WEC


Line plots across dimensions of each concept
Tables

Table of contents



us-gaap:CommonStockValue

us-gaap:CommonStockSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare
us-gaap:MajorCustomers, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues
us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofNonUtilityOperatingRevenues, wec:TypesofOperatingRevenues
us-gaap:ProductOrService, wec:TypesofNonUtilityOperatingRevenues, wec:TypesofOperatingRevenues
us-gaap:ProductOrService, wec:TypesofOperatingRevenues
us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues
us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues
wec:TypesofOperatingRevenues

us-gaap:Revenues
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues
us-gaap:ProductOrService, wec:TypesofOperatingRevenues
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues
wec:TypesofOperatingRevenues

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostsAndExpenses
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:OperatingIncomeLoss
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:InterestExpense
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:NonoperatingIncomeExpense
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxesPaidNet

us-gaap:ProfitLoss

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:NetIncomeLoss

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents

us-gaap:Assets
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:LiabilitiesAndStockholdersEquity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StockholdersEquity

us-gaap:AssetsCurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:AccountsReceivableNetCurrent

us-gaap:OtherAssetsCurrent

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures

us-gaap:Goodwill
us-gaap:StatementBusinessSegments

us-gaap:OtherAssetsNoncurrent

us-gaap:LiabilitiesCurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:AccountsPayableCurrent

us-gaap:OtherLiabilitiesCurrent

us-gaap:LiabilitiesNoncurrent
us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebt
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:LongTermDebtNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StockholdersEquity

us-gaap:CommonStockValue

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:NetIncomeLoss

us-gaap:ProfitLoss

us-gaap:DepreciationDepletionAndAmortization
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInInventories

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:RepaymentsOfLongTermDebt

us-gaap:EffectiveIncomeTaxRateContinuingOperations
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
us-gaap:AwardType, us-gaap:SubsequentEventType

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries
us-gaap:StatementBusinessSegments

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs
us-gaap:StatementBusinessSegments

us-gaap:CapitalExpendituresIncurredButNotYetPaid

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CommonStockDividendsPerShareDeclared
us-gaap:SubsequentEventType
wec:TypesofNonUtilityOperatingRevenues
us-gaap:ContractWithCustomerLiabilityRevenueRecognized

us-gaap:DeferredIncomeTaxesAndTaxCredits
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost

us-gaap:DerivativeGainLossOnDerivativeNet
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeNonmonetaryNotionalAmountEnergyMeasure

us-gaap:DividendsCommonStockCash
us-gaap:StatementEquityComponents

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate

us-gaap:EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments

us-gaap:EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount

us-gaap:EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent

us-gaap:EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes

us-gaap:EffectiveIncomeTaxRateReconciliationTaxCreditsOther

us-gaap:EquityMethodInvestmentDividendsOrDistributions
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements

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

us-gaap:IncomeTaxReconciliationChangeInEnactedTaxRate

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

us-gaap:IncomeTaxReconciliationOtherAdjustments

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes

us-gaap:IncomeTaxReconciliationTaxCreditsOther

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInOtherCurrentAssets

us-gaap:IncreaseDecreaseInOtherCurrentLiabilities

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities
us-gaap:StatementBusinessSegments

us-gaap:InterestPaidNet
us-gaap:ConsolidatedEntities, us-gaap:DerivativeInstrumentRisk
us-gaap:InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax

us-gaap:OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax

us-gaap:OtherCostAndExpenseOperating
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsOfDividendsCommonStock

us-gaap:PaymentsToAcquireBusinessTwoNetOfCashAcquired

us-gaap:PaymentsToAcquireInterestInSubsidiariesAndAffiliates

us-gaap:PensionAndOtherPostretirementBenefitContributions
us-gaap:RetirementPlanType

us-gaap:ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:DebtInstrument, us-gaap:SubsequentEventType, dei:LegalEntity
us-gaap:ProceedsFromIssuanceOfDebt

us-gaap:ProceedsFromLifeInsurancePolicies

us-gaap:ProceedsFromOtherShortTermDebt
us-gaap:ShortTermDebtType

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromSaleOfRestrictedInvestments

us-gaap:ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets

us-gaap:ProceedsFromStockOptionsExercised

us-gaap:ProvisionForDoubtfulAccounts
us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty

us-gaap:RepaymentsOfCommercialPaper
us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues
us-gaap:RevenueNotFromContractWithCustomer
wec:TypesofOperatingRevenues
wec:TypesofOperatingRevenues, wec:TypesofOtherOperatingRevenues
us-gaap:AwardType, us-gaap:SubsequentEventType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
us-gaap:AwardType, us-gaap:SubsequentEventType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid
us-gaap:AwardType, us-gaap:SubsequentEventType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
us-gaap:AwardType, us-gaap:SubsequentEventType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
us-gaap:AwardType, us-gaap:SubsequentEventType
us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised
us-gaap:StatementEquityComponents

us-gaap:StockRepurchasedDuringPeriodValue
us-gaap:StatementEquityComponents

us-gaap:StockholdersEquityOther
us-gaap:StatementEquityComponents

us-gaap:TaxesExcludingIncomeAndExciseTaxes
us-gaap:ConsolidatedEntities, us-gaap:DerivativeInstrumentRisk
us-gaap:UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss

wec:CapitalContributions
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:EffectiveIncomeTaxReconciliationTaxexpensebenefitfederalexcessdeferredtaxamortizationWisconsinunprotected

wec:EffectiveIncomeTaxreconciliationFederalexcessdeferredtaxamortizationWIUnprotectedpercent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
wec:RelatedPartyTransactionChargesToRelatedParty
us-gaap:AwardType, us-gaap:SubsequentEventType
wec:Taxbenefitfromawardsotherthanoptions

wec:Taxrepairsamount

wec:Taxrepairspercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:AccountsPayableRelatedPartiesCurrentAndNoncurrent

us-gaap:AccountsReceivableGross
us-gaap:StatementBusinessSegments

us-gaap:AccountsReceivableNet
us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:AccountsReceivableRelatedPartiesCurrent
us-gaap:ProductOrService, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:AccrualForEnvironmentalLossContingencies

us-gaap:AccruedEnvironmentalLossContingenciesNoncurrent

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:AllowanceForDoubtfulAccountsReceivable
us-gaap:StatementBusinessSegments

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

us-gaap:AssetsNoncurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ShortTermDebtType
us-gaap:CommercialPaper

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredRevenueNoncurrent
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear

us-gaap:DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset

us-gaap:DerivativeAssets

us-gaap:DerivativeCollateralRightToReclaimCash

us-gaap:DerivativeInstrumentsAndHedges
us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent
us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeInstrumentsAndHedgesNoncurrent
us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeLiabilities

us-gaap:DerivativeLiabilityCollateralRightToReclaimCashOffset

us-gaap:DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset

us-gaap:DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency

us-gaap:EmployeeRelatedLiabilitiesCurrent

us-gaap:EnergyRelatedInventory

us-gaap:EnergyRelatedInventoryNaturalGasInStorage

us-gaap:EnergyRelatedInventoryOtherFossilFuel
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:EquityMethodInvestmentOwnershipPercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestments
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:EquitySecuritiesFvNiRestricted
us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
us-gaap:FairValueByMeasurementBasis
us-gaap:FinanceLeaseLiability

us-gaap:GuaranteeObligationsMaximumExposure
us-gaap:GuaranteeObligationsByNature
us-gaap:GuaranteeObligationsByNature, dei:LegalEntity

us-gaap:InventoryRawMaterialsAndSuppliesNetOfReserves

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility

us-gaap:LongTermDebtAndCapitalLeaseObligations

us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent

us-gaap:OtherMinorityInterests
us-gaap:ShortTermDebtType
us-gaap:OtherShortTermBorrowings

us-gaap:PreferredStockValue
us-gaap:FairValueByMeasurementBasis

us-gaap:PrepaidExpenseCurrent

us-gaap:RegulatoryAssets
us-gaap:ProductOrService, us-gaap:LossContingenciesByNatureOfContingency, us-gaap:RegulatoryAsset
us-gaap:RegulatoryAsset

us-gaap:RegulatoryAssetsCurrent

us-gaap:RegulatoryAssetsNoncurrent

us-gaap:RegulatoryLiabilities
us-gaap:RegulatoryLiability

us-gaap:RegulatoryLiabilityCurrent

us-gaap:RegulatoryLiabilityNoncurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:RelatedPartyTransactionDueFromToRelatedParty

us-gaap:RestrictedCashNoncurrent

us-gaap:ShortTermBorrowings
us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtWeightedAverageInterestRate

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents

wec:AccountsReceivablePastDueGreaterthan90Days
us-gaap:StatementBusinessSegments
us-gaap:BusinessAcquisition, dei:LegalEntity
wec:Acquisitionpurchaseprice
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType, dei:LegalEntity
us-gaap:BusinessAcquisition, dei:LegalEntity
wec:Additionalownershipinterestacquired
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType, dei:LegalEntity
us-gaap:BusinessAcquisition, dei:LegalEntity
wec:Bonusdepreciationpercentage
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType
us-gaap:BusinessAcquisition, dei:LegalEntity
wec:CapacityOfGenerationUnit
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType

wec:DerivativeInstrumentsAndHedgesLiabilitiesGrossCurrent
us-gaap:DerivativeInstrumentRisk

wec:GuaranteeObligationsMaximumExposureExpireLessThanOneYear
us-gaap:GuaranteeObligationsByNature

wec:GuaranteeObligationsMaximumExposureExpireOverThreeYears
us-gaap:GuaranteeObligationsByNature

wec:GuaranteeObligationsMaximumExposureExpireWithinOneToThreeYears
us-gaap:GuaranteeObligationsByNature
us-gaap:BusinessAcquisition, dei:LegalEntity
wec:Ownershipinterestofwindgeneratingfacilityacquired
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType, dei:LegalEntity

wec:Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect
us-gaap:StatementBusinessSegments

wec:TotalCommonShareholdersEquity

Tables

  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
us-gaap:CommonStockValue ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁█▅▅▅▅▅▄▄▄▄▄333333333333333333384564510441943984367432241984195420341474081
us-gaap:CommonStockSharesOutstanding ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄315315315315315315315315315315315315315315315315315315315NANA225NANANANANANANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding 316NA316316316NA316316316NA317317317NA316317317NA317229227NA227227227228230231232233
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic 315NA315315315NA315315315NA315315315NA315315315NA315227225NA225225225226228228230230
us-gaap:IncomeLossFromContinuingOperationsPerBasicShare 1.43NA0.740.751.33NA0.740.731.24NA0.680.631.13NA0.690.571.1NA0.580.360.87NA0.560.590.920.610.520.770.680.52
us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare 1.43NA0.740.741.33NA0.740.731.23NA0.680.631.12NA0.680.571.09NA0.580.350.86NA0.560.580.910.60.520.760.670.51
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService,wec:TypesofOperatingRevenues wec:CommercialandIndustrialCustomer,us-gaap:NaturalGasUsRegulated,wec:Illinois,us-gaap:TransferredOverTime,us-gaap:RevenueFromContractWithCustomer▆▄▁▂█▅▁▂▇91712945116802947109NANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService,wec:TypesofOperatingRevenues wec:CommercialandIndustrialCustomer,us-gaap:NaturalGasUsRegulated,wec:OtherStates,us-gaap:TransferredOverTime,us-gaap:RevenueFromContractWithCustomer▆▅▁▂█▅▁▂▇514411207244121864NANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService,wec:TypesofOperatingRevenues wec:CommercialandIndustrialCustomer,us-gaap:NaturalGasUsRegulated,wec:PublicUtility,us-gaap:TransferredOverTime,us-gaap:RevenueFromContractWithCustomer294NANANA387NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService,wec:TypesofOperatingRevenues wec:CommercialandIndustrialCustomer,us-gaap:NaturalGasUsRegulated,wec:Wisconsin,us-gaap:TransferredOverTime,us-gaap:RevenueFromContractWithCustomer▆▅▁▂█▆▁▂█15113430551991503563187NANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService,wec:TypesofOperatingRevenues wec:DowntownMilwaukeeSteamCustomers,us-gaap:ElectricityUsRegulated,wec:Wisconsin,us-gaap:TransferredOverTime,us-gaap:RevenueFromContractWithCustomer▆▄▁▃█▅▁▃▇8624107249NANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService,wec:TypesofOperatingRevenues wec:Largecommercialandindustrialcustomers,us-gaap:ElectricityUsRegulated,wec:Wisconsin,us-gaap:TransferredOverTime,us-gaap:RevenueFromContractWithCustomer▁▂▆▄▃▄█▇▂194203237217212217249241203NANANANANANANANANANANANANANANANANANANANANA
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
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us-gaap:NetCashProvidedByUsedInFinancingActivities ▂▄▃▃▂▄▄▃▁▄▃▄▂▃▃▂▁▄▃█▂▃▃▂▂-24427194-94-186333216-78-44537531135-38059-112-270-522251-1321285-17038-42-156-244NANA-195NANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
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 us-gaap:DepreciationDepletionAndAmortization us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:PublicUtilities,wec:Illinois█▇▆▆▆▆▅▃▃▃▁4746454544444341404038NANANANANANANANANANANANANANANANANANANA
 us-gaap:DepreciationDepletionAndAmortization us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:PublicUtilities,wec:Wisconsin█▆▆▅▅▃▂▂▂▁▁165157155152151139137134135132131NANANANANANANANANANANANANANANANANANANA
 us-gaap:DepreciationDepletionAndAmortization us-gaap:StatementBusinessSegments wec:NonUtilityEnergyInfrastructure█▇▇▆▆▄▃▂▂▂▂▁▁▁▁242323222220191818181817171717NANANANANANANANANANANANANANANA
us-gaap:IncreaseDecreaseInInventories ▂▄▇▇▁▄▇▇▂▃█▇▂▄█▅▁▄█▆▃▅▆▆▃-158-43131131-218-6014190-163-13316292-170-6615923-217-3217338-110217569-94NANA-93NANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
us-gaap:NetCashProvidedByUsedInInvestingActivities ▆▅▅▆▆▅▅▆▇▅▆▅▇▆▇▇█▇▇▁█████-463-760-668-459-606-664-723-561-435-702-528-698-325-512-392-260-188-326-416-1522-156-227-216-173-139NANA-145NANA
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▄█▅▄▃▇▅▄▃▅▄▄▃▃▃▂▂▄▃▂▁▂▂▁▁▁▁▁▁▁4961017656496358926575475439650519460329423381306312501408207149223207176129190173133163171
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
us-gaap:NetCashProvidedByUsedInFinancingActivities ▂▄▃▃▂▄▄▃▁▄▃▄▂▃▃▂▁▄▃█▂▃▃▂▂-24427194-94-186333216-78-44537531135-38059-112-270-522251-1321285-17038-42-156-244NANA-195NANA
us-gaap:ProceedsFromIssuanceOfLongTermDebt ▁▅▇▁▃█▁▅▁▂▁057597003501140060002250NANA200200NANA500200NANA002500NANA0NANA
us-gaap:RepaymentsOfLongTermDebt ▁▄▂▁▁▄▁█▁▂▁▁▁▂▁▂▂▆▁▁▁▁▁▄▁1425488413258136681212712212521110213950215292103028NANA8NANA
us-gaap:PaymentsForRepurchaseOfCommonStock ▅▁▄▄█▄▃▁▂▂▃▃▃▁▂▄▇▂▄▂▃▅▄▁▆40131357030224151020192021134598348233926452NANA66NANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
us-gaap:RepaymentsOfLongTermDebt ▁▄▂▁▁▄▁█▁▂▁▁▁▂▁▂▂▆▁▁▁▁▁▄▁1425488413258136681212712212521110213950215292103028NANA8NANA

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-312006-12-31
Value333333333333333333384564510441943984367432242334198419542034135414740814051396339403947390438023727367736413566333630992888
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.029.629.829.129.929.929.228.729.229.329.428.930.029.429.328.629.730.229.629.129.329.028.628.126.40.00.0

Common Stock Par Or Stated Value Per Share

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value315315315315315315315315315315315315315315315315315315315225225229230116116
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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
Value316316316316316316316317317317316317317317229227227227227228230231232233233234236236118118118118117118
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
Value315315315315315315315315315315315315315315227225225225225226228228230230230232233233116116116116116116
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

Earnings Per Share Diluted

Income Loss From Continuing Operations Per Basic Share

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value1.430.740.751.330.740.731.240.680.631.130.690.571.10.580.360.870.560.590.920.610.520.770.680.520.750.560.420.731.080.960.751.110.980.50.541.21
Percentage of IncomeLossFromContinuingOperationsPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Diluted Share

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value1.430.740.741.330.740.731.230.680.631.120.680.571.090.580.350.860.560.580.910.60.520.760.670.510.740.550.410.721.060.950.741.10.97000000000000020.490.531.2
Percentage of IncomeLossFromContinuingOperationsPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:MajorCustomers, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

wec:CommercialandIndustrialCustomer, us-gaap:NaturalGasUsRegulated, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value91712945116802947109
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.33.71.82.84.93.91.82.84.8
Percentage of Revenues wec:CommercialandIndustrialCustomer us-gaap:NaturalGasUsRegulated wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:CommercialandIndustrialCustomer, us-gaap:NaturalGasUsRegulated, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value514411207244121864
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax56.662.939.245.562.054.542.939.559.1
Percentage of Revenues2.52.30.71.33.02.10.81.12.8
Percentage of Revenues wec:CommercialandIndustrialCustomer us-gaap:NaturalGasUsRegulated wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:CommercialandIndustrialCustomer, us-gaap:NaturalGasUsRegulated, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-03-31
Value294387
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax322.1333.8
Percentage of Revenues14.016.3
Percentage of Revenues wec:CommercialandIndustrialCustomer us-gaap:NaturalGasUsRegulated wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.0

wec:CommercialandIndustrialCustomer, us-gaap:NaturalGasUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value15113430551991503563187
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax165.5189.0102.4123.7171.9186.0119.0134.2171.8
Percentage of Revenues7.26.91.93.58.47.22.13.88.2
Percentage of Revenues wec:CommercialandIndustrialCustomer us-gaap:NaturalGasUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:DowntownMilwaukeeSteamCustomers, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8624107249
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.29.18.29.58.78.99.29.58.9
Percentage of Revenues0.40.30.10.30.40.30.20.30.4
Percentage of Revenues wec:DowntownMilwaukeeSteamCustomers us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Largecommercialandindustrialcustomers, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value194203237217212217249241203
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax212.9286.8811.9482.9182.7268.6849.3510.8186.4
Percentage of Revenues9.210.514.813.78.910.415.214.48.9
Percentage of Revenues wec:Largecommercialandindustrialcustomers us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Otherretailcustomer, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value776777777
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.010.723.516.26.79.325.515.27.0
Percentage of Revenues0.30.40.40.50.30.40.50.40.3
Percentage of Revenues wec:Otherretailcustomer us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Otherutility, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value881510213202
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.312.452.223.32.217.07.50.82.5
Percentage of Revenues0.40.51.00.70.10.70.10.00.1
Percentage of Revenues wec:Otherutility us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Otherutility, us-gaap:NaturalGasUsRegulated, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-13-5-1-13-121478-12
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-14.7-7.3-4.1-29.3-11.017.926.517.3-11.1
Percentage of Revenues-0.6-0.3-0.1-0.8-0.50.70.50.5-0.5
Percentage of Revenues wec:Otherutility us-gaap:NaturalGasUsRegulated wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Otherutility, us-gaap:NaturalGasUsRegulated, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-17-54-2-23485-25
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-19.4-8.314.3-4.7-19.95.728.211.6-22.9
Percentage of Revenues-0.8-0.30.3-0.1-1.00.20.50.3-1.1
Percentage of Revenues wec:Otherutility us-gaap:NaturalGasUsRegulated wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Otherutility, us-gaap:NaturalGasUsRegulated, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-604013-766242-84
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-66.4137.930.6-65.8213.389.0-77.5
Percentage of Revenues-2.92.50.9-3.23.82.5-3.7
Percentage of Revenues wec:Otherutility us-gaap:NaturalGasUsRegulated wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0

wec:Otherutility, us-gaap:NaturalGasUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-29-323729-40-184628-47
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-32.4-45.3127.664.5-34.9-23.3158.560.0-43.5
Percentage of Revenues-1.4-1.72.31.8-1.7-0.92.81.7-2.1
Percentage of Revenues wec:Otherutility us-gaap:NaturalGasUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:ResaleCustomers, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value454329494052402573
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax49.561.0100.7109.535.165.1138.453.167.5
Percentage of Revenues2.12.21.83.11.72.52.51.53.2
Percentage of Revenues wec:ResaleCustomers us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Residentialcustomer, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value404390454356406393465393384
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax443.0549.21551.9790.9350.0486.41582.7832.3351.3
Percentage of Revenues19.220.128.322.417.118.928.323.516.8
Percentage of Revenues wec:Residentialcustomer us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Residentialcustomer, us-gaap:NaturalGasUsRegulated, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value282232117154354268112163332
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax309.5326.4401.4341.7304.6332.3383.3346.1304.0
Percentage of Revenues13.411.97.39.714.912.96.99.814.5
Percentage of Revenues wec:Residentialcustomer us-gaap:NaturalGasUsRegulated wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Residentialcustomer, us-gaap:NaturalGasUsRegulated, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value95712239125822037123
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax104.3100.176.887.1107.7101.668.480.1112.6
Percentage of Revenues4.53.71.42.55.34.01.22.35.4
Percentage of Revenues wec:Residentialcustomer us-gaap:NaturalGasUsRegulated wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Residentialcustomer, us-gaap:NaturalGasUsRegulated, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-03-31
Value691863
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax756.3742.8
Percentage of Revenues32.836.3
Percentage of Revenues wec:Residentialcustomer us-gaap:NaturalGasUsRegulated wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.0

wec:Residentialcustomer, us-gaap:NaturalGasUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3132586912638327771128356
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax342.6363.6236.5279.8330.4343.8244.6270.8326.1
Percentage of Revenues14.813.34.37.916.113.44.47.715.6
Percentage of Revenues wec:Residentialcustomer us-gaap:NaturalGasUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Smallcommercialandindustrial, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value323333385331333336388353330
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax354.0469.51316.0734.6287.3416.31320.4746.9302.3
Percentage of Revenues15.317.124.020.814.016.223.621.114.5
Percentage of Revenues wec:Smallcommercialandindustrial us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:TotalRetailCustomers, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value93093510859139609531110995926
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1017.91316.23703.42024.6826.81180.63777.92105.3847.0
Percentage of Revenues44.148.167.557.440.445.967.659.540.5
Percentage of Revenues wec:TotalRetailCustomers us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:TotalRetailCustomers, us-gaap:NaturalGasUsRegulated, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value374303146199470349142211442
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax409.5426.4501.4441.7404.6432.3483.3446.1404.0
Percentage of Revenues17.815.69.112.519.816.88.612.619.3
Percentage of Revenues wec:TotalRetailCustomers us-gaap:NaturalGasUsRegulated wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:TotalRetailCustomers, us-gaap:NaturalGasUsRegulated, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value14711534591971263256187
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax160.8163.0116.0132.6169.7156.1111.2119.7171.8
Percentage of Revenues7.06.02.13.88.36.12.03.48.2
Percentage of Revenues wec:TotalRetailCustomers us-gaap:NaturalGasUsRegulated wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:TotalRetailCustomers, us-gaap:NaturalGasUsRegulated, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-03-31
Value9851251
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1078.41076.6
Percentage of Revenues46.752.6
Percentage of Revenues wec:TotalRetailCustomers us-gaap:NaturalGasUsRegulated wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.0

wec:TotalRetailCustomers, us-gaap:NaturalGasUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value46439299182583428106191544
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax508.1552.6338.9403.5502.2529.8363.6405.1497.8
Percentage of Revenues22.020.26.211.424.520.66.511.523.8
Percentage of Revenues wec:TotalRetailCustomers us-gaap:NaturalGasUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Transportationcustomers, us-gaap:NaturalGasUsRegulated, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value726744468768435477
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax79.594.2151.2103.875.084.8147.3115.471.0
Percentage of Revenues3.43.42.82.93.73.32.63.33.4
Percentage of Revenues wec:Transportationcustomers us-gaap:NaturalGasUsRegulated wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Transportationcustomers, us-gaap:NaturalGasUsRegulated, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value108561110469
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.512.119.114.09.612.616.714.49.0
Percentage of Revenues0.50.40.30.40.50.50.30.40.4
Percentage of Revenues wec:Transportationcustomers us-gaap:NaturalGasUsRegulated wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Transportationcustomers, us-gaap:NaturalGasUsRegulated, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-03-31
Value107120
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax117.4103.4
Percentage of Revenues5.15.1
Percentage of Revenues wec:Transportationcustomers us-gaap:NaturalGasUsRegulated wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.0

wec:Transportationcustomers, us-gaap:NaturalGasUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value242014162119131621
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.428.349.135.918.824.147.334.719.2
Percentage of Revenues1.11.00.91.00.90.90.81.00.9
Percentage of Revenues wec:Transportationcustomers us-gaap:NaturalGasUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Wholesalecustomer, us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value424453444734625854
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.162.0181.298.941.043.1210.9123.550.2
Percentage of Revenues2.02.33.32.82.01.73.83.52.4
Percentage of Revenues wec:Wholesalecustomer us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues

us-gaap:ElectricityUsRegulated, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value103410381185102110611062121810841067
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1131.91460.84045.72265.9913.81314.64143.92292.2976.0
Percentage of Revenues49.153.373.764.344.751.174.164.846.7
Percentage of Revenues us-gaap:ElectricityUsRegulated wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:ElectricityUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value103410381185102110611062121810841067
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1131.91460.84045.72265.9913.81314.64143.92292.2976.0
Percentage of Revenues49.153.373.764.344.751.174.164.846.7
Percentage of Revenues us-gaap:ElectricityUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:NaturalGasUsRegulated, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value433365190232544432193273507
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax474.4513.4648.5516.2468.7535.0657.1578.9464.0
Percentage of Revenues20.618.711.814.622.920.811.816.422.2
Percentage of Revenues us-gaap:NaturalGasUsRegulated wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:NaturalGasUsRegulated, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value13911843641851404568172
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax153.0166.8149.5141.9159.4174.4156.1145.7157.9
Percentage of Revenues6.66.12.74.07.86.82.84.17.6
Percentage of Revenues us-gaap:NaturalGasUsRegulated wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:NaturalGasUsRegulated, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1032864384524129410024065791198
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1129.41215.81313.71162.11114.21240.11382.71224.31095.3
Percentage of Revenues49.044.423.933.054.548.224.734.652.4
Percentage of Revenues us-gaap:NaturalGasUsRegulated wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:NaturalGasUsRegulated, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value458380151227564428167236518
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax502.1535.6515.7504.0486.1530.7569.4499.8473.5
Percentage of Revenues21.819.69.414.323.820.610.214.122.7
Percentage of Revenues us-gaap:NaturalGasUsRegulated wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value433365190232544432193273507
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax474.4513.4648.5516.2468.7535.0657.1578.9464.0
Percentage of Revenues20.618.711.814.622.920.811.816.422.2
Percentage of Revenues us-gaap:PublicUtilities wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value13911843641851404568172
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax153.0166.8149.5141.9159.4174.4156.1145.7157.9
Percentage of Revenues6.66.12.74.07.86.82.84.17.6
Percentage of Revenues us-gaap:PublicUtilities wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value206619031570154623562064162416632266
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2261.42676.55359.43427.92028.02554.75526.53516.52071.3
Percentage of Revenues98.097.797.797.299.199.498.999.499.1
Percentage of Revenues us-gaap:PublicUtilities wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value149314191336124916261491138513201585
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1634.01996.34561.42769.81399.91845.34713.32792.01449.5
Percentage of Revenues70.872.983.178.668.471.884.379.069.4
Percentage of Revenues us-gaap:PublicUtilities wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Othernonutilityrevenues, wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.00.00.0100000.00.0100000.0100000.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.00.00.00.10.00.30.20.0
Percentage of Revenues0.00.00.00.00.00.00.00.00.0
Percentage of Revenues wec:Othernonutilityrevenues wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Othernonutilityrevenues, wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value444444433
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.85.814.39.33.55.313.68.23.6
Percentage of Revenues0.20.20.30.30.20.20.20.20.2
Percentage of Revenues wec:Othernonutilityrevenues wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Othernonutilityrevenues, wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value444444443
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.85.814.39.33.65.313.98.53.6
Percentage of Revenues0.20.20.30.30.20.20.20.20.2
Percentage of Revenues wec:Othernonutilityrevenues wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues

us-gaap:NaturalGasUsRegulated, srt:ConsolidationEliminations, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-14-8-9-14-12-12
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-15.4-28.7-20.2-12.7-43.2-26.8
Percentage of Revenues-0.7-0.5-0.6-0.6-0.8-0.8
Percentage of Revenues us-gaap:NaturalGasUsRegulated srt:ConsolidationEliminations us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.0

us-gaap:NaturalGasUsRegulated, wec:NonUtilityEnergyInfrastructure, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1412891610101014
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax15.917.330.421.714.113.034.021.113.6
Percentage of Revenues0.70.60.60.60.70.50.60.60.7
Percentage of Revenues us-gaap:NaturalGasUsRegulated wec:NonUtilityEnergyInfrastructure us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, srt:ConsolidationEliminations, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-14-8-9-14-12-12
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-15.4-28.7-20.2-12.7-43.2-26.8
Percentage of Revenues-0.7-0.5-0.6-0.6-0.8-0.8
Percentage of Revenues us-gaap:PublicUtilities srt:ConsolidationEliminations us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:NonUtilityEnergyInfrastructure, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1412891610101014
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax15.917.330.421.714.113.034.021.113.6
Percentage of Revenues0.70.60.60.60.70.50.60.60.7
Percentage of Revenues us-gaap:PublicUtilities wec:NonUtilityEnergyInfrastructure us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Othernonutilityrevenues, srt:ConsolidationEliminations, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-10-300-3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.8-2.4-6.9-0.6-2.4-6.6
Percentage of Revenues-0.1-0.0-0.2-0.0-0.0-0.2
Percentage of Revenues wec:Othernonutilityrevenues srt:ConsolidationEliminations us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.0

wec:Othernonutilityrevenues, us-gaap:CorporateAndOther, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value001011221
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.40.64.41.81.31.97.85.91.2
Percentage of Revenues0.00.00.10.10.10.10.10.20.1
Percentage of Revenues wec:Othernonutilityrevenues us-gaap:CorporateAndOther us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

wec:Othernonutilityrevenues, wec:NonUtilityEnergyInfrastructure, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value161412151310797
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.920.541.033.911.412.726.919.76.5
Percentage of Revenues0.80.70.71.00.60.50.50.60.3
Percentage of Revenues wec:Othernonutilityrevenues wec:NonUtilityEnergyInfrastructure us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofNonUtilityOperatingRevenues, wec:TypesofOperatingRevenues

wec:Othernonutilityrevenues, us-gaap:TransferredOverTime, naics:ZZ811412, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value444444433
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.85.814.39.33.55.113.68.23.6
Percentage of Revenues0.20.20.30.30.20.20.20.20.2
Percentage of Revenues wec:Othernonutilityrevenues us-gaap:TransferredOverTime naics:ZZ811412 us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

wec:Othernonutilityrevenues, us-gaap:TransferredOverTime, us-gaap:AlternativeEnergy, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-03-31
Value96
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax10.25.3
Percentage of Revenues0.40.3
Percentage of Revenues wec:Othernonutilityrevenues us-gaap:TransferredOverTime us-gaap:AlternativeEnergy us-gaap:RevenueFromContractWithCustomer0.00.0

us-gaap:ProductOrService, wec:TypesofNonUtilityOperatingRevenues, wec:TypesofOperatingRevenues

wec:Othernonutilityrevenues, wec:Distributedrenewablesolarprojectrevenues, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value001011221
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.40.64.41.81.32.07.85.91.2
Percentage of Revenues0.00.00.10.10.10.10.10.20.1
Percentage of Revenues wec:Othernonutilityrevenues wec:Distributedrenewablesolarprojectrevenues us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

wec:Othernonutilityrevenues, wec:Other, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.0100000.00.00.0100000.00.0100000.0100000.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.10.00.00.10.00.30.20.0
Percentage of Revenues0.00.00.00.00.00.00.00.00.0
Percentage of Revenues wec:Othernonutilityrevenues wec:Other us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.00.0

wec:Othernonutilityrevenues, wec:WePowerrevenues, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value56666666
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.021.814.05.57.821.813.15.9
Percentage of Revenues0.30.40.40.30.30.40.40.3
Percentage of Revenues wec:Othernonutilityrevenues wec:WePowerrevenues us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.0100.0100.0

us-gaap:ProductOrService, wec:TypesofOperatingRevenues

us-gaap:ElectricityUsRegulated, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value103410381185102110611062121810841067
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1131.91460.84045.72265.9913.81314.64143.92292.2976.0
Percentage of Revenues49.153.373.764.344.751.174.164.846.7
Percentage of Revenues us-gaap:ElectricityUsRegulated us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:NaturalGasUsRegulated, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1032864385524129610044035761210
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1129.91216.31315.41163.61115.71242.61373.51218.61106.7
Percentage of Revenues49.044.424.033.054.548.324.634.552.9
Percentage of Revenues us-gaap:NaturalGasUsRegulated us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value206719031570154623582066162216602278
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2261.82677.15361.13429.52029.42557.25517.33510.82082.6
Percentage of Revenues98.097.797.797.399.299.598.799.399.6
Percentage of Revenues us-gaap:PublicUtilities us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Othernonutilityrevenues, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value191716171814131311
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax21.425.257.338.115.718.346.327.510.6
Percentage of Revenues0.90.91.01.10.80.70.80.80.5
Percentage of Revenues wec:Othernonutilityrevenues us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues

wec:Illinois, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value433365190232544432193273507
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax474.4513.4648.5516.2468.8535.0657.5579.1464.0
Percentage of Revenues20.618.711.814.622.920.811.816.422.2
Percentage of Revenues wec:Illinois us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:OtherStates, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value14412248681891454972176
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax157.8172.6163.8151.2162.9179.7169.7153.9161.4
Percentage of Revenues6.86.33.04.38.07.03.04.47.7
Percentage of Revenues wec:OtherStates us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:PublicUtility, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value207119071574155023602068162816672269
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2266.22682.35373.73437.32031.62560.05540.53524.92074.9
Percentage of Revenues98.297.997.997.599.399.699.199.799.3
Percentage of Revenues wec:PublicUtility us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

wec:Wisconsin, us-gaap:TransferredOverTime, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value149314191336124916261491138513201585
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1634.01996.34561.42769.81399.91845.34713.32792.01449.5
Percentage of Revenues70.872.983.178.668.471.884.379.069.4
Percentage of Revenues wec:Wisconsin us-gaap:TransferredOverTime us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.00.00.0

us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues

srt:ConsolidationEliminations, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-15-9-12-15-13-15
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-17.2-31.1-27.1-13.3-45.6-33.4
Percentage of Revenues-0.7-0.6-0.8-0.6-0.8-0.9
Percentage of Revenues srt:ConsolidationEliminations us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.0

us-gaap:CorporateAndOther, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value001011221
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.40.64.41.81.31.97.85.91.2
Percentage of Revenues0.00.00.10.10.10.10.10.20.1
Percentage of Revenues us-gaap:CorporateAndOther us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

wec:NonUtilityEnergyInfrastructure, us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value302620252920171922
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax33.837.871.355.725.625.760.940.820.1
Percentage of Revenues1.51.41.31.61.21.01.11.21.0
Percentage of Revenues wec:NonUtilityEnergyInfrastructure us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

wec:TypesofOperatingRevenues

us-gaap:RevenueFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value208619211587156323762081163516732290
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2283.32702.35418.43467.62045.22575.55563.63538.32093.2
Percentage of Revenues99.098.798.798.3100.0100.299.5100.1100.2
Percentage of Revenues us-gaap:RevenueFromContractWithCustomer0.00.00.00.00.00.00.0100.0100.0

Revenues

us-gaap:Revenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value2108194716081590237720761643167222862055165716312304196317121602219418481698991138712251033104316951053101212751039944
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues

us-gaap:PublicUtilities, wec:Illinois, wec:ExternalRevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value447379198242536426197268507389187
Percentage of Revenues21.219.512.315.322.620.612.016.022.219.011.3
Percentage of Revenues21.219.512.315.322.620.612.016.022.219.011.3
Percentage of Revenues us-gaap:PublicUtilities wec:Illinois wec:ExternalRevenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PublicUtilities, wec:OtherStates, wec:ExternalRevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1461234868185145507216913749
Percentage of Revenues6.96.33.04.37.87.03.14.37.46.73.0
Percentage of Revenues6.96.33.04.37.87.03.14.37.46.73.0
Percentage of Revenues us-gaap:PublicUtilities wec:OtherStates wec:ExternalRevenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PublicUtilities, wec:Wisconsin, wec:ExternalRevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value14981421133912531633149113881325158915121401
Percentage of Revenues71.173.083.378.868.771.884.579.369.573.684.5
Percentage of Revenues71.173.083.378.868.771.884.579.369.573.684.5
Percentage of Revenues us-gaap:PublicUtilities wec:Wisconsin wec:ExternalRevenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductOrService, wec:TypesofOperatingRevenues

us-gaap:PublicUtilities, wec:ExternalRevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value20921923158615652355206316361665226620401638
Percentage of Revenues99.398.898.698.499.199.499.699.699.199.398.8
Percentage of Revenues99.398.898.698.499.199.499.699.699.199.398.8
Percentage of Revenues us-gaap:PublicUtilities wec:ExternalRevenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-03-31
Value186177
Percentage of Revenues8.97.5
Percentage of Revenues8.97.5
Percentage of Revenues wec:TransmissionAffiliate100.0100.0

us-gaap:StatementBusinessSegments

srt:ConsolidationEliminations



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-114-98-99-107-110-113
Percentage of Revenues-5.4-6.2-6.2-4.5-6.7-6.8
Percentage of Revenues-5.4-6.2-6.2-4.5-6.7-6.8
Percentage of Revenues srt:ConsolidationEliminations100.0100.0100.0100.0100.0100.0

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value001011231253234411162700000000000
Percentage of Revenues0.00.00.10.10.10.10.10.20.10.10.30.20.10.20.20.30.50.91.60.10.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.00.00.10.10.10.10.10.20.10.10.30.20.10.20.20.30.50.91.60.10.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:Illinois



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value447379198242536426197268507
Percentage of Revenues21.219.512.315.322.620.612.016.022.2
Percentage of Revenues21.219.512.315.322.620.612.016.022.2
Percentage of Revenues wec:Illinois100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:NonUtilityEnergyInfrastructure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-30
Value129125119123127118115117118121366
Percentage of Revenues6.16.47.47.85.45.77.07.05.20.60.80.30.4
Percentage of Revenues6.16.47.47.85.45.77.07.05.20.60.80.30.4
Percentage of Revenues wec:NonUtilityEnergyInfrastructure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:OtherStates



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value14612348681851455072169
Percentage of Revenues6.96.33.04.37.87.03.14.37.4
Percentage of Revenues6.96.33.04.37.87.03.14.37.4
Percentage of Revenues wec:OtherStates100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:PublicUtility



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value209219231586156523552063163616652266
Percentage of Revenues99.398.898.698.499.199.499.699.699.1
Percentage of Revenues99.398.898.698.499.199.499.699.699.1
Percentage of Revenues wec:PublicUtility100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:Wisconsin



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value149814211339125316331491138813251589
Percentage of Revenues71.173.083.378.868.771.884.579.369.5
Percentage of Revenues71.173.083.378.868.771.884.579.369.5
Percentage of Revenues wec:Wisconsin100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues

us-gaap:CorporateAndOther, wec:ExternalRevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value00101123125
Percentage of Revenues0.00.00.10.10.10.10.10.20.10.10.3
Percentage of Revenues0.00.00.10.10.10.10.10.20.10.10.3
Percentage of Revenues us-gaap:CorporateAndOther wec:ExternalRevenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IntersegmentElimination, wec:IntersegmentTransactions



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-114-102-98-99-107-107-110-113-99-113-111
Percentage of Revenues-5.4-5.3-6.2-6.2-4.5-5.2-6.7-6.8-4.3-5.5-6.7
Percentage of Revenues-5.4-5.3-6.2-6.2-4.5-5.2-6.7-6.8-4.3-5.5-6.7
Percentage of Revenues us-gaap:IntersegmentElimination wec:IntersegmentTransactions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:NonUtilityEnergyInfrastructure, wec:ExternalRevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value15232024201143181213
Percentage of Revenues0.71.21.31.50.90.50.30.20.80.60.8
Percentage of Revenues0.71.21.31.50.90.50.30.20.80.60.8
Percentage of Revenues wec:NonUtilityEnergyInfrastructure wec:ExternalRevenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:NonUtilityEnergyInfrastructure, wec:IntersegmentTransactions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value114102989910710711011399113111
Percentage of Revenues5.45.36.26.24.55.26.76.84.35.56.7
Percentage of Revenues5.45.36.26.24.55.26.76.84.35.56.7
Percentage of Revenues wec:NonUtilityEnergyInfrastructure wec:IntersegmentTransactions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:TypesofOperatingRevenues

wec:ExternalRevenues



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value21081608159023771643167222861657
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues wec:ExternalRevenues100.0100.0100.0100.0100.0100.0100.0100.0

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value7346934844911009854524547972797542541941745554508838682590353613523407
Percentage of CostOfGoodsAndServicesSold100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues34.835.630.130.942.541.131.932.742.538.832.733.240.838.032.431.738.236.934.835.644.242.739.4

Operating Expenses

Costs And Expenses

us-gaap:CostsAndExpenses



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value14821584129712751834178713411341
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues70.381.480.780.277.286.081.680.2

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-03-31
Value9590
Percentage of CostsAndExpenses6.44.9
Percentage of Revenues4.53.8
Percentage of Revenues wec:TransmissionAffiliate51.050.9

Operating Income Loss

us-gaap:OperatingIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value626363310314542289302330545412393362617361399332589380345165358243246240381258229321280222295224174295215203163229199104118243
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues29.718.619.319.822.814.018.419.823.820.123.722.226.818.423.320.726.820.620.416.725.919.923.823.122.524.522.725.227.023.60.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService

us-gaap:PublicUtilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value625374313317541210211244457309288
Percentage of OperatingIncomeLoss99.9103.2100.8100.999.772.869.974.083.975.273.4
Percentage of Revenues29.719.219.520.022.810.212.914.620.015.117.4
Percentage of Revenues us-gaap:PublicUtilities0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:PublicUtilities, wec:Illinois



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1618624421375115411476514
Percentage of OperatingIncomeLoss25.823.98.013.525.417.65.112.627.115.83.6
Percentage of Revenues7.74.41.52.75.82.50.92.56.53.20.9
Percentage of Revenues us-gaap:PublicUtilities wec:Illinois0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:OtherStates



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3721-244129-583619-3
Percentage of OperatingIncomeLoss6.05.9-0.71.57.610.3-1.82.46.64.7-0.8
Percentage of Revenues1.81.1-0.10.31.71.4-0.30.51.60.9-0.2
Percentage of Revenues us-gaap:PublicUtilities wec:OtherStates0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:Wisconsin



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value426266290270361130201195273225277
Percentage of OperatingIncomeLoss68.173.593.585.966.744.966.559.050.254.770.5
Percentage of Revenues20.213.718.117.015.26.312.311.712.011.016.7
Percentage of Revenues us-gaap:PublicUtilities wec:Wisconsin0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-4-17-6-7-3-90-6-5-21-6-1-3-4-10-9-3-68-9-13-5-6-1-1-1-1-1-1-1-1-1
Percentage of OperatingIncomeLoss-0.7-4.8-1.9-2.3-0.7-3.4-0.1-2.0-1.0-0.50.3-1.7-0.2-1.0-1.1-0.5-0.1-2.4-1.1-41.1-2.6-5.4-2.4-2.6-0.3-0.7-0.4-0.4-0.7-0.6-0.4-0.5-0.9
Percentage of Revenues-0.2-0.9-0.4-0.4-0.2-0.5-0.0-0.4-0.2-0.10.1-0.4-0.1-0.2-0.3-0.1-0.0-0.5-0.2-6.9-0.7-1.1-0.6-0.6-0.1-0.2-0.1-0.1-0.2-0.10.00.00.0
Percentage of Revenues us-gaap:CorporateAndOther-840.0-3480.0-461.5-788.9-229.4-550.0-16.7-209.7-385.7-105.019.6-193.8-41.4-120.0-112.5-36.4-2.5-58.1-14.0-13620.0-3100.0-3275.0-1966.7-2066.7-366.7-450.0-333.3-400.0-633.3-433.30.00.00.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-86-86-86-87-870000000000000000
Percentage of OperatingIncomeLoss-13.8-23.9-27.9-27.7-16.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues-4.1-4.4-5.4-5.5-3.70.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues us-gaap:IntersegmentElimination0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

wec:NonUtilityEnergyInfrastructure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value91929091928891929310110398979493
Percentage of OperatingIncomeLoss14.625.429.029.017.130.630.327.917.124.526.327.315.826.123.5
Percentage of Revenues4.34.75.65.73.94.35.65.54.14.96.26.04.24.85.5
Percentage of Revenues wec:NonUtilityEnergyInfrastructure70.673.675.674.072.575.279.579.078.7789.1760.30.00.01524.21511.3

Interest Expense

us-gaap:InterestExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value129127125124124117112108106105103101104102991001001051036259596059626263656061585657635152534937383940
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues6.16.57.87.85.25.76.86.54.75.16.36.24.55.25.86.24.65.76.16.34.34.95.85.73.75.96.35.15.96.50.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService

us-gaap:PublicUtilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value161160159158160696462636261
Percentage of InterestExpense124.7126.3127.1127.7129.058.957.658.059.859.459.5
Percentage of Revenues7.68.29.910.06.83.33.93.82.83.03.7
Percentage of Revenues us-gaap:PublicUtilities0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:PublicUtilities, wec:Illinois



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1615141314131212121211
Percentage of InterestExpense12.412.311.711.211.911.711.411.311.511.410.6
Percentage of Revenues0.80.80.90.90.60.70.80.70.50.60.7
Percentage of Revenues us-gaap:PublicUtilities wec:Illinois0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:OtherStates



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value22212222222
Percentage of InterestExpense1.71.61.81.51.82.01.91.92.02.12.2
Percentage of Revenues0.10.10.10.10.10.10.10.10.10.10.1
Percentage of Revenues us-gaap:PublicUtilities wec:OtherStates0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PublicUtilities, wec:Wisconsin



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value143143142142143534948494848
Percentage of InterestExpense110.6112.4113.6115.0115.345.144.344.746.345.946.7
Percentage of Revenues6.87.38.99.06.02.63.02.92.22.42.9
Percentage of Revenues us-gaap:PublicUtilities wec:Wisconsin0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value353335363534323028262526292929303133311412121212121212121212131313
Percentage of InterestExpense27.126.328.529.428.229.329.427.926.224.724.526.327.828.930.030.231.031.730.222.520.420.120.520.719.620.619.919.721.221.022.223.223.2
Percentage of Revenues1.71.72.22.31.51.72.01.81.21.31.51.61.31.51.71.91.41.81.81.40.91.01.21.20.71.21.21.01.21.40.00.00.0
Percentage of Revenues us-gaap:CorporateAndOther7020.06680.02761.54055.62064.71922.21370.8977.42000.01300.0453.6837.51003.4990.0742.5686.4263.0209.4112.22800.04066.73000.04133.34066.74066.73200.04200.04266.74300.04300.00.00.00.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-87-87-88-89-89-2-10-100-1-1-1-2-2-2-2-200
Percentage of InterestExpense-67.3-68.4-70.3-71.8-71.9-1.8-1.2-0.6-1.10.70.4-1.1-1.7-1.9-2.0-2.0-2.7-2.6-2.0-0.3-0.2
Percentage of Revenues-4.1-4.5-5.5-5.6-3.8-0.1-0.1-0.0-0.10.00.0-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.0-0.0
Percentage of Revenues us-gaap:IntersegmentElimination0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

wec:ElectricTransmissionSegment



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
Value4432200000000000
Percentage of InterestExpense3.73.82.42.22.10.30.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.20.20.20.20.10.00.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues wec:ElectricTransmissionSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

wec:NonUtilityEnergyInfrastructure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value151515151515151616161615151515
Percentage of InterestExpense11.812.112.312.512.613.314.214.715.115.315.614.914.614.915.7
Percentage of Revenues0.70.81.01.00.70.81.01.00.70.81.00.90.70.80.9
Percentage of Revenues wec:NonUtilityEnergyInfrastructure11.812.313.012.612.313.313.813.713.6125.8119.10.00.0246.8251.6

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value52521233052631719161315873232181126312815549816161412996
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.31.31.41.51.30.31.61.90.30.91.00.80.70.40.42.01.51.00.72.60.20.10.30.80.10.50.60.30.90.90.00.00.00.00.00.00.0

Income Loss From Continuing Operations

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value542277245251485218250282478357345315570306345295559318293144318199206207337218189277245185268199146
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues25.714.315.315.820.410.515.216.920.917.420.819.324.715.620.218.425.517.217.214.522.916.320.019.919.920.718.721.723.719.70.00.00.0

Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value452234235420233231390215
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.514.614.817.714.213.817.113.0

Nonoperating Income Expense

us-gaap:NonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value-84-85-65-63-57-71-52-48-66-54-48-47-47-55-53-36-29-61-52-21-40-44-39
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-4.0-4.4-4.1-4.0-2.4-3.4-3.2-2.9-2.9-2.7-2.9-2.9-2.0-2.8-3.1-2.3-1.4-3.3-3.1-2.2-2.9-3.6-3.8

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-03-31
Value-28-28
Percentage of NonoperatingIncomeExpense33.950.2
Percentage of Revenues-1.4-1.2
Percentage of Revenues wec:TransmissionAffiliate-15.3-16.2

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value903311156513175188-751291152131111281132131371106312276807413080701008966966948896763477167323781
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.31.70.71.02.70.61.03.13.9-3.77.87.19.35.77.57.19.77.56.56.48.86.37.87.17.77.76.97.98.67.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-03-312009-12-312009-09-30
Value1190140-398470220-8-28-4-707-1-1404710215-2444514260
Percentage of IncomeTaxesPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.50.50.00.90.0-1.90.52.9-0.00.10.1-0.0-0.4-1.4-0.3-0.50.00.4-0.1-0.10.30.00.40.70.60.20.00.00.00.00.00.00.0

Profit Loss

us-gaap:ProfitLoss



Period End2020-03-312019-03-312018-12-312017-12-312015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-06-302009-03-31
Value452420206433801951211261332071371191761561191721291091701128812963141
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.517.79.921.18.214.19.912.212.712.213.111.813.815.012.60.00.00.00.00.00.00.00.00.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302011-03-312010-03-31
Value44924623323341820023322839143321519835619321618134517218292195121126133171129
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.312.714.514.717.69.614.213.717.121.113.012.215.59.912.611.315.89.310.79.314.19.912.212.70.00.0

Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-03-312018-12-312018-09-30
Value-200000.00.0-300000.00.00.00.0
Percentage of ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest100.00.0100.00.00.00.0
Percentage of Revenues-0.00.0-0.00.00.00.0

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312010-09-302009-09-30
Value4492472332334192002332293924332151993561932161813461731829219611258
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.312.714.514.717.69.614.213.717.121.113.012.215.59.912.611.315.89.410.89.314.10.00.0

Net Income Loss

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:NetIncomeLoss

wec:TransmissionAffiliate



Period End2020-03-312019-03-31
Value6358
Percentage of NetIncomeLoss100.0100.0
Percentage of Revenues3.02.5
Percentage of Revenues wec:TransmissionAffiliate33.832.9

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value45224323423542020523323139043221519935619421718134617918280195121126133207
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.512.514.614.817.79.914.213.817.121.113.012.215.59.912.711.315.89.710.78.214.19.912.212.712.2

us-gaap:StatementEquityComponents

us-gaap:Parent



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value452234235420233231390
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.514.614.817.714.213.817.1
Percentage of Revenues us-gaap:Parent0.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value452234235420233231390
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.514.614.817.714.213.817.1
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.0

Net Income Loss Attributable To Noncontrolling Interest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-200000.00.0-300000.0-200000.00.00.00.00.0
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.00.0100.0100.00.00.00.00.0
Percentage of Revenues-0.00.0-0.0-0.00.00.00.00.0

us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest



Period End2020-03-312019-09-302019-06-30
Value-200000.0-300000.0-200000.0
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.0100.0100.0
Percentage of Revenues-0.0-0.0-0.0
Percentage of Revenues us-gaap:NoncontrollingInterest0.00.00.0

Assets

us-gaap:Assets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302008-12-31
Value348323495134377339343373733475325623193731785315903101330559300163012329443291752910429355287692861415135151631472414619148001476914372143171429514285138341388713821138621324913076131881305912718126931272112697124201229812617
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value53655328
Percentage of Assets15.415.2
Percentage of Assets15.415.2
Percentage of Assets wec:TransmissionAffiliate100.0100.0

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
Value34832349513437733934337373347532562319373178531590310133055930016301232944329175291042935528769286141513515163147241461914800147691437214317142951428513834138871382113862132491307613188130591271812693127211269712617
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

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value53655328
Percentage of LiabilitiesAndStockholdersEquity15.415.2
Percentage of Assets15.415.2
Percentage of Assets wec:TransmissionAffiliate100.0100.0

Stockholders Equity

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:StockholdersEquity

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value22182214
Percentage of StockholdersEquity100.0100.0
Percentage of Assets6.46.3
Percentage of Assets wec:TransmissionAffiliate41.341.6

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
Value1845209317731838200822471839181019802213182317791855216818171765189622062181227613261535127412851545155112381271131313131084123612791426113211711459133111881273131914611707
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 Assets5.36.05.25.46.06.75.65.76.27.05.95.86.27.26.26.16.57.57.68.08.810.18.78.810.410.58.68.99.29.27.88.99.310.38.59.011.110.29.310.010.411.513.5

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value8284
Percentage of AssetsCurrent4.54.0
Percentage of Assets0.20.2
Percentage of Assets wec:TransmissionAffiliate1.51.6

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
Value1537203730841429483818364537253234492221465618833272618212435131318141510236241110122091117322737
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 Assets0.00.10.10.10.10.30.00.10.20.10.10.10.20.10.10.10.10.20.10.70.40.40.60.20.20.20.10.10.20.20.10.10.10.10.10.11.80.20.10.10.10.20.10.10.00.30.00.0

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent



Period End2020-03-312019-12-312018-12-312017-12-312016-12-312015-12-312015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value117611761280135012411028667437352339404605406299327389285298297386349314344425344300317407304369
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.43.43.84.34.13.52.32.92.32.32.84.12.72.12.32.72.02.22.12.82.52.42.63.22.62.42.53.22.42.9

Inventory Raw Materials And Supplies

Other Assets Current

us-gaap:OtherAssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value61688180507761493474434739974989595838121078785
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.10.20.20.20.10.20.10.20.10.30.20.30.20.20.30.10.80.60.7

Prepaid Expense And Other Assets Current

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value9042887888078705858985158589851288198618852584338312821481418049800579197930785745604485444943844323425742024140409840363972391538553797374136873639362435813538352434723312
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets26.025.425.625.725.525.426.426.727.727.327.527.627.727.327.727.627.527.027.627.530.129.630.230.029.228.829.228.928.728.328.728.227.927.428.228.227.627.728.227.927.727.326.3

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
Value23797236202303522535221932200021663210782146621347208822052419990199151961219398192591918918785185291131611257111341102410941109061080510704106161057210438103401023510160999998219639960193999290923790708502
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 Assets68.367.667.066.465.865.766.566.067.567.667.367.266.666.166.666.566.265.465.364.874.874.275.675.473.973.875.274.874.374.075.574.574.173.375.575.173.173.573.973.272.671.467.4

Long Term Investments

Investments In Affiliates Subsidiaries Associates And Joint Ventures

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value171717201720169616701665161315961598155314431380431424423416409402396390383378372362355349346341336330327323321314276
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.94.95.05.05.05.05.05.05.04.94.84.72.82.82.92.92.82.72.82.72.72.62.72.62.62.52.62.62.52.52.62.62.52.52.2

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
Value30523052305230523052305230523052305230533053305330463046304630462999302333893386441441441441441441441441441441441441441441441441441441441441441441441
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 Assets8.88.78.99.09.09.19.49.69.69.79.810.010.110.110.310.410.310.311.811.82.92.93.03.03.03.03.13.13.13.13.23.23.23.23.33.43.43.43.53.53.53.53.5

us-gaap:StatementBusinessSegments

wec:Illinois



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312016-09-302016-06-302016-03-312015-12-312014-12-312013-12-31
Value75875875875875875875875875875875875875875875872273100
Percentage of Goodwill24.924.924.924.924.924.924.924.924.924.824.824.824.924.924.924.124.20.00.0
Percentage of Assets2.22.22.22.22.22.32.32.42.42.42.42.52.52.62.62.52.50.00.0
Percentage of Assets wec:Illinois0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

wec:NonUtilityEnergyInfrastructure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312015-12-31
Value6666666667700
Percentage of Goodwill0.20.20.20.20.20.20.20.20.20.20.20.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets wec:NonUtilityEnergyInfrastructure0.00.20.00.00.00.20.00.00.00.20.00.00.0

wec:OtherStates



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312016-09-302016-06-302016-03-312015-12-312014-12-312013-12-31
Value18318318318318318318318318318318318318318318317918200
Percentage of Goodwill6.06.06.06.06.06.06.06.06.06.06.06.06.06.06.06.06.00.00.0
Percentage of Assets0.50.50.50.50.50.50.60.60.60.60.60.60.60.60.60.60.60.00.0
Percentage of Assets wec:OtherStates0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

wec:WisconsinSegment



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
Value210421042104210421042104210421042104210421042109
Percentage of Goodwill68.968.968.968.968.968.968.968.968.968.969.169.8
Percentage of Assets6.06.06.16.26.26.36.56.66.66.77.07.2
Percentage of Assets wec:WisconsinSegment0.00.00.00.00.00.00.00.00.00.00.00.0

Intangible Assets Net Excluding Goodwill

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
Value853957796803802704749753757619584549527461418419379403511455317200321321328322186185179204179180184201210209215218183182184172214
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 Assets2.42.72.32.42.42.12.32.42.42.01.91.81.81.51.41.41.31.41.81.62.11.32.22.22.22.21.31.31.31.41.31.31.31.51.61.61.61.71.41.41.51.41.7

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
Value284731822818336228893331360230533605386930262787205424312025213722292709266629401560166810659801424149612911280127814431387142811711364108911431340172116091652125518811735
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 Assets8.29.18.29.98.610.011.19.611.312.29.89.16.88.16.97.37.79.29.310.310.311.07.26.79.610.19.08.98.910.110.010.38.59.88.28.710.213.212.713.09.914.813.8

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value526502
Percentage of LiabilitiesCurrent18.515.8
Percentage of Assets1.51.4
Percentage of Assets wec:TransmissionAffiliate9.89.4

Long Term Debt Current

Accounts Payable Current

us-gaap:AccountsPayableCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value597908769715674876690681592859743724582861663620584815777777291363315288435342296276257368277267239325274309269315254270279292441
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.72.62.22.12.02.62.12.11.92.72.42.41.92.92.32.12.02.82.72.71.92.42.12.02.92.32.11.91.82.62.01.91.72.32.12.42.02.42.02.12.22.33.5

Taxes Payable 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
Value443550503457578464393364747553442440421388240358375471466592219168155166150177170178219167173177262230286245294259297247287246319
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 Assets1.31.61.51.31.71.41.21.12.41.81.41.41.41.30.81.21.31.61.62.11.51.11.11.11.01.21.21.21.51.21.31.31.91.72.21.92.22.02.31.92.31.92.5

Liabilities Noncurrent

us-gaap:LiabilitiesNoncurrent



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
Value214992151421372204242073520301191171912818481182291876118589188061873117961
Percentage of LiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets61.761.662.260.261.560.658.759.958.157.760.560.862.762.261.2

Long Term Debt

us-gaap:FairValueByMeasurementBasis

us-gaap:LongTermDebt

us-gaap:CarryingReportedAmountFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value11844118581154110666106701033594649477954995619467947992729285913989529055922193009118454345524554456546174626465947124772
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets34.033.933.631.431.630.929.129.730.030.330.531.030.930.831.030.731.131.432.331.930.030.030.931.231.231.332.432.933.4
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:EstimateOfFairValueFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value1292013035127511154311257105549762982710054103411013510128973098181024899849790968193869181515751264979499549544911495150975447
Percentage of LongTermDebt109.1109.9110.5108.2105.5102.1103.1103.7105.3108.2107.1106.8104.9105.7112.1111.5108.1105.0100.9100.7113.5112.6109.3109.4107.3106.2106.3108.2114.1
Percentage of Assets37.137.337.134.033.431.530.030.831.632.732.733.132.432.634.834.233.633.032.632.134.133.833.834.233.533.334.535.638.1
Percentage of Assets us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Long Term Debt Noncurrent

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:LongTermDebtNoncurrent

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value23132312
Percentage of LongTermDebtNoncurrent100.0100.0
Percentage of Assets6.66.6
Percentage of Assets wec:TransmissionAffiliate43.143.4

Deferred Tax Liabilities Noncurrent

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value324326411414418422489490523397463451458498545541541543427428203203168169169173214225233244149251221222100233227353335329324319635
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.90.91.21.21.21.31.51.51.61.31.51.51.51.71.91.91.91.91.51.51.31.31.11.21.11.21.51.61.61.71.11.81.61.60.81.81.72.72.62.62.62.55.0

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
Value11061128111611061109110812331203119112061194117111611164116711321067107110341626294303273275280295289288276285298302300314336333359290360352374284263
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 Assets3.23.23.23.33.33.33.83.83.73.83.93.83.93.94.03.93.73.73.65.71.92.01.91.91.92.02.02.01.92.02.22.22.22.32.52.62.72.22.82.82.92.22.1

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value307298
Percentage of OtherLiabilitiesNoncurrent27.826.5
Percentage of Assets0.90.9
Percentage of Assets wec:TransmissionAffiliate5.75.6

Stockholders Equity

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:StockholdersEquity

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value22182214
Percentage of StockholdersEquity100.0100.0
Percentage of Assets6.46.3
Percentage of Assets wec:TransmissionAffiliate41.341.6

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-312006-12-31
Value333333333333333333384564510441943984367432242334198419542034135414740814051396339403947390438023727367736413566333630992888
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.029.629.829.129.929.929.228.729.229.329.428.930.029.429.328.629.730.229.629.129.329.028.628.126.40.00.0

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value61805927586958215772553855085449539251764908485748224613457545154489429942644117
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets17.717.017.117.217.116.516.917.117.016.415.815.916.115.315.515.515.414.614.827.2

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value-7-4-7-6-4-2224222223444110
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value69050454955573543749461989433147855371438149752869522135738632916331333638533034039115623012030319520221020
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues32.725.934.234.930.921.130.137.039.116.228.933.931.019.529.133.031.712.021.039.023.813.330.332.222.725.90.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-463-760-668-459-606-664-723-561-435-702-528-698-325-512-392-260-188-326-416-1522-156-227-216-173-139-145-130-144-223-134-104-171-260-171-161-143
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-22.0-39.0-41.5-28.9-25.5-32.0-44.0-33.5-19.1-34.2-31.9-42.8-14.1-26.1-22.9-16.3-8.6-17.7-24.5-153.6-11.3-18.6-20.9-16.7-8.2-11.40.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-24427194-94-186333216-78-44537531135-38059-112-270-522251-1321285-17038-42-156-244-195-206-3580-94-17-14075-33-53107
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-11.613.95.9-5.9-7.816.013.2-4.7-19.518.31.98.3-16.53.0-6.6-16.9-23.813.6-7.8129.7-12.33.1-4.1-15.0-14.4-15.40.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value69050454955573543749461989433147855371438149752869522135738632916331333638533034039115623012030319520221020
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues32.725.934.234.930.921.130.137.039.116.228.933.931.019.529.133.031.712.021.039.023.813.330.332.222.725.90.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:NetIncomeLoss

wec:TransmissionAffiliate



Period End2020-03-312019-03-31
Value6358
Percentage of NetIncomeLoss100.0100.0
Percentage of Revenues3.02.5
Percentage of Revenues wec:TransmissionAffiliate33.832.9

Profit Loss

us-gaap:ProfitLoss



Period End2020-03-312019-03-312018-12-312017-12-312015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-06-302009-03-31
Value452420206433801951211261332071371191761561191721291091701128812963141
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues21.517.79.921.18.214.19.912.212.712.213.111.813.815.012.60.00.00.00.00.00.00.00.00.0

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value2392362332292262172122062082052011971941931911901871791761051051031031011009696959190878282817776
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductOrService

us-gaap:PublicUtilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value220211208204202190186180182179176
Percentage of DepreciationDepletionAndAmortization92.389.489.089.089.287.787.787.587.587.487.8

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:PublicUtilities, wec:Illinois



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value4746454544444341404038
Percentage of DepreciationDepletionAndAmortization19.919.519.519.619.720.520.220.219.619.519.3

us-gaap:PublicUtilities, wec:OtherStates



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value77666664666
Percentage of DepreciationDepletionAndAmortization3.33.22.92.92.93.03.02.23.23.13.1

us-gaap:PublicUtilities, wec:Wisconsin



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value165157155152151139137134135132131
Percentage of DepreciationDepletionAndAmortization69.266.766.666.566.764.264.565.164.864.765.4

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value656666777766591112105600000000000000
Percentage of DepreciationDepletionAndAmortization2.62.52.62.62.83.13.33.63.73.73.13.22.94.85.96.35.43.13.50.10.20.20.00.40.10.20.20.20.30.20.10.20.1

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-12-4-3-3-40000000000000000
Percentage of DepreciationDepletionAndAmortization-5.1-1.7-1.5-1.6-2.00.00.00.00.00.00.00.00.00.00.00.00.00.1-0.10.00.0

wec:NonUtilityEnergyInfrastructure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value242323222220191818181817171717
Percentage of DepreciationDepletionAndAmortization10.29.810.010.010.09.29.08.98.88.99.08.89.08.98.9

Increase Decrease In Other Operating Capital Net

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-158-43131131-218-6014190-163-13316292-170-6615923-217-3217338-110217569-94-93-70-94-4332-3042-7874-12393
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

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-463-760-668-459-606-664-723-561-435-702-528-698-325-512-392-260-188-326-416-1522-156-227-216-173-139-145-130-144-223-134-104-171-260-171-161-143
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-22.0-39.0-41.5-28.9-25.5-32.0-44.0-33.5-19.1-34.2-31.9-42.8-14.1-26.1-22.9-16.3-8.6-17.7-24.5-153.6-11.3-18.6-20.9-16.7-8.2-11.40.00.00.00.00.00.00.00.00.00.0

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value4961017656496358926575475439650519460329423381306312501408207149223207176129190173133163171
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-24427194-94-186333216-78-44537531135-38059-112-270-522251-1321285-17038-42-156-244-195-206-3580-94-17-14075-33-53107
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-11.613.95.9-5.9-7.816.013.2-4.7-19.518.31.98.3-16.53.0-6.6-16.9-23.813.6-7.8129.7-12.33.1-4.1-15.0-14.4-15.40.00.00.00.00.00.00.00.00.00.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312011-01-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value057597003501140060002250200200500200002500004204200005302500011
Percentage of ProceedsFromIssuanceOfLongTermDebt0.0100.0100.00.0100.0100.00.0100.00.0100.00.0100.0100.0100.0100.00.00.0100.00.00.00.0100.0100.00.00.00.0100.0100.00.00.0100.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value1425488413258136681212712212521110213950215292103028885126126119148151
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Payments For Repurchase Of Common Stock

us-gaap:PaymentsForRepurchaseOfCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value401313570302241510201920211345983482339264526629242859373181045
Percentage of PaymentsForRepurchaseOfCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value1425488413258136681212712212521110213950215292103028885126126119148151
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Debt Instrument Interest Rate Stated Percentage

Effective Income Tax Rate Continuing Operations

us-gaap:EffectiveIncomeTaxRateContinuingOperations



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.1660.0460.0610.1340.0680.1810.184
Percentage of EffectiveIncomeTaxRateContinuingOperations100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod

us-gaap:PerformanceShares



Period End2020-03-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312015-01-312014-12-312014-09-302014-06-302014-03-312014-01-312013-03-312013-01-312012-03-312012-01-312011-01-312010-01-31
Value140455.0148036.00.00.00.0217560.00.00.00.0237650.0-92.00.013892.0283505.00.00.00.0195365.0195365.00.00.00.0233735.0233735.0239120.0239120.0346570.0346570.0435690.0555830.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod100.0100.00.00.00.0100.00.00.00.0100.0100.00.0100.0100.00.00.00.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestrictedStock



Period End2020-03-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312015-01-312014-12-312014-09-302014-06-302014-03-312014-01-312013-09-302013-06-302013-03-312013-01-312012-09-302012-06-30
Value84540.073571.00.00.00.0156340.00.00.00.082622.00.00.06044.0140897.00.082943.00.060164.060164.00.00.00.071504.071504.00.00.074290.074290.00.00.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod60.249.70.00.00.071.90.00.00.034.8-0.00.043.549.70.00.00.030.830.80.00.00.030.630.60.00.031.131.10.00.0

us-gaap:AwardType, us-gaap:SubsequentEventType

us-gaap:PerformanceShares, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-312017-01-31
Value140455.0148036.0217560.0237650.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod100.0100.00.00.0

us-gaap:RestrictedStock, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-312017-01-31
Value84540.073571.0131731.082622.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod60.249.70.00.0

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 End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-312014-12-31
Value6582669089146405271583858737216861
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Proceeds From Repayments Of Short Term Debt

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries



Period End2020-03-31
Value15
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value0.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries0.0

wec:Illinois



Period End2020-03-31
Value4
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries31.0

wec:OtherStates



Period End2020-03-31
Value400000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries2.5

wec:PublicUtility



Period End2020-03-31
Value15
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries100.0

wec:Wisconsin



Period End2020-03-31
Value10
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries66.5

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs



Period End2020-03-31
Value52
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value0.0
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs0.0

wec:Illinois



Period End2020-03-31
Value31
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs60.1

wec:OtherStates



Period End2020-03-31
Value1
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs2.5

wec:PublicUtility



Period End2020-03-31
Value52
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs100.0

wec:Wisconsin



Period End2020-03-31
Value19
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs37.5

us-gaap:CapitalExpendituresIncurredButNotYetPaid



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value102-2256274-6-5274-317391165702390-217511-3
Percentage of CapitalExpendituresIncurredButNotYetPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect



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-1615-241-57105-11-191320-19-150
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStockDividendsPerShareDeclared



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-012015-07-062015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value0.63250.590.590.590.590.55250.55250.55250.55250.520.520.520.520.4950.4950.4950.4950.449999999999999960.45750.00.45750.86290.42250.39000000000000010.390.390.390.38250.340.340.30.30.30.260.260.260.40.40.40.337500000000000130.33750.33750.3375
Percentage of CommonStockDividendsPerShareDeclared100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SubsequentEventType

us-gaap:SubsequentEvent



Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-012018-09-302018-04-192018-03-312017-10-192017-07-202017-04-202017-01-312016-10-20
Value0.63250.63250.590.590.590.590.55250.55250.55250.55250.520.520.520.520.495
Percentage of CommonStockDividendsPerShareDeclared0.0100.0100.0100.0100.0100.00.0100.00.0100.00.00.00.00.00.0

wec:TypesofNonUtilityOperatingRevenues

us-gaap:ContractWithCustomerLiabilityRevenueRecognized

wec:WePowerrevenues



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value5666666
Percentage of ContractWithCustomerLiabilityRevenueRecognized100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxesAndTaxCredits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value92104-37781726221417-17216912415054132922141989815106697076111426771105-8256510717-2
Percentage of DeferredIncomeTaxesAndTaxCredits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value512200000000-1-2-2
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-24-20-18-18-19-23-23-23-23-21-21-21-21-21-20
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses-448.1-1089.5-945.0-935.0-2714.311700.07866.711950.07700.02700.03071.421100.01460.01038.1927.3

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-3-3-3-3-3-3-3-3-3-3-2-2-2-2-2
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value400000.0600000.0500000.0500000.0600000.0700000.0700000.0600000.0700000.0700000.0700000.0800000.0700000.0800000.0900000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit-10.8-15.8-12.8-13.2-15.4-17.9-18.4-15.4-18.4-17.9-25.0-28.6-25.0-33.3-39.1

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value151313131314141414141313131313
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value474848484848494849484848494849
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets317.2351.1352.6354.4355.5328.2330.2329.7332.9334.2358.8356.6362.0373.3371.2

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value466667777788899
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value262930303028282828303030313133
Percentage of DefinedBenefitPlanInterestCost555.3457.8466.2479.4470.8384.0380.0387.8377.3396.1360.7359.5367.1337.6360.9

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-15-9-9-9-7-5-5-5-4-3-1-2022
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value161620141315151614151719151917
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-105.2-185.6-231.1-150.5-183.8-300.0-318.0-300.0-317.0-405.1-1361.5-839.1-7950.0804.2712.5

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0-1-7-1000000-2-50-10
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value444346556665666
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value131211111111111112111110111210
Percentage of DefinedBenefitPlanServiceCost319.5307.5282.9310.5256.8190.0201.7210.7193.5183.9185.0185.7185.7192.3167.7

us-gaap:DerivativeGainLossOnDerivativeNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value-23-6-5013381-1-2132-13-19-31-24-11-5-5-1151446-5-2-11
Percentage of DerivativeGainLossOnDerivativeNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk

wec:CommodityContractFinancialTransmissionRights



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value137321733442317130302
Percentage of DerivativeGainLossOnDerivativeNet-6.0-49.3-135.7-3000.0127.83.688.8205.3-370.0-209.1262.571.0136.4-88.9215.2-8.2-9.5-2.8-28.2-16.0-41.2

wec:CommodityContractNaturalGas



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-24-10-13-30310-2-5-6-210-2-3-20-33-24-13-5-7
Percentage of DerivativeGainLossOnDerivativeNet106.0149.3235.73100.0-27.895.55.0-121.1520.0313.6-131.241.9-13.6150.0-103.0103.1106.098.8120.0118.0139.2

us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeNonmonetaryNotionalAmountEnergyMeasure

wec:CommodityContractFinancialTransmissionRights



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value777887768899989776856
Percentage of DerivativeNonmonetaryNotionalAmountEnergyMeasure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:CommodityContractNaturalGas



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value584637435648363948382425343730325038241013
Percentage of DerivativeNonmonetaryNotionalAmountEnergyMeasure811.1632.9484.6547.5692.6638.2464.6586.8586.6474.4264.9268.1370.7429.5308.1441.9659.2586.4281.4169.5214.5

us-gaap:DividendsCommonStockCash



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-31
Value199186186186174174174164
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:Parent



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value199186186186174174174174164
Percentage of DividendsCommonStockCash100.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value199186186186174174174174164
Percentage of DividendsCommonStockCash100.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312018-01-012017-12-312017-09-302017-06-302017-03-31
Value0.210.00.210.210.210.00.210.210.210.210.00.00.00.35
Percentage of EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate100.00.0100.0100.0100.00.0100.0100.0100.0100.00.00.00.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.0240.033-0.049-0.03-0.0270.017-0.0130.005-0.032
Percentage of EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.0020.014000000000000002-0.028-0.018-0.0090.015-0.05-0.0170.007
Percentage of EffectiveIncomeTaxRateReconciliationOtherAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-40-3-4-7-30-10
Percentage of EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-0.009-0.016-0.017-0.015-0.004-0.003-0.002
Percentage of EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.0630.0820.0620.0640.0640.0630.062
Percentage of EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationTaxCreditsOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.0340.00.0280.0250.0280.00.0180.0070.008
Percentage of EffectiveIncomeTaxRateReconciliationTaxCreditsOther100.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:EquityMethodInvestmentDividendsOrDistributions



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302017-12-312017-09-302017-06-302015-03-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value40302934275085353410141414131212
Percentage of EquityMethodInvestmentDividendsOrDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value40303029340275085353406325311532311010141414
Percentage of EquityMethodInvestmentDividendsOrDistributions100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.0100.00.0100.0100.0

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value23454453224334422223334
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments



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
Value3915383636413328323139414138383038254014161318171717171617161515151515151515141414
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:ATCHoldCoLLC



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
Value0-400000-10-3-1-1-5
Percentage of IncomeLossFromEquityMethodInvestments0.5-29.61.0-1.4-1.1-0.7-2.7-3.8-1.8-10.2-4.3-2.4-13.8

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value392038373641342933433941413838303825401416131817171717161716151515
Percentage of IncomeLossFromEquityMethodInvestments99.5129.699.0101.4101.1100.7102.7103.8101.8137.3100.0100.0100.0100.0100.0100.0100.0100.0100.0100.7100.0100.8100.0100.0100.0100.0100.699.4100.0100.6100.0100.6100.7

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-100000.00.0-100000.00.00.00.00.0-100000.0100000.00.0-100000.00.0-100000.0-100000.0
Percentage of IncomeLossFromEquityMethodInvestments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.70.0-0.80.00.00.00.0-0.60.60.0-0.60.0-0.6-0.7

wec:ElectricTransmissionSegment



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
Value39153836364133283231394141383830
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationChangeInEnactedTaxRate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1332-12-7-1317-31-15
Percentage of IncomeTaxReconciliationChangeInEnactedTaxRate100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value113585152101455259100
Percentage of IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationOtherAdjustments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-111-7-4-413-12-43
Percentage of IncomeTaxReconciliationOtherAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value34132015318161729
Percentage of IncomeTaxReconciliationStateAndLocalIncomeTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationTaxCreditsOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value18766131423
Percentage of IncomeTaxReconciliationTaxCreditsOther100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value3262-92-392124288-76-29560396-63-192-55365-55-17848185
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsPayable



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-25019330-18-2041811385-170119298-2121291711-12346-8398-715124-14794-104-82-4861-106-3670-31-37-119
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

us-gaap:IncreaseDecreaseInOtherCurrentAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-65117-90105-125122-332-8163-4225-41-14-21-13063102-58
Percentage of IncreaseDecreaseInOtherCurrentAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherCurrentLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-278053-10954-11042-1281281385-729072-5-14456-8399
Percentage of IncreaseDecreaseInOtherCurrentLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities



Period End2020-03-31
Value32
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value0.0
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities0.0

wec:Illinois



Period End2020-03-31
Value29
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities89.9

wec:OtherStates



Period End2020-03-31
Value0.0
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities0.0

wec:PublicUtility



Period End2020-03-31
Value32
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities100.0

wec:Wisconsin



Period End2020-03-31
Value3
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities10.1

us-gaap:InterestPaidNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302009-12-312009-09-30
Value85168701816616362147681554815256151511684017834962097211012121261296081-9
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidatedEntities, us-gaap:DerivativeInstrumentRisk

us-gaap:InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet

srt:ParentCompany, us-gaap:InterestRateSwap



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-100000.0100000.0200000.0400000.0400000.0300000.0200000.0500000.0600000.0
Percentage of InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders



Period End2020-03-312019-09-302019-06-30
Value500000.0600000.0900000.0
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest



Period End2020-03-312019-09-302019-06-30
Value500000.0600000.0900000.0
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value00000-1100000000000
Percentage of OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax100.00.00.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-06-30
Value-30-2-1000000000001100
Percentage of OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-330-2-1-50-2100000000-60110000000000
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-30-2-10-21
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0

us-gaap:Parent



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-30-2-1-50-21
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0112.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value-100000.0200000.0300000.0300000.0400000.0400000.0200000.0300000.0400000.0300000.0300000.0400000.0300000.0300000.0300000.0300000.0400000.0100000.00.00.00.00.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value-30-2-10000
Percentage of OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax100.0100.0100.0100.0100.00.00.00.0

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value10000000
Percentage of OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:OtherCostAndExpenseOperating



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value455601529503550667553537511602471479501600517522531557535337280249
Percentage of OtherCostAndExpenseOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductOrService

us-gaap:PublicUtilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value456584524494548758652631607708581
Percentage of OtherCostAndExpenseOperating100.297.199.098.299.6113.5118.0117.4118.6117.6123.2

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:PublicUtilities, wec:Illinois



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value10412410110712815110410411214399
Percentage of OtherCostAndExpenseOperating22.820.619.221.223.322.718.919.421.923.821.0

us-gaap:PublicUtilities, wec:OtherStates



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2125222327262324262821
Percentage of OtherCostAndExpenseOperating4.84.24.24.65.04.04.24.65.24.74.6

us-gaap:PublicUtilities, wec:Wisconsin



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value330434400363392580525502468537460
Percentage of OtherCostAndExpenseOperating72.672.275.672.371.386.994.993.491.589.197.6

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-09-30
Value-11111-14-4201-12-1-3-3-6-312
Percentage of OtherCostAndExpenseOperating-0.42.00.20.4-0.20.6-0.80.4-0.10.3-0.30.6-0.3-0.6-0.6-1.2-0.72.4

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-09-30
Value-40000-98-98-100-96-110-109-112-109-106-105-107-104-103
Percentage of OtherCostAndExpenseOperating-1.00.00.00.1-0.1-14.7-17.7-18.7-18.9-18.3-23.1-23.5-21.7-17.7-20.3-20.7-19.7-19.3

wec:NonUtilityEnergyInfrastructure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value553633341212000
Percentage of OtherCostAndExpenseOperating1.10.90.71.40.70.50.50.80.30.40.30.60.10.10.1

us-gaap:OtherOperatingActivitiesCashFlowStatement



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-3221-3-581083413134-71-51-55-1951-11-37-56-64-1135-48
Percentage of OtherOperatingActivitiesCashFlowStatement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-91-1-3-13-13-3-40-60-2-2-2-26-5-364-1459-12-6613972818211631222423
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfDividendsCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value1991861861861861741741741741641641641641561561561561441209595888887887769604646464639393939
Percentage of PaymentsOfDividendsCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireBusinessTwoNetOfCashAcquired



Period End2020-03-312019-12-312019-03-312018-12-312018-09-302017-12-312017-09-30
Value002680000
Percentage of PaymentsToAcquireBusinessTwoNetOfCashAcquired0.00.0100.00.00.00.00.0

us-gaap:PaymentsToAcquireInterestInSubsidiariesAndAffiliates



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value315151839111912461222271515393311224312210037656
Percentage of PaymentsToAcquireInterestInSubsidiariesAndAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0

us-gaap:PensionAndOtherPostretirementBenefitContributions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-09-302011-03-312010-03-31
Value35334463445535106544151190100-121200001351220
Percentage of PensionAndOtherPostretirementBenefitContributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.00.00.00.0100.0100.00.0

us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0100111
Percentage of PensionAndOtherPostretirementBenefitContributions5.428.919.514.331.725.030.2

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value3233233
Percentage of PensionAndOtherPostretirementBenefitContributions94.671.180.585.768.375.069.8

us-gaap:ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital



Period End2020-03-31
Value5
Percentage of ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:ATCHoldCoLLC



Period End2020-03-31
Value5
Percentage of ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital100.0

wec:TransmissionAffiliate



Period End2020-03-31
Value0.0
Percentage of ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital0.0

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

us-gaap:ProceedsFromIssuanceOfDebt

wec:MERCSeniorNotes2.69dueMay12025, us-gaap:SubsequentEvent, wec:MinnesotaEnergyResourcesCorporation



Period End2020-04-29
Value50
Percentage of ProceedsFromIssuanceOfDebt100.0

wec:MGUSeniorNotes2.69dueMay12025, us-gaap:SubsequentEvent, wec:MGU



Period End2020-04-29
Value60
Percentage of ProceedsFromIssuanceOfDebt120.0

us-gaap:ProceedsFromLifeInsurancePolicies



Period End2020-03-312019-03-31
Value88
Percentage of ProceedsFromLifeInsurancePolicies100.0100.0

us-gaap:ProceedsFromOtherShortTermDebt



Period End2020-03-312019-03-31
Value3400
Percentage of ProceedsFromOtherShortTermDebt100.00.0

us-gaap:ShortTermDebtType

us-gaap:NotesPayableOtherPayables



Period End2020-03-30
Value340
Percentage of ProceedsFromOtherShortTermDebt0.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value-2-6-8-3-3-10-1-30-30-20-10-2190-12-10464-2570-1272-30100
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfRestrictedInvestments



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
Value17000010200160008
Percentage of ProceedsFromSaleOfRestrictedInvestments100.00.0100.00.0100.0100.0100.00.0100.0100.00.00.0100.0

us-gaap:ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets



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
Value1521910137012713505410625
Percentage of ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromStockOptionsExercised



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value1601617321583251095151321314381814215271213143223194633
Percentage of ProceedsFromStockOptionsExercised100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProvisionForDoubtfulAccounts



Period End2020-03-31
Value28
Percentage of ProvisionForDoubtfulAccounts100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value0.0
Percentage of ProvisionForDoubtfulAccounts0.0

wec:Illinois



Period End2020-03-31
Value14
Percentage of ProvisionForDoubtfulAccounts50.0

wec:OtherStates



Period End2020-03-31
Value700000.0
Percentage of ProvisionForDoubtfulAccounts2.4

wec:PublicUtility



Period End2020-03-31
Value28
Percentage of ProvisionForDoubtfulAccounts100.0

wec:Wisconsin



Period End2020-03-31
Value13
Percentage of ProvisionForDoubtfulAccounts47.6

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value8687868787848484848787878785899110087825959
Percentage of RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfCommercialPaper



Period End2020-03-312019-03-31
Value343294
Percentage of RepaymentsOfCommercialPaper100.0100.0

us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues

us-gaap:RevenueNotFromContractWithCustomer

srt:ConsolidationEliminations, wec:Otheroperatingrevenues



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-98-89-86-91-97-97
Percentage of RevenueNotFromContractWithCustomer100.0100.0100.0100.0100.0100.0

us-gaap:CorporateAndOther, wec:Otheroperatingrevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value100000.0100000.00.0100000.0200000.0300000.0100000.0300000.0100000.0
Percentage of RevenueNotFromContractWithCustomer-0.10.0-0.0-0.1-0.20.0-0.1-0.30.0

wec:Illinois, wec:Otheroperatingrevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1414810-8-54-50
Percentage of RevenueNotFromContractWithCustomer-14.20.0-8.9-11.68.90.0-4.76.00.0

wec:NonUtilityEnergyInfrastructure, wec:Otheroperatingrevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value989898989897979796
Percentage of RevenueNotFromContractWithCustomer-100.00.0-109.7-113.1-106.90.0-100.0-100.00.0

wec:OtherStates, wec:Otheroperatingrevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2000-4000-6
Percentage of RevenueNotFromContractWithCustomer-2.20.0-1.0-0.74.50.0-0.30.40.0

wec:PublicUtility, wec:Otheroperatingrevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value21161114-5-47-1-3
Percentage of RevenueNotFromContractWithCustomer-21.90.0-13.0-17.16.10.0-8.11.40.0

wec:Wisconsin, wec:Otheroperatingrevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value512460343
Percentage of RevenueNotFromContractWithCustomer-5.50.0-3.1-4.7-7.30.0-3.1-5.00.0

wec:TypesofOperatingRevenues

wec:Otheroperatingrevenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value212620260-48-1-3
Percentage of RevenueNotFromContractWithCustomer-22.00.0-22.7-30.3-1.00.0-8.21.10.0

wec:TypesofOperatingRevenues, wec:TypesofOtherOperatingRevenues

wec:Otheroperatingrevenues, wec:Alternativerevenuesutility



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8711-19-13-1-14-16
Percentage of RevenueNotFromContractWithCustomer-8.60.0-1.6-1.321.50.02.014.50.0

wec:Otheroperatingrevenues, wec:Latepaymentcharges



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value12891213891111
Percentage of RevenueNotFromContractWithCustomer-12.30.0-10.8-13.8-14.40.0-9.7-11.40.0

wec:Otheroperatingrevenues, wec:Leases



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1991370021
Percentage of RevenueNotFromContractWithCustomer-1.10.0-10.4-15.2-8.10.0-0.5-2.00.0

us-gaap:AwardType, us-gaap:SubsequentEventType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue

us-gaap:RestrictedStock, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-312017-01-31
Value91.4968.1864.9758.1
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue100.0100.0100.0100.0

us-gaap:AwardType, us-gaap:SubsequentEventType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid

us-gaap:PerformanceShares, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-31
Value34187
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid100.0100.0100.0

us-gaap:AwardType, us-gaap:SubsequentEventType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross

us-gaap:EmployeeStockOption, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-312017-01-31
Value512139.0476418.0660655.0552215.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross100.0100.0100.0100.0

us-gaap:AwardType, us-gaap:SubsequentEventType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue

us-gaap:EmployeeStockOption, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-312017-01-31
Value10.828.67.847.45
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue100.0100.0100.0100.0

us-gaap:AwardType, us-gaap:SubsequentEventType

us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice

us-gaap:EmployeeStockOption, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-312017-01-31
Value91.4968.1866.0258.31
Percentage of ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-31
Value161617328325
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value16161732158325
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised100.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:Parent



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value16161732158325
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised100.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:StockRepurchasedDuringPeriodValue



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value403135703022415108348233926452662824
Percentage of StockRepurchasedDuringPeriodValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value40313570302241510
Percentage of StockRepurchasedDuringPeriodValue100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Parent



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value40313570302241510
Percentage of StockRepurchasedDuringPeriodValue100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockholdersEquityOther



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-5-2-2-1-4-4-2
Percentage of StockholdersEquityOther100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-5-3-2-1-3-4-4-2-2
Percentage of StockholdersEquityOther100.0103.496.6100.00.097.6102.2100.00.0

us-gaap:NoncontrollingInterest



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value0.0100000.0-100000.00.0400000.00.00.00.00.0
Percentage of StockholdersEquityOther-0.0-3.43.4-0.00.0-0.0-0.0-0.00.0

us-gaap:Parent



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-5-3-2-1-3-4-4-2-2
Percentage of StockholdersEquityOther100.0103.496.6100.00.0100.0100.0100.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value0.00.00.00.00.0-100000.0100000.00.00.0
Percentage of StockholdersEquityOther-0.0-0.0-0.0-0.00.02.4-2.2-0.00.0

us-gaap:TaxesExcludingIncomeAndExciseTaxes



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value5253495048475149484748504948493131303030302929293030302828
Percentage of TaxesExcludingIncomeAndExciseTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidatedEntities, us-gaap:DerivativeInstrumentRisk

us-gaap:UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss

srt:ParentCompany, us-gaap:InterestRateSwap



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-400-3-1-3000
Percentage of UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss100.0100.0100.0100.0100.0100.0100.00.00.0

wec:CapitalContributions



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value315183111912122227
Percentage of CapitalContributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:ATCHoldCoLLC



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value0000210073
Percentage of CapitalContributions0.01.92.211.819.57.76.25.534.112.7

wec:TransmissionAffiliate



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value3151839181212222715393311223
Percentage of CapitalContributions100.098.197.888.280.592.393.8100.0100.0100.00.00.00.00.00.00.00.00.00.00.0

wec:EffectiveIncomeTaxReconciliationTaxexpensebenefitfederalexcessdeferredtaxamortizationWisconsinunprotected



Period End2020-03-312019-03-31
Value-220
Percentage of EffectiveIncomeTaxReconciliationTaxexpensebenefitfederalexcessdeferredtaxamortizationWisconsinunprotected100.00.0

wec:EffectiveIncomeTaxreconciliationFederalexcessdeferredtaxamortizationWIUnprotectedpercent



Period End2020-03-312019-03-31
Value-0.0410.0
Percentage of EffectiveIncomeTaxreconciliationFederalexcessdeferredtaxamortizationWIUnprotectedpercent100.00.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:RelatedPartyTransactionChargesToRelatedParty

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value699348544443454444522
Percentage of RelatedPartyTransactionChargesToRelatedParty100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AwardType, us-gaap:SubsequentEventType

wec:Taxbenefitfromawardsotherthanoptions

us-gaap:PerformanceShares, us-gaap:SubsequentEvent



Period End2020-03-312019-03-312018-01-31
Value841
Percentage of Taxbenefitfromawardsotherthanoptions100.0100.0100.0

wec:Taxrepairsamount



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1-32-30-30-29-36-35-22-25
Percentage of Taxrepairsamount100.0100.0100.0100.0100.0100.0100.0100.0100.0

wec:Taxrepairspercentage



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.003-0.006000000000000005-0.125-0.121-0.061-0.015-0.143-0.08-0.053
Percentage of Taxrepairspercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:AccountsPayableRelatedPartiesCurrentAndNoncurrent

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value29292929292828282431292929283030302819
Percentage of AccountsPayableRelatedPartiesCurrentAndNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccountsReceivableGross



Period End2020-03-31
Value1341
Percentage of AccountsReceivableGross100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value2
Percentage of AccountsReceivableGross0.2

wec:Illinois



Period End2020-03-31
Value404
Percentage of AccountsReceivableGross30.2

wec:NonUtilityEnergyInfrastructure



Period End2020-03-31
Value5
Percentage of AccountsReceivableGross0.4

wec:OtherStates



Period End2020-03-31
Value79
Percentage of AccountsReceivableGross5.9

wec:PublicUtility



Period End2020-03-31
Value1333
Percentage of AccountsReceivableGross99.4

wec:Wisconsin



Period End2020-03-31
Value849
Percentage of AccountsReceivableGross63.3

us-gaap:AccountsReceivableNet



Period End2020-03-31
Value1176
Percentage of AccountsReceivableNet100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value2
Percentage of AccountsReceivableNet0.2

wec:Illinois



Period End2020-03-31
Value311
Percentage of AccountsReceivableNet26.5

wec:NonUtilityEnergyInfrastructure



Period End2020-03-31
Value5
Percentage of AccountsReceivableNet0.5

wec:OtherStates



Period End2020-03-31
Value75
Percentage of AccountsReceivableNet6.4

wec:PublicUtility



Period End2020-03-31
Value1168
Percentage of AccountsReceivableNet99.3

wec:Wisconsin



Period End2020-03-31
Value781
Percentage of AccountsReceivableNet66.4

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:AccountsReceivableRelatedPartiesCurrent

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value2332232111111211210
Percentage of AccountsReceivableRelatedPartiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductOrService, us-gaap:LossContingenciesByNatureOfContingency

us-gaap:AccrualForEnvironmentalLossContingencies

us-gaap:NaturalGasUsRegulated, wec:ManufacturedGasPlantRemediation



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value589589631631631616617617
Percentage of AccrualForEnvironmentalLossContingencies100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedEnvironmentalLossContingenciesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value58958963163163161661761761761761762263063360861761762861132
Percentage of AccruedEnvironmentalLossContingenciesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdditionalPaidInCapitalCommonStock



Period End2020-03-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value416741864250427843094347300
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivable



Period End2020-03-312019-12-31
Value164140
Percentage of AllowanceForDoubtfulAccountsReceivable100.0100.0

us-gaap:StatementBusinessSegments

wec:Illinois



Period End2020-03-312019-12-31
Value9375
Percentage of AllowanceForDoubtfulAccountsReceivable56.554.2

wec:NonUtilityEnergyInfrastructure



Period End2020-03-31
Value0.0
Percentage of AllowanceForDoubtfulAccountsReceivable0.0

wec:OtherStates



Period End2020-03-312019-12-31
Value34
Percentage of AllowanceForDoubtfulAccountsReceivable2.42.9

wec:PublicUtility



Period End2020-03-312019-12-31
Value164139
Percentage of AllowanceForDoubtfulAccountsReceivable99.999.9

wec:Wisconsin



Period End2020-03-312019-12-31
Value6759
Percentage of AllowanceForDoubtfulAccountsReceivable41.142.8

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value16414013714316314915315716014311211112310810910911411312874615861585748
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetsNoncurrent



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
Value329863285832604320953172831228307223012729804293772918928779281612795427148
Percentage of AssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-31
Value52835244
Percentage of AssetsNoncurrent16.016.0

us-gaap:ShortTermDebtType

us-gaap:CommercialPaper

us-gaap:CommercialPaper



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-09-30
Value48783068612621145144017881444860661
Percentage of CommercialPaper100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxLiabilitiesNet



Period End2020-03-312019-12-31
Value38703769
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0

us-gaap:DeferredRevenueNoncurrent



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
Value428497502508514520525531538543549554561566569572576579588596604614627639651664676689702709714727740754767781795805791778764739545
Percentage of DeferredRevenueNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value04564573
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value8524826583
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear1000.01273.292.5137.768.31214.8107.697.4

us-gaap:DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value56151510152323512151714412537691315
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:CoalContract, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value000010001100121112
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement5.25.83.85.111.72.53.52.520.48.95.74.06.94.87.13.526.220.2

wec:CommodityContractFinancialTransmissionRights, us-gaap:FairValueInputsLevel3, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value03610371116147111591313
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement15.544.939.565.830.146.550.070.527.835.546.567.411.712.336.235.618.036.4

wec:CommodityContractNaturalGas, us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value31526695112121051001
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement67.220.333.116.558.339.641.722.831.514.517.86.915.924.321.726.99.816.2

wec:CommodityContractNaturalGas, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value02320100033392481211
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement12.129.023.612.70.011.31.32.59.331.523.620.065.558.233.933.027.915.2

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:CoalContract, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value00001000110012112
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement5.25.83.85.111.72.53.52.520.48.95.74.06.94.87.13.520.2

wec:CommodityContractFinancialTransmissionRights, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value0361037111614711159133
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement15.544.939.565.830.146.550.070.527.835.546.567.411.712.336.235.636.4

wec:CommodityContractNaturalGas, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value438468962564113414223
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement79.349.356.729.158.350.943.025.340.746.041.426.981.482.555.559.831.3

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value3152669523312105101231
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement67.220.333.116.558.339.641.724.542.624.224.28.615.924.822.827.927.928.322.27.2

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value124212111544102610133347
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement17.234.827.417.711.713.88.35.129.640.329.324.072.463.040.936.454.135.434.847.1

us-gaap:FairValueInputsLevel3, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value0361037111614711159131357
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement15.544.939.565.830.146.550.070.527.835.546.567.411.712.336.235.618.036.443.045.8

us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value561515101523235121517144125379
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value315304322433143413
Percentage of DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value151012911192137121413362233461511172015
Percentage of DerivativeAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeCollateralRightToReclaimCash



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value283428303264111624251916212230423511
Percentage of DerivativeCollateralRightToReclaimCash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentsAndHedges



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value4615159152123511141714382434581214
Percentage of DerivativeInstrumentsAndHedges100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk

us-gaap:CoalContract



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value000010000000111111
Percentage of DerivativeInstrumentsAndHedges4.93.01.93.210.91.31.92.215.75.14.24.17.13.95.43.830.219.3

wec:CommodityContractFinancialTransmissionRights



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value03610371116147111591313
Percentage of DerivativeInstrumentsAndHedges22.046.340.367.133.748.453.272.029.437.351.069.012.113.438.339.120.840.9

wec:CommodityContractNaturalGas



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value3384579525541131131912
Percentage of DerivativeInstrumentsAndHedges73.250.757.829.755.450.344.924.143.147.537.825.180.982.255.056.332.129.5

us-gaap:DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value446632001101101261060
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk

us-gaap:CoalContract



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value000000000001100245
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent0.00.01.50.00.00.00.00.00.012.5100.073.385.7100.081.8100.065.756.0

us-gaap:InterestRateSwap



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value43443100
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent100.078.065.772.7100.090.50.00.0

wec:CommodityContractNaturalGas



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value002100001100000013
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent0.022.032.827.30.09.5100.0100.0100.087.50.026.714.30.018.20.026.933.0

us-gaap:DerivativeInstrumentsAndHedgesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value10001010001003130100
Percentage of DerivativeInstrumentsAndHedgesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk

us-gaap:CoalContract



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value100000.0200000.0300000.0300000.0200000.0200000.0400000.0100000.0300000.0500000.0300000.00.00.0500000.0500000.00.00.0300000.0
Percentage of DerivativeInstrumentsAndHedgesNoncurrent5.9100.0100.0100.018.233.328.620.0100.083.321.40.00.014.735.70.00.027.3

us-gaap:InterestRateSwap



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value0.00.00.00.00.00.0800000.00.0
Percentage of DerivativeInstrumentsAndHedgesNoncurrent0.00.00.00.00.00.057.10.0

wec:CommodityContractNaturalGas



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value100000000010020300
Percentage of DerivativeInstrumentsAndHedgesNoncurrent94.10.00.00.081.866.714.380.00.016.778.6100.0100.085.364.397.075.045.5

us-gaap:DerivativeLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-312013-12-312012-12-31
Value10776331012343121535361201
Percentage of DerivativeLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeLiabilityCollateralRightToReclaimCashOffset



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312018-03-312017-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value1820182111400121910
Percentage of DerivativeLiabilityCollateralRightToReclaimCashOffset100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0

us-gaap:DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value222123240432393310341322
Percentage of DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value322831314742511684251949594612
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:CoalContract, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value00000000023312121412
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement0.30.70.60.32.11.311.55.96.934.442.571.479.239.763.330.020.8

us-gaap:InterestRateSwap, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1066632
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement30.520.821.821.578.729.1

wec:CommodityContractNaturalGas, us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value22212323043237120010816
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement69.274.074.176.519.159.573.580.866.760.324.625.00.08.322.42.518.028.0

wec:CommodityContractNaturalGas, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value01100010132200152125
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement0.04.53.51.60.010.126.57.727.532.841.031.221.48.320.727.144.342.9

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:CoalContract, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value000000000233121212
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement0.30.70.60.32.11.311.55.96.934.442.571.479.239.763.320.8

us-gaap:InterestRateSwap, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1066632
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement30.520.821.821.578.729.1

wec:CommodityContractNaturalGas, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value22222424054241044002541
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement69.278.577.578.119.169.6100.088.594.193.165.656.221.416.743.129.670.8

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value222123230423712002112211711
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement69.274.074.176.519.159.580.866.760.324.626.27.112.539.79.525.736.336.892.0

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value107873301445323183637241
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement30.826.025.923.580.940.519.233.339.775.473.892.987.560.390.574.363.751.68.0

us-gaap:FairValueInputsLevel3, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value0000000000000000050
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.011.60.0

us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value32283131472511684251959
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EmployeeRelatedLiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value128199167159125185143130107169136140107163127134102169154135589571707396907571100101897810588
Percentage of EmployeeRelatedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnergyRelatedInventory



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
Value391549593461330548608466376539672510417587654494470687719562289400379304234329367317266360342335311382368339284379422390337379344
Percentage of EnergyRelatedInventory100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnergyRelatedInventoryNaturalGasInStorage



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value67227266130392322741213420930113745223298120892843101301247773989193
Percentage of EnergyRelatedInventoryNaturalGasInStorage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnergyRelatedInventoryOtherFossilFuel



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value928790946088106123127118145155163158146156163183182182125117165169182181
Percentage of EnergyRelatedInventoryOtherFossilFuel100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:EquityMethodInvestmentOwnershipPercentage

wec:ATCHoldCoLLC



Period End2020-03-31
Value0.75
Percentage of EquityMethodInvestmentOwnershipPercentage100.0

wec:AmericanTransmissionCompanyLLC



Period End2020-03-31
Value0.6
Percentage of EquityMethodInvestmentOwnershipPercentage80.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-292015-03-312013-12-312012-12-31
Value0.60.60.60.60.60.60.60.60.60.60.60.60.60.60.60.60.60.60.60.2620.2620.2620.262
Percentage of EquityMethodInvestmentOwnershipPercentage80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:EquityMethodInvestments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value171717201720169616701665161315961598155315601544151314431453142514221380999424
Percentage of EquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RelatedPartyTransactionsByRelatedParty

wec:ATCHoldCoLLC



Period End2020-03-312019-12-31
Value3136
Percentage of EquityMethodInvestments1.82.1

wec:AmericanTransmissionCompanyLLC



Period End2020-03-312019-12-31
Value16861684
Percentage of EquityMethodInvestments98.297.9

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

wec:ATCHoldCoLLC



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value3136403940403938373734-20
Percentage of EquityMethodInvestments1.82.12.42.42.42.42.42.42.42.40.20.3-0.20.0

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value168616841679165616301625157415581561151515601544151314431453142514221380999987431424423416409402378
Percentage of EquityMethodInvestments98.297.997.697.697.697.697.697.697.697.6100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.00.00.00.00.00.0

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:EquitySecuritiesFvNiRestricted

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value548578777465115120
Percentage of EquitySecuritiesFvNiRestricted100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value548578777465115120
Percentage of EquitySecuritiesFvNiRestricted100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312012-12-31
Value036103711161471115913130237101434
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByMeasurementBasis

us-gaap:FinanceLeaseLiability

us-gaap:CarryingReportedAmountFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value4445482122
Percentage of FinanceLeaseLiability100.0100.0100.0100.0100.0

us-gaap:GuaranteeObligationsMaximumExposure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302011-12-312011-09-302011-06-302011-03-312010-12-31
Value149156131128130119131130100836471484723723326631229727622222
Percentage of GuaranteeObligationsMaximumExposure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteeObligationsByNature

us-gaap:GuaranteeTypeOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value12111210111112111110111087383858707167
Percentage of GuaranteeObligationsMaximumExposure8.17.59.28.18.510.09.78.911.113.017.214.016.815.916.016.522.122.623.924.2

us-gaap:IndemnificationGuarantee



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value1211121011111211111011108789910106
Percentage of GuaranteeObligationsMaximumExposure8.17.59.28.18.510.09.78.911.113.017.214.016.815.93.74.03.73.33.72.5

us-gaap:StandbyLettersOfCredit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value9510310310110292104103715535442929363628282819
Percentage of GuaranteeObligationsMaximumExposure64.166.078.279.179.077.679.179.771.165.855.361.560.561.415.315.610.69.19.67.2

us-gaap:SuretyBond



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
Value99999999999910101111103836
Percentage of GuaranteeObligationsMaximumExposure6.66.37.57.67.17.77.07.19.811.615.013.222.722.84.64.83.812.412.3

wec:CommodityTransactionsGuarantee



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value31316675558888152147168174161156
Percentage of GuaranteeObligationsMaximumExposure21.220.15.15.25.54.74.24.38.19.712.511.364.063.163.455.954.256.6

us-gaap:GuaranteeObligationsByNature, dei:LegalEntity

wec:CommodityTransactionsGuarantee, wec:Bluewater



Period End2020-03-312019-12-312019-09-302019-06-30
Value6622
Percentage of GuaranteeObligationsMaximumExposure4.24.02.02.1

wec:CommodityTransactionsGuarantee, wec:UpperMichiganEnergyResourcesCorporation



Period End2020-03-312019-12-312019-09-302019-06-30
Value4444
Percentage of GuaranteeObligationsMaximumExposure2.82.63.03.1

us-gaap:InventoryRawMaterialsAndSuppliesNetOfReserves



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302014-12-31
Value230234236236230226227221213211225216208206209217217219226249150
Percentage of InventoryRawMaterialsAndSuppliesNetOfReserves100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity



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
Value3140280028002800280028002800280028002800250025002500250025002500250025002300
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidatedEntities, us-gaap:CreditFacility

srt:ParentCompany, us-gaap:LineOfCredit



Period End2020-03-31
Value340
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity10.8

us-gaap:LongTermDebtAndCapitalLeaseObligations



Period End2020-03-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value11194112119994874691589124418643634453461439323875
Percentage of LongTermDebtAndCapitalLeaseObligations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value69469369276636636536929395784270970815815715742434241232473295
Percentage of LongTermDebtAndCapitalLeaseObligationsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherMinorityInterests



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value1101101051019723370
Percentage of OtherMinorityInterests100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:ShortTermDebtType

us-gaap:OtherShortTermBorrowings

us-gaap:NotesPayableOtherPayables



Period End2020-03-312019-12-31
Value3400
Percentage of OtherShortTermBorrowings100.00.0

us-gaap:PreferredStockValue



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
Value30303030303030303030303030303030303081813030303030303030303030303030303030303030303030
Percentage of PreferredStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value3030303030303030303030303030303030308181303030303030303030
Percentage of PreferredStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EstimateOfFairValueFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value2829292828282828293029302828292928277880282725252526262726
Percentage of PreferredStockValue93.197.096.192.893.193.193.194.495.7100.397.4100.395.194.798.497.794.189.896.798.392.189.183.684.983.685.586.588.885.5

us-gaap:PrepaidExpenseCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value200261166254167256137178165210142181161204217235243285148145145140227206190239179210165213323
Percentage of PrepaidExpenseCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RegulatoryAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-31
Value35783527403640354037385536732840313831011271110813801265201091144372219
Percentage of RegulatoryAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductOrService, us-gaap:LossContingenciesByNatureOfContingency, us-gaap:RegulatoryAsset

us-gaap:NaturalGasUsRegulated, wec:ManufacturedGasPlantRemediation, us-gaap:EnvironmentalRestorationCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value686685719707697687
Percentage of RegulatoryAssets19.219.417.817.517.317.8

us-gaap:RegulatoryAsset

us-gaap:AssetRetirementObligationCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-31
Value18813722221222318522419217917317
Percentage of RegulatoryAssets5.33.95.55.35.54.86.16.85.75.61.4

us-gaap:DeferredDerivativeGainLoss



Period End2020-03-312019-12-312018-12-31
Value313317
Percentage of RegulatoryAssets0.91.00.5

us-gaap:DeferredIncomeTaxCharges



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value457457451424384369272152852481761691761218978
Percentage of RegulatoryAssets12.813.011.210.59.59.67.40.69.18.013.815.312.89.67.9412.6

us-gaap:EnvironmentalRestorationCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value686685719707697687680676702697454747485668
Percentage of RegulatoryAssets19.219.417.817.517.317.818.523.822.422.53.64.23.43.85.0356.5

us-gaap:OtherRegulatoryAssetsLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-31
Value776073707511710516318823477
Percentage of RegulatoryAssets2.21.71.81.71.93.12.95.76.07.66.1

us-gaap:PensionAndOtherPostretirementPlansCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value10421066112611531173119310711142
Percentage of RegulatoryAssets29.130.227.928.629.131.029.240.2

us-gaap:StrandedCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312010-12-312009-12-31
Value85185610321031102783277815138157
Percentage of RegulatoryAssets23.824.325.625.625.521.621.20.512.1826.2

wec:SystemSupportResource



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value140151320319317316315298
Percentage of RegulatoryAssets3.94.37.97.97.98.28.610.5

wec:UncollectibleExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-31
Value835239434738393525
Percentage of RegulatoryAssets2.31.51.01.11.21.01.11.20.8

wec:WePowerGeneration



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-31
Value18252938364348715445
Percentage of RegulatoryAssets0.50.70.71.00.91.11.32.51.71.5

us-gaap:RegulatoryAssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-312011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value1220362827503037503705353545454545882
Percentage of RegulatoryAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RegulatoryAssetsNoncurrent



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
Value3566350639994007400938053643364529292803310731083084308730043031306030642805279612701271109610941098110812671285132313391280128712861238108210551057109011391143117911921261
Percentage of RegulatoryAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RegulatoryLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-31
Value4142408042484330437842883985376015971426830879868915162720899172310
Percentage of RegulatoryLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RegulatoryLiability

us-gaap:DeferredIncomeTaxCharges



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-31
Value222222482358238924012406227921340
Percentage of RegulatoryLiabilities53.755.155.555.254.856.157.256.80.0

us-gaap:OtherRegulatoryAssetsLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-31
Value126121413144944354936
Percentage of RegulatoryLiabilities0.30.20.30.30.30.31.21.22.23.54.4

us-gaap:PensionAndOtherPostretirementPlansCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value349354227231235238106114
Percentage of RegulatoryLiabilities8.48.75.35.35.45.62.73.0

us-gaap:RemovalCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-31
Value1195118113131304133013291313129412621209741
Percentage of RegulatoryLiabilities28.829.030.930.130.431.033.034.479.184.889.2

wec:Decoupling



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value353646485130221
Percentage of RegulatoryLiabilities0.80.91.11.11.20.70.60.0

wec:EarningsSharingMechanisms



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value404328302930202
Percentage of RegulatoryLiabilities1.01.10.70.70.70.70.50.1

wec:ElectricTransmissionCosts



Period End2020-03-312019-12-312018-12-31
Value51429
Percentage of RegulatoryLiabilities1.21.00.2

wec:EnergyCostsRefundableThroughRateAdjustments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-31
Value162894590103392542887618
Percentage of RegulatoryLiabilities3.92.21.12.12.40.90.61.15.65.42.3

wec:EnergyEfficiencyProgramCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value3530334245313021
Percentage of RegulatoryLiabilities0.90.80.81.01.00.70.80.6

wec:UncollectibleExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-31
Value3939323129302324363130
Percentage of RegulatoryLiabilities0.91.00.80.70.70.70.60.72.32.23.6

us-gaap:RegulatoryLiabilityCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312016-12-312015-12-312014-12-312011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-31
Value1558749861033625413333015151566121168222310
Percentage of RegulatoryLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RegulatoryLiabilityNoncurrent



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
Value398739924198424342744251396039593924371815341574156315631451146914111392131213138208308398548748798308548538668729069119029189319248838808908968861084
Percentage of RegulatoryLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:RelatedPartyTransactionDueFromToRelatedParty

wec:TransmissionAffiliate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value22203229
Percentage of RelatedPartyTransactionDueFromToRelatedParty100.0100.0100.00.0100.0100.0

us-gaap:RestrictedCashNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value5044465256592522231920212634
Percentage of RestrictedCashNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShortTermBorrowings



Period End2020-03-312019-12-312017-12-312016-12-312015-12-312009-12-31
Value827830144486010954
Percentage of ShortTermBorrowings100.0100.0100.0100.0100.0100.0

us-gaap:ShortTermDebtType

us-gaap:ShortTermDebtWeightedAverageInterestRate

us-gaap:CommercialPaper



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value0.03030.020.02230.02580.02750.02920.02350.02360.02240.01770.01380.01420.01180.00960.00690.00660.00610.00680.00320.00220.0020.0030.00270.0030.0028
Percentage of ShortTermDebtWeightedAverageInterestRate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NotesPayableOtherPayables



Period End2020-03-31
Value0.0212
Percentage of ShortTermDebtWeightedAverageInterestRate70.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-31
Value10484102541018610148101129842984297569698949192258960
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-31
Value-7-4-7-6-4-2224222
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-0.1-0.0-0.1-0.1-0.0-0.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-31
Value416741864185419742134250426142714267427842814309
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest39.740.841.141.441.743.243.343.844.045.146.448.1

us-gaap:NoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-31
Value11011010510197233700000
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest1.11.11.01.01.00.20.40.00.00.00.00.0

us-gaap:Parent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-31
Value1034410113100511001699849788977597259667946191958929
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest98.798.698.798.798.799.599.399.799.799.799.799.7

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-31
Value618059275869582157725538550854495392517649084613
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest59.057.857.657.457.156.356.055.955.654.553.251.5

wec:AccountsReceivablePastDueGreaterthan90Days



Period End2020-03-31
Value97
Percentage of AccountsReceivablePastDueGreaterthan90Days100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value0.0
Percentage of AccountsReceivablePastDueGreaterthan90Days0.0

wec:Illinois



Period End2020-03-31
Value35
Percentage of AccountsReceivablePastDueGreaterthan90Days36.8

wec:NonUtilityEnergyInfrastructure



Period End2020-03-31
Value0.0
Percentage of AccountsReceivablePastDueGreaterthan90Days0.0

wec:OtherStates



Period End2020-03-31
Value3
Percentage of AccountsReceivablePastDueGreaterthan90Days4.0

wec:PublicUtility



Period End2020-03-31
Value97
Percentage of AccountsReceivablePastDueGreaterthan90Days100.0

wec:Wisconsin



Period End2020-03-31
Value57
Percentage of AccountsReceivablePastDueGreaterthan90Days59.2

us-gaap:BusinessAcquisition, dei:LegalEntity

wec:Acquisitionpurchaseprice

wec:BloomingGroveWindEnergyCenter, wec:WECInfrastructureLLC



Period End2020-02-192020-01-27
Value44345
Percentage of Acquisitionpurchaseprice100.0100.0

wec:ThunderheadWindEnergyLLC, wec:WECInfrastructureLLC



Period End2020-02-192019-12-312019-08-31
Value43338338
Percentage of Acquisitionpurchaseprice97.70.00.0

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

wec:BloomingGroveWindEnergyCenter, us-gaap:SubsequentEvent, wec:WECInfrastructureLLC



Period End2020-02-192020-01-27
Value44345
Percentage of Acquisitionpurchaseprice100.0100.0

wec:ThunderheadWindEnergyLLC, us-gaap:SubsequentEvent, wec:WECInfrastructureLLC



Period End2020-02-19
Value43
Percentage of Acquisitionpurchaseprice97.7

us-gaap:BusinessAcquisition, dei:LegalEntity

wec:Additionalownershipinterestacquired

wec:BloomingGroveWindEnergyCenter, wec:WECInfrastructureLLC



Period End2020-02-19
Value0.1
Percentage of Additionalownershipinterestacquired100.0

wec:ThunderheadWindEnergyLLC, wec:WECInfrastructureLLC



Period End2020-02-19
Value0.1
Percentage of Additionalownershipinterestacquired100.0

us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType

wec:UpstreamWindEnergyCenter, us-gaap:SubsequentEvent



Period End2020-02-19
Value0.1
Percentage of Additionalownershipinterestacquired100.0

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

wec:BloomingGroveWindEnergyCenter, us-gaap:SubsequentEvent, wec:WECInfrastructureLLC



Period End2020-02-19
Value0.1
Percentage of Additionalownershipinterestacquired100.0

wec:ThunderheadWindEnergyLLC, us-gaap:SubsequentEvent, wec:WECInfrastructureLLC



Period End2020-02-19
Value0.1
Percentage of Additionalownershipinterestacquired100.0

wec:UpstreamWindEnergyCenter, us-gaap:SubsequentEvent, wec:WECInfrastructureLLC



Period End2020-04-30
Value0.1
Percentage of Additionalownershipinterestacquired0.0

us-gaap:BusinessAcquisition, dei:LegalEntity

wec:Bonusdepreciationpercentage

wec:BloomingGroveWindEnergyCenter, wec:WECInfrastructureLLC



Period End2020-01-27
Value1.0
Percentage of Bonusdepreciationpercentage100.0

us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType

wec:BloomingGroveWindEnergyCenter, us-gaap:SubsequentEvent



Period End2020-01-27
Value1.0
Percentage of Bonusdepreciationpercentage100.0

us-gaap:BusinessAcquisition, dei:LegalEntity

wec:CapacityOfGenerationUnit

wec:BloomingGroveWindEnergyCenter, wec:WECInfrastructureLLC



Period End2020-01-27
Value250.0
Percentage of CapacityOfGenerationUnit100.0

us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType

wec:BloomingGroveWindEnergyCenter, us-gaap:SubsequentEvent



Period End2020-01-27
Value250.0
Percentage of CapacityOfGenerationUnit100.0

wec:DerivativeInstrumentsAndHedgesLiabilitiesGrossCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value272424241542410562141742493911
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesGrossCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk

us-gaap:CoalContract



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0000000000121119106
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesGrossCurrent0.40.80.40.45.91.70.014.37.56.025.935.464.373.729.857.324.313.7

us-gaap:InterestRateSwap



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value5221000
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesGrossCurrent18.311.310.07.841.26.90.0

wec:CommodityContractNaturalGas



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value222122220541394400252838
Percentage of DerivativeInstrumentsAndHedgesLiabilitiesGrossCurrent81.487.989.691.852.991.4100.085.792.594.074.163.125.021.148.934.567.878.6

wec:GuaranteeObligationsMaximumExposureExpireLessThanOneYear



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value2122171721294040647347553838120116139172175140
Percentage of GuaranteeObligationsMaximumExposureExpireLessThanOneYear100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteeObligationsByNature

us-gaap:GuaranteeTypeOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value00000000000000002020204
Percentage of GuaranteeObligationsMaximumExposureExpireLessThanOneYear4.24.10.00.00.01.71.21.20.80.71.10.91.31.30.50.614.811.911.83.1

us-gaap:StandbyLettersOfCredit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value11115132525465428382827363618182819
Percentage of GuaranteeObligationsMaximumExposureExpireLessThanOneYear5.75.45.75.826.347.862.762.071.574.961.170.272.472.130.031.013.410.716.314.1

us-gaap:SuretyBond



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
Value99998999999710101011103836
Percentage of GuaranteeObligationsMaximumExposureExpireLessThanOneYear46.744.656.255.541.031.322.422.815.113.320.614.226.426.68.79.77.322.420.9

wec:CommodityTransactionsGuarantee



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value9106675558888736889958983
Percentage of GuaranteeObligationsMaximumExposureExpireLessThanOneYear43.445.938.138.732.719.213.813.912.611.117.214.760.858.764.455.051.059.3

wec:GuaranteeObligationsMaximumExposureExpireOverThreeYears



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value127133112109106898989101010977104105117129122135
Percentage of GuaranteeObligationsMaximumExposureExpireOverThreeYears100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteeObligationsByNature

us-gaap:GuaranteeTypeOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value111011910101111101010977303138495062
Percentage of GuaranteeObligationsMaximumExposureExpireOverThreeYears8.88.110.08.79.511.812.712.4100.0100.0100.0100.0100.0100.029.229.532.538.541.246.2

us-gaap:StandbyLettersOfCredit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value9410110110096787878000000000000
Percentage of GuaranteeObligationsMaximumExposureExpireOverThreeYears73.876.290.091.390.588.287.387.60.00.00.00.00.00.00.20.20.20.20.00.0

wec:CommodityTransactionsGuarantee



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value22210000000000747479797273
Percentage of GuaranteeObligationsMaximumExposureExpireOverThreeYears17.415.70.00.00.00.00.00.00.00.00.00.070.670.367.361.458.853.8

wec:GuaranteeObligationsMaximumExposureExpireWithinOneToThreeYears



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value00112110250771212129900
Percentage of GuaranteeObligationsMaximumExposureExpireWithinOneToThreeYears100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteeObligationsByNature

us-gaap:GuaranteeTypeOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value00000000000000660000
Percentage of GuaranteeObligationsMaximumExposureExpireWithinOneToThreeYears0.00.064.375.039.175.075.00.00.00.00.00.00.00.054.056.71.11.050.050.0

us-gaap:StandbyLettersOfCredit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value000010002507511009900
Percentage of GuaranteeObligationsMaximumExposureExpireWithinOneToThreeYears50.050.035.716.747.816.716.7100.099.6100.0100.076.461.171.41.61.798.999.050.050.0

us-gaap:SuretyBond



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
Value0000000000010000000
Percentage of GuaranteeObligationsMaximumExposureExpireWithinOneToThreeYears0.00.00.08.313.08.38.30.00.40.00.023.638.928.64.80.00.00.00.0

wec:CommodityTransactionsGuarantee



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value000000000000550000
Percentage of GuaranteeObligationsMaximumExposureExpireWithinOneToThreeYears50.050.00.00.00.00.00.00.00.00.00.00.039.741.70.00.00.00.0

us-gaap:BusinessAcquisition, dei:LegalEntity

wec:Ownershipinterestofwindgeneratingfacilityacquired

wec:BloomingGroveWindEnergyCenter, wec:WECInfrastructureLLC



Period End2020-01-27
Value0.8
Percentage of Ownershipinterestofwindgeneratingfacilityacquired100.0

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

wec:BloomingGroveWindEnergyCenter, us-gaap:SubsequentEvent, wec:WECInfrastructureLLC



Period End2020-01-27
Value0.8
Percentage of Ownershipinterestofwindgeneratingfacilityacquired100.0

wec:Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect



Period End2020-03-31
Value0.934
Percentage of Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect100.0

us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther



Period End2020-03-31
Value0.0
Percentage of Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect0.0

wec:Illinois



Period End2020-03-31
Value1.0
Percentage of Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect107.1

wec:NonUtilityEnergyInfrastructure



Period End2020-03-31
Value0.0
Percentage of Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect0.0

wec:OtherStates



Period End2020-03-31
Value0.0
Percentage of Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect0.0

wec:PublicUtility



Period End2020-03-31
Value0.934
Percentage of Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect100.0

wec:Wisconsin



Period End2020-03-31
Value0.957
Percentage of Percentofaccountsreceivablepastduegreaterthan90dayswithregulatorymechanismstocollect102.5

wec:TotalCommonShareholdersEquity



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
Value1034410113100511001699849788977597259667946191959152912589298654
Percentage of TotalCommonShareholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Line plots across dimensions of each concept

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MajorCustomers, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, wec:TypesofOperatingRevenues


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofNonUtilityOperatingRevenues, wec:TypesofOperatingRevenues


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, wec:TypesofNonUtilityOperatingRevenues, wec:TypesofOperatingRevenues


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:StatementBusinessSegments, wec:TypesofOperatingRevenues


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService, wec:TypesofOperatingRevenues


us-gaap:Revenues us-gaap:StatementBusinessSegments


us-gaap:OperatingIncomeLoss us-gaap:StatementBusinessSegments


us-gaap:OperatingIncomeLoss us-gaap:ProductOrService, us-gaap:StatementBusinessSegments


us-gaap:InterestExpense us-gaap:StatementBusinessSegments


us-gaap:InterestExpense us-gaap:ProductOrService, us-gaap:StatementBusinessSegments


us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:StatementEquityComponents


us-gaap:Goodwill us-gaap:StatementBusinessSegments


us-gaap:LongTermDebt us-gaap:FairValueByMeasurementBasis


us-gaap:DepreciationDepletionAndAmortization us-gaap:StatementBusinessSegments


us-gaap:DepreciationDepletionAndAmortization us-gaap:ProductOrService, us-gaap:StatementBusinessSegments