SubsegmentsConsolidationItems cnp:NaturalGasDistribution,us-gaap:ReportableSubsegments█▆▂▃█▅▁▂▆▄▁▂▅1318108951565013898994024871143839390470907NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:Revenues us-gaap:StatementBusinessSegments,us-gaap:SubsegmentsConsolidationItems,dei:LegalEntity cnp:ElectricTransmissionDistribution,us-gaap:ReportableSubsegments,cnp:HoustonElectric▁▂▇▄▂▄█▇634680859765686728897854NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:CostsAndExpenses ▃▇▅▅█▆▃▃▇▅▃▃▅▃▂▁▂▂▁▁▄▄▂▂▆▃▁195029282350251132862869198619992904234218191920246118381605139217341565136513462177215115741698286819731396NANANANANANANANANANANANANANANANANANA
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us-gaap:OperatingIncomeLoss ▄▆█▆▅▃▄▃▅▆▅▄▅▅▆▃▅▄▅▃▅▄▄▃▆▄▅▄▇▆▁▆▇▅▇▆▇▆▇▅▇▆▆▅▆21730239228724516722618725129627922327424328418225022626518625622123318629521124422333231088302338274357303364302327263357299287253285
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us-gaap:InterestAndDebtExpense ██▇▇▆▄▂▃▁▁▁▁▁▂▂▂▂▂▂▂▂▃▂▂▂13913913413412110290917878807778828386878688898992888984NA868598NA104104110NA114111116NA121121122129126129129
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us-gaap:IncomeLossFromContinuingOperations -1053NANANA143NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▁▇██▇▇█▆█████▇█▇█▃▄▇███▇█-1400182332224191181209-882122862672112991622768240-818-635114209209213169294NA229144233NA128200219NA590190235NA199NANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest dei:LegalEntity cnp:CercCorp█▄▂▃█▄▁▄▆▇▂▅16642-82816443-374698135-583NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest dei:LegalEntity cnp:HoustonElectric▁▂█▄▁▂▆▄▂▃▇▄385422612333511791286778201117NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest -1053NANANA143NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity cnp:CercCorp131NANANA110NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementBusinessSegments cnp:NaturalGasDistribution204NANANA120NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:IncomeTaxExpenseBenefit ▅▇█▇▇██▇█▁█████▇█▅▆██████-347256229226151-1347-1010987610761971086-309-2443778337062109NA7824486NA1187472NA2047187NA764510247384348
 us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity cnp:CercCorp█▇▇▇█▇▇██▁▇█35-11-10268-21020-334-129NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity cnp:HoustonElectric▆▆▇▆▆▆▇▆▆▁█▇5104123611362715-1327142NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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 us-gaap:IncomeTaxExpenseBenefit us-gaap:StatementBusinessSegments cnp:IndianaElectricIntegrated3NANANA-2NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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 us-gaap:IncomeTaxExpenseBenefit us-gaap:StatementBusinessSegments,dei:LegalEntity cnp:NaturalGasDistribution,cnp:CercCorp44NANANA26NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeTaxExpenseBenefit us-gaap:StatementBusinessSegments,dei:LegalEntity us-gaap:CorporateAndOther,cnp:CercCorp-9NANANA-8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeTaxesPaidNet ▅▄▅█▅▅▅▇▅▅▅▅▅▅▅▅▁▃▆█▁▆▅█▅0-1932146-40192-41313-212132-158-5750128-1663517141-1NANANA-3NANANA-8NANA-46-160NA66152-8-6622926
 us-gaap:IncomeTaxesPaidNet dei:LegalEntity cnp:CercCorp▁█▁▆▁▁▁▆▁▁▃04030003001NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeTaxesPaidNet dei:LegalEntity cnp:HoustonElectric▁▁▃▆▁▃▂█▂▁▁0-6207303221041600NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:ComprehensiveIncomeNetOfTax ▁▅▅▅▅▅▅▄▅█▅▅▅▅▅▄▅▃▃▅▅▅▅▅▅-12304926819717050162-74170130016713619294182-4155-494-39079133175145109186NA154-98150NA13129149NA975122150NA12683117NANANANA
 us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity cnp:CercCorp▂▂▁▁▃▂▁▂▃█▂▂6758-728138339361305093854NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity cnp:HoustonElectric▂▂▇▄▁▁▆▄▂█▅▃334418510026191461015621013075NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLoss ▁▅▅▅▅▅▅▄▅█▅▅▅▅▅▄▅▃▃▅▅▅▅▅▅▅▅▄▅▅▄▅▅▅▇▅▅▅▅▅▅▅▅▅▅-1199157270195169120158-751651296169135192101179-2154-509-39177131176143107185113151-10014713410126147117973119148124123811141051148667
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 us-gaap:NetIncomeLoss dei:LegalEntity cnp:HoustonElectric▂▂▇▄▁▂▆▄▂█▅▃▁33441851002740143101522101307518NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:RetainedEarnings,cnp:CercCorp▅▄▁▃█▃▂▃6753-72813833936NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:RetainedEarnings,cnp:HoustonElectric▁▂█▄▁▂▆▄33441851002740143101NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:Assets ▇██▇▇▄▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▂▂▂▂▂▂▂▃▂▂▂▂▂▁▁▁▁▁▁▁333953543934642341893390227009222282210822410227362213522045219312182921286210122100421334217782260222670232002204821920222642187021575216582237022871224772247522351217032095119677195942011119399195211935119773NANANA
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 us-gaap:Assets dei:LegalEntity cnp:HoustonElectric▄▇███▂▁▁1087011262114631147811420105071043610430NA10292NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:LiabilitiesAndStockholdersEquity ▇██▇▇▄▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▂▂▂▂▂▂▂▃▂▂▂▂▂▁▁▁▁▁▁▁333953543934642341893390227009222282210822410227362213522045219312182921286210122100421334217782260222670232002204821920222642187021575216582237022871224772247522351217032095119677195942011119399195211935119773NANANA
 us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity cnp:CercCorp▄▄▃▃▃▄▁█81508439792978158065821473059642NA10112NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity cnp:HoustonElectric▄▇███▂▁▁1087011262114631147811420105071043610430NA10292NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:StockholdersEquity ▆█████▅▃▄▄▂▂▂▂▂▂▂▂▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▁▁697083598346825782168058550846704857468836183563353734603472339735063461405845504574454844734425441443294261419143714301425743324286422242073313326631983129306127092639NANANA
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 us-gaap:StockholdersEquity dei:LegalEntity cnp:HoustonElectric▄▇█▇▇▃▂▂▁▁2899325134833358327426822549246423942369NANANA2117NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital██████▁▁▁▁6086608060726065606060724221421542084209NANANA4195NANANA4180NANANA4169NANANA4157NANANA4130NANANA4120NANANA4100NANANA3671NANANA
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 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:AdditionalPaidInCapital,cnp:CercCorp▅▅▄▄▄▄▁███2116211620152015201520151668252825272528NANANA2489NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:AdditionalPaidInCapital,cnp:HoustonElectric█████▃▁▁▁▁2486248624862486248618961696169716971696NANANA1696NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:AssetsCurrent ▄▄▃▃▃█▂▂▂▃▂▂▂▂▂▁▁▂▂▂▂▃▂▂▂▂▁▂▂▂▂▂▂▁▁▁▁▂▁▂▂▂416438473416332634197025272627013049339529352865289629232529227223352689240025092691326825762529295526582319248023632874275229552968233719822042201425822143235223842904NANANA
 us-gaap:AssetsCurrent dei:LegalEntity cnp:CercCorp▃▅▁▂▆█▁▁12631415107411591547177010601040NA1592NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AssetsCurrent dei:LegalEntity cnp:HoustonElectric▁▅▇██▂▃▃73612901666173617869499941003NA830NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▁▁▁▁▁█▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▁▁▂▁▂▂▃▃▁▁▁▁▁▁▂▁▂▁▁▁22024125927125542312933282192602012482543412702712182642272452342982302063792082194972456467221123109622010319095199995833297406115165
 us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity cnp:HoustonElectric▁▂▃▄▃█▅▄196216228260243335279253NA238NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:AccountsReceivableNetCurrent ▂▇▅▆█▆▄▄▅▅▃▃▃▂▂▁▁▁▁▂▄▃▂▃▆▃▁▂▃▃▂▂▂▃▂▃▃▃▂▂▄▃71112491091117314151190918958108110007837628407406826055775935686408978377128341142851617694860768698643713773722750852835691716933790NANANA
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us-gaap:InventoryRawMaterialsAndSupplies ███▇▇▄▄▄▃▃▄▄▃▃▄▃▃▃▃▃▂▃▂▂▁▁▁▁▃▃▃▃▃▂▃278269273267256200198192176175190192178181191187176179174178161168156155146145137137181177182176168166168NANA164NANANANANANANA
 us-gaap:InventoryRawMaterialsAndSupplies dei:LegalEntity cnp:CercCorp█▆▇▆▃▁▄▃7471737167656967NA56NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PrepaidExpenseAndOtherAssetsCurrent ▂▄▃▅▇▅▃▄▅▇▄▄▅▄▃▂▂▃▁▁▂▄▄▄▄▂▁▂▃▆██▆▅▅120161156181241192157167189241175167184161154135127140111105132178177173158125112116137216245253220192190NANA274NANANANANANANA
 us-gaap:PrepaidExpenseAndOtherAssetsCurrent dei:LegalEntity cnp:HoustonElectric▂▅▁▃▅█▆█3649304146615059NA62NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:PropertyPlantAndEquipmentGross ███▇▇▄▄▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▃▃▃▃▂▂▂▂▂▂▂▂▂▁308303068530066295522901120267198611958519294190311858118374180701783117500172181690016650162641596715633153581497514674143681413813909136231859818377180101735017073168681659116426162351600515635153821500114770NANANA
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 us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity cnp:HoustonElectric█▅▅▂▁▁▁▁38443797379537623743374637423741NA3633NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:Goodwill ▇████▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▂▂▂▂▂▂▂▂▂▂▂▂▂4697516451795179512986786786786786786786786786286286184084084084084084084084084084084084014681468146816961696169616961696169616961696169616961696NANANA
 us-gaap:Goodwill dei:LegalEntity cnp:CercCorp▁▅██████757819867867867867867867NA867NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:Goodwill us-gaap:StatementBusinessSegments cnp:IndianaElectricIntegrated▇█▇▇▁▁93611211008100800NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:LiabilitiesCurrent █▇▆▄▅▅▂▃▃▄▅▄▃▄▂▁▂▂▅▅▅▆▄▄▄▄▂▃▅▆▅▅▃▂▁▂▁▃▄▄▅▄404238883434299631393302258128422616306932213038264230802398224125342467319131253187347530083026305930192595267531263575336432062735259323192361220126202881303232023038NANANA
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us-gaap:OtherLiabilitiesCurrent ▂▅▄▃▃▃▅▃▃▄▃▁▁▃▄▃▃▃▅▅▅▅▄▄▄▅▃▄▃▄▃▃▁▄▃▃▄▆▇▇█▆300414375343338341392344343368339269267325353334317343384385394383373355365402343358347380347327281366319322350438464450497445NANANA
 us-gaap:OtherLiabilitiesCurrent dei:LegalEntity cnp:CercCorp▁█▂▁▁▂▆▃134191143132136137171152NA137NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:OtherLiabilitiesCurrent dei:LegalEntity cnp:HoustonElectric▃▁▂▂▃▅█▅78636973768911193NA120NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:LongTermDebtNoncurrent █████▂▁▂▂▂▁▁▂▁▁▂▁▂▁▁▂▂▂▂▂▂▂▂▂▂▂▂▃▂▂▂▂▃▂▂▂▃13830142441401414121137598682725277608176819575317587789275327736778073547901766276147767800977977755805678177758791981308357841585839005864184978510873290018267841084109119NANANA
 us-gaap:LongTermDebtNoncurrent dei:LegalEntity cnp:CercCorp▁▇▆▆▅▅▅█17842546247723972384237122572722NA2457NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebtNoncurrent dei:LegalEntity cnp:HoustonElectric▆▆▇▇█▁▂▃46844719478948164884425843264473NA4319NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ▁▂▃▄▄▂▁▁▁▂▄▄▄▄▄▄▄▄▄▄▄▅▁▂▂▂▇▇██▆▆▇▇▃▄▄▄7467548128728887967227237237858869089169139099049099048899259289537187738028021052110211371143994102010661065842903905906NANANANANANANA
 us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent dei:LegalEntity cnp:CercCorp▁▂▇▆▆▆██8083959494939898NA97NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherLiabilitiesNoncurrent ██▇▇▆▃▄▄▃▃▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▂▁▂▂▂▂▁▂▁▄▄▄▄▃▃▃751763672653609402433412361357284292287278282279276273259250253251207206203205251232258247276263239305236407473447405374375361NANANA
 us-gaap:OtherLiabilitiesNoncurrent dei:LegalEntity cnp:CercCorp▇█▅▃▃▁▂▃411428381357362329350352NA297NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:OtherLiabilitiesNoncurrent dei:LegalEntity cnp:HoustonElectric█▅▂▅▄▄█▁8069616968657956NA54NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:StockholdersEquity ▆█████▅▃▄▄▂▂▂▂▂▂▂▂▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▁▁697083598346825782168058550846704857468836183563353734603472339735063461405845504574454844734425441443294261419143714301425743324286422242073313326631983129306127092639NANANA
 us-gaap:StockholdersEquity dei:LegalEntity cnp:CercCorp▅▄▃▄▄▃▁▇██2671264124832506256124432137306331513108NANANA2922NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockholdersEquity dei:LegalEntity cnp:HoustonElectric▄▇█▇▇▃▂▂▁▁2899325134833358327426822549246423942369NANANA2117NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital██████▁▁▁▁6086608060726065606060724221421542084209NANANA4195NANANA4180NANANA4169NANANA4157NANANA4130NANANA4120NANANA4100NANANA3671NANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:PreferredStock██████▄▁▁▁174017401740174017401740790000NANANA0NANANA0NANANA0NANANA0NANANA0NANANA0NANANA0NANANA0NANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:AdditionalPaidInCapital,cnp:CercCorp▅▅▄▄▄▄▁███2116211620152015201520151668252825272528NANANA2489NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:AdditionalPaidInCapital,cnp:HoustonElectric█████▃▁▁▁▁2486248624862486248618961696169716971696NANANA1696NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:CommonStockValue ██████▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁555555444444444444444444444444444444444444NANANA
us-gaap:RetainedEarningsAccumulatedDeficit ▂██▇▇▆▇▇█▇▃▂▂▂▂▂▂▂▅▇▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▂▂▂▁▁▁▁-761632636552518349551513708543-518-571-591-668-658-726-613-657-41456486461387346341258233171360302255331291231199-690-725-789-830-871-875-912NANANA
 us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity cnp:CercCorp█▆▃▅█▁▃▇545515463486541423463529NA574NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity cnp:HoustonElectric▁▅█▇▅▅▆▅4287801012887803800846763NA673NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▄▄▄▄▄▃███▇▇▇▇▇▇▇▇▇▆▆▆▅▆▅▅▅▂▁▁▁▂▂▁▁▃▃▃▃▃▂▂▂-100-98-107-105-107-108-58-62-63-68-72-70-71-71-64-67-65-66-81-82-84-86-85-87-89-90-127-130-132-135-125-128-131-133-110-112-115-117-116-119-121-124NANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity cnp:CercCorp██▁▁▁▁▂▂1010555566NA6NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities █▆▅▂▁▄▇▇▅▃▂▃▂662552512303271457586609484393351360317NANANANANANANANANANANANANANANA533NANANA424NANA510627NA165383435404381623433
 us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity cnp:CercCorp█▁▃▅▆▁▃██▁▂381-4764201248-36104360386-3434NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity cnp:HoustonElectric▂▇█▄▁▇█▆▄█▆10332335517466327345263180338288NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▇▇▁▇███████-654-646-626-610-6539-533-40764-331-360-257-268-372NANANANANANANANANANANANANANANA-274NANANA-292NANA-264-308NA-295-416-303-314-78-243-261
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cnp:HoustonElectric█▇▆▇▁▆▆▇▅▆▆1929-193-74-1237-248-195-104-364-207-151NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▂▂▂▂▅█▂▁▂▂▂▂▂-32687928423454023-214-564-19234-141-102-36NANANANANANANANANANANANANANANA-660NANANA744NANA-151-423NA-354287-543589-393-294-274
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities █▆▅▂▁▄▇▇▅▃▂▃▂662552512303271457586609484393351360317NANANANANANANANANANANANANANANA533NANANA424NANA510627NA165383435404381623433
 us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity cnp:CercCorp█▁▃▅▆▁▃██▁▂381-4764201248-36104360386-3434NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity cnp:HoustonElectric▂▇█▄▁▇█▆▄█▆10332335517466327345263180338288NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLoss ▁▅▅▅▅▅▅▄▅█▅▅▅▅▅▄▅▃▃▅▅▅▅▅▅▅▅▄▅▅▄▅▅▅▇▅▅▅▅▅▅▅▅▅▅-1199157270195169120158-751651296169135192101179-2154-509-39177131176143107185113151-10014713410126147117973119148124123811141051148667
 us-gaap:NetIncomeLoss dei:LegalEntity cnp:CercCorp▂▂▁▁▃▂▁▂▃█▂▂6753-728138339361305063854NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity cnp:HoustonElectric▂▂▇▄▁▂▆▄▂█▅▃▁33441851002740143101522101307518NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:RetainedEarnings,cnp:CercCorp▅▄▁▃█▃▂▃6753-72813833936NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents,dei:LegalEntity us-gaap:RetainedEarnings,cnp:HoustonElectric▁▂█▄▁▂▆▄33441851002740143101NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:DepreciationDepletionAndAmortization ▅▆██▆▃▇█▆▅▄▃▂▃▇▅▃▃▄▂▁▂▅▃▂282300334340313261326342314287269254226253324289260246268239217229293256235NA248253240NA301275224NANANANANANANANANANANANA
 us-gaap:DepreciationDepletionAndAmortization dei:LegalEntity cnp:CercCorp▆█▆▇█▃█▄▅█▁▁747775767771777273776868NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DepreciationDepletionAndAmortization dei:LegalEntity cnp:HoustonElectric▁▁▃▃▃▄▇█▆▅▄▄129129168176175180242262233199193180NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DepreciationDepletionAndAmortization us-gaap:StatementBusinessSegments cnp:ElectricTransmissionDistribution129NANANA175NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DepreciationDepletionAndAmortization us-gaap:StatementBusinessSegments cnp:NaturalGasDistribution111NANANA95NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DepreciationDepletionAndAmortization us-gaap:StatementBusinessSegments,dei:LegalEntity cnp:NaturalGasDistribution,cnp:CercCorp74NANANA73NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncreaseDecreaseInInventories ▃▄▇█▂▅▇▇▂▄▆▇▃▄▇▆▃▅▇▇▁▅██▃-110-3395110-120-116287-139-453294-74-396849-11257076-179-24116123-113NANANA-119NANANA-94NANA115-181NA-107-13716146-142-84416
 us-gaap:IncreaseDecreaseInInventories dei:LegalEntity cnp:HoustonElectric█▆▆█▅▇▆█▄▁▆10328-16410-4-182NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▇▇▁▇███████-654-646-626-610-6539-533-40764-331-360-257-268-372NANANANANANANANANANANANANANANA-274NANANA-292NANA-264-308NA-295-416-303-314-78-243-261
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cnp:HoustonElectric█▇▆▇▁▆▆▇▅▆▆1929-193-74-1237-248-195-104-364-207-151NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▂▂▂▂▅█▂▁▂▂▂▂▂-32687928423454023-214-564-19234-141-102-36NANANANANANANANANANANANANANANA-660NANANA744NANA-151-423NA-354287-543589-393-294-274
us-gaap:ProceedsFromIssuanceOfLongTermDebt ▁▁▇▆▄█▁▁▆▁▅▁▂▁▂▂▁▁▁▁▁▁▁▁▄001195100072114980099707980298030030000000000600NANANA0NANANA1695NANA0550NA00066500500
 us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity cnp:HoustonElectric▁▁▁▁█▁▁▁▅▁▁000069600039800NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:RepaymentsOfLongTermDebt ▁▁▂▁█▁▂▁▂▅▂▁▄▃▁▅▂▂▁▃▂▁▁▂▂637714883994116138651656141286440536312058814713111326113960104142231NANANA612NANANA526NANA0766NA335744171050110
 us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity cnp:HoustonElectric▁▁▆▁█▁▆▁▇▁▅636814867175661386516564128NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PaymentsOfDividends dei:LegalEntity cnp:CercCorp▂▁▁▃▂▃▃▄▃█▃▅32116832074751258626489140NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PaymentsOfDividends dei:LegalEntity cnp:HoustonElectric█▆▂▁▁▂▂▁▁▃▂▁38527660162486603132934510NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PaymentsOfDividends dei:LegalEntity cnp:CercCorp▂▁▁▃▂▃▃▄▃█▃▅32116832074751258626489140NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PaymentsOfDividends dei:LegalEntity cnp:HoustonElectric█▆▂▁▁▂▂▁▁▃▂▁38527660162486603132934510NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:RepaymentsOfLongTermDebt ▁▁▂▁█▁▂▁▂▅▂▁▄▃▁▅▂▂▁▃▂▁▁▂▂637714883994116138651656141286440536312058814713111326113960104142231NANANA612NANANA526NANA0766NA335744171050110
 us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity cnp:HoustonElectric▁▁▆▁█▁▆▁▇▁▅636814867175661386516564128NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value555555444444444444444444444444444444444444
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Par Or Stated Value Per Share

Shares Outstanding

Shares Issued

Common Stock Shares Issued

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value502502502502502501431431431431431431430430430430430430430430430429429429429428428428428427427427427426425425425424423421394391
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value502502502502502501431431431431431430
Percentage of CommonStockSharesOutstanding99.9100.0100.0100.0100.0100.099.999.999.9100.0100.199.9

Common Stock Shares Authorized

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-09-302009-06-302009-03-31
Value5025055055034344314344344334334334304324304314314314314304304304294294294284284284270039500349
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-09-302009-06-302009-03-31
Value5025025025014314314314314304304304304304304304294294294294284284274274274264254254250039300347
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-2.440.250.480.330.280.180.35-0.170.383.010.390.310.450.230.42-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.280.280.350.290.290.20.290.270.310.240.19
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-2.440.250.470.330.280.180.35-0.170.382.990.390.310.440.230.41-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.270.280.350.290.290.20.290.270.310.240.19
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Basic Share

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare



Period End2020-03-312019-03-312012-09-302011-12-312011-09-302011-06-302011-03-31
Value-2.150.230.020.270.90.280.35
Percentage of IncomeLossFromContinuingOperationsPerBasicShare100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Diluted Share

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare



Period End2020-03-312019-03-312012-09-302011-12-312011-09-302011-06-302011-03-31
Value-2.150.230.020.270.90.280.35
Percentage of IncomeLossFromContinuingOperationsPerDilutedShare100.0100.0100.0100.0100.0100.0100.0

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value214132302093205625393036138514492126263813471338171220811889157419841791163015322433237218071884316321841640189423882138170515252084214518811837258720981908175630232299157616402766
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value984984477597137210744805871364979493579
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.030.522.829.054.035.434.740.564.237.136.643.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.030.522.829.054.035.434.740.564.237.136.643.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value638665861768690710904860761747852758644
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.820.641.137.427.223.465.359.435.828.363.356.737.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.820.641.137.427.223.465.359.435.828.363.356.737.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:IndianaElectricIntegrated, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value129135165140830000
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.04.27.96.83.30.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.04.27.96.83.30.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated us-gaap:ReportableSubsegments100.0100.0100.0100.0100.00.00.00.00.0

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1293109951865714069183985091186854396463925
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax60.434.024.732.055.430.228.735.155.832.429.434.654.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax60.434.024.732.055.430.228.735.155.832.429.434.654.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value818591784121211211
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.82.64.33.81.60.10.10.10.00.00.10.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.82.64.33.81.60.10.10.10.00.00.10.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems, dei:LegalEntity

cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value638665861768690710904860
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.820.641.137.427.223.465.359.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.820.641.137.427.223.465.359.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments cnp:HoustonElectric100.0100.0100.0100.0100.0100.0100.0100.0

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value9818443935101205918398509
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax45.826.118.824.847.530.228.735.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax45.826.118.824.847.530.228.735.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution us-gaap:ReportableSubsegments cnp:CercCorp100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value31301100
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.00.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.00.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther us-gaap:ReportableSubsegments cnp:CercCorp100.0100.0100.00.0100.0100.00.00.0

Revenues

us-gaap:Revenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value216732302742279835313036221221863155263820982143273520811889157419841791163015322433237218071884316321841640189423882138170515252084214518811837258720981908175630232299157616402766
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax101.2100.0131.0136.1139.1100.0159.7150.9148.4100.0155.8160.2159.8100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value101117341126134223682303131213282400187212511387
Percentage of Revenues46.753.741.148.067.175.959.360.876.171.059.664.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax47.253.753.865.393.375.994.791.6112.971.092.9103.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp102.7176.2236.1224.8172.6214.4273.3226.2176.0191.2253.8239.6

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value634680859765686728897854755765843752638
Percentage of Revenues29.321.131.327.319.424.040.639.123.929.040.235.123.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.621.141.037.227.024.064.858.935.529.062.656.237.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:MajorCustomers, dei:LegalEntity

cnp:AffiliatesOfNrgEnergyInc, cnp:HoustonElectric



Period End2020-03-312019-03-31
Value156151
Percentage of Revenues7.24.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.35.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesOfNrgEnergyInc cnp:HoustonElectric0.00.0

cnp:AffiliatesofVistraEnergyCorp., cnp:HoustonElectric



Period End2020-03-312019-03-31
Value8154
Percentage of Revenues3.71.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.82.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesofVistraEnergyCorp. cnp:HoustonElectric0.00.0

us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments

cnp:AffiliatesOfNrgEnergyInc, cnp:ElectricTransmissionDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-30
Value156180231165151162213169161173221167152171223159145163222172184183222164166202148144196
Percentage of Revenues7.25.68.45.94.35.39.67.75.16.610.57.85.68.211.810.17.39.113.611.27.67.712.38.75.212.37.86.011.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.35.611.08.05.95.315.411.77.66.616.412.58.98.211.810.17.39.113.611.27.67.712.38.75.212.37.86.011.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesOfNrgEnergyInc cnp:ElectricTransmissionDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:AffiliatesofVistraEnergyCorp., cnp:ElectricTransmissionDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value81678359545979595457725347547150
Percentage of Revenues3.72.13.02.11.51.93.62.71.72.23.42.51.72.63.83.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.82.14.02.92.11.95.74.12.52.25.34.02.72.63.83.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesofVistraEnergyCorp. cnp:ElectricTransmissionDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302011-09-30
Value638683859765689730897854751763843752639729908763660701827705612679839698629745656532748707
Percentage of Revenues29.421.131.327.319.524.040.639.123.828.940.235.123.435.048.148.533.339.150.746.025.228.646.437.019.945.434.622.343.937.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.821.141.037.227.124.064.858.935.328.962.656.237.335.048.148.533.339.150.746.025.228.646.437.019.945.434.622.343.937.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:IndianaElectricIntegrated



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value12913516514083000
Percentage of Revenues6.04.26.05.02.40.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.04.27.96.83.30.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated0.00.00.00.00.00.00.00.0

cnp:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-30
Value13181089515650138989940248711438393904709077083704148886453534201185892375526147837552410433513608493794481207395
Percentage of Revenues60.833.718.823.239.329.618.222.336.231.818.621.933.234.019.626.344.836.021.727.448.737.620.827.946.722.927.743.720.623.640.720.124.446.720.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax61.633.724.631.654.729.629.033.653.831.829.035.153.034.019.626.344.836.021.727.448.737.620.827.946.722.927.743.720.623.640.720.124.446.720.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302011-09-30
Value82859380424344343443443434443443333
Percentage of Revenues3.82.63.42.91.20.10.10.20.10.10.20.10.10.20.20.30.20.20.20.20.20.20.20.20.10.20.20.10.20.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.82.64.43.91.70.10.20.30.20.10.30.20.20.20.20.30.20.20.20.20.20.20.20.20.10.20.20.10.20.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementBusinessSegments, dei:LegalEntity

cnp:NaturalGasDistribution, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value10088343895031211899402487
Percentage of Revenues46.525.814.218.034.329.618.222.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax47.125.818.624.547.729.629.033.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution cnp:CercCorp0.00.00.00.00.00.00.00.0

us-gaap:CorporateAndOther, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value31301100
Percentage of Revenues0.10.00.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.00.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther cnp:CercCorp0.00.00.00.00.00.00.00.0

us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value638683859765689730897854751763843752639
Percentage of Revenues29.421.131.327.319.524.040.639.123.828.940.235.123.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.821.141.037.227.124.064.858.935.328.962.656.237.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments100.0102.799.899.699.9102.899.299.398.7102.198.999.299.2

cnp:IndianaElectricIntegrated, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value129135165140830000
Percentage of Revenues6.04.26.05.02.40.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.04.27.96.83.30.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated us-gaap:ReportableSubsegments100.0100.0100.0100.0100.00.00.00.00.0

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1318108951565013898994024871143839390470907
Percentage of Revenues60.833.718.823.239.329.618.222.336.231.818.621.933.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax61.633.724.631.654.729.629.033.653.831.829.035.153.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution us-gaap:ReportableSubsegments101.999.199.498.998.897.9101.095.796.498.298.5101.598.1

us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value828593804243443434
Percentage of Revenues3.82.63.42.91.20.10.10.20.10.10.20.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.82.64.43.91.70.10.20.30.20.10.30.20.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther us-gaap:ReportableSubsegments101.2100.0102.2102.6102.4200.0300.0200.0400.0300.0200.0300.0400.0

us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems, dei:LegalEntity

cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value634680859765686728897854
Percentage of Revenues29.321.131.327.319.424.040.639.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.621.141.037.227.024.064.858.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments cnp:HoustonElectric99.4102.399.899.699.4102.599.299.3

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value10088343895031211899402487
Percentage of Revenues46.525.814.218.034.329.618.222.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax47.125.818.624.547.729.629.033.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution us-gaap:ReportableSubsegments cnp:CercCorp102.898.899.098.6100.597.9101.095.7

us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value31301100
Percentage of Revenues0.10.00.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.00.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther us-gaap:ReportableSubsegments cnp:CercCorp100.0100.0100.00.0100.0100.00.00.0

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value641016852910125114378647901273942832
Percentage of CostOfGoodsAndServicesSold100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.031.540.744.349.347.362.454.559.935.761.8

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value6876687769117114378647901273942832
Percentage of CostOfGoodsAndServicesSold9.486.280.684.593.6100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.327.132.837.446.147.362.454.559.935.761.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp0.689.0144.0128.885.3133.8180.0134.693.396.2168.8

us-gaap:StatementOperatingActivitiesSegment

us-gaap:SegmentDiscontinuedOperations



Period End2020-03-312019-03-31
Value8871251
Percentage of CostOfGoodsAndServicesSold1385.9100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax41.449.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SegmentDiscontinuedOperations0.00.0

us-gaap:StatementOperatingActivitiesSegment, dei:LegalEntity

us-gaap:SegmentDiscontinuedOperations, cnp:CercCorp



Period End2020-03-312019-03-31
Value7861171
Percentage of CostOfGoodsAndServicesSold1228.193.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax36.746.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SegmentDiscontinuedOperations cnp:CercCorp0.00.0

Operating Expenses

Costs And Expenses

us-gaap:CostsAndExpenses



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value195029282350251132862869198619992904234218191920246118381605139217341565136513462177215115741698286819731396
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax91.190.7112.3122.1129.494.5143.4138.0136.688.8135.0143.5143.888.385.088.487.487.483.787.989.590.787.190.190.790.385.1

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value81116611103128421722227131913062269169412201328
Percentage of CostsAndExpenses41.656.746.951.166.177.666.465.378.172.367.169.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.951.452.762.585.573.495.290.1106.764.290.699.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp82.4168.8231.2215.1158.3207.4274.8222.5166.3173.0247.5229.4

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value552581590596605630670673636638589581
Percentage of CostsAndExpenses28.319.825.123.718.422.033.733.721.927.232.430.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax25.818.028.229.023.820.848.446.429.924.243.743.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value21730239228724516722618725129627922327424328418225022626518625622123318629521124422333231088302338274357303364302327263357299287253285
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax10.19.318.714.09.65.516.312.911.811.220.716.716.011.715.011.612.612.616.312.110.59.312.99.99.39.714.911.813.914.55.219.816.212.819.016.514.114.417.115.011.813.018.215.410.3

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value20073235819676-7221311783159
Percentage of OperatingIncomeLoss92.224.25.920.280.045.5-3.111.852.260.111.126.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.32.31.12.87.72.5-0.51.56.26.72.34.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp20.37.44.89.714.37.1-1.53.79.618.26.310.2

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value8299269169819822718111912725417185
Percentage of OperatingIncomeLoss37.832.868.658.933.158.7100.496.847.442.991.076.731.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.83.112.98.23.23.216.412.55.64.818.912.85.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest And Debt Expense

us-gaap:InterestAndDebtExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value13913913413412110290917878807778828386878688898992888984868598104104110114111116121121122129126129129
Percentage of InterestAndDebtExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.54.36.46.54.83.46.56.33.73.05.95.84.63.94.45.54.44.85.45.83.73.94.94.72.75.24.54.16.16.85.36.16.04.56.36.94.05.68.07.94.7

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value302928302930303329313231
Percentage of InterestAndDebtExpense21.620.920.922.424.029.433.336.337.239.740.040.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.40.91.31.51.11.02.22.31.41.22.42.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp3.02.95.95.02.12.86.25.62.13.26.55.4

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value414141424037323633313232
Percentage of InterestAndDebtExpense29.529.530.631.333.136.335.639.642.339.740.041.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.91.32.02.01.61.22.32.51.61.22.42.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value1310911203494310171617-6201471012131181099110612106104533189184
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.60.30.40.50.81.10.60.30.10.41.31.21.0-0.31.10.90.40.60.70.80.50.30.60.50.30.70.00.30.70.70.30.50.20.20.20.20.00.30.61.10.1

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-4-2-30-3-30-1-4-12-4-4
Percentage of OtherNonoperatingIncomeExpense-30.8-20.0-33.30.0-15.0-8.80.0-25.0-133.3-120.0-23.5-25.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.1-0.10.0-0.1-0.10.0-0.1-0.2-0.5-0.3-0.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-0.4-0.2-0.60.0-0.2-0.30.0-0.2-0.3-1.2-0.8-0.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value3476430-3-31-3-2
Percentage of OtherNonoperatingIncomeExpense23.140.077.854.520.08.80.0-75.0-100.010.0-17.6-12.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.10.30.30.20.10.0-0.2-0.10.0-0.2-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations

us-gaap:IncomeLossFromContinuingOperations



Period End2020-03-312019-03-31
Value-1053143
Percentage of IncomeLossFromContinuingOperations100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-49.25.6

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value13153-72813835-35-878469-4
Percentage of IncomeLossFromContinuingOperations-12.40.00.00.096.50.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.11.6-0.31.45.41.2-2.5-0.63.717.8-0.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp13.35.4-1.54.710.13.3-7.3-1.45.747.9-0.8

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-30
Value-1400182332224191181209-882122862672112991622768240-818-635114209209213169294229144233128200219590190235199
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-65.45.615.910.97.56.015.1-6.110.010.819.815.817.57.814.60.512.1-45.7-39.07.48.68.811.89.09.314.07.69.87.513.110.531.410.39.110.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value16642-82816443-374698135-583
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest-11.923.1-2.412.585.923.8-17.7-52.346.247.2-1.939.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.81.3-0.41.46.51.4-2.73.24.65.1-0.46.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp16.94.3-1.74.712.04.0-7.77.87.213.8-1.014.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value385422612333511791286778201117
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest-2.729.768.154.917.328.285.6-145.531.627.375.355.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.81.710.86.01.31.712.98.83.23.014.98.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest



Period End2020-03-312019-03-31
Value-1053143
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-49.25.6

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-03-31
Value131110
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-12.476.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.14.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp13.38.0

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-03-31
Value3730
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-3.521.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.71.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution0.00.0

cnp:IndianaElectricIntegrated



Period End2020-03-312019-03-31
Value-171-9
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest16.2-6.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-8.0-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated0.00.0

cnp:MidstreamInvestments



Period End2020-03-312019-03-31
Value-112724
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest107.016.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-52.60.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:MidstreamInvestments0.00.0

cnp:NaturalGasDistribution



Period End2020-03-312019-03-31
Value204120
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-19.483.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.54.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution0.00.0

us-gaap:CorporateAndOther



Period End2020-03-312019-03-31
Value4-22
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-0.4-15.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.2-0.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther0.00.0

us-gaap:StatementBusinessSegments, dei:LegalEntity

cnp:NaturalGasDistribution, cnp:CercCorp



Period End2020-03-312019-03-31
Value134119
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-12.783.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.34.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution cnp:CercCorp0.00.0

us-gaap:CorporateAndOther, cnp:CercCorp



Period End2020-03-312019-03-31
Value-3-9
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest0.3-6.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.1-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther cnp:CercCorp0.00.0

Nonoperating Income Expense

us-gaap:NonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-1617-120-60-63-5414-17-275-39-10-12-1225-81-8-174-10-1044-900-72-47-12-20-17-1-15-79-9940-102-119233-113-129-128-137-141-147-135-124-170
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-75.5-3.7-2.9-3.1-2.10.5-1.2-19.0-1.8-0.4-0.9-0.91.5-3.9-0.4-11.1-0.5-58.3-55.2-4.7-1.9-0.5-1.1-0.9-0.0-0.9-4.2-4.12.3-6.7-5.712.4-6.2-5.0-6.7-7.8-4.7-6.4-8.6-7.6-6.1

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-34-31-31-30-32-33-3024-33-43-3624
Percentage of NonoperatingIncomeExpense2.125.851.747.659.3-235.7176.5-8.784.6430.0300.0-200.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.6-1.0-1.5-1.5-1.3-1.1-2.21.7-1.6-1.6-2.71.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-3.5-3.2-6.5-5.0-2.3-3.1-6.24.1-2.4-4.4-7.34.1

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-44-45-43-46-48-47-48-53-52-49-53-54
Percentage of NonoperatingIncomeExpense2.737.571.773.088.9-335.7282.419.3133.3490.0441.7450.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.1-1.4-2.1-2.2-1.9-1.5-3.5-3.7-2.4-1.9-3.9-4.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-347256229226151-1347-1010987610761971086-309-2443778337062109782448611874722047187764510247384348
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-16.20.83.01.40.92.03.7-0.92.2-38.37.35.76.22.95.10.64.3-17.3-15.02.43.21.43.93.33.44.812.93.66.94.93.510.83.93.44.02.63.42.02.42.61.7

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value35-11-10268-21020-334-129
Percentage of IncomeTaxExpenseBenefit-10.1-44.0-1.60.0118.213.1-3.9-76.942.633.1-1.038.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.6-0.3-0.00.01.00.3-0.10.70.9-12.7-0.12.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp3.6-1.1-0.20.01.90.7-0.41.71.5-34.1-0.25.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value5104123611362715-1327142
Percentage of IncomeTaxExpenseBenefit-1.440.066.179.327.318.070.6-207.731.913.172.455.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.32.01.10.20.42.61.90.7-5.05.33.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-03-31
Value56
Percentage of IncomeTaxExpenseBenefit-1.427.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution0.00.0

cnp:IndianaElectricIntegrated



Period End2020-03-312019-03-31
Value3-2
Percentage of IncomeTaxExpenseBenefit-0.9-9.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.1-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated0.00.0

cnp:MidstreamInvestments



Period End2020-03-312019-03-31
Value-36128
Percentage of IncomeTaxExpenseBenefit104.0127.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-16.91.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:MidstreamInvestments0.00.0

cnp:NaturalGasDistribution



Period End2020-03-312019-03-31
Value5626
Percentage of IncomeTaxExpenseBenefit-16.1118.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.61.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution0.00.0

us-gaap:CorporateAndOther



Period End2020-03-312019-03-31
Value-50-44
Percentage of IncomeTaxExpenseBenefit14.4-200.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.3-1.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther0.00.0

us-gaap:StatementBusinessSegments, dei:LegalEntity

cnp:NaturalGasDistribution, cnp:CercCorp



Period End2020-03-312019-03-31
Value4426
Percentage of IncomeTaxExpenseBenefit-12.7118.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.11.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution cnp:CercCorp0.00.0

us-gaap:CorporateAndOther, cnp:CercCorp



Period End2020-03-312019-03-31
Value-9-8
Percentage of IncomeTaxExpenseBenefit2.6-36.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.4-0.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther cnp:CercCorp0.00.0

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value0-1932146-40192-41313-212132-158-5750128-1663517141-1-3-8-46-16066152-8-6622926
Percentage of IncomeTaxesPaidNet0.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.0-0.61.57.1-0.20.00.16.3-0.20.00.21.0-0.10.01.12.0-8.0-3.23.18.4-6.81.50.97.5-0.0-0.1-0.4-2.5-6.23.58.7-0.3-2.90.11.80.9

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value04030003001
Percentage of IncomeTaxesPaidNet0.0-21.10.02.1-0.00.00.03.3-0.00.033.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.10.00.10.00.00.00.20.00.00.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp0.00.40.00.50.00.00.00.50.00.00.2

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0-6207303221041600
Percentage of IncomeTaxesPaidNet0.031.662.550.0-0.00.0200.0113.0-400.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.0-0.21.03.60.01.10.17.20.80.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-12304926819717050162-74170130016713619294182-4155-494-39079133175145109186154-981501312914997512215012683117
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-57.41.512.89.66.71.611.7-5.18.049.312.410.211.24.59.6-0.37.8-27.6-23.95.25.57.48.05.85.99.4-5.26.30.88.57.151.86.65.86.64.73.9

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value6758-728138339361305093854
Percentage of ComprehensiveIncomeNetOfTax-5.4118.4-2.614.281.266.05.6-48.676.539.222.839.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.11.8-0.31.45.41.10.62.56.119.32.84.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp6.85.9-1.54.710.13.11.96.19.552.07.79.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value334418510026191461015621013075
Percentage of ComprehensiveIncomeNetOfTax-2.789.869.050.815.338.090.1-136.532.916.277.855.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.51.48.84.91.00.610.57.02.68.09.75.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-1199157270195169120158-751651296169135192101179-2154-509-39177131176143107185113151-10014713410126147117973119148124123811141051148667
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-56.04.912.99.56.74.011.4-5.27.849.112.510.111.24.99.5-0.17.8-28.4-24.05.05.47.47.95.75.85.29.2-5.36.26.30.68.37.15.551.76.55.75.96.44.63.84.67.25.22.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value6753-728138339361305063854
Percentage of NetIncomeLoss-5.633.8-2.614.481.727.55.7-48.078.839.022.540.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.11.6-0.31.45.41.10.62.56.119.22.84.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp6.85.4-1.54.710.13.11.96.19.551.77.79.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value33441851002740143101522101307518
Percentage of NetIncomeLoss-2.828.068.551.316.033.390.5-134.731.516.276.955.69.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.51.48.84.91.11.310.37.02.48.09.75.61.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1199157270195169120158-75165
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-56.04.912.99.56.74.011.4-5.27.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:RetainedEarnings, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value6753-72813833936
Percentage of NetIncomeLoss-5.633.8-2.614.481.727.55.7-48.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.11.6-0.31.45.41.10.62.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings cnp:CercCorp0.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value33441851002740143101
Percentage of NetIncomeLoss-2.828.068.551.316.033.390.5-134.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.51.48.84.91.11.310.37.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings cnp:HoustonElectric0.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-122812824116514090153-751651296169135192
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-57.44.011.58.05.53.011.0-5.27.849.112.510.111.2

us-gaap:StatementOperatingActivitiesSegment

us-gaap:SegmentContinuingOperations



Period End2020-03-312019-03-31
Value-1082114
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic88.181.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-50.54.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SegmentContinuingOperations0.00.0

Net Income Loss Available To Common Stockholders Diluted

us-gaap:StatementOperatingActivitiesSegment

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:SegmentContinuingOperations



Period End2020-03-312019-03-31
Value-1082114
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-50.54.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SegmentContinuingOperations0.00.0

Assets

us-gaap:Assets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value33395354393464234189339022700922228221082241022736221352204521931218292128621012210042133421778226022267023200220482192022264218702157521658223702287122477224752235121703209511967719594201111939919521193511977319676
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-31
Value81508439792978158065821473059642101129218
Percentage of Assets24.423.822.922.923.830.432.943.644.542.2
Percentage of Assets24.423.822.922.923.830.432.943.644.542.2
Percentage of Assets cnp:CercCorp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value108701126211463114781142010507104361043010292
Percentage of Assets32.531.833.133.633.738.946.947.245.3
Percentage of Assets32.531.833.133.633.738.946.947.245.3
Percentage of Assets cnp:HoustonElectric100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, cnp:ElectricTransmissionDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302012-12-31
Value10870112641146311478114201050910436104301035810292102891031910245102111009010065996010049996099449788100669819980996051036411174
Percentage of Assets32.531.833.133.633.738.946.947.246.245.346.546.846.746.847.447.947.447.145.744.043.243.444.544.743.948.048.9
Percentage of Assets32.531.833.133.633.738.946.947.246.245.346.546.846.746.847.447.947.447.145.744.043.243.444.544.743.948.048.9
Percentage of Assets us-gaap:OperatingSegments cnp:ElectricTransmissionDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, cnp:IndianaElectricIntegrated



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value301531683009298919530
Percentage of Assets9.08.98.78.75.80.0
Percentage of Assets9.08.98.78.75.80.0
Percentage of Assets us-gaap:OperatingSegments cnp:IndianaElectricIntegrated100.0100.0100.0100.0100.00.0

us-gaap:OperatingSegments, cnp:MidstreamInvestments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-30
Value9152473252929152839248224572451246724722481248725022505253525362580259436044471450145214525451745184525
Percentage of Assets2.77.07.38.58.49.211.111.111.010.911.211.311.411.511.912.112.312.216.519.819.919.520.520.620.721.0
Percentage of Assets2.77.07.38.58.49.211.111.111.010.911.211.311.411.511.912.112.312.216.519.819.919.520.520.620.721.0
Percentage of Assets us-gaap:OperatingSegments cnp:MidstreamInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, cnp:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302012-12-31
Value13979139031323512946104926956655765016438660860676022597560995732558556615657536053015335546450594989497647764775
Percentage of Assets41.939.238.237.930.925.829.529.428.729.127.427.327.227.926.926.627.026.524.623.523.523.622.922.822.822.120.9
Percentage of Assets41.939.238.237.930.925.829.529.428.729.127.427.327.227.926.926.627.026.524.623.523.523.622.922.822.822.120.9
Percentage of Assets us-gaap:OperatingSegments cnp:NaturalGasDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302012-12-31
Value296947844884427835156156220623112500249726942703267926812920277129532902283129993153336827592902302627802600
Percentage of Assets8.913.514.112.510.422.89.910.511.211.012.212.312.212.313.713.214.113.613.013.313.914.512.513.213.812.911.4
Percentage of Assets8.913.514.112.510.422.89.910.511.211.012.212.312.212.313.713.214.113.613.013.313.914.512.513.213.812.911.4
Percentage of Assets us-gaap:OperatingSegments us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments, dei:LegalEntity

us-gaap:OperatingSegments, cnp:NaturalGasDistribution, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312017-12-31
Value756274977018684369566608
Percentage of Assets22.621.220.320.025.829.1
Percentage of Assets22.621.220.320.025.829.1
Percentage of Assets us-gaap:OperatingSegments cnp:NaturalGasDistribution cnp:CercCorp100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:CorporateAndOther, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312017-12-31
Value-871491211086670
Percentage of Assets-0.30.40.30.30.20.3
Percentage of Assets-0.30.40.30.30.20.3
Percentage of Assets us-gaap:OperatingSegments us-gaap:CorporateAndOther cnp:CercCorp100.0100.0100.0100.0100.0100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value33395354393464234189339022700922228221082241022736221352204521931218292128621012210042133421778226022267023200220482192022264218702157521658223702287122477224752235121703209511967719594201111939919521193511977319676
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value8150843979297815806582147305964210112
Percentage of LiabilitiesAndStockholdersEquity24.423.822.922.923.830.432.943.644.5
Percentage of Assets24.423.822.922.923.830.432.943.644.5
Percentage of Assets cnp:CercCorp100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value108701126211463114781142010507104361043010292
Percentage of LiabilitiesAndStockholdersEquity32.531.833.133.633.738.946.947.245.3
Percentage of Assets32.531.833.133.633.738.946.947.245.3
Percentage of Assets cnp:HoustonElectric100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value69708359834682578216805855084670485746883618356335373460347233973506346140584550457445484473442544144329426141914371430142574332428642224207331332663198312930612709263920221811
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets20.923.624.124.224.229.824.821.121.720.616.316.216.115.916.316.216.716.218.620.120.219.620.320.219.819.819.719.419.518.818.919.319.219.520.116.816.715.916.115.714.013.310.30.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value26712641248325062561244321373063315131082922
Percentage of StockholdersEquity38.331.629.830.431.230.338.865.664.966.384.5
Percentage of Assets8.07.57.27.37.69.09.613.914.113.713.4
Percentage of Assets cnp:CercCorp32.831.331.332.131.829.729.331.80.030.731.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value28993251348333583274268225492464239423692117
Percentage of StockholdersEquity41.638.941.740.739.833.346.352.849.350.561.2
Percentage of Assets8.79.210.19.89.79.911.511.110.710.49.7
Percentage of Assets cnp:HoustonElectric26.728.930.429.328.725.524.423.60.023.00.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-100-98-107-105-107-108-58-62-63-68-71-66-86-90-135-133-117-124-131-44
Percentage of StockholdersEquity-1.4-1.2-1.3-1.3-1.3-1.3-1.1-1.3-1.3-1.5-2.1-1.9-1.9-2.1-3.1-3.2-3.7-4.7-6.5-2.4
Percentage of Assets-0.3-0.3-0.3-0.3-0.3-0.4-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.4-0.6-0.6-0.6-0.6-0.70.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-312006-12-31
Value608660806072606560606072422142154208420941954180416941574130412041003671315830462977
Percentage of StockholdersEquity87.372.772.873.573.875.476.690.386.689.8121.2120.891.796.096.097.6128.2139.1156.2168.20.0
Percentage of Assets18.217.217.517.717.922.519.019.118.818.519.219.618.019.018.119.020.418.616.10.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-312006-12-31
Value555555444444444444333
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.20.10.20.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value17401740174017401740174079000000000000
Percentage of StockholdersEquity25.020.820.821.121.221.614.30.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets5.24.95.05.15.16.43.60.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-312006-12-31
Value-761632636552518349551513708543-668-657461258302231-789-912-1008-1194-1355
Percentage of StockholdersEquity-10.97.67.66.76.34.310.011.014.611.6-19.3-19.010.16.07.05.5-24.7-34.6-49.9-65.90.0
Percentage of Assets-2.31.81.81.61.51.32.52.33.22.4-3.1-3.12.01.21.31.1-3.9-4.6-5.10.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncome, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value1010555566663
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.1
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome cnp:CercCorp0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value-15-15-15-15-15-1474401
Percentage of StockholdersEquity-0.2-0.2-0.2-0.2-0.2-0.20.10.10.10.00.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.10.00.00.00.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value21162116201520152015201516682528252725282489
Percentage of StockholdersEquity30.425.324.124.424.525.030.354.152.053.971.9
Percentage of Assets6.36.05.85.95.97.57.511.411.311.111.4
Percentage of Assets us-gaap:AdditionalPaidInCapital cnp:CercCorp0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value24862486248624862486189616961697169716961696
Percentage of StockholdersEquity35.729.729.830.130.323.530.836.334.936.249.0
Percentage of Assets7.47.07.27.37.37.07.67.77.67.57.8
Percentage of Assets us-gaap:AdditionalPaidInCapital cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value545515463486541423463529618574430
Percentage of StockholdersEquity7.86.25.55.96.65.28.411.312.712.212.4
Percentage of Assets1.61.51.31.41.61.62.12.42.82.52.0
Percentage of Assets us-gaap:RetainedEarnings cnp:CercCorp0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value4287801012887803800846763693673420
Percentage of StockholdersEquity6.19.312.110.79.89.915.416.314.314.412.1
Percentage of Assets1.32.22.92.62.43.03.83.53.13.01.9
Percentage of Assets us-gaap:RetainedEarnings cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value4164384734163326341970252726270130493395293528652896292325292272233526892400250926913268257625292955265823192480236328742752295529682337198220422014258221432352238429043035
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets12.510.99.99.710.126.012.312.213.614.913.313.013.213.411.910.811.112.611.011.111.914.111.711.513.312.210.711.510.612.612.213.113.310.89.510.410.312.811.012.012.314.715.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value126314151074115915471770106010401592
Percentage of AssetsCurrent30.336.831.434.845.225.238.938.546.9
Percentage of Assets3.84.03.13.44.66.64.84.77.0
Percentage of Assets cnp:CercCorp15.516.813.514.819.221.514.510.815.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value73612901666173617869499941003830
Percentage of AssetsCurrent17.733.548.852.252.213.536.537.124.4
Percentage of Assets2.23.64.85.15.33.54.54.53.7
Percentage of Assets cnp:HoustonElectric6.811.514.515.115.69.09.59.68.1

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-312008-12-312007-12-312006-12-31
Value22024125927125542312933282192602012482543412702712182642272452342982302063792082194972456467221123109622010319095199995833297406115165167129127
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.70.70.80.815.71.31.51.01.10.91.11.21.61.31.31.01.21.01.11.01.31.00.91.71.01.02.31.12.83.25.04.91.00.51.00.51.00.53.01.73.70.00.00.00.80.00.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302016-12-31
Value12211141112111
Percentage of CashAndCashEquivalentsAtCarryingValue0.50.80.80.40.40.30.30.34.60.50.40.3
Percentage of Assets0.00.00.00.00.00.10.00.00.10.00.00.0
Percentage of Assets cnp:CercCorp0.00.00.00.00.00.20.00.00.10.00.00.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value196216228260243335279253238
Percentage of CashAndCashEquivalentsAtCarryingValue89.189.688.095.995.37.995.277.191.5
Percentage of Assets0.60.60.70.80.71.21.31.11.0
Percentage of Assets cnp:HoustonElectric1.81.92.02.32.13.22.72.42.3

us-gaap:ConsolidatedEntities

us-gaap:VariableInterestEntityPrimaryBeneficiary



Period End2020-03-312019-12-31
Value190216
Percentage of CashAndCashEquivalentsAtCarryingValue86.489.6
Percentage of Assets0.60.6
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

us-gaap:ConsolidatedEntities, dei:LegalEntity

us-gaap:VariableInterestEntityPrimaryBeneficiary, cnp:HoustonElectric



Period End2020-03-312019-12-31
Value190216
Percentage of CashAndCashEquivalentsAtCarryingValue86.489.6
Percentage of Assets0.60.6
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary cnp:HoustonElectric0.00.0

Short Term Investments

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value711124910911173141511909189581081100078376284074068260557759356864089783771283411428516176948607686986437137737227508528356917169337901009
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.13.53.13.44.24.44.14.34.84.43.53.53.83.43.22.92.72.82.62.84.03.63.23.85.13.92.93.23.83.43.12.93.23.63.43.84.34.23.63.74.84.05.1

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value324693428506856894527566713
Percentage of AccountsReceivableNetCurrent45.655.539.243.160.575.157.459.171.3
Percentage of Assets1.02.01.21.52.53.32.42.63.1
Percentage of Assets cnp:CercCorp4.08.25.46.510.610.97.25.97.1

us-gaap:ConsolidatedEntities

us-gaap:VariableInterestEntityPrimaryBeneficiary



Period End2020-03-312019-12-31
Value2226
Percentage of AccountsReceivableNetCurrent3.12.1
Percentage of Assets0.10.1
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

us-gaap:ConsolidatedEntities, dei:LegalEntity

us-gaap:VariableInterestEntityPrimaryBeneficiary, cnp:HoustonElectric



Period End2020-03-312019-12-31
Value2226
Percentage of AccountsReceivableNetCurrent3.12.1
Percentage of Assets0.10.1
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary cnp:HoustonElectric0.00.0

Inventory Net

Inventory Raw Materials And Supplies

us-gaap:InventoryRawMaterialsAndSupplies



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value278269273267256200198192176175190192178181191187176179174178161168156155146145137137181177182176168166168164
Percentage of InventoryRawMaterialsAndSupplies100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.80.80.80.80.70.90.90.80.80.90.90.80.80.90.90.80.80.80.80.70.70.70.70.70.70.60.60.80.80.80.80.80.80.80.8

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value747173716765696756
Percentage of InventoryRawMaterialsAndSupplies26.626.426.726.626.232.534.834.932.0
Percentage of Assets0.20.20.20.20.20.20.30.30.2
Percentage of Assets cnp:CercCorp0.90.80.90.90.80.80.90.70.6

Other Assets Current

Prepaid Expense And Other Assets Current

us-gaap:PrepaidExpenseAndOtherAssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value120161156181241192157167189241175167184161154135127140111105132178177173158125112116137216245253220192190274
Percentage of PrepaidExpenseAndOtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.50.50.50.70.70.70.80.81.10.80.80.80.70.70.60.60.70.50.50.60.80.80.80.70.60.50.50.60.91.11.11.00.90.91.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value8443639651158580166
Percentage of PrepaidExpenseAndOtherAssetsCurrent6.727.323.121.527.059.954.147.968.9
Percentage of Assets0.00.10.10.10.20.40.40.40.7
Percentage of Assets cnp:CercCorp0.10.50.50.50.81.41.20.81.6

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value364930414661505962
Percentage of PrepaidExpenseAndOtherAssetsCurrent30.030.419.222.719.131.831.835.325.7
Percentage of Assets0.10.10.10.10.10.20.20.30.3
Percentage of Assets cnp:HoustonElectric0.30.40.30.40.40.60.50.60.6

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value308303068530066295522901120267198611958519294190311858118374180701783117500172181690016650162641596715633153581497514674143681413813909136231859818377180101735017073168681659116426162351600515635153821500114770
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets92.386.686.886.485.675.089.488.686.183.783.983.382.481.782.281.980.578.074.770.669.066.267.966.964.564.664.562.983.180.480.177.276.477.779.283.582.979.680.678.877.574.7

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value821081247892771075337431726071046888
Percentage of PropertyPlantAndEquipmentGross26.626.526.226.126.036.736.636.336.2
Percentage of Assets24.622.922.822.622.227.532.732.130.3
Percentage of Assets cnp:CercCorp100.796.399.598.793.490.599.473.768.1

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value130581282912621124571228712148119621181211496
Percentage of PropertyPlantAndEquipmentGross42.441.842.042.242.459.960.260.360.4
Percentage of Assets39.136.236.436.436.245.053.853.450.6
Percentage of Assets cnp:HoustonElectric120.1113.9110.1108.5107.6115.6114.6113.3111.7

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value985297409738962094996223620861886089597458815730561855245417532051825113507950564963485647704695460545454523443948904780467346114561446644334445437842734215416540733982
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets29.527.528.128.128.023.027.928.027.226.326.626.025.625.325.425.324.724.023.322.421.920.921.621.420.720.821.020.521.920.920.820.520.420.621.222.622.321.221.721.321.020.1

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value231222882330230622602205218521362036
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment23.523.523.924.023.835.435.234.534.1
Percentage of Assets6.96.56.76.76.78.29.89.79.0
Percentage of Assets cnp:CercCorp28.427.129.429.528.026.829.922.220.1

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value384437973795376237433746374237413633
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment39.039.039.039.139.460.260.360.560.8
Percentage of Assets11.510.711.011.011.013.916.816.916.0
Percentage of Assets cnp:HoustonElectric35.433.733.132.832.835.735.935.935.3

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value209782094520328199321951214044136531339713205130571270012644124521230712083118981171811537111851091110670105021020599799763959393869184137081359713337127391251212402121581198111857117321142011217109281078810296
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets62.859.158.758.357.652.061.460.658.957.457.457.456.856.456.856.655.854.151.448.347.145.346.345.543.943.943.542.461.359.559.356.756.057.158.060.960.558.358.957.556.554.652.3

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value589858365562540452735226507549684852
Percentage of PropertyPlantAndEquipmentNet28.127.927.427.127.037.237.237.137.2
Percentage of Assets17.716.516.115.815.619.322.822.521.3
Percentage of Assets cnp:CercCorp72.469.270.169.165.463.669.551.548.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value921490328826869585448402822080717863
Percentage of PropertyPlantAndEquipmentNet43.943.143.443.643.859.860.260.260.2
Percentage of Assets27.625.525.525.425.231.137.036.534.6
Percentage of Assets cnp:HoustonElectric84.880.277.075.874.880.078.877.476.4

Investments In Affiliates Subsidiaries Associates And Joint Ventures

Goodwill

us-gaap:Goodwill



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value46975164517951795129867867867867867867867867862862861840840840840840840840840840840840840146814681468169616961696169616961696169616961696169616961696
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets14.114.615.015.115.13.23.93.93.93.83.93.94.03.94.04.14.03.93.93.73.73.63.83.83.83.83.93.96.66.46.57.57.67.88.18.68.78.48.78.78.88.68.6

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value757819867867867867867867867
Percentage of Goodwill16.115.916.716.716.9100.0100.0100.0100.0
Percentage of Assets2.32.32.52.52.63.23.93.93.8
Percentage of Assets cnp:CercCorp9.39.710.911.110.810.611.99.08.6

us-gaap:StatementBusinessSegments

cnp:IndianaElectricIntegrated



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value93611211008100800
Percentage of Goodwill19.921.719.519.50.00.0
Percentage of Assets2.83.22.92.90.00.0
Percentage of Assets cnp:IndianaElectricIntegrated0.00.00.00.00.00.0

cnp:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value3312331232753275746746746746746746746746746746746746746746746746746746746746746746746746746746746746746746746746
Percentage of Goodwill70.564.163.263.214.586.086.086.086.086.086.086.086.086.586.586.688.888.888.888.888.888.888.888.888.888.888.888.850.850.850.844.044.044.044.044.0
Percentage of Assets9.99.39.59.62.22.83.43.43.33.33.43.43.43.43.53.63.63.53.43.33.33.23.43.43.43.43.53.43.33.33.33.33.33.43.63.7
Percentage of Assets cnp:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.014.615.00.015.915.815.616.316.616.516.117.016.3

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value44944943143111111111111111111111111111111111111111111111111111111111
Percentage of Goodwill9.68.78.38.30.21.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.30.70.70.70.6
Percentage of Assets1.31.31.21.30.00.00.00.00.00.00.00.00.10.10.10.10.10.10.10.00.00.00.00.10.00.10.10.10.00.00.00.1
Percentage of Assets us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.30.40.00.40.40.40.50.5

Intangible Assets Net Excluding Goodwill

Finite Lived Intangible Assets Net

us-gaap:FiniteLivedIntangibleAssetsNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value56321356370460656769717449
Percentage of FiniteLivedIntangibleAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.91.01.11.40.20.30.30.30.30.2

us-gaap:FiniteLivedIntangibleAssetsByMajorClass

cnp:Operationandmaintenanceagreements



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value11111111470
Percentage of FiniteLivedIntangibleAssetsNet19.63.43.13.010.20.0
Percentage of Assets0.00.00.00.00.10.0
Percentage of Assets cnp:Operationandmaintenanceagreements0.00.00.00.00.00.0

us-gaap:CustomerRelationships



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value28243266270284596061636545
Percentage of FiniteLivedIntangibleAssetsNet50.075.774.773.061.790.889.688.488.787.891.8
Percentage of Assets0.10.70.80.80.80.20.30.30.30.30.2
Percentage of Assets us-gaap:CustomerRelationships0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OrderOrProductionBacklog



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value141017460
Percentage of FiniteLivedIntangibleAssetsNet1.81.22.84.610.00.0
Percentage of Assets0.00.00.00.00.10.0
Percentage of Assets us-gaap:OrderOrProductionBacklog0.00.00.00.00.00.0

us-gaap:OtherIntangibleAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value110101212556671
Percentage of FiniteLivedIntangibleAssetsNet1.83.12.83.22.67.77.58.78.59.52.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:OtherIntangibleAssets0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TradeNames



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value15535859700
Percentage of FiniteLivedIntangibleAssetsNet26.816.516.315.915.20.0
Percentage of Assets0.00.10.20.20.20.0
Percentage of Assets us-gaap:TradeNames0.00.00.00.00.00.0

Deferred Tax Assets Liabilities Net

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value223216273273286223190216194191194207204173134147109146148151144147150161159162140187197197183193159157154158157172194220228230277
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.60.80.80.80.80.91.00.90.80.90.90.90.80.60.70.50.70.70.70.60.60.70.70.70.70.60.90.90.90.80.90.70.70.70.80.80.91.01.11.21.21.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value401201731541651329597104
Percentage of OtherAssetsNoncurrent17.955.663.456.457.759.250.044.954.5
Percentage of Assets0.10.30.50.50.50.50.40.40.5
Percentage of Assets cnp:CercCorp0.51.42.22.02.01.61.31.01.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value292520313432203529
Percentage of OtherAssetsNoncurrent13.011.67.311.411.914.310.516.215.2
Percentage of Assets0.10.10.10.10.10.10.10.20.1
Percentage of Assets cnp:HoustonElectric0.30.20.20.30.30.30.20.30.3

Liabilities Current

us-gaap:LiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value4042388834342996313933022581284226163069322130382642308023982241253424673191312531873475300830263059301925952675312635753364320627352593231923612201262028813032320230382848
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets12.111.09.98.89.312.211.612.911.713.514.613.812.014.111.310.712.111.614.713.814.115.013.613.813.713.812.012.414.015.615.014.312.211.911.112.011.213.014.915.516.515.414.5

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value1471103879977497913408468091659
Percentage of LiabilitiesCurrent36.426.723.325.831.240.632.828.554.1
Percentage of Assets4.42.92.32.32.95.03.83.77.3
Percentage of Assets cnp:CercCorp18.012.310.19.912.116.311.68.416.4

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value8288307468528191090103110041082
Percentage of LiabilitiesCurrent20.521.321.728.426.133.039.935.335.3
Percentage of Assets2.52.32.22.52.44.04.64.54.8
Percentage of Assets cnp:HoustonElectric7.67.46.57.47.210.49.99.610.5

Debt Current

Long Term Debt Current

Accounts Payable Current

us-gaap:AccountsPayableCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value739113888893611811240708706712963657631634657422407378483367367476716441519802689364404510561371331366560417394449667
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.23.22.62.73.54.63.23.23.24.23.02.92.93.02.01.91.82.31.71.62.13.12.02.43.63.21.71.92.32.51.71.51.62.62.02.02.33.3

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value235557393406570856429434669
Percentage of AccountsPayableCurrent31.848.944.343.448.369.060.661.569.5
Percentage of Assets0.71.61.11.21.73.21.92.02.9
Percentage of Assets cnp:CercCorp2.96.65.05.27.110.45.94.56.6

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value259268232226238262220208243
Percentage of AccountsPayableCurrent35.023.626.124.120.221.131.129.525.2
Percentage of Assets0.80.80.70.70.71.01.00.91.1
Percentage of Assets cnp:HoustonElectric2.42.42.02.02.12.52.12.02.4

Taxes Payable Current

us-gaap:TaxesPayableCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value177241193158214204152103176181199153108172134921011581289014216113912922018413095123160171132164207184139140156
Percentage of TaxesPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.70.60.50.60.80.70.50.80.80.90.70.50.80.60.40.50.70.60.40.60.70.60.61.00.80.60.40.50.70.80.60.71.00.90.70.70.8

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value808466518182644875
Percentage of TaxesPayableCurrent45.234.934.232.337.940.242.146.641.4
Percentage of Assets0.20.20.20.10.20.30.30.20.3
Percentage of Assets cnp:CercCorp1.01.00.80.71.01.00.90.50.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value6112310763651158861116
Percentage of TaxesPayableCurrent34.551.055.439.930.456.457.959.264.1
Percentage of Assets0.20.30.30.20.20.40.40.30.5
Percentage of Assets cnp:HoustonElectric0.61.10.90.50.61.10.80.61.1

Accrued Income Taxes Current

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value300414375343338341392344343368339269267325353334317343384385394383373355365402343358347380347327281366319322350438464450497445504
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.91.21.11.01.01.31.81.61.51.61.51.21.21.51.71.61.51.61.81.71.71.71.71.61.61.81.61.71.61.71.51.51.31.71.51.61.82.22.42.32.62.32.6

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value134191143132136137171152137
Percentage of OtherLiabilitiesCurrent44.746.138.138.540.240.243.644.237.2
Percentage of Assets0.40.50.40.40.40.50.80.70.6
Percentage of Assets cnp:CercCorp1.62.31.81.71.71.72.31.61.4

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value78636973768911193120
Percentage of OtherLiabilitiesCurrent26.015.218.421.322.526.128.327.032.6
Percentage of Assets0.20.20.20.20.20.30.50.40.5
Percentage of Assets cnp:HoustonElectric0.70.60.60.60.70.81.10.91.2

Dividends Payable Current

Liabilities Noncurrent

Long Term Debt

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value1383014244140141412113759868272527760817681957531758778927532773677807354790176627614776780097797775580567817775879198130835784158583900586418497851087329001826784108410911910181
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets41.440.240.541.340.632.132.635.136.536.034.034.436.034.536.337.035.037.035.233.734.334.535.435.436.235.736.036.636.336.537.438.240.339.840.643.244.644.842.643.143.546.151.7

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value178425462477239723842371225727222457
Percentage of LongTermDebtNoncurrent12.917.917.717.017.327.331.135.130.0
Percentage of Assets5.37.27.27.07.08.810.212.310.8
Percentage of Assets cnp:CercCorp21.930.231.230.729.628.930.928.224.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value468447194789481648844258432644734319
Percentage of LongTermDebtNoncurrent33.933.134.234.135.549.059.757.652.7
Percentage of Assets14.013.313.814.114.415.819.520.219.0
Percentage of Assets cnp:HoustonElectric43.141.941.842.042.840.541.542.942.0

Deferred Tax Liabilities Noncurrent

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value7467548128728887967227237237858869089169139099049099048899259289537187738028021052110211371143994102010661065842903905906
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.22.12.32.62.62.93.23.33.23.54.04.14.24.24.34.34.34.24.14.14.14.13.33.53.63.74.95.15.15.04.44.54.84.94.04.64.64.5

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value808395949493989897
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent10.711.011.710.810.611.713.613.612.4
Percentage of Assets0.20.20.30.30.30.30.40.40.4
Percentage of Assets cnp:CercCorp1.01.01.21.21.21.11.31.01.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value727584878891142143146
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent9.79.910.310.09.911.419.719.818.6
Percentage of Assets0.20.20.20.30.30.30.60.60.6
Percentage of Assets cnp:HoustonElectric0.70.70.70.80.80.91.41.41.4

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value751763672653609402433412361357284292287278282279276273259250253251207206203205251232258247276263239305236407473447405374375361276
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.22.21.91.91.81.51.91.91.61.61.31.31.31.31.31.31.31.31.21.11.11.10.90.90.90.91.21.11.21.11.21.21.11.41.12.12.42.22.11.91.91.81.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value411428381357362329350352297
Percentage of OtherLiabilitiesNoncurrent54.756.156.754.759.481.880.885.483.2
Percentage of Assets1.21.21.11.01.11.21.61.61.3
Percentage of Assets cnp:CercCorp5.05.14.84.64.54.04.83.72.9

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value806961696865795654
Percentage of OtherLiabilitiesNoncurrent10.79.09.110.611.216.218.213.615.1
Percentage of Assets0.20.20.20.20.20.20.40.30.2
Percentage of Assets cnp:HoustonElectric0.70.60.50.60.60.60.80.50.5

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value69708359834682578216805855084670485746883618356335373460347233973506346140584550457445484473442544144329426141914371430142574332428642224207331332663198312930612709263920221811
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets20.923.624.124.224.229.824.821.121.720.616.316.216.115.916.316.216.716.218.620.120.219.620.320.219.819.819.719.419.518.818.919.319.219.520.116.816.715.916.115.714.013.310.30.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value26712641248325062561244321373063315131082922
Percentage of StockholdersEquity38.331.629.830.431.230.338.865.664.966.384.5
Percentage of Assets8.07.57.27.37.69.09.613.914.113.713.4
Percentage of Assets cnp:CercCorp32.831.331.332.131.829.729.331.80.030.731.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value28993251348333583274268225492464239423692117
Percentage of StockholdersEquity41.638.941.740.739.833.346.352.849.350.561.2
Percentage of Assets8.79.210.19.89.79.911.511.110.710.49.7
Percentage of Assets cnp:HoustonElectric26.728.930.429.328.725.524.423.60.023.00.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-100-98-107-105-107-108-58-62-63-68-71-66-86-90-135-133-117-124-131-44
Percentage of StockholdersEquity-1.4-1.2-1.3-1.3-1.3-1.3-1.1-1.3-1.3-1.5-2.1-1.9-1.9-2.1-3.1-3.2-3.7-4.7-6.5-2.4
Percentage of Assets-0.3-0.3-0.3-0.3-0.3-0.4-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.4-0.6-0.6-0.6-0.6-0.70.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-312006-12-31
Value608660806072606560606072422142154208420941954180416941574130412041003671315830462977
Percentage of StockholdersEquity87.372.772.873.573.875.476.690.386.689.8121.2120.891.796.096.097.6128.2139.1156.2168.20.0
Percentage of Assets18.217.217.517.717.922.519.019.118.818.519.219.618.019.018.119.020.418.616.10.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-312006-12-31
Value555555444444444444333
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.20.10.20.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value17401740174017401740174079000000000000
Percentage of StockholdersEquity25.020.820.821.121.221.614.30.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets5.24.95.05.15.16.43.60.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-312006-12-31
Value-761632636552518349551513708543-668-657461258302231-789-912-1008-1194-1355
Percentage of StockholdersEquity-10.97.67.66.76.34.310.011.014.611.6-19.3-19.010.16.07.05.5-24.7-34.6-49.9-65.90.0
Percentage of Assets-2.31.81.81.61.51.32.52.33.22.4-3.1-3.12.01.21.31.1-3.9-4.6-5.10.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncome, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value1010555566663
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.1
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome cnp:CercCorp0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value-15-15-15-15-15-1474401
Percentage of StockholdersEquity-0.2-0.2-0.2-0.2-0.2-0.20.10.10.10.00.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.10.00.00.00.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value21162116201520152015201516682528252725282489
Percentage of StockholdersEquity30.425.324.124.424.525.030.354.152.053.971.9
Percentage of Assets6.36.05.85.95.97.57.511.411.311.111.4
Percentage of Assets us-gaap:AdditionalPaidInCapital cnp:CercCorp0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value24862486248624862486189616961697169716961696
Percentage of StockholdersEquity35.729.729.830.130.323.530.836.334.936.249.0
Percentage of Assets7.47.07.27.37.37.07.67.77.67.57.8
Percentage of Assets us-gaap:AdditionalPaidInCapital cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value545515463486541423463529618574430
Percentage of StockholdersEquity7.86.25.55.96.65.28.411.312.712.212.4
Percentage of Assets1.61.51.31.41.61.62.12.42.82.52.0
Percentage of Assets us-gaap:RetainedEarnings cnp:CercCorp0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value4287801012887803800846763693673420
Percentage of StockholdersEquity6.19.312.110.79.89.915.416.314.314.412.1
Percentage of Assets1.32.22.92.62.43.03.83.53.13.01.9
Percentage of Assets us-gaap:RetainedEarnings cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value555555444444444444444444444444444444444444
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value-761632636552518349551513708543-518-571-591-668-658-726-613-657-41456486461387346341258233171360302255331291231199-690-725-789-830-871-875-912
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-2.31.81.81.61.51.32.52.33.22.4-2.3-2.6-2.7-3.1-3.1-3.5-2.9-3.1-0.22.02.12.01.81.61.51.21.10.81.61.31.11.51.31.10.9-3.5-3.7-3.9-4.3-4.5-4.5-4.6

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value545515463486541423463529574
Percentage of RetainedEarningsAccumulatedDeficit-71.681.572.888.0104.4121.284.0103.1105.7
Percentage of Assets1.61.51.31.41.61.62.12.42.5
Percentage of Assets cnp:CercCorp6.76.15.86.26.75.16.35.55.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value4287801012887803800846763673
Percentage of RetainedEarningsAccumulatedDeficit-56.2123.4159.1160.7155.0229.2153.5148.7123.9
Percentage of Assets1.32.22.92.62.43.03.83.53.0
Percentage of Assets cnp:HoustonElectric3.96.98.87.77.07.68.17.36.5

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value-100-98-107-105-107-108-58-62-63-68-72-70-71-71-64-67-65-66-81-82-84-86-85-87-89-90-127-130-132-135-125-128-131-133-110-112-115-117-116-119-121-124
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.3-0.3-0.3-0.3-0.3-0.4-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.4-0.4-0.4-0.4-0.4-0.4-0.4-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.5-0.6-0.6-0.6-0.6-0.6-0.6-0.6

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value10105555666
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-10.0-10.2-4.7-4.8-4.7-4.6-10.3-9.7-8.8
Percentage of Assets0.00.00.00.00.00.00.00.00.0
Percentage of Assets cnp:CercCorp0.10.10.10.10.10.10.10.10.1

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value-15-15-15-15-15-14740
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax15.015.314.014.314.013.0-12.1-6.5-0.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.10.00.00.0
Percentage of Assets cnp:HoustonElectric-0.1-0.1-0.1-0.1-0.1-0.10.10.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value662552512303271457586609484393351360317533424510627165383435404381623433
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax30.917.124.514.710.715.142.342.022.814.926.126.918.522.320.327.824.28.621.814.417.624.238.015.7

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value381-4764201248-36104360386-3434
Percentage of NetCashProvidedByUsedInOperatingActivities57.6-8.512.566.391.5-7.917.759.179.8-8.79.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.8-1.53.19.89.8-1.27.524.818.2-1.32.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp38.7-4.813.433.718.1-3.421.761.328.3-3.56.9

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value10332335517466327345263180338288
Percentage of NetCashProvidedByUsedInOperatingActivities15.658.569.357.424.471.658.943.237.286.082.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.810.017.08.52.610.824.918.28.512.821.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-654-646-626-610-6539-533-40764-331-360-257-268-372-274-292-264-308-295-416-303-314-78-243-261
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-30.5-20.0-29.9-29.7-257.5-17.6-29.44.4-15.6-13.6-19.1-20.0-21.7-11.5-14.0-14.4-11.9-15.5-23.7-10.0-13.7-4.9-14.8-9.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-177-147-129-136-250-338-162-100-97-66-75
Percentage of NetCashProvidedByUsedInInvestingActivities27.122.820.622.33.863.439.8-156.229.318.329.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-8.3-4.6-6.2-6.6-9.8-11.1-11.7-6.9-4.6-2.5-5.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-18.0-14.9-27.0-22.8-18.2-31.5-33.8-17.0-7.1-6.7-15.2

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1929-193-74-1237-248-195-104-364-207-151
Percentage of NetCashProvidedByUsedInInvestingActivities-29.4-1.430.812.118.946.547.9-162.5110.057.558.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.00.3-9.2-3.6-48.7-8.2-14.1-7.2-17.1-7.8-11.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-32687928423454023-214-564-19234-141-102-36-660744-151-423-354287-543589-393-294-274
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.52.13.813.892.4132.5-15.5-38.9-9.01.3-10.5-7.6-2.1-27.635.7-8.2-16.4-18.616.3-18.025.6-24.9-17.9-9.9

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-20519462-72-1139858-286-27411141
Percentage of NetCashProvidedByUsedInFinancingActivities640.6285.378.5-25.4-0.59.9-27.150.7142.7326.5-29.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-9.66.03.0-3.5-0.413.14.2-19.7-12.94.23.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-20.819.713.0-12.1-0.837.112.1-48.7-20.111.38.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-315-344-208-841078-26-124-97139-97-174
Percentage of NetCashProvidedByUsedInFinancingActivities984.4-505.9-263.3-29.646.0-0.657.917.2-72.4-285.3123.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-14.7-10.7-9.9-4.142.5-0.9-9.0-6.76.5-3.7-12.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value662552512303271457586609484393351360317533424510627165383435404381623433
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax30.917.124.514.710.715.142.342.022.814.926.126.918.522.320.327.824.28.621.814.417.624.238.015.7

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value381-4764201248-36104360386-3434
Percentage of NetCashProvidedByUsedInOperatingActivities57.6-8.512.566.391.5-7.917.759.179.8-8.79.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.8-1.53.19.89.8-1.27.524.818.2-1.32.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp38.7-4.813.433.718.1-3.421.761.328.3-3.56.9

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value10332335517466327345263180338288
Percentage of NetCashProvidedByUsedInOperatingActivities15.658.569.357.424.471.658.943.237.286.082.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.810.017.08.52.610.824.918.28.512.821.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-1199157270195169120158-751651296169135192101179-2154-509-39177131176143107185113151-10014713410126147117973119148124123811141051148667
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-56.04.912.99.56.74.011.4-5.27.849.112.510.111.24.99.5-0.17.8-28.4-24.05.05.47.47.95.75.85.29.2-5.36.26.30.68.37.15.551.76.55.75.96.44.63.84.67.25.22.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value6753-728138339361305063854
Percentage of NetIncomeLoss-5.633.8-2.614.481.727.55.7-48.078.839.022.540.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.11.6-0.31.45.41.10.62.56.119.22.84.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp6.85.4-1.54.710.13.11.96.19.551.77.79.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value33441851002740143101522101307518
Percentage of NetIncomeLoss-2.828.068.551.316.033.390.5-134.731.516.276.955.69.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.51.48.84.91.11.310.37.02.48.09.75.61.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1199157270195169120158-75165
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-56.04.912.99.56.74.011.4-5.27.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:RetainedEarnings, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value6753-72813833936
Percentage of NetIncomeLoss-5.633.8-2.614.481.727.55.7-48.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.11.6-0.31.45.41.10.62.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings cnp:CercCorp0.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value33441851002740143101
Percentage of NetIncomeLoss-2.828.068.551.316.033.390.5-134.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.51.48.84.91.11.310.37.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings cnp:HoustonElectric0.00.00.00.00.00.00.00.0

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-31
Value282300334340313261326342314287269254226253324289260246268239217229293256235248253240301275224
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value747775767771777273776868
Percentage of DepreciationDepletionAndAmortization26.225.722.522.424.627.223.621.123.226.825.326.8

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value129129168176175180242262233199193180
Percentage of DepreciationDepletionAndAmortization45.743.050.351.855.969.074.276.674.269.371.770.9

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-03-31
Value129175
Percentage of DepreciationDepletionAndAmortization45.755.9

cnp:IndianaElectricIntegrated



Period End2020-03-312019-03-31
Value2516
Percentage of DepreciationDepletionAndAmortization8.95.1

cnp:NaturalGasDistribution



Period End2020-03-312019-03-31
Value11195
Percentage of DepreciationDepletionAndAmortization39.430.4

us-gaap:CorporateAndOther



Period End2020-03-312019-03-31
Value1714
Percentage of DepreciationDepletionAndAmortization6.04.5

us-gaap:StatementBusinessSegments, dei:LegalEntity

cnp:NaturalGasDistribution, cnp:CercCorp



Period End2020-03-312019-03-31
Value7473
Percentage of DepreciationDepletionAndAmortization26.223.3

Increase Decrease In Other Operating Capital Net

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-110-3395110-120-116287-139-453294-74-396849-11257076-179-24116123-113-119-94115-181-107-13716146-142-84416
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-114-357393-119-165777-135-2731
Percentage of IncreaseDecreaseInInventories103.6106.176.884.599.2145.591.988.597.160.096.9

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value10328-16410-4-182
Percentage of IncreaseDecreaseInInventories-9.1-9.12.17.30.8-54.56.511.52.940.06.2

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-654-646-626-610-6539-533-40764-331-360-257-268-372-274-292-264-308-295-416-303-314-78-243-261
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-30.5-20.0-29.9-29.7-257.5-17.6-29.44.4-15.6-13.6-19.1-20.0-21.7-11.5-14.0-14.4-11.9-15.5-23.7-10.0-13.7-4.9-14.8-9.4

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-177-147-129-136-250-338-162-100-97-66-75
Percentage of NetCashProvidedByUsedInInvestingActivities27.122.820.622.33.863.439.8-156.229.318.329.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-8.3-4.6-6.2-6.6-9.8-11.1-11.7-6.9-4.6-2.5-5.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-18.0-14.9-27.0-22.8-18.2-31.5-33.8-17.0-7.1-6.7-15.2

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1929-193-74-1237-248-195-104-364-207-151
Percentage of NetCashProvidedByUsedInInvestingActivities-29.4-1.430.812.118.946.547.9-162.5110.057.558.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.00.3-9.2-3.6-48.7-8.2-14.1-7.2-17.1-7.8-11.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Payments To Acquire Investments

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-32687928423454023-214-564-19234-141-102-36-660744-151-423-354287-543589-393-294-274
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.52.13.813.892.4132.5-15.5-38.9-9.01.3-10.5-7.6-2.1-27.635.7-8.2-16.4-18.616.3-18.025.6-24.9-17.9-9.9

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-20519462-72-1139858-286-27411141
Percentage of NetCashProvidedByUsedInFinancingActivities640.6285.378.5-25.4-0.59.9-27.150.7142.7326.5-29.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-9.66.03.0-3.5-0.413.14.2-19.7-12.94.23.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-20.819.713.0-12.1-0.837.112.1-48.7-20.111.38.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-315-344-208-841078-26-124-97139-97-174
Percentage of NetCashProvidedByUsedInFinancingActivities984.4-505.9-263.3-29.646.0-0.657.917.2-72.4-285.3123.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-14.7-10.7-9.9-4.142.5-0.9-9.0-6.76.5-3.7-12.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value00119510007211498009970798029803003000000000060001695055000066500500
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.0100.0100.0100.0100.00.00.0100.00.0100.00.0100.00.0100.0100.00.00.00.00.00.00.00.00.0100.00.0100.00.0100.00.00.00.0100.00.00.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value000069600039800
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.00.00.096.50.00.00.039.90.00.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-02-292012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value6377148839941161386516561412864405363120588147131113261139601041422316122755260766335744171050110
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.0100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value636814867175661386516564128
Percentage of RepaymentsOfLongTermDebt100.088.3100.080.717.656.9100.0100.0100.010.4100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Payments Of Dividends

dei:LegalEntity

us-gaap:PaymentsOfDividends

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value32116832074751258626489140
Percentage of PaymentsOfDividends100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value38527660162486603132934510
Percentage of PaymentsOfDividends1203.127600.0375.019.3120.0116.280.024.837.235.250.67.1

Payments Of Dividends

dei:LegalEntity

us-gaap:PaymentsOfDividends

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value32116832074751258626489140
Percentage of PaymentsOfDividends100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value38527660162486603132934510
Percentage of PaymentsOfDividends1203.127600.0375.019.3120.0116.280.024.837.235.250.67.1

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-02-292012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value6377148839941161386516561412864405363120588147131113261139601041422316122755260766335744171050110
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.0100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value636814867175661386516564128
Percentage of RepaymentsOfLongTermDebt100.088.3100.080.717.656.9100.0100.0100.010.4100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.0

Debt Instrument Interest Rate Stated Percentage

Effective Income Tax Rate Continuing Operations

dei:LegalEntity

us-gaap:EffectiveIncomeTaxRateContinuingOperations

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value0.130.00.180.190.180.00.20.210.22-0.380.350.36
Percentage of EffectiveIncomeTaxRateContinuingOperations100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementOperatingActivitiesSegment

us-gaap:SegmentContinuingOperations



Period End2020-03-312019-03-31
Value0.250.09
Percentage of EffectiveIncomeTaxRateContinuingOperations192.350.0

us-gaap:SegmentDiscontinuedOperations



Period End2020-03-312019-03-31
Value0.10.24
Percentage of EffectiveIncomeTaxRateContinuingOperations76.9133.3

us-gaap:StatementOperatingActivitiesSegment, dei:LegalEntity

us-gaap:SegmentContinuingOperations, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0.21-0.080000000000000020.130.00.14-0.049999999999999990.050.33
Percentage of EffectiveIncomeTaxRateContinuingOperations161.50.072.20.077.80.025.0157.1

us-gaap:SegmentDiscontinuedOperations, cnp:CercCorp



Period End2020-03-312019-03-312018-12-312018-09-302018-06-30
Value0.150.220.0100000000000000090.230.24
Percentage of EffectiveIncomeTaxRateContinuingOperations115.4122.20.0115.0114.3

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price

Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period

Deferred Tax Liabilities

Deferred Tax Assets Net

Unrecognized Tax Benefits

Deferred Tax Assets Valuation Allowance

Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions

Operating Lease Right Of Use Asset

Cash And Cash Equivalents Period Increase Decrease

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value2472712973323554278331366257296233280290381300
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value1225122511271210
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents0.40.70.71.53.40.60.30.310.54.10.30.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value215235247293277370317291229274240277381299
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents87.086.783.288.378.08.695.879.589.192.6103.098.9100.099.7

Proceeds From Repayments Of Short Term Debt

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:Accountspayablerelatedtocapitalexpendituresdiscontinuedoperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value46
Percentage of Accountspayablerelatedtocapitalexpendituresdiscontinuedoperations100.0100.0

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value23
Percentage of Accountspayablerelatedtocapitalexpendituresdiscontinuedoperations50.050.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value46
Percentage of Accountspayablerelatedtocapitalexpendituresdiscontinuedoperations100.0100.0

cnp:AmountOfAllowedEquityReturnNotRecognizedInPeriod



Period End2020-03-31
Value162
Percentage of AmountOfAllowedEquityReturnNotRecognizedInPeriod100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-31
Value162
Percentage of AmountOfAllowedEquityReturnNotRecognizedInPeriod100.0

cnp:AmountOfAllowedEquityReturnRecognizedInPeriod



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value6714131112172421131216129162017151512816138643543
Percentage of AmountOfAllowedEquityReturnRecognizedInPeriod100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value6714131112172421121310
Percentage of AmountOfAllowedEquityReturnRecognizedInPeriod100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:BasisDifferenceAccretionGain

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value12121112121211121213121212121212124211-132155
Percentage of BasisDifferenceAccretionGain100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:ComprehensiveIncomeNetofTaxBeforePreferredStockDividend



Period End2020-03-312019-03-31
Value-1201170
Percentage of ComprehensiveIncomeNetofTaxBeforePreferredStockDividend100.0100.0

us-gaap:StatementEquityComponents, dei:LegalEntity

cnp:ContributionFromParent

us-gaap:AdditionalPaidInCapital, cnp:CercCorp



Period End2020-03-312019-03-312018-12-312018-09-30
Value00360600
Percentage of ContributionFromParent0.00.0100.0100.0

us-gaap:AdditionalPaidInCapital, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value000059020000
Percentage of ContributionFromParent0.00.00.00.00.055.60.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents

cnp:CostMethodInvestmentDividendsOrDistributions

cnp:EnableMidstreamPartners, us-gaap:PreferredStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value99999999999999940
Percentage of CostMethodInvestmentDividendsOrDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:DilutionLossEquityMethodInvestment

cnp:EnableMidstreamPartners



Period End2020-03-312019-03-31
Value111
Percentage of DilutionLossEquityMethodInvestment100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationafterDisposalPipelineconstructionandrepaircharges

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value14
Percentage of DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationafterDisposalPipelineconstructionandrepaircharges100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:DiscontinuedoperationCapitalizedfees

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value3419
Percentage of DiscontinuedoperationCapitalizedfees100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:InfrastructureServicesDisposalGroup, cnp:CercCorp



Period End2020-03-312019-03-31
Value0.01000000.0
Percentage of DiscontinuedoperationCapitalizedfees0.05.3

cnp:DisposalGroupIncludingDiscontinuedOperationOperationandMaintenanceExpense



Period End2020-03-312019-03-31
Value183113
Percentage of DisposalGroupIncludingDiscontinuedOperationOperationandMaintenanceExpense100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value2017
Percentage of DisposalGroupIncludingDiscontinuedOperationOperationandMaintenanceExpense10.915.0

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value16396
Percentage of DisposalGroupIncludingDiscontinuedOperationOperationandMaintenanceExpense89.185.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value2017
Percentage of DisposalGroupIncludingDiscontinuedOperationOperationandMaintenanceExpense10.915.0

cnp:DisposalGroupIncludingDiscontinuedOperationTaxesOtherthanIncomeTaxes



Period End2020-03-312019-03-31
Value20
Percentage of DisposalGroupIncludingDiscontinuedOperationTaxesOtherthanIncomeTaxes100.00.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value1000000.00.0
Percentage of DisposalGroupIncludingDiscontinuedOperationTaxesOtherthanIncomeTaxes50.00.0

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value1000000.00.0
Percentage of DisposalGroupIncludingDiscontinuedOperationTaxesOtherthanIncomeTaxes50.00.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value1000000.00.0
Percentage of DisposalGroupIncludingDiscontinuedOperationTaxesOtherthanIncomeTaxes50.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents

cnp:Distributionpershareofcommonunits

cnp:EnableMidstreamPartners, us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.33050.33049999999999990.33050.3180.3180.3180.3180.3180.318
Percentage of Distributionpershareofcommonunits100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EquityMethodInvestmentGrossEquityInEarningsLosses

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value55466626189704657535647603261194837-54642516876
Percentage of EquityMethodInvestmentGrossEquityInEarningsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value10411010811010510610096969990
Percentage of EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EquityMethodInvestmentSummarizedFinancialInformationImpairmentofGoodwillandLongLivedAssets

cnp:EnableMidstreamPartners



Period End2020-03-312019-03-312017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302014-12-312014-09-30
Value280001829110571
Percentage of EquityMethodInvestmentSummarizedFinancialInformationImpairmentofGoodwillandLongLivedAssets100.00.00.00.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EquityMethodInvestmentSummarizedFinancialInformationOperatingIncomeLoss

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value14662175167165212171126139129137122140861395710366-97593104134151
Percentage of EquityMethodInvestmentSummarizedFinancialInformationOperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel

cnp:FairValueInputsPricePerMMBtu

srt:Maximum, us-gaap:ForwardContracts, us-gaap:FairValueInputsLevel3



Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value4.83-0.88999999999999970.4500000000000002-0.59000000000000076.23
Percentage of FairValueInputsPricePerMMBtu100.0100.0100.0100.0100.0

srt:Minimum, us-gaap:ForwardContracts, us-gaap:FairValueInputsLevel3



Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value1.150.06000000000000005-0.24000000000000021.590.03
Percentage of FairValueInputsPricePerMMBtu23.8-6.7-53.3-269.50.5

us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

srt:Maximum, us-gaap:ForwardContracts, us-gaap:FairValueInputsLevel3, cnp:CercCorp



Period End2020-03-312019-12-312019-09-30
Value4.83-0.88999999999999970.4500000000000002
Percentage of FairValueInputsPricePerMMBtu100.0100.0100.0

srt:Minimum, us-gaap:ForwardContracts, us-gaap:FairValueInputsLevel3, cnp:CercCorp



Period End2020-03-312019-12-312019-09-30
Value1.150.06000000000000005-0.2400000000000002
Percentage of FairValueInputsPricePerMMBtu23.8-6.7-53.3

cnp:GainLossOnIndexedDebtSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value135-76-62-68-8684-44-254-18108-36-13-10-155-72-130-5612129-9124-57-22-5043-42-27-51-529-33880-23-532-27-14-30-4622
Percentage of GainLossOnIndexedDebtSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:Goodwillimpairmentandlossfromreclassificationtoheldforsale



Period End2020-03-312019-03-31
Value2140
Percentage of Goodwillimpairmentandlossfromreclassificationtoheldforsale100.00.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-03-31
Value1320
Percentage of Goodwillimpairmentandlossfromreclassificationtoheldforsale61.70.0

us-gaap:PartnerTypeOfPartnersCapitalAccount, dei:LegalEntity

cnp:IncentiveDistributionRightPercentage

cnp:EnableGPLLC, cnp:CenterpointEnergy



Period End2020-03-312019-12-312019-09-30
Value0.40.00.0
Percentage of IncentiveDistributionRightPercentage100.00.00.0

cnp:EnableGPLLC, cnp:OGE



Period End2020-03-312019-12-312019-09-30
Value0.60.00.0
Percentage of IncentiveDistributionRightPercentage150.00.00.0

dei:LegalEntity

cnp:IncreaseDecreaseInAccountsReceivablePayableAffiliates

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0-3-2-718-9-14104-10
Percentage of IncreaseDecreaseInAccountsReceivablePayableAffiliates0.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value316-28332-3290-835-314
Percentage of IncreaseDecreaseInAccountsReceivablePayableAffiliates0.0-533.31400.0-42.9177.8355.6-642.9-830.0125.0300.00.0

cnp:IncreaseDecreaseInContractWithCustomerAssetOtherAccruedUnbilledReceivables



Period End2020-03-31
Value-149
Percentage of IncreaseDecreaseInContractWithCustomerAssetOtherAccruedUnbilledReceivables100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-31
Value-109
Percentage of IncreaseDecreaseInContractWithCustomerAssetOtherAccruedUnbilledReceivables73.2

cnp:HoustonElectric



Period End2020-03-31
Value-25
Percentage of IncreaseDecreaseInContractWithCustomerAssetOtherAccruedUnbilledReceivables16.8

cnp:IncreaseDecreaseInterestAndTaxesAccrued



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-31
Value-95143-128-1169311-32-3231965-8253162-662927-39-2736-15-6319-76-87
Percentage of IncreaseDecreaseInterestAndTaxesAccrued100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-11258-23-8912-11-10-2814
Percentage of IncreaseDecreaseInterestAndTaxesAccrued11.617.5-800.0-82.16.99.7109.134.431.2-933.373.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-8041624-5848-59-543513
Percentage of IncreaseDecreaseInterestAndTaxesAccrued84.228.7-600.085.750.051.6-45.5-28.1168.81166.768.4

cnp:IncreaseDecreaseinAccountsReceivableonContractswithCustomers



Period End2020-03-312019-12-312019-09-30
Value46268-52
Percentage of IncreaseDecreaseinAccountsReceivableonContractswithCustomers100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-30
Value43145-54
Percentage of IncreaseDecreaseinAccountsReceivableonContractswithCustomers93.554.1103.8

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-30
Value-1-11520
Percentage of IncreaseDecreaseinAccountsReceivableonContractswithCustomers-2.2-42.9-38.5

cnp:IndexedDebtSecuritiesGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value135-76-62-68-8684-44-254-18108-36-13-10-155-72-130-5612129-9124-57-22
Percentage of IndexedDebtSecuritiesGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:InterestIncomeExpenseNetRelatedParty

cnp:CercCorp



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value0111-20-20
Percentage of InterestIncomeExpenseNetRelatedParty0.0100.0100.0100.0100.00.0100.00.0

cnp:HoustonElectric



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value15631001
Percentage of InterestIncomeExpenseNetRelatedParty0.0500.0600.0300.0-50.00.0-0.00.0

cnp:InterestIncomeonTransitionandSystemRestorationBonds



Period End2020-03-312019-03-31
Value12
Percentage of InterestIncomeonTransitionandSystemRestorationBonds100.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-03-31
Value12
Percentage of InterestIncomeonTransitionandSystemRestorationBonds100.0100.0

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-03-31
Value12
Percentage of InterestIncomeonTransitionandSystemRestorationBonds100.0100.0

cnp:InterestOnTransitionAndSystemRestorationBonds



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value88910121316141619182020212323242525272828303030323435373837313233-34-36-36-33-32-33-33
Percentage of InterestOnTransitionAndSystemRestorationBonds100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value889101213161416191820
Percentage of InterestOnTransitionAndSystemRestorationBonds100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-03-31
Value812
Percentage of InterestOnTransitionAndSystemRestorationBonds100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:InventoryWritedowndiscontinuedoperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value31
Percentage of InventoryWritedowndiscontinuedoperations100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value31
Percentage of InventoryWritedowndiscontinuedoperations100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:Lossfromreclassificationtoheldforsale

cnp:EnergyServices



Period End2020-03-31
Value70
Percentage of Lossfromreclassificationtoheldforsale100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-31
Value70
Percentage of Lossfromreclassificationtoheldforsale100.0

cnp:Lossfromreclassificationtoheldforsaleincludingimpairment



Period End2020-03-31
Value234
Percentage of Lossfromreclassificationtoheldforsaleincludingimpairment100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-31
Value138
Percentage of Lossfromreclassificationtoheldforsaleincludingimpairment59.0

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-31
Value96
Percentage of Lossfromreclassificationtoheldforsaleincludingimpairment41.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-31
Value132
Percentage of Lossfromreclassificationtoheldforsaleincludingimpairment56.4

us-gaap:PartnerTypeOfPartnersCapitalAccount, dei:LegalEntity

cnp:ManagementRightsOwnershipPercentage

cnp:EnableGPLLC, cnp:CenterpointEnergy



Period End2020-03-312019-12-312019-09-30
Value0.50.00.0
Percentage of ManagementRightsOwnershipPercentage100.00.00.0

cnp:EnableGPLLC, cnp:OGE



Period End2020-03-312019-12-312019-09-30
Value0.50.00.0
Percentage of ManagementRightsOwnershipPercentage100.00.00.0

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cnp:Netaffiliateservicechargesbillings

cnp:OperationAndMaintenanceExpense, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value61322933
Percentage of Netaffiliateservicechargesbillings100.0100.0100.0100.0100.0100.0100.0100.0

cnp:OperationAndMaintenanceExpense, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-6-1-3-2-2-9-3-3
Percentage of Netaffiliateservicechargesbillings-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0

cnp:OtherRevenueExcludingAssessedTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value261462-10137-18-3614-510-12
Percentage of OtherRevenueExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value27-153-3-712-14-33-6213
Percentage of OtherRevenueExcludingAssessedTax103.8-7.183.3150.030.0-53.8171.477.891.7-42.9-40.0130.0

us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value015-2-3-418-7-6-618-9-6-6
Percentage of OtherRevenueExcludingAssessedTax0.0107.1-33.3-150.040.0138.5-100.033.316.7128.6180.0-60.050.0

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value25-163-7-712-14-33-6214-9
Percentage of OtherRevenueExcludingAssessedTax96.2-7.1100.0150.070.0-53.8171.477.891.7-42.9-40.0140.075.0

us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1022122232223
Percentage of OtherRevenueExcludingAssessedTax3.80.033.3100.0-10.015.428.6-11.1-8.314.3-40.020.0-25.0

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cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-415-2-3-418-7-6
Percentage of OtherRevenueExcludingAssessedTax-15.4107.1-33.3-150.040.0138.5-100.033.3

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value27-1536-712-14
Percentage of OtherRevenueExcludingAssessedTax103.8-7.183.3150.0-60.0-53.8171.477.8

cnp:Othercomprehensivelossfromunconsolidatedaffiliatesnetoftax



Period End2020-03-312019-12-312019-09-302019-03-312018-12-312018-09-30
Value3-12000
Percentage of Othercomprehensivelossfromunconsolidatedaffiliatesnetoftax100.0100.0100.00.00.00.0

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cnp:PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths

cnp:VCC, us-gaap:LineOfCredit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.650.00.00.00.65
Percentage of PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths100.00.00.00.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.650.00.00.00.65
Percentage of PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths100.00.00.00.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.650.00.00.00.65
Percentage of PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths100.00.00.00.0100.0

us-gaap:CreditFacility, dei:LegalEntity

us-gaap:LineOfCredit, cnp:CercCorp



Period End2020-03-312019-12-312019-09-30
Value0.650.00.0
Percentage of PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths100.00.00.0

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Period End2020-03-312019-12-312019-09-30
Value0.650.00.0
Percentage of PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths100.00.00.0

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cnp:PercentageReductionofDividendorDistributionAmount

cnp:EnableMidstreamPartners, cnp:CommonUnits, us-gaap:SubsequentEvent



Period End2020-04-01
Value0.5
Percentage of PercentageReductionofDividendorDistributionAmount100.0

cnp:SaleofUnitsPercentageTriggerRightofFirstRefusal



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.050.00.00.00.050.00.00.00.050.00.00.00.05
Percentage of SaleofUnitsPercentageTriggerRightofFirstRefusal100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

dei:LegalEntity

cnp:OGE



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.050.00.00.00.050.00.00.00.050.00.00.00.05
Percentage of SaleofUnitsPercentageTriggerRightofFirstRefusal100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

us-gaap:ConsolidatedEntities, us-gaap:SubsequentEventType

cnp:Salespriceofoutstandingequityinterests

cnp:EnergyServices, us-gaap:SubsequentEvent



Period End2020-02-24
Value400
Percentage of Salespriceofoutstandingequityinterests100.0

cnp:InfrastructureServices, us-gaap:SubsequentEvent



Period End2020-02-03
Value850
Percentage of Salespriceofoutstandingequityinterests0.0

us-gaap:ConsolidatedEntities, us-gaap:SubsequentEventType, dei:LegalEntity

cnp:EnergyServices, us-gaap:SubsequentEvent, cnp:CercCorp



Period End2020-02-24
Value400
Percentage of Salespriceofoutstandingequityinterests100.0

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cnp:SiteContingencyLossExposure

srt:Maximum, cnp:MinnesotaandIndianaGasServiceTerritories



Period End2020-03-31
Value53
Percentage of SiteContingencyLossExposure100.0

srt:Minimum, cnp:MinnesotaandIndianaGasServiceTerritories



Period End2020-03-31
Value7
Percentage of SiteContingencyLossExposure13.2

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srt:Maximum, cnp:MinnesotaandIndianaGasServiceTerritories, cnp:CercCorp



Period End2020-03-31
Value32
Percentage of SiteContingencyLossExposure60.4

srt:Minimum, cnp:MinnesotaandIndianaGasServiceTerritories, cnp:CercCorp



Period End2020-03-31
Value5
Percentage of SiteContingencyLossExposure9.4

us-gaap:LongtermDebtType

cnp:SubordinatedNoteCashExchangeablePercentageOfFairValue

cnp:SubordinatedDebtZENS



Period End2020-03-312019-12-312019-09-30
Value0.950.00.0
Percentage of SubordinatedNoteCashExchangeablePercentageOfFairValue100.00.00.0

cnp:TotaldistributionsreceivedfromEnable



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value86868684838383848383838483
Percentage of TotaldistributionsreceivedfromEnable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel

cnp:VolumetricallyWeightedAveragePricePerMMBtu

us-gaap:ForwardContracts, us-gaap:FairValueInputsLevel3



Period End2020-03-31
Value2.22
Percentage of VolumetricallyWeightedAveragePricePerMMBtu100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

us-gaap:ForwardContracts, us-gaap:FairValueInputsLevel3, cnp:CercCorp



Period End2020-03-31
Value2.22
Percentage of VolumetricallyWeightedAveragePricePerMMBtu100.0

us-gaap:AmortizationOfFinancingCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value77877141612666667676677777778887777891010
Percentage of AmortizationOfFinancingCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value31413232223
Percentage of AmortizationOfFinancingCosts42.914.350.014.342.914.318.816.733.333.350.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value34323323334
Percentage of AmortizationOfFinancingCosts42.957.137.528.642.921.412.525.050.050.066.7

us-gaap:AmortizationOfIntangibleAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1573932238212
Percentage of AmortizationOfIntangibleAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeStatementLocation

cnp:Depreciationandamortizationexpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value157763223
Percentage of AmortizationOfIntangibleAssets100.0100.0100.0233.366.7100.0100.0100.0100.0

us-gaap:CostOfSales



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value15737000
Percentage of AmortizationOfIntangibleAssets100.0100.0100.0100.077.80.00.00.0

us-gaap:StatementClassOfStock

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:CommonStock



Period End2020-03-312018-06-30
Value23
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount100.0100.0

us-gaap:SeriesBPreferredStock



Period End2020-03-312019-09-302019-06-302019-03-31
Value35333234
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount1399.40.00.00.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:CapitalExpenditureDiscontinuedOperations

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value1627
Percentage of CapitalExpenditureDiscontinuedOperations100.0100.0

us-gaap:CapitalExpendituresIncurredButNotYetPaid



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value200585716661731102335337312-47728697241-1519599288-38751683713-367
Percentage of CapitalExpendituresIncurredButNotYetPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value66113234914-3303939
Percentage of CapitalExpendituresIncurredButNotYetPaid33.019.060.0328.629.523.0-42.996.838.29.1180.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value110265-12983712-37834-5
Percentage of CapitalExpendituresIncurredButNotYetPaid55.044.8100.0-171.459.060.7171.4-9.776.5103.0-100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-24-26-35-23-39233947-35109-3963-47-10-91
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-10-3-7-13240-2615
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect4.2-0.08.630.40.30.6-0.0-23.9-38.5

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-20-12-4616-93532662-4534-37
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect83.346.2131.4-69.62.41.3-74.356.9115.454.078.7

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us-gaap:ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1

us-gaap:EnergyRelatedDerivative, us-gaap:FairValueHedging, us-gaap:DesignatedAsHedgingInstrument, cnp:IncomeLossfromdiscontinuedoperations



Period End2020-03-312019-03-31
Value76
Percentage of ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1100.0100.0

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

us-gaap:EnergyRelatedDerivative, us-gaap:FairValueHedging, us-gaap:DesignatedAsHedgingInstrument, cnp:IncomeLossfromdiscontinuedoperations, cnp:CercCorp



Period End2020-03-312019-03-31
Value76
Percentage of ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1100.0100.0

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

us-gaap:EnergyRelatedDerivative, us-gaap:FairValueHedging, cnp:IncomeLossfromdiscontinuedoperations



Period End2020-03-312019-03-31
Value-7-6
Percentage of ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1-100.0-100.0

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us-gaap:EnergyRelatedDerivative, us-gaap:FairValueHedging, cnp:IncomeLossfromdiscontinuedoperations, cnp:CercCorp



Period End2020-03-312019-03-31
Value-7-6
Percentage of ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1-100.0-100.0

us-gaap:StatementClassOfStock

us-gaap:CommonStockDividendsPerShareCashPaid

us-gaap:CommonStock



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.290.28750000000000010.28750.28750.277499999999999970.27750.2775
Percentage of CommonStockDividendsPerShareCashPaid100.0100.0100.0100.0100.0100.0100.0

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us-gaap:CommonStock, cnp:FirstQuarter2020



Period End2020-03-31
Value0.29
Percentage of CommonStockDividendsPerShareCashPaid100.0

us-gaap:CommonStockDividendsPerShareDeclared



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-132017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-09-302009-06-302009-03-31
Value0.290.285000000000000030.28750.28750.00.56500000000000010.27750.27750.00.27750.54499999999999990.26750.26750.26750.257500000000000060.25750.25750.25750.247499999999999940.24750.24750.24750.237499999999999930.23750.23750.23750.20750.20750.20750.20250.20250.20250.19750.19750.19750.1950.1950.1950.190.190.19
Percentage of CommonStockDividendsPerShareDeclared100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementClassOfStock

us-gaap:CommonStock



Period End2020-03-312019-10-172019-12-312019-07-312019-09-302019-04-252019-06-302019-03-312018-12-122018-10-232018-12-312018-07-262018-09-302018-04-262018-06-302018-03-312017-12-132017-10-252017-07-272017-04-272017-01-052016-10-272016-07-282016-04-282016-01-20
Value0.28750.28750.57500000000000010.28750.28750.28750.28750.00.28750.27750.84250.27750.27750.27750.27750.00.27750.26750.26750.26750.26750.25750.25750.25750.2575
Percentage of CommonStockDividendsPerShareDeclared99.1201.80.0100.00.0100.00.00.0149.10.00.0100.00.0100.00.00.0100.00.00.00.00.00.00.00.00.0

us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType

us-gaap:CommonStock, us-gaap:SubsequentEvent



Period End2020-04-242020-02-032019-10-172019-07-312019-04-252018-10-23
Value0.150.290.28750.28750.28750.2775
Percentage of CommonStockDividendsPerShareDeclared0.00.00.00.00.00.0

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us-gaap:CommonStock, us-gaap:SubsequentEvent, cnp:PreviousDividendorDistribution



Period End2020-04-01
Value0.29
Percentage of CommonStockDividendsPerShareDeclared0.0

us-gaap:CommonStock, us-gaap:SubsequentEvent, cnp:RevisedDividendorDistribution



Period End2020-04-01
Value0.15
Percentage of CommonStockDividendsPerShareDeclared0.0

us-gaap:ContractWithCustomerLiabilityRevenueRecognized



Period End2020-03-312019-12-312019-09-30
Value2518
Percentage of ContractWithCustomerLiabilityRevenueRecognized100.0100.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-30
Value1000000.00.01000000.0
Percentage of ContractWithCustomerLiabilityRevenueRecognized4.00.012.5

us-gaap:AdjustmentsForNewAccountingPronouncements

us-gaap:CumulativeEffectOnRetainedEarningsBeforeTax1

us-gaap:AccountingStandardsUpdate201613



Period End2020-03-31
Value5
Percentage of CumulativeEffectOnRetainedEarningsBeforeTax1100.0

us-gaap:AdjustmentsForNewAccountingPronouncements, dei:LegalEntity

us-gaap:AccountingStandardsUpdate201613, cnp:CercCorp



Period End2020-03-31
Value5
Percentage of CumulativeEffectOnRetainedEarningsBeforeTax1100.0

us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:AccountingStandardsUpdate201613, cnp:EnergyServices



Period End2020-03-31
Value2
Percentage of CumulativeEffectOnRetainedEarningsBeforeTax140.0

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us-gaap:DebtInstrumentBasisSpreadOnVariableRate1

us-gaap:LineOfCredit, us-gaap:LondonInterbankOfferedRateLIBOR, cnp:CercCorp



Period End2020-03-31
Value0.0125
Percentage of DebtInstrumentBasisSpreadOnVariableRate1100.0

us-gaap:LineOfCredit, us-gaap:LondonInterbankOfferedRateLIBOR, cnp:HoustonElectric



Period End2020-03-31
Value0.0125
Percentage of DebtInstrumentBasisSpreadOnVariableRate1100.0

us-gaap:DeferredIncomeTaxExpenseBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-3776129-7-1415455-17-9559010856381465-149-268-371868194576412980149-3-34191724830
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value23-196-12125-352714-293-46
Percentage of DeferredIncomeTaxExpenseBenefit-6.1-31.120.714.3-150.0166.7-77.8540.0-82.430.7-51.1

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-115-12-12-15-1414-18-20-1276
Percentage of DeferredIncomeTaxExpenseBenefit0.324.6-41.4171.4107.1-93.331.1-360.0117.613.36.7

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-10-13-13-13-13-11-10-11-11-15-14-15-14
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0322223222232
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.00.00.00.00.01000000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit0.00.00.00.00.050.0

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-1-1-2-1-1-2
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit0.0-50.0-100.0-50.0-33.3-100.0

us-gaap:RetirementPlanType

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value454353434
Percentage of DefinedBenefitPlanContributionsByEmployer100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2156527223262
Percentage of DefinedBenefitPlanContributionsByEmployer50.0300.01625.0900.040.066.775.066.71550.0

us-gaap:RetirementPlanType, dei:LegalEntity

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Period End2020-03-312019-12-312019-09-302019-06-30
Value1000000.00.01000000.01000000.0
Percentage of DefinedBenefitPlanContributionsByEmployer25.00.025.033.3

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Period End2020-03-312019-12-312019-09-302019-06-30
Value2232
Percentage of DefinedBenefitPlanContributionsByEmployer50.040.075.066.7

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value1312121121
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherNonoperatingIncomeExpense, us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value28262727252727262725242424
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets2800.00.0900.02700.01250.00.02700.01300.02700.00.02400.01200.02400.0

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.00.01000000.00.00.01000000.0
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets0.00.0100.00.00.050.0

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us-gaap:DefinedBenefitPlanInterestCost

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value3444343444
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherNonoperatingIncomeExpense, us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value19232525232020192023222222
Percentage of DefinedBenefitPlanInterestCost633.30.0625.0625.0575.00.0666.7475.0666.70.0550.0550.0550.0

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value121111
Percentage of DefinedBenefitPlanInterestCost33.350.025.025.033.325.0

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value112222
Percentage of DefinedBenefitPlanInterestCost33.325.050.050.066.750.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1222211212222
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value11232424221516151524232523
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost1100.01150.01200.01200.01100.01500.01600.0750.01500.01200.01150.01250.01150.0

us-gaap:RetirementPlanType, dei:LegalEntity

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value12211121
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.050.050.0100.0200.050.0

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-1000000.00.0-1000000.0-1000000.00.00.00.0-1000000.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-100.00.0-50.0-50.00.00.00.0-50.0

us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments

us-gaap:OtherNonoperatingIncomeExpense, us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.00.00.01000000.00.00.00.00.0
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments0.00.00.00.0100.00.00.00.00.0

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value0201010010
Percentage of DefinedBenefitPlanServiceCost0.0100.00.0100.00.0100.00.00.0100.00.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1010101010910999999
Percentage of DefinedBenefitPlanServiceCost0.00.0500.00.01000.00.00.0900.00.00.00.0900.00.0

us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType, dei:LegalEntity

cnp:OperationAndMaintenanceExpense, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, cnp:CercCorp



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.00.01000000.00.01000000.00.0
Percentage of DefinedBenefitPlanServiceCost0.00.00.00.00.00.0

us-gaap:DepreciationAndAmortizationDiscontinuedOperations



Period End2020-03-312019-03-31
Value013
Percentage of DepreciationAndAmortizationDiscontinuedOperations0.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-03-31
Value04
Percentage of DepreciationAndAmortizationDiscontinuedOperations0.030.8

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value09
Percentage of DepreciationAndAmortizationDiscontinuedOperations0.069.2

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

us-gaap:DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet

us-gaap:EnergyRelatedDerivative, us-gaap:FairValueHedging, cnp:IncomeLossfromdiscontinuedoperations



Period End2020-03-312019-03-31
Value-38-14
Percentage of DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:IncomeStatementLocation, dei:LegalEntity

us-gaap:EnergyRelatedDerivative, us-gaap:FairValueHedging, cnp:IncomeLossfromdiscontinuedoperations, cnp:CercCorp



Period End2020-03-312019-03-31
Value-38-14
Percentage of DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet100.0100.0

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-30
Value210-21718-82123-42-252-30176-151419-139-54-121-4725138-8323-47-4-4152-33-18-49-4914-6385
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value755569864372257493027
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet35.7-261.9985.7477.8-4.930.1-4.8-0.8-190.027.8-200.0192.9

us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation

cnp:IDSDerivative, us-gaap:NonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value135-76-62-68-8684-44-254-18108-36-13-10-155-72-130-5612129-9124-57-22-5043-73-42
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet64.3361.9-885.7-377.8104.968.3104.8100.860.061.4240.0-92.9-52.6111.5133.3107.4119.148.093.5109.6104.3121.3550.0122.082.70.0127.3

us-gaap:EnergyRelatedDerivative, cnp:IncomeLossfromdiscontinuedoperations



Period End2020-03-312019-03-31
Value754
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet35.7-4.9

us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation, dei:LegalEntity

us-gaap:EnergyRelatedDerivative, cnp:IncomeLossfromdiscontinuedoperations, cnp:CercCorp



Period End2020-03-312019-03-31
Value754
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet35.7-4.9

us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeNonmonetaryNotionalAmountVolume

us-gaap:EnergyRelatedDerivative



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value2126.0-26.066.0-12.02198.0-191.03.0127.01735.0-71.0-40.01.01905.0-45.0-5.0334.0751.0-9.0-717224.0-31000.0749000.0-7000.0
Percentage of DerivativeNonmonetaryNotionalAmountVolume100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, dei:LegalEntity

us-gaap:EnergyRelatedDerivative, cnp:CercCorp



Period End2020-03-312019-12-312019-09-30
Value2126.0-26.066.0
Percentage of DerivativeNonmonetaryNotionalAmountVolume100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:Position

us-gaap:EnergyRelatedDerivative, us-gaap:Long



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-03-312016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value232.00.019.0-140.0495.0-170.042.0-169.0437.0178.0114.0139.035.0-76923.0-49000.0126000.026000.0
Percentage of DerivativeNonmonetaryNotionalAmountVolume10.9-0.028.81166.722.589.01400.0-133.125.2-250.76.018.5-388.910.7158.116.8-371.4

us-gaap:DerivativeInstrumentRisk, us-gaap:Position, dei:LegalEntity

us-gaap:EnergyRelatedDerivative, us-gaap:Long, cnp:CercCorp



Period End2020-03-312019-12-312019-09-30
Value232.00.019.0
Percentage of DerivativeNonmonetaryNotionalAmountVolume10.9-0.028.8

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax



Period End2020-03-312019-03-31
Value7134
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value5736
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax80.3105.9

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value14-2
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax19.7-5.9

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value5736
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax80.3105.9

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare



Period End2020-03-312019-03-31
Value-0.290.05
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare



Period End2020-03-312019-03-31
Value-0.290.05
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationAfterDisposalExpense

cnp:EnergyServices



Period End2020-03-312019-03-31
Value4564
Percentage of DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationAfterDisposalExpense100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value4463
Percentage of DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationAfterDisposalExpense97.898.4

us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation



Period End2020-03-312019-03-31
Value-178
Percentage of DiscontinuedOperationTaxEffectOfDiscontinuedOperation100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-11000021314172926
Percentage of DiscontinuedOperationTaxEffectOfDiscontinuedOperation64.70.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value-128
Percentage of DiscontinuedOperationTaxEffectOfDiscontinuedOperation70.6100.0

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-31
Value-5
Percentage of DiscontinuedOperationTaxEffectOfDiscontinuedOperation29.4

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value-118
Percentage of DiscontinuedOperationTaxEffectOfDiscontinuedOperation64.7100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold



Period End2020-03-312019-03-31
Value8521228
Percentage of DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value8081185
Percentage of DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold94.896.5

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value4443
Percentage of DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold5.23.5

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value8081185
Percentage of DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold94.896.5

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization



Period End2020-03-312019-03-31
Value013
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization0.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value04
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization0.030.8

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value09
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization0.069.2

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value04
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization0.030.8

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense



Period End2020-03-312019-03-31
Value10371354
Percentage of DisposalGroupIncludingDiscontinuedOperationOperatingExpense100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value8291206
Percentage of DisposalGroupIncludingDiscontinuedOperationOperatingExpense79.989.1

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value208148
Percentage of DisposalGroupIncludingDiscontinuedOperationOperatingExpense20.110.9

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value8291206
Percentage of DisposalGroupIncludingDiscontinuedOperationOperatingExpense79.989.1

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherExpense

cnp:EnergyServices



Period End2020-03-31
Value6
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherExpense100.0

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-31
Value14
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherExpense233.3

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-31
Value6
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherExpense100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue



Period End2020-03-312019-03-31
Value11081388
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue100.0100.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value8861242
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue80.089.5

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value222146
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue20.010.5

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value8861242
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue80.089.5

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType

us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit

cnp:EnableMidstreamPartners, cnp:CommonUnits, us-gaap:SubsequentEvent



Period End2020-05-052020-02-072019-11-052019-08-022019-04-292019-02-08
Value0.165250.33050.33050.33050.3180.318
Percentage of DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType, cnp:DividendsDistributionsChange

cnp:EnableMidstreamPartners, cnp:CommonUnits, us-gaap:SubsequentEvent, cnp:PreviousDividendorDistribution



Period End2020-04-01
Value0.3305
Percentage of DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit0.0

cnp:EnableMidstreamPartners, cnp:CommonUnits, us-gaap:SubsequentEvent, cnp:RevisedDividendorDistribution



Period End2020-04-01
Value0.16525
Percentage of DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit0.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:DividendsCash

us-gaap:RetainedEarnings, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value3211683207475125
Percentage of DividendsCash100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RetainedEarnings, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value385276601624866031
Percentage of DividendsCash1203.127600.0375.019.3120.0116.280.024.8

us-gaap:StatementClassOfStock

us-gaap:DividendsCommonStockCash

us-gaap:CommonStock



Period End2020-03-312019-10-172019-12-312019-07-312019-09-302019-04-252019-06-302019-03-312018-12-122018-10-232018-12-312018-07-262018-09-302018-04-262018-06-302018-03-312017-12-132017-10-252017-07-272017-04-272017-01-052016-10-272016-07-282016-04-282016-01-20
Value1451440145145144144144144139163120120120120120120116115115115111111111110
Percentage of DividendsCommonStockCash100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementClassOfStock, cnp:Period

us-gaap:CommonStock, cnp:FirstQuarter2020



Period End2020-03-31
Value145
Percentage of DividendsCommonStockCash100.0

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-03-312018-09-30
Value1451450120
Percentage of DividendsCommonStockCash100.0100.00.0100.0

us-gaap:StatementClassOfStock

us-gaap:DividendsPreferredStockCash

us-gaap:SeriesAPreferredStock



Period End2020-03-312019-12-312019-07-312019-09-302019-06-302019-03-312018-12-12
Value25-26242402626
Percentage of DividendsPreferredStockCash100.0100.0100.0100.00.0100.0100.0

us-gaap:SeriesBPreferredStock



Period End2020-03-312019-10-172019-12-312019-07-312019-09-302019-04-252019-06-302019-03-312018-12-122018-10-23
Value1717017171717171711
Percentage of DividendsPreferredStockCash68.0-0.00.070.870.80.00.065.465.40.0

us-gaap:StatementClassOfStock, cnp:Period

us-gaap:SeriesAPreferredStock, cnp:FirstQuarter2020



Period End2020-03-31
Value25
Percentage of DividendsPreferredStockCash100.0

us-gaap:SeriesBPreferredStock, cnp:FirstQuarter2020



Period End2020-03-31
Value17
Percentage of DividendsPreferredStockCash68.0

us-gaap:StatementClassOfStock, us-gaap:StatementEquityComponents

us-gaap:SeriesAPreferredStock, us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-30
Value25024
Percentage of DividendsPreferredStockCash100.0-0.0100.0

us-gaap:EquityMethodInvestmentDividendsOrDistributions



Period End2020-03-312019-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value707475747372707194707239
Percentage of EquityMethodInvestmentDividendsOrDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType

cnp:EnableMidstreamPartners, cnp:CommonUnits, us-gaap:SubsequentEvent



Period End2020-05-052020-02-072019-11-052019-08-022019-04-292019-02-08
Value397777777474
Percentage of EquityMethodInvestmentDividendsOrDistributions0.00.00.00.00.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents

cnp:EnableMidstreamPartners, us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value77777775747474757474747574747475747574
Percentage of EquityMethodInvestmentDividendsOrDistributions110.00.00.00.0100.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestmentOtherThanTemporaryImpairment

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312016-12-312016-09-302015-12-312015-09-302014-12-312014-09-30
Value15410001120000097525000
Percentage of EquityMethodInvestmentOtherThanTemporaryImpairment100.00.00.00.0100.0100.00.00.00.00.00.0100.0100.00.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestmentSummarizedFinancialInformationCostOfSales

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value226321263317378484516444375445349279308300268254195241287277292364439478633488458
Percentage of EquityMethodInvestmentSummarizedFinancialInformationCostOfSales100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value103912311511316512986105991048611159110358665-9857791122139120149101123
Percentage of EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestmentSummarizedFinancialInformationRevenue

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value6487316997357959509288057488067056266666146205295095666465906167358048261002825796
Percentage of EquityMethodInvestmentSummarizedFinancialInformationRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value14-129-2911-9-5129-36-95-416638-1602961-2-22
Percentage of FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value14-129-29113-42104
Percentage of FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss100.0100.0100.0100.0100.0100.0100.0-33.380.016.3-0.0-44.4

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value151413-1261-11-4134-38-66-19042500862-2-22
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value151413-12611226-27
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings100.0100.0100.0100.0100.0100.0100.0-9.1-50.019.45.3-116.7

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value104121531-4434610438115423301-1-111
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value10412-1531134610
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements100.0100.0100.0100.0-100.0100.0100.0-2.3100.0100.0100.00.0

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersIntoLevel3



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value000-2170105711-7170050100000-110
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersIntoLevel30.00.00.0100.0100.0100.00.0100.00.0100.0100.0100.0100.0100.00.00.0100.00.0100.00.00.00.00.00.0100.0100.00.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value000-217010571
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersIntoLevel30.00.00.0100.0100.0100.00.0100.00.0100.0100.0100.0

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersOutOfLevel3



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0022222-65002567-1000100010000
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersOutOfLevel30.00.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.00.00.0100.00.00.00.0100.00.00.00.00.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value0022-222-902567
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersOutOfLevel30.00.0100.0100.0-100.0100.01.40.0100.0100.0100.0100.0

us-gaap:GoodwillImpairmentLoss



Period End2020-03-312019-03-312013-09-302012-09-302011-09-30
Value185002520
Percentage of GoodwillImpairmentLoss100.00.00.0100.00.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-31
Value62
Percentage of GoodwillImpairmentLoss33.5

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-31
Value82
Percentage of GoodwillImpairmentLoss44.3

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-31
Value62
Percentage of GoodwillImpairmentLoss33.5

us-gaap:StatementBusinessSegments

cnp:IndianaElectricIntegrated



Period End2020-03-31
Value185
Percentage of GoodwillImpairmentLoss100.0

us-gaap:StatementOperatingActivitiesSegment

us-gaap:SegmentContinuingOperations



Period End2020-03-31
Value185
Percentage of GoodwillImpairmentLoss100.0

us-gaap:Range, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:IncentiveDistributionDistributionPerUnit

srt:Maximum, cnp:EnableMidstreamPartners



Period End2020-03-31
Value0.330625
Percentage of IncentiveDistributionDistributionPerUnit100.0

srt:Minimum, cnp:EnableMidstreamPartners



Period End2020-03-31
Value0.2875
Percentage of IncentiveDistributionDistributionPerUnit87.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity



Period End2020-03-312019-03-31
Value-14626
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-640000-24444523742
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity43.80.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:EnergyServices



Period End2020-03-312019-03-31
Value-6928
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity47.3107.7

cnp:InfrastructureServicesDisposalGroup



Period End2020-03-312019-03-31
Value-77-2
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity52.7-7.7

us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, dei:LegalEntity

cnp:EnergyServices, cnp:CercCorp



Period End2020-03-312019-03-31
Value-6428
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity43.8107.7

us-gaap:IncomeLossFromEquityMethodInvestments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-147517777462998158696668597244733160-934-7944352677971918037588988610757-3110
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value-147516777462998158696668597244733160-934-7944352677969886377
Percentage of IncomeLossFromEquityMethodInvestments100.094.1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.097.296.70.096.2

us-gaap:StatementBusinessSegments

cnp:MidstreamInvestments



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value-14757774628158696859
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-31
Value-236295-58-325-138509-123-193-3943218-120-11420361-80-67105-83-310-57309-137-46425366-193
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-169401-99-452-102604-110-310-29489-51
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables71.6135.9170.7139.173.9118.789.4160.674.4113.2-283.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-19-1222877-21-106-12116-9-5868
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables8.1-41.4-48.3-23.715.2-20.89.8-60.123.1-13.4377.8

us-gaap:IncreaseDecreaseInAccountsPayable



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-192191-52-262-332482-16-37-20927321-36-12222319-27-82108-5-119-208234-63-302128-33-172-52-168-68-90-125290-25-77-425
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-159153-16-187-255424-13-75-173291-24
Percentage of IncreaseDecreaseInAccountsPayable82.880.130.871.476.888.081.2202.782.8106.6-114.3

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-2101025010-16-4648
Percentage of IncreaseDecreaseInAccountsPayable1.05.2-1.9-0.0-0.61.0-0.0-27.07.7-16.8228.6

us-gaap:IncreaseDecreaseInContractWithCustomerLiability



Period End2020-03-312019-12-312019-09-30
Value-736-12
Percentage of IncreaseDecreaseInContractWithCustomerLiability100.0100.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-30
Value5-1-1
Percentage of IncreaseDecreaseInContractWithCustomerLiability-71.4-2.88.3

us-gaap:IncreaseDecreaseInDerivativeAssetsAndLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value53-2-53140-4010-643141732-7-1-14-809-1-1815110-10
Percentage of IncreaseDecreaseInDerivativeAssetsAndLiabilities100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value540-23626-381-1-60312
Percentage of IncreaseDecreaseInDerivativeAssetsAndLiabilities101.9-0.040.0116.165.095.0100.00.093.8100.050.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value00050-25-5000
Percentage of IncreaseDecreaseInDerivativeAssetsAndLiabilities0.0-0.0-0.0161.3-62.512.50.00.0-0.0

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-31
Value-13370690-38-139000-14-167713-1691043038-19019000030-4-134-11300
Percentage of IncreaseDecreaseInIncomeTaxesReceivable100.0100.00.0100.00.0100.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.0100.0100.0100.00.00.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value00-1313-5-4-142300-44
Percentage of IncreaseDecreaseInIncomeTaxesReceivable-0.00.00.018.80.010.51400.059.00.00.00.0

us-gaap:IncreaseDecreaseInMarginDepositsOutstanding



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-31
Value-21232131-19-3-11-192866-346-360-38-27245-29466113-1-12-14
Percentage of IncreaseDecreaseInMarginDepositsOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-21232131-19-3-11-192866
Percentage of IncreaseDecreaseInMarginDepositsOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

us-gaap:IncreaseDecreaseInNotesPayableRelatedParties

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value133000-1-74750-60600
Percentage of IncreaseDecreaseInNotesPayableRelatedParties100.00.00.00.0100.0100.0100.00.0100.0100.00.0

dei:LegalEntity

us-gaap:IncreaseDecreaseInNotesReceivableRelatedParties

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0-87-93-40106114000
Percentage of IncreaseDecreaseInNotesReceivableRelatedParties0.0100.0100.0100.0100.0100.00.00.00.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-481-291-22-1859790-26-107133-67-24
Percentage of IncreaseDecreaseInNotesReceivableRelatedParties0.0334.523.7462.5923.60.00.00.00.00.00.0

us-gaap:IncreaseDecreaseInOtherCurrentAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value553-11-4-1611-15-111520-8-163813-2-2121-6-1722-63-20-87-23
Percentage of IncreaseDecreaseInOtherCurrentAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value110-40-730-4-314-4
Percentage of IncreaseDecreaseInOtherCurrentAssets20.018.936.4-0.043.827.3-0.036.4-20.070.050.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-13203-5-1315-9-2-214-6
Percentage of IncreaseDecreaseInOtherCurrentAssets-260.037.7-27.3125.081.2136.460.018.2-13.370.075.0

us-gaap:IncreaseDecreaseInOtherCurrentLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value-371138-55-101-4029-1411548-2-27-91023-2-1423-410305-55-32-57-32
Percentage of IncreaseDecreaseInOtherCurrentLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-133112-13-8-2716-1119209
Percentage of IncreaseDecreaseInOtherCurrentLiabilities35.1281.831.623.67.967.555.278.61900.0133.318.8

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value8-613-7-172-9-2-932
Percentage of IncreaseDecreaseInOtherCurrentLiabilities-21.6-54.52.6-5.56.942.56.964.3-200.0-60.066.7

us-gaap:IncreaseDecreaseInOtherNoncurrentAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value-19-22-5-18-58-900312-341600011-66-6-431-9-1-2-2
Percentage of IncreaseDecreaseInOtherNoncurrentAssets100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-18-81-10120-1-1-3130
Percentage of IncreaseDecreaseInOtherNoncurrentAssets94.736.4-20.055.6-20.7-0.00.00.0-100.01300.00.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value032-7-37-2-1-1-123
Percentage of IncreaseDecreaseInOtherNoncurrentAssets-0.0-13.6-40.038.95.2-77.80.00.0-33.3-1200.0150.0

us-gaap:IncreaseDecreaseInOtherNoncurrentLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value1-3289-39-12-3655581121511298-112-2-1128813787
Percentage of IncreaseDecreaseInOtherNoncurrentLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-15-40-1-7108-544842-6
Percentage of IncreaseDecreaseInOtherNoncurrentLiabilities-1500.0125.0-12.5-77.8-25.6-66.7150.087.380.025.0-600.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value81-10-2-11144-2-3-2
Percentage of IncreaseDecreaseInOtherNoncurrentLiabilities800.0-3.1-125.0-22.22.6-8.3-38.97.3-40.0-37.5-200.0

us-gaap:IncreaseDecreaseInOverUnderEnergyRecovery



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-11-2410-20-582016-5-64551866292614328150-86-16151527-1054332-13-50-3312648-19-4-30
Percentage of IncreaseDecreaseInOverUnderEnergyRecovery100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-9-1810-20-582016-5-645518
Percentage of IncreaseDecreaseInOverUnderEnergyRecovery81.875.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value3813247431613-15-42-2810149-1534523-229-14-20-5831-7-19-27-39-422-17-3719-190-221
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-19164-192319-37-55-127
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities-2.669.266.75.4-633.3143.8146.2246.7131.03.626.7

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value11-10-1125443173326-190
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities28.9-76.9-45.833.81466.7193.853.8-220.0-61.93.689.1

us-gaap:AwardType

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:RestrictedStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value002220302032202020011011102
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements0.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestExpenseOther



Period End2020-03-312019-03-31
Value139121
Percentage of InterestExpenseOther100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-03-31
Value3029
Percentage of InterestExpenseOther21.624.0

us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination



Period End2020-03-312019-03-31
Value5041
Percentage of InterestExpenseOther36.033.9

us-gaap:ConsolidationItems, dei:LegalEntity

us-gaap:IntersegmentElimination, cnp:CercCorp



Period End2020-03-312019-03-31
Value2221
Percentage of InterestExpenseOther15.817.4

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-03-31
Value4140
Percentage of InterestExpenseOther29.533.1

cnp:IndianaElectricIntegrated



Period End2020-03-312019-03-31
Value63
Percentage of InterestExpenseOther4.32.5

cnp:MidstreamInvestments



Period End2020-03-312019-03-31
Value1412
Percentage of InterestExpenseOther10.19.9

cnp:NaturalGasDistribution



Period End2020-03-312019-03-31
Value3223
Percentage of InterestExpenseOther23.019.0

us-gaap:CorporateAndOther



Period End2020-03-312019-03-31
Value9684
Percentage of InterestExpenseOther69.169.4

us-gaap:StatementBusinessSegments, dei:LegalEntity

cnp:NaturalGasDistribution, cnp:CercCorp



Period End2020-03-312019-03-31
Value2119
Percentage of InterestExpenseOther15.115.7

us-gaap:InterestIncomeOther



Period End2020-03-312019-03-31
Value012
Percentage of InterestIncomeOther0.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-03-31
Value14
Percentage of InterestIncomeOther0.033.3

us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination



Period End2020-03-312019-03-31
Value-50-41
Percentage of InterestIncomeOther0.0-341.7

us-gaap:ConsolidationItems, dei:LegalEntity

us-gaap:IntersegmentElimination, cnp:CercCorp



Period End2020-03-312019-03-31
Value-22-21
Percentage of InterestIncomeOther0.0-175.0

us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution



Period End2020-03-312019-03-31
Value14
Percentage of InterestIncomeOther0.033.3

cnp:MidstreamInvestments



Period End2020-03-312019-03-31
Value02
Percentage of InterestIncomeOther0.016.7

us-gaap:CorporateAndOther



Period End2020-03-312019-03-31
Value4846
Percentage of InterestIncomeOther0.0383.3

us-gaap:StatementBusinessSegments, dei:LegalEntity

us-gaap:CorporateAndOther, cnp:CercCorp



Period End2020-03-312019-03-31
Value2120
Percentage of InterestIncomeOther0.0166.7

us-gaap:InterestPaidNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value148721337715462134511167212470112821248711310311494115961358112214717890186213101191117209116182
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3521332035203511393030
Percentage of InterestPaidNet23.629.224.826.022.732.326.121.633.641.724.2

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value6826902786278329612982
Percentage of InterestPaidNet45.936.167.735.155.843.561.956.952.640.366.1

us-gaap:InventoryWriteDown



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value3-1221010100000001020262000406000006
Percentage of InventoryWriteDown100.0100.0100.0100.0100.00.0100.00.0100.00.00.00.00.00.00.00.0100.00.0100.00.0100.0100.0100.00.00.00.0100.00.0100.00.00.00.00.00.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3-1221010100
Percentage of InventoryWriteDown100.0100.0100.0100.0100.00.0100.00.0100.00.00.0

us-gaap:LeaseIncome



Period End2020-03-312019-03-31
Value12
Percentage of LeaseIncome100.0100.0

us-gaap:MarketableSecuritiesGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-14476596483-8843221-97372344139772090-21-13479-17903172-30543074771346-80183219-2238144755-34
Percentage of MarketableSecuritiesGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:MarketableSecuritiesUnrealizedGainLossExcludingOtherThanTemporaryImpairments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value-14476596483-8843221-97372344139772090-21-13479-179031
Percentage of MarketableSecuritiesUnrealizedGainLossExcludingOtherThanTemporaryImpairments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:StatementEquityComponents

us-gaap:NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification

us-gaap:AccountingStandardsUpdate201613, us-gaap:RetainedEarnings



Period End2020-03-31
Value-7
Percentage of NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification100.0

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

us-gaap:AccountingStandardsUpdate201613, us-gaap:RetainedEarnings, cnp:CercCorp



Period End2020-03-31
Value-5
Percentage of NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification71.4

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value-1-7-2-2-114-1-2-1-40-1-18-11-1-15-1-2-22-2-2-1-36-3
Percentage of OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value1-20-1-14-10-1-2-2-1-15-22-1-9-10-2-1-1-2-1-20-2
Percentage of OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax

us-gaap:InterestRateContract



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0-6201-11-41-5
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax0.0100.0100.00.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, dei:LegalEntity

us-gaap:InterestRateContract, cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0.00.00.00.00.0-1000000.00.00.0
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax0.0-0.00.00.00.09.1-0.00.0

us-gaap:InterestRateContract, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0-2001-10-30
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax0.033.30.00.0100.090.975.00.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0-20-13-14
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent0.0100.00.0100.0100.0100.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value000-1304
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent0.0-0.00.0100.0100.0-0.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.00.00.00.0-1000000.00.01000000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax0.00.00.00.0100.00.0100.0

dei:LegalEntity

cnp:HoustonElectric



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.00.00.00.01000000.00.01000000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax0.00.00.00.0-100.00.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.00.00.0-1000000.00.00.00.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax0.00.00.0100.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.00.00.01000000.00.00.00.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax0.00.00.0100.00.00.00.0

us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-29-221-35415
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncome, cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0000-1-2130
Percentage of OtherComprehensiveIncomeLossNetOfTax-0.00.0-0.00.0-100.060.075.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-06-302010-03-31
Value-29-221-354154-210-73-2115122-122132333223223
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

cnp:CercCorp



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value050000000
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent-0.055.6-0.00.00.0-0.00.00.00.0

cnp:HoustonElectric



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value0000-1-21304000
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent-0.00.0-0.00.0-100.060.075.00.080.00.0-0.00.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-30
Value-2-2-2-2-2-1-2-1-2-2-2-1-2-3-2-1-2-3-1-2-4-2-3-2-4
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossTaxPortionAttributableToParent1



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value11011