false--12-31FY201900007833258515900000887870000014920000014000000000450000092000002.082.212.360.013250000003155231923154345310.03220.550.45362000001231000003050000017320000031200000183900000180000006000000060000012000001000000080000013000000.03600.06000.0600100100251001001000.01100100251001001000.010001010001600004300005000000228650045000100000015000000000260000444980000026000000440000000P3YP1Y0.0250.0280.0270.0070.0160.0250.330.3300000.0050100100294000000.5250.52520000000.2010.1010P1YP1YP1YP1YP1Y0.650.651.0222220.500.500.500.500.33330.3310.00250.0050 0000783325 2019-01-01 2019-12-31 0000783325 2020-01-31 0000783325 2019-06-30 0000783325 2018-01-01 2018-12-31 0000783325 2017-01-01 2017-12-31 0000783325 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2018-01-01 2018-12-31 0000783325 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2019-01-01 2019-12-31 0000783325 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2017-01-01 2017-12-31 0000783325 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2019-12-31 0000783325 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2018-12-31 0000783325 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2017-12-31 0000783325 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2018-12-31 0000783325 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2017-12-31 0000783325 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2017-01-01 2017-12-31 0000783325 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2018-01-01 2018-12-31 0000783325 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2019-01-01 2019-12-31 0000783325 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2019-12-31 0000783325 2019-12-31 0000783325 2018-12-31 0000783325 2017-12-31 0000783325 2016-12-31 0000783325 wec:BishopHillIIIWindEnergyCenterMember 2018-01-01 2018-12-31 0000783325 wec:UpstreamWindEnergyLLCMember 2019-01-01 2019-12-31 0000783325 us-gaap:PreferredStockMember 2016-12-31 0000783325 wec:TotalEquityMember 2018-01-01 2018-12-31 0000783325 us-gaap:PreferredStockMember 2017-12-31 0000783325 us-gaap:PreferredStockMember 2019-01-01 2019-12-31 0000783325 us-gaap:AdditionalPaidInCapitalMember 2018-01-01 2018-12-31 0000783325 us-gaap:NoncontrollingInterestMember 2019-01-01 2019-12-31 0000783325 us-gaap:AdditionalPaidInCapitalMember 2017-12-31 0000783325 us-gaap:ParentMember 2019-01-01 2019-12-31 0000783325 wec:TotalEquityMember 2017-01-01 2017-12-31 0000783325 us-gaap:NoncontrollingInterestMember 2017-01-01 2017-12-31 0000783325 us-gaap:CommonStockMember 2019-01-01 2019-12-31 0000783325 us-gaap:RetainedEarningsMember 2018-01-01 2018-12-31 0000783325 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-12-31 0000783325 us-gaap:AdditionalPaidInCapitalMember 2019-12-31 0000783325 us-gaap:PreferredStockMember 2017-01-01 2017-12-31 0000783325 us-gaap:AdditionalPaidInCapitalMember 2017-01-01 2017-12-31 0000783325 us-gaap:PreferredStockMember 2018-01-01 2018-12-31 0000783325 us-gaap:ParentMember 2017-12-31 0000783325 us-gaap:ParentMember 2016-12-31 0000783325 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-01-01 2019-12-31 0000783325 us-gaap:RetainedEarningsMember 2019-01-01 2019-12-31 0000783325 us-gaap:RetainedEarningsMember 2017-12-31 0000783325 us-gaap:ParentMember 2017-01-01 2017-12-31 0000783325 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-01-01 2017-12-31 0000783325 wec:TotalEquityMember 2019-01-01 2019-12-31 0000783325 us-gaap:NoncontrollingInterestMember 2018-01-01 2018-12-31 0000783325 us-gaap:AdditionalPaidInCapitalMember 2019-01-01 2019-12-31 0000783325 us-gaap:CommonStockMember 2018-01-01 2018-12-31 0000783325 us-gaap:ParentMember 2018-01-01 2018-12-31 0000783325 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-12-31 0000783325 us-gaap:RetainedEarningsMember 2019-12-31 0000783325 us-gaap:ParentMember 2019-12-31 0000783325 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-12-31 0000783325 us-gaap:PreferredStockMember 2018-12-31 0000783325 us-gaap:RetainedEarningsMember 2017-01-01 2017-12-31 0000783325 wec:AccumulatedOtherComprehensiveIncomeAttributabletoParentOtherMember 2018-01-01 2018-12-31 0000783325 us-gaap:AdditionalPaidInCapitalMember 2018-12-31 0000783325 wec:TotalEquityMember 2016-12-31 0000783325 wec:ASU201802ReclassificationOfStrandedTaxEffectsInAOCIMember 2017-12-31 0000783325 us-gaap:RetainedEarningsMember 2018-12-31 0000783325 us-gaap:AdditionalPaidInCapitalMember 2016-12-31 0000783325 us-gaap:CommonStockMember 2017-01-01 2017-12-31 0000783325 us-gaap:CommonStockMember 2016-12-31 0000783325 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-01-01 2018-12-31 0000783325 us-gaap:NoncontrollingInterestMember 2018-12-31 0000783325 us-gaap:NoncontrollingInterestMember 2017-12-31 0000783325 wec:TotalEquityMember 2017-12-31 0000783325 us-gaap:CommonStockMember 2018-12-31 0000783325 us-gaap:NoncontrollingInterestMember 2016-12-31 0000783325 us-gaap:ParentMember 2018-12-31 0000783325 wec:TotalEquityMember 2018-12-31 0000783325 us-gaap:PreferredStockMember 2019-12-31 0000783325 us-gaap:CommonStockMember 2017-12-31 0000783325 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-12-31 0000783325 us-gaap:RetainedEarningsMember 2016-12-31 0000783325 wec:TotalEquityMember 2019-12-31 0000783325 us-gaap:NoncontrollingInterestMember 2019-12-31 0000783325 us-gaap:CommonStockMember 2019-12-31 0000783325 wec:TransmissionAffiliateMember 2019-12-31 0000783325 wec:ATCHoldCoLLCMember 2019-12-31 0000783325 wec:ElectricOperationsMember 2019-12-31 0000783325 wec:NaturalGasOperationsMember 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember 2019-01-01 2019-12-31 0000783325 wec:WholesalecustomerMember us-gaap:ElectricityUsRegulatedMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:WePowerrevenuesMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:UpstreamWindEnergyCenterMember us-gaap:AlternativeEnergyMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember srt:MaximumMember naics:ZZ811412 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:WePowerrevenuesMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:AlternativeEnergyMember 2019-01-01 2019-12-31 0000783325 wec:PGLAndNSGMember 2019-12-31 0000783325 wec:PGLAndNSGMember 2018-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember 2017-01-01 2017-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember 2019-01-01 2019-12-31 0000783325 wec:MGUMember 2017-01-01 2017-12-31 0000783325 wec:WisconsinGasLLCMember 2019-01-01 2019-12-31 0000783325 wec:MGUMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember 2019-01-01 2019-12-31 0000783325 wec:MinnesotaEnergyResourcesCorporationMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinGasLLCMember 2017-01-01 2017-12-31 0000783325 wec:MGUMember 2018-01-01 2018-12-31 0000783325 wec:MinnesotaEnergyResourcesCorporationMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember 2017-01-01 2017-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember 2019-01-01 2019-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember 2018-01-01 2018-12-31 0000783325 wec:NorthShoreGasCompanyMember 2018-01-01 2018-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember 2019-01-01 2019-12-31 0000783325 wec:MinnesotaEnergyResourcesCorporationMember 2017-01-01 2017-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember 2017-01-01 2017-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember 2017-01-01 2017-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember 2018-01-01 2018-12-31 0000783325 wec:NorthShoreGasCompanyMember 2019-01-01 2019-12-31 0000783325 wec:NorthShoreGasCompanyMember 2017-01-01 2017-12-31 0000783325 wec:WisconsinGasLLCMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember 2018-01-01 2018-12-31 0000783325 srt:MinimumMember us-gaap:SoftwareAndSoftwareDevelopmentCostsMember 2019-01-01 2019-12-31 0000783325 srt:MaximumMember wec:ERGSMember 2019-01-01 2019-12-31 0000783325 srt:MaximumMember wec:PWGSMember 2019-01-01 2019-12-31 0000783325 srt:MinimumMember wec:ERGSMember 2019-01-01 2019-12-31 0000783325 srt:MinimumMember wec:PWGSMember 2019-01-01 2019-12-31 0000783325 srt:MaximumMember us-gaap:SoftwareAndSoftwareDevelopmentCostsMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinGasMember 2017-01-01 2017-12-31 0000783325 wec:WBSMember 2019-01-01 2019-12-31 0000783325 wec:OthersubsidiariesMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinGasMember 2019-01-01 2019-12-31 0000783325 wec:WBSMember 2017-01-01 2017-12-31 0000783325 wec:WisconsinGasMember 2018-01-01 2018-12-31 0000783325 wec:WBSMember 2018-01-01 2018-12-31 0000783325 wec:OthersubsidiariesMember 2017-01-01 2017-12-31 0000783325 wec:OthersubsidiariesMember 2019-01-01 2019-12-31 0000783325 wec:WBSMember wec:RetailOperationsMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:RetailOperationsMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:WholesaleOperationsMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:WholesaleOperationsMember 2019-01-01 2019-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember wec:RetailOperationsMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinGasMember wec:RetailOperationsMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:RetailOperationsMember 2019-01-01 2019-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2019-12-31 0000783325 srt:MaximumMember us-gaap:PerformanceSharesMember 2019-01-01 2019-12-31 0000783325 us-gaap:AccountingStandardsUpdate201609Member 2016-12-31 0000783325 us-gaap:PerformanceSharesMember 2019-01-01 2019-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2019-01-01 2019-12-31 0000783325 srt:MinimumMember us-gaap:PerformanceSharesMember 2019-01-01 2019-12-31 0000783325 srt:DirectorMember wec:GrantedafterJanuary12017Member us-gaap:RestrictedStockMember 2019-01-01 2019-12-31 0000783325 srt:ManagementMember us-gaap:RestrictedStockMember 2019-01-01 2019-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2017-01-01 2017-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2018-01-01 2018-12-31 0000783325 srt:DirectorMember wec:GrantedpriortoJanuary12017Member us-gaap:RestrictedStockMember 2019-01-01 2019-12-31 0000783325 srt:OfficerMember wec:GrantedafterJanuary12017Member us-gaap:RestrictedStockMember 2019-01-01 2019-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2019-01-01 2019-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2018-01-01 2018-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2017-01-01 2017-12-31 0000783325 2019-01-01 2019-01-31 0000783325 2019-01-01 0000783325 us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0000783325 wec:WECInfrastructureLLCMember wec:CoyoteRidgeWindLLCMember 2018-12-01 2018-12-31 0000783325 wec:WECInfrastructureLLCMember wec:CoyoteRidgeWindLLCMember 2018-12-31 0000783325 wec:WECInfrastructureLLCMember wec:BishopHillIIIWindEnergyCenterMember 2018-08-01 2018-08-31 0000783325 wec:WECInfrastructureLLCMember wec:BishopHillIIIWindEnergyCenterMember 2018-08-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ForwardWindEnergyCenterAcquisitionMember 2018-04-30 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ForwardWindEnergyCenterAcquisitionMember 2018-04-01 2018-04-30 0000783325 wec:BluewaterMember 2017-06-01 2017-06-30 0000783325 wec:BluewaterMember 2017-06-30 0000783325 wec:WECInfrastructureLLCMember wec:UpstreamWindEnergyCenterMember 2019-01-01 2019-12-31 0000783325 wec:WECInfrastructureLLCMember wec:CoyoteRidgeWindLLCMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ForwardWindEnergyCenterAcquisitionMember 2019-01-01 2019-12-31 0000783325 wec:BluewaterMember 2019-01-01 2019-12-31 0000783325 wec:WECInfrastructureLLCMember wec:BishopHillIIIWindEnergyCenterMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:WECInfrastructureLLCMember wec:CoyoteRidgeWindLLCMember 2019-12-01 2019-12-31 0000783325 wec:WECInfrastructureLLCMember wec:UpstreamWindEnergyCenterMember 2019-01-31 0000783325 wec:WECInfrastructureLLCMember wec:ThunderheadWindEnergyLLCMember 2019-08-31 0000783325 wec:WECInfrastructureLLCMember wec:ThunderheadWindEnergyLLCMember 2019-12-31 0000783325 wec:WECInfrastructureLLCMember wec:ThunderheadWindEnergyLLCMember us-gaap:SubsequentEventMember 2020-02-19 0000783325 wec:UpstreamWindEnergyCenterMember 2019-01-31 0000783325 wec:WECInfrastructureLLCMember wec:BloomingGroveWindEnergyCenterMember us-gaap:SubsequentEventMember 2020-02-19 0000783325 wec:ThunderheadWindEnergyLLCMember 2019-08-31 0000783325 wec:BishopHillIIIWindEnergyCenterMember 2018-08-31 0000783325 wec:BloomingGroveWindEnergyCenterMember us-gaap:SubsequentEventMember 2020-01-27 0000783325 wec:CoyoteRidgeWindLLCMember 2018-12-31 0000783325 wec:ForwardWindEnergyCenterAcquisitionMember 2018-04-30 0000783325 wec:ForwardWindEnergyCenterAcquisitionMember 2018-04-01 2018-04-30 0000783325 wec:WECInfrastructureLLCMember wec:UpstreamWindEnergyCenterMember us-gaap:SubsequentEventMember 2020-02-19 0000783325 wec:CoyoteRidgeWindLLCMember 2018-12-01 2018-12-31 0000783325 wec:WECInfrastructureLLCMember wec:BishopHillIIIWindEnergyCenterMember 2018-12-31 0000783325 wec:BishopHillIIIWindEnergyCenterMember 2018-08-01 2018-08-31 0000783325 wec:WECInfrastructureLLCMember wec:BloomingGroveWindEnergyCenterMember us-gaap:SubsequentEventMember 2020-01-27 0000783325 wec:UpstreamWindEnergyCenterMember us-gaap:SubsequentEventMember 2020-02-19 0000783325 wec:ThunderheadWindEnergyLLCMember 2019-08-01 2019-08-31 0000783325 wec:UpstreamWindEnergyCenterMember 2019-01-01 2019-01-31 0000783325 wec:BishopHillIIIWindEnergyCenterMember 2018-12-31 0000783325 wec:WECInfrastructureLLCMember wec:UpstreamWindEnergyCenterMember 2019-01-01 2019-01-31 0000783325 us-gaap:CorporateAndOtherMember 2019-01-01 2019-12-31 0000783325 wec:IncometaxexpenseMember us-gaap:CorporateAndOtherMember 2019-01-01 2019-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:OtherMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:WePowerrevenuesMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:OtherMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:TransferredOverTimeMember us-gaap:AlternativeEnergyMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:TransferredOverTimeMember naics:ZZ811412 us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:TransferredOverTimeMember naics:ZZ811412 us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:DistributedrenewablesolarprojectrevenuesMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:DistributedrenewablesolarprojectrevenuesMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:TransferredOverTimeMember us-gaap:AlternativeEnergyMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherutilityMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TransportationcustomersMember us-gaap:NaturalGasUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:CommercialandIndustrialCustomerMember us-gaap:NaturalGasUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherStatesMember wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:MaterialReconcilingItemsMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinMember 2019-01-01 2019-12-31 0000783325 wec:OtherStatesMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:PublicUtilityMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinMember wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:IllinoisMember wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember 2019-01-01 2019-12-31 0000783325 us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:MaterialReconcilingItemsMember wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:PublicUtilityMember wec:OtheroperatingrevenuesMember 2019-01-01 2019-12-31 0000783325 wec:IllinoisMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:DowntownMilwaukeeSteamCustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:WholesalecustomerMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:ResaleCustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:SmallcommercialandindustrialMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:WholesalecustomerMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:TotalRetailCustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherretailcustomerMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:LargecommercialandindustrialcustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:SmallcommercialandindustrialMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherretailcustomerMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:OtherutilityMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:LargecommercialandindustrialcustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:DowntownMilwaukeeSteamCustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:ResaleCustomersMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 wec:ResidentialcustomerMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherutilityMember us-gaap:ElectricityUsRegulatedMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2019-01-01 2019-12-31 0000783325 us-gaap:MaterialReconcilingItemsMember 2018-01-01 2018-12-31 0000783325 us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherStatesMember wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:PublicUtilityMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinMember 2018-01-01 2018-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:MaterialReconcilingItemsMember wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 wec:IllinoisMember wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 wec:IllinoisMember 2018-01-01 2018-12-31 0000783325 us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:CorporateAndOtherMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtherStatesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinMember wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:NonUtilityEnergyInfrastructureMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OthernonutilityrevenuesMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:PublicUtilityMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember us-gaap:MaterialReconcilingItemsMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:OtherStatesMember us-gaap:TransferredOverTimeMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember us-gaap:CorporateAndOtherMember us-gaap:RevenueFromContractWithCustomerMember 2018-01-01 2018-12-31 0000783325 wec:PublicUtilityMember wec:OtheroperatingrevenuesMember 2018-01-01 2018-12-31 0000783325 wec:OtheroperatingrevenuesMember wec:LatepaymentchargesMember 2019-01-01 2019-12-31 0000783325 wec:OtheroperatingrevenuesMember wec:AlternativerevenuesutilityMember 2019-01-01 2019-12-31 0000783325 wec:OtheroperatingrevenuesMember wec:AlternativerevenuesutilityMember 2018-01-01 2018-12-31 0000783325 wec:OtheroperatingrevenuesMember wec:LatepaymentchargesMember 2018-01-01 2018-12-31 0000783325 wec:OtheroperatingrevenuesMember wec:LeasesMember 2018-01-01 2018-12-31 0000783325 wec:OtheroperatingrevenuesMember wec:LeasesMember 2019-01-01 2019-12-31 0000783325 us-gaap:EnvironmentalRestorationCostsMember 2019-12-31 0000783325 us-gaap:EnvironmentalRestorationCostsMember 2019-01-01 2019-12-31 0000783325 wec:ElectricTransmissionCostsMember 2019-12-31 0000783325 wec:ElectricTransmissionCostsMember 2018-12-31 0000783325 us-gaap:DeferredDerivativeGainLossMember 2018-12-31 0000783325 us-gaap:RemovalCostsMember 2018-12-31 0000783325 wec:MinesDeferralMember 2018-12-31 0000783325 us-gaap:PensionAndOtherPostretirementPlansCostsMember 2018-12-31 0000783325 wec:UncollectibleExpenseMember 2018-12-31 0000783325 us-gaap:DeferredIncomeTaxChargesMember 2018-12-31 0000783325 wec:DecouplingMember 2018-12-31 0000783325 us-gaap:DeferredIncomeTaxChargesMember 2019-12-31 0000783325 us-gaap:DeferredDerivativeGainLossMember 2019-12-31 0000783325 us-gaap:OtherRegulatoryAssetsLiabilitiesMember 2019-12-31 0000783325 us-gaap:OtherRegulatoryAssetsLiabilitiesMember 2018-12-31 0000783325 wec:ElectricTransmissionCostsMember 2018-12-31 0000783325 wec:UncollectibleExpenseMember 2019-12-31 0000783325 wec:MinesDeferralMember 2019-12-31 0000783325 wec:DecouplingMember 2019-12-31 0000783325 wec:EnergyEfficiencyProgramCostsMember 2019-12-31 0000783325 wec:EarningsSharingMechanismsMember 2019-12-31 0000783325 us-gaap:RemovalCostsMember 2019-12-31 0000783325 wec:EarningsSharingMechanismsMember 2018-12-31 0000783325 wec:EnergyCostsRefundableThroughRateAdjustmentsMember 2018-12-31 0000783325 us-gaap:PensionAndOtherPostretirementPlansCostsMember 2019-12-31 0000783325 wec:EnergyEfficiencyProgramCostsMember 2018-12-31 0000783325 wec:EnergyCostsRefundableThroughRateAdjustmentsMember 2019-12-31 0000783325 us-gaap:DeferredIncomeTaxChargesMember 2018-12-31 0000783325 us-gaap:OtherRegulatoryAssetsLiabilitiesMember 2019-12-31 0000783325 wec:WePowerGenerationMember 2018-12-31 0000783325 us-gaap:AssetRetirementObligationCostsMember 2018-12-31 0000783325 us-gaap:PensionAndOtherPostretirementPlansCostsMember 2018-12-31 0000783325 us-gaap:AssetRetirementObligationCostsMember 2019-12-31 0000783325 us-gaap:StrandedCostsMember 2019-12-31 0000783325 us-gaap:DeferredDerivativeGainLossMember 2018-12-31 0000783325 wec:UncollectibleExpenseMember 2019-12-31 0000783325 us-gaap:DeferredIncomeTaxChargesMember 2019-12-31 0000783325 us-gaap:PensionAndOtherPostretirementPlansCostsMember 2019-12-31 0000783325 us-gaap:EnvironmentalRestorationCostsMember 2018-12-31 0000783325 wec:SystemSupportResourceMember 2019-12-31 0000783325 wec:WePowerGenerationMember 2019-12-31 0000783325 us-gaap:OtherRegulatoryAssetsLiabilitiesMember 2018-12-31 0000783325 wec:SystemSupportResourceMember 2018-12-31 0000783325 wec:ElectricTransmissionCostsMember 2019-12-31 0000783325 us-gaap:StrandedCostsMember 2018-12-31 0000783325 wec:UncollectibleExpenseMember 2018-12-31 0000783325 us-gaap:DeferredDerivativeGainLossMember 2019-12-31 0000783325 wec:WisconsinMember 2017-12-31 0000783325 wec:PleasantPrairiePowerPlantMember 2019-12-31 0000783325 wec:PresqueIslePowerPlantPIPPMember 2019-01-01 2019-12-31 0000783325 wec:PleasantPrairiePowerPlantMember 2019-01-01 2019-12-31 0000783325 wec:PresqueIslePowerPlantPIPPMember 2019-12-31 0000783325 wec:PulliamPowerPlantMember 2019-12-31 0000783325 wec:EdgewaterUnit4Member 2019-12-31 0000783325 us-gaap:UnregulatedOperationMember 2019-12-31 0000783325 wec:WePowerGeneratingFacilitiesMember us-gaap:UnregulatedOperationMember 2019-12-31 0000783325 us-gaap:UnregulatedOperationMember 2018-12-31 0000783325 wec:RenewableGenerationMember us-gaap:UnregulatedOperationMember 2018-12-31 0000783325 us-gaap:UnregulatedOperationMember wec:NonUtilityEnergyInfrastructureMember 2019-12-31 0000783325 wec:CorporateServicesEquipmentMember us-gaap:UnregulatedOperationMember 2018-12-31 0000783325 us-gaap:ElectricGenerationEquipmentMember us-gaap:RegulatedOperationMember 2018-12-31 0000783325 wec:PropertyplantandequipmenttobeabandonedMember us-gaap:RegulatedOperationMember 2018-12-31 0000783325 us-gaap:PropertyPlantAndEquipmentOtherTypesMember us-gaap:RegulatedOperationMember 2018-12-31 0000783325 us-gaap:ElectricGenerationEquipmentMember us-gaap:RegulatedOperationMember 2019-12-31 0000783325 us-gaap:RegulatedOperationMember 2018-12-31 0000783325 us-gaap:RegulatedOperationMember 2019-12-31 0000783325 us-gaap:PropertyPlantAndEquipmentOtherTypesMember us-gaap:UnregulatedOperationMember 2019-12-31 0000783325 us-gaap:UnregulatedOperationMember wec:NonUtilityEnergyInfrastructureMember 2018-12-31 0000783325 wec:RenewableGenerationMember us-gaap:UnregulatedOperationMember 2019-12-31 0000783325 us-gaap:ElectricDistributionMember us-gaap:RegulatedOperationMember 2019-12-31 0000783325 wec:WePowerGeneratingFacilitiesMember us-gaap:UnregulatedOperationMember 2018-12-31 0000783325 us-gaap:PropertyPlantAndEquipmentOtherTypesMember us-gaap:UnregulatedOperationMember 2018-12-31 0000783325 us-gaap:ElectricDistributionMember us-gaap:RegulatedOperationMember 2018-12-31 0000783325 wec:PropertyplantandequipmenttobeabandonedMember us-gaap:RegulatedOperationMember 2019-12-31 0000783325 wec:NaturalGasStorageTransportationandDistributionMember us-gaap:RegulatedOperationMember 2018-12-31 0000783325 wec:NaturalGasStorageTransportationandDistributionMember us-gaap:RegulatedOperationMember 2019-12-31 0000783325 wec:NaturalGasStorageEquipmentMember us-gaap:UnregulatedOperationMember 2019-12-31 0000783325 wec:CorporateServicesEquipmentMember us-gaap:UnregulatedOperationMember 2019-12-31 0000783325 us-gaap:PropertyPlantAndEquipmentOtherTypesMember us-gaap:RegulatedOperationMember 2019-12-31 0000783325 wec:NaturalGasStorageEquipmentMember us-gaap:UnregulatedOperationMember 2018-12-31 0000783325 wec:WisconsinMember 2018-12-31 0000783325 wec:WisconsinMember 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ForwardWindEnergyCenterMember 2019-12-31 0000783325 wec:WePowerMember wec:ERGSUnitsER1andER2Member 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:Weston4Member 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ColumbiaEnergyCenterUnits1And2Member 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:BadgerHollowSolarFarmMember 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:BadgerHollowandTwoCreeksSolarFarmsMember 2018-05-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:BadgerHollowandTwoCreeksSolarFarmsMember 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:TwoCreeksSolarFarmMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:BadgerHollowSolarFarmIIMember 2019-08-01 0000783325 wec:WisconsinElectricPowerCompanyMember 2019-01-01 2019-12-31 0000783325 wec:PulliamPowerPlantMember 2018-01-01 2018-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember 2019-01-01 2019-12-31 0000783325 wec:UpstreamWindEnergyLLCAndCoyoteRidgeWindLLCMember 2019-01-01 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember 2018-01-01 2018-12-31 0000783325 wec:ForwardWindEnergyCenterandBishopHillEnergyIIILLCMember 2018-01-01 2018-12-31 0000783325 2019-07-01 2019-07-01 0000783325 wec:NonUtilityEnergyInfrastructureMember 2018-12-31 0000783325 wec:WisconsinSegmentMember 2018-12-31 0000783325 wec:IllinoisMember 2018-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember 2017-12-31 0000783325 wec:WisconsinSegmentMember 2019-01-01 2019-12-31 0000783325 wec:OtherStatesMember 2017-12-31 0000783325 wec:IllinoisMember 2017-12-31 0000783325 wec:IllinoisMember 2019-12-31 0000783325 wec:OtherStatesMember 2018-12-31 0000783325 wec:OtherStatesMember 2019-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember 2019-12-31 0000783325 wec:WisconsinSegmentMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinSegmentMember 2019-12-31 0000783325 wec:WisconsinSegmentMember 2017-12-31 0000783325 us-gaap:EmployeeStockOptionMember us-gaap:SubsequentEventMember 2020-01-01 2020-03-31 0000783325 us-gaap:RestrictedStockMember us-gaap:SubsequentEventMember 2020-01-01 2020-03-31 0000783325 us-gaap:PerformanceSharesMember 2019-12-31 0000783325 us-gaap:RestrictedStockMember 2017-01-01 2017-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember srt:MinimumMember wec:PublicServiceCommissionofWisconsinMember 2019-01-01 2019-12-31 0000783325 us-gaap:RestrictedStockMember 2018-01-01 2018-12-31 0000783325 us-gaap:PerformanceSharesMember 2018-01-01 2018-12-31 0000783325 us-gaap:SubsequentEventMember 2020-01-01 2020-03-31 0000783325 us-gaap:RestrictedStockMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember srt:MaximumMember wec:SerialPreferredStock360SeriesRedeemableMember wec:Commonstockequitytototalcapitalizationislessthan25Member 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember srt:MaximumMember wec:SerialPreferredStock360SeriesRedeemableMember wec:Commonstockequitytototalcapitalizationislessthan20Member 2019-01-01 2019-12-31 0000783325 us-gaap:PerformanceSharesMember us-gaap:SubsequentEventMember 2020-01-01 2020-03-31 0000783325 us-gaap:PerformanceSharesMember 2017-01-01 2017-12-31 0000783325 us-gaap:RestrictedStockMember 2019-01-01 2019-12-31 0000783325 srt:MaximumMember us-gaap:SubsequentEventMember 2020-01-01 2020-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember srt:MaximumMember wec:SerialPreferredStock360SeriesRedeemableMember wec:Commonstockequitytototalcapitalizationislessthan25Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember srt:MaximumMember wec:SerialPreferredStock360SeriesRedeemableMember wec:Commonstockequitytototalcapitalizationislessthan20Member 2019-12-31 0000783325 srt:MinimumMember us-gaap:SubsequentEventMember 2020-01-01 2020-12-31 0000783325 us-gaap:SubsequentEventMember 2020-01-01 2020-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SerialPreferredStock360SeriesRedeemableMember 2019-01-01 2019-12-31 0000783325 us-gaap:RestrictedStockMember 2018-12-31 0000783325 2019-07-01 2019-09-30 0000783325 2019-01-01 2019-03-31 0000783325 2019-04-01 2019-06-30 0000783325 2019-10-01 2019-12-31 0000783325 us-gaap:EmployeeStockOptionMember 2018-12-31 0000783325 wec:BluewaterGasStorageLLCMember 2019-01-01 2019-12-31 0000783325 wec:ATCHoldingLLCMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember srt:MinimumMember wec:SerialPreferredStock360SeriesRedeemableMember wec:Commonstockequitytototalcapitalizationislessthan25Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember srt:MinimumMember wec:PublicServiceCommissionofWisconsinMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinGasLLCMember srt:MinimumMember wec:PublicServiceCommissionofWisconsinMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SerialPreferredStock25ParValueAuthorized5000000SharesNoneOutstandingMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:WEC0.01parvaluePreferredStockMember 2019-12-31 0000783325 wec:NorthShoreGasCompanyMember wec:A100parvalueCumulativePreferredStockNSGMember 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:A100parvalueCumulativePreferredStockPGLMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SixPerCentPreferredStockMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SerialPreferredStock360SeriesRedeemableMember 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:A100parvaluePreferredStockWPSMember 2019-12-31 0000783325 wec:NorthShoreGasCompanyMember wec:A100parvalueCumulativePreferredStockNSGMember 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SixPerCentPreferredStockMember 2018-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:A100parvalueCumulativePreferredStockPGLMember 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SerialPreferredStock25ParValueAuthorized5000000SharesNoneOutstandingMember 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SerialPreferredStock360SeriesRedeemableMember 2018-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:A100parvaluePreferredStockWPSMember 2018-12-31 0000783325 srt:ParentCompanyMember wec:WEC0.01parvaluePreferredStockMember 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SixPerCentPreferredStockMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SixPerCentPreferredStockMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SerialPreferredStock360SeriesRedeemableMember 2018-01-01 2018-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:CreditfacilitymaturingOctober2022Member 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:CreditfacilitymaturingOctober2022Member 2019-12-31 0000783325 srt:ParentCompanyMember wec:CreditfacilitymaturingOctober2022Member 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:CreditfacilitymaturingOctober2022Member 2019-12-31 0000783325 wec:WisconsinGasMember wec:CreditfacilitymaturingOctober2022Member 2019-12-31 0000783325 us-gaap:CommercialPaperMember 2019-12-31 0000783325 us-gaap:LetterOfCreditMember 2019-12-31 0000783325 us-gaap:CommercialPaperMember 2018-12-31 0000783325 us-gaap:CommercialPaperMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember 2019-01-01 2019-12-31 0000783325 wec:WisconsinGasMember wec:CreditfacilitymaturingOctober2022Member 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:CreditfacilitymaturingOctober2022Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:CreditfacilitymaturingOctober2022Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:CreditfacilitymaturingOctober2022Member 2019-01-01 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:CreditfacilitymaturingOctober2022Member 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember us-gaap:InterestRateSwapMember 2019-12-31 0000783325 wec:ATCHoldingLLCMember wec:ATCHoldingSeniorNotesdueSeptember2029Member 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:WPSSeniorNotesdue2049Member 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:JuniorNotesUnsecured625Due2067Member 2018-12-31 0000783325 srt:ParentCompanyMember wec:WECSeniorNotesdue2022Member 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLSeriesIIIdue2031Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:WPSSeniorNotesdue2049Member 2019-12-31 0000783325 wec:IntegrysHoldingIncMember wec:IntegrysJuniorNotesdue2073Member 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLSeriesGGGdue2029Member 2019-12-31 0000783325 srt:ParentCompanyMember wec:JuniorNotesUnsecured625Due2067Member 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLSeriesIIIdue2031Member 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLFirstandRefundingMortgageBondsdue2033Member 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:DebenturesUnsecured425Due2019Member 2019-01-01 2019-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember wec:UMERCSeniorNotesdue2029Member 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLSeriesGGGdue2029Member 2019-01-01 2019-12-31 0000783325 wec:ATCHoldingLLCMember wec:ATCHoldingSeniorNotesdueSeptember2029Member 2019-01-01 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLFirstandRefundingMortgageBondsdue2019Member 2019-12-31 0000783325 srt:ParentCompanyMember wec:WECEnergyGropuSeniorNotesdue2033Member 2019-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember wec:UMERCSeniorNotesdue2029Member 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember us-gaap:InterestRateSwapMember 2019-01-01 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLFirstandRefundingMortgageBondsdue2019Member 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:WECSeniorNotesdue2022Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinGasLLCMember wec:WGDebenturesdue2024Member 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLSeriesHHHdue2024Member 2019-01-01 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:PGLSeriesHHHdue2024Member 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:WEDebenturesdue2024Member 2019-12-31 0000783325 wec:WisconsinGasLLCMember wec:WGDebenturesdue2024Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:WEDebenturesdue2024Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:DebenturesUnsecured425Due2019Member 2019-12-31 0000783325 wec:WePowerLLCMember wec:WePowerSubsidiariesNotesdue20082033Member 2019-12-31 0000783325 wec:WePowerLLCMember wec:WePowerSubsidiariesNotesdue20112031Member 2019-12-31 0000783325 srt:ParentCompanyMember wec:WECEnergyGroupSeniorNotesdue2020Member 2019-12-31 0000783325 wec:WePowerLLCMember wec:WEPowerSubsidiariesNotesdue20052030Member 2019-12-31 0000783325 wec:WePowerLLCMember wec:Notessecurednonrecourse5.209due20102030MemberMember 2019-12-31 0000783325 wec:BluewaterGasStorageLLCMember wec:BluewaterGasStorageSeniorNotesdue2047Member 2019-12-31 0000783325 wec:IntegrysHoldingIncMember wec:IntegrysSeniorNotesdue2020Member 2019-12-31 0000783325 wec:MinnesotaEnergyResourcesCorporationMember 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember 2019-12-31 0000783325 srt:ParentCompanyMember 2019-12-31 0000783325 wec:ATCHoldingLLCMember 2019-12-31 0000783325 wec:WisconsinGasLLCMember 2019-12-31 0000783325 wec:BluewaterGasStorageLLCMember 2019-12-31 0000783325 wec:NorthShoreGasCompanyMember 2018-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember 2018-12-31 0000783325 wec:WePowerLLCMember 2019-12-31 0000783325 wec:MGUMember 2018-12-31 0000783325 wec:NorthShoreGasCompanyMember 2019-12-31 0000783325 wec:WePowerLLCMember 2018-12-31 0000783325 wec:IntegrysHoldingIncMember 2018-12-31 0000783325 wec:WisconsinEnergyCapitalCorporationMember 2018-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember 2019-12-31 0000783325 wec:BluewaterGasStorageLLCMember 2018-12-31 0000783325 srt:ParentCompanyMember 2018-12-31 0000783325 wec:ATCHoldingLLCMember 2018-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember 2019-12-31 0000783325 wec:IntegrysHoldingIncMember 2019-12-31 0000783325 wec:IntegrysHoldingIncMember wec:IntegrysJuniorNotesdue2073Member 2018-12-31 0000783325 wec:WisconsinGasLLCMember 2018-12-31 0000783325 wec:MGUMember 2019-12-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember 2018-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember 2018-12-31 0000783325 wec:WisconsinEnergyCapitalCorporationMember 2019-12-31 0000783325 wec:MinnesotaEnergyResourcesCorporationMember 2019-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember 2018-12-31 0000783325 wec:IntegrysHoldingIncMember wec:IntegrysJuniorNotesdue2073Member 2019-01-01 2019-12-31 0000783325 wec:FinanceOrCapitalLeaseMember 2018-01-01 2018-12-31 0000783325 wec:FinanceOrCapitalLeaseMember 2019-01-01 2019-12-31 0000783325 wec:FinanceOrCapitalLeaseMember 2017-01-01 2017-12-31 0000783325 wec:TwoCreeksSolarFarmMember 2019-12-31 0000783325 wec:PowerPurchaseContractMember 2019-12-31 0000783325 wec:BadgerHollowSolarFarmMember 2019-12-31 0000783325 wec:BadgerHollowSolarFarmMember 2018-12-31 0000783325 wec:PowerPurchaseContractMember 2018-12-31 0000783325 wec:TwoCreeksSolarFarmMember 2018-12-31 0000783325 wec:PowerPurchaseContractMember 2019-01-01 2019-12-31 0000783325 wec:TwoCreeksSolarFarmMember 2019-01-01 2019-12-31 0000783325 us-gaap:StateAndLocalJurisdictionMember 2019-12-31 0000783325 us-gaap:DomesticCountryMember 2019-12-31 0000783325 2017-12-01 2017-12-31 0000783325 2018-01-01 2018-01-01 0000783325 wec:WisconsinElectricPowerCompanyMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2019-01-01 2019-12-31 0000783325 us-gaap:DomesticCountryMember 2018-12-31 0000783325 us-gaap:ForeignCountryMember 2018-12-31 0000783325 us-gaap:StateAndLocalJurisdictionMember 2018-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2019-12-31 0000783325 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-12-31 0000783325 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0000783325 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0000783325 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:CoalContractMember us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractNaturalGasMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 us-gaap:InterestRateSwapMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember 2018-01-01 2018-12-31 0000783325 wec:CommodityContractPetroleumProductsMember 2018-01-01 2018-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember 2019-01-01 2019-12-31 0000783325 wec:CommodityContractPetroleumProductsMember 2019-01-01 2019-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember 2017-01-01 2017-12-31 0000783325 wec:CommodityContractNaturalGasMember 2019-01-01 2019-12-31 0000783325 wec:CommodityContractNaturalGasMember 2017-01-01 2017-12-31 0000783325 wec:CommodityContractPetroleumProductsMember 2017-01-01 2017-12-31 0000783325 wec:CommodityContractNaturalGasMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:InterestRateSwapMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember us-gaap:InterestRateSwapMember 2018-01-01 2018-12-31 0000783325 us-gaap:InterestRateSwapMember 2019-12-31 0000783325 wec:CommodityContractNaturalGasMember 2018-12-31 0000783325 wec:CommodityContractNaturalGasMember 2019-12-31 0000783325 us-gaap:CoalContractMember 2018-12-31 0000783325 us-gaap:InterestRateSwapMember 2018-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember 2019-12-31 0000783325 us-gaap:CoalContractMember 2019-12-31 0000783325 wec:CommodityContractFinancialTransmissionRightsMember 2018-12-31 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember wec:CommodityTransactionsGuaranteeMember 2019-12-31 0000783325 wec:WECInfrastructureLLCMember wec:CommodityTransactionsGuaranteeMember 2019-12-31 0000783325 us-gaap:IndemnificationGuaranteeMember 2019-12-31 0000783325 wec:BluewaterMember wec:CommodityTransactionsGuaranteeMember 2019-12-31 0000783325 us-gaap:SuretyBondMember 2019-12-31 0000783325 wec:CommodityTransactionsGuaranteeMember 2019-12-31 0000783325 us-gaap:GuaranteeTypeOtherMember 2019-12-31 0000783325 us-gaap:StandbyLettersOfCreditMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueMeasuredAtNetAssetValuePerShareMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueMeasuredAtNetAssetValuePerShareMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:DebtSecurityGovernmentandCorporateNonUSMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel12And3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueMeasuredAtNetAssetValuePerShareMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel12And3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:USTreasurySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:FairValueMeasuredAtNetAssetValuePerShareMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:NetperiodicbenefitcostassumptionsMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:NetperiodicbenefitcostassumptionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:NetperiodicbenefitcostassumptionsMember 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:NetperiodicbenefitcostassumptionsMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:NetperiodicbenefitcostassumptionsMember 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:NetperiodicbenefitcostassumptionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:NetperiodicbenefitcostassumptionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:NetperiodicbenefitcostassumptionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:NetperiodicbenefitcostassumptionsMember 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:NetperiodicbenefitcostassumptionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:NetperiodicbenefitcostassumptionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:NetperiodicbenefitcostassumptionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:NetperiodicbenefitcostassumptionsMember 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:NetperiodicbenefitcostassumptionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:NetperiodicbenefitcostassumptionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:BenefitobligationassumptionsMember 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:BenefitobligationassumptionsMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:BenefitobligationassumptionsMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:BenefitobligationassumptionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:BenefitobligationassumptionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:BenefitobligationassumptionsMember 2018-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember wec:BenefitobligationassumptionsMember 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Pre65Member wec:BenefitobligationassumptionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Post65Member wec:BenefitobligationassumptionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember wec:BenefitobligationassumptionsMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:BenefitobligationassumptionsMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:BenefitobligationassumptionsMember 2018-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-01-01 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-01-01 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember 2019-01-01 2019-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember 2017-01-01 2017-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000783325 wec:PrivateEquityandRealEstateMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000783325 wec:PrivateEquityandRealEstateMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000783325 wec:PrivateEquityandRealEstateMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000783325 wec:PrivateEquityandRealEstateMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000783325 wec:PrivateEquityandRealEstateMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000783325 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000783325 wec:PrivateEquityandRealEstateMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:BenefitobligationassumptionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember wec:NetperiodicbenefitcostassumptionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember wec:NetperiodicbenefitcostassumptionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember wec:NetperiodicbenefitcostassumptionsMember 2018-01-01 2018-12-31 0000783325 wec:IntegrysHoldingIncMember us-gaap:DefinedBenefitPlanDebtSecurityMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap:SubsequentEventMember wec:NetperiodicbenefitcostassumptionsMember 2020-01-01 2020-12-31 0000783325 wec:WisconsinEnergyMember wec:PrivateEquityandRealEstateMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:WisconsinEnergyMember us-gaap:DefinedBenefitPlanEquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:WisconsinEnergyMember us-gaap:DefinedBenefitPlanDebtSecurityMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust2Member 2019-12-31 0000783325 wec:WisconsinEnergyMember us-gaap:DefinedBenefitPlanEquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust2Member 2019-12-31 0000783325 wec:WisconsinEnergyMember us-gaap:DefinedBenefitPlanDebtSecurityMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust1Member 2019-12-31 0000783325 wec:IntegrysHoldingIncMember us-gaap:DefinedBenefitPlanEquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust1Member 2019-12-31 0000783325 wec:WisconsinEnergyMember us-gaap:DefinedBenefitPlanEquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust1Member 2019-12-31 0000783325 us-gaap:PensionPlansDefinedBenefitMember us-gaap:SubsequentEventMember wec:NetperiodicbenefitcostassumptionsMember 2020-01-01 2020-12-31 0000783325 wec:IntegrysHoldingIncMember us-gaap:DefinedBenefitPlanDebtSecurityMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust1Member 2019-12-31 0000783325 wec:WisconsinEnergyMember us-gaap:DefinedBenefitPlanDebtSecurityMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:IntegrysHoldingIncMember wec:PrivateEquityandRealEstateMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:IntegrysHoldingIncMember us-gaap:DefinedBenefitPlanEquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0000783325 wec:IntegrysHoldingIncMember us-gaap:DefinedBenefitPlanEquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust2Member 2019-12-31 0000783325 wec:IntegrysHoldingIncMember us-gaap:DefinedBenefitPlanDebtSecurityMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember wec:Largesttrust2Member 2019-12-31 0000783325 wec:TransmissionAffiliateMember 2017-12-31 0000783325 wec:TransmissionAffiliatesMember 2017-01-01 2017-12-31 0000783325 wec:ATCHoldCoLLCMember 2016-12-31 0000783325 wec:ATCHoldCoLLCMember 2017-01-01 2017-12-31 0000783325 wec:ATCHoldCoLLCMember 2017-12-31 0000783325 wec:TransmissionAffiliateMember 2017-01-01 2017-12-31 0000783325 wec:TransmissionAffiliatesMember 2016-12-31 0000783325 wec:TransmissionAffiliatesMember 2017-12-31 0000783325 wec:TransmissionAffiliateMember 2016-12-31 0000783325 wec:TransmissionAffiliateMember 2018-12-31 0000783325 wec:TransmissionAffiliatesMember 2018-12-31 0000783325 wec:TransmissionAffiliateMember 2019-01-01 2019-12-31 0000783325 wec:ATCHoldCoLLCMember 2019-01-01 2019-12-31 0000783325 wec:TransmissionAffiliatesMember 2019-01-01 2019-12-31 0000783325 wec:TransmissionAffiliatesMember 2019-12-31 0000783325 wec:ATCHoldCoLLCMember 2018-12-31 0000783325 wec:TransmissionAffiliateMember 2019-11-01 2019-11-30 0000783325 wec:TransmissionAffiliateMember 2018-01-01 2018-12-31 0000783325 wec:ATCHoldCoLLCMember 2018-01-01 2018-12-31 0000783325 wec:TransmissionAffiliatesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 us-gaap:CorporateAndOtherMember 2017-01-01 2017-12-31 0000783325 us-gaap:IntersegmentEliminationMember 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember 2017-01-01 2017-12-31 0000783325 wec:ElectricTransmissionSegmentMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember 2017-01-01 2017-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember 2017-01-01 2017-12-31 0000783325 us-gaap:IntersegmentEliminationMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember 2017-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:CorporateAndOtherMember 2017-12-31 0000783325 us-gaap:IntersegmentEliminationMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 us-gaap:IntersegmentEliminationMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 wec:ElectricTransmissionSegmentMember 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember 2017-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 wec:ElectricTransmissionSegmentMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 wec:ElectricTransmissionSegmentMember wec:ExternalRevenuesMember 2017-01-01 2017-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:IntersegmentTransactionsMember 2017-01-01 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:IntersegmentEliminationMember 2019-01-01 2019-12-31 0000783325 us-gaap:IntersegmentEliminationMember 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 wec:ElectricTransmissionSegmentMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember 2019-01-01 2019-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:CorporateAndOtherMember 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 wec:ElectricTransmissionSegmentMember 2019-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 wec:ElectricTransmissionSegmentMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 us-gaap:IntersegmentEliminationMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:IntersegmentEliminationMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 wec:ElectricTransmissionSegmentMember wec:IntersegmentTransactionsMember 2019-01-01 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember 2019-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember wec:ExternalRevenuesMember 2019-01-01 2019-12-31 0000783325 wec:CoyoteRidgeWindLLCMember wec:NonUtilityEnergyInfrastructureMember 2019-12-31 0000783325 wec:ATCHoldCoLLCMember wec:ElectricTransmissionSegmentMember 2019-12-31 0000783325 wec:UpstreamWindEnergyCenterMember wec:NonUtilityEnergyInfrastructureMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember us-gaap:IntersegmentEliminationMember 2018-12-31 0000783325 wec:BishopHillIIIWindEnergyCenterMember wec:NonUtilityEnergyInfrastructureMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember us-gaap:IntersegmentEliminationMember 2019-12-31 0000783325 wec:TransmissionAffiliateMember wec:ElectricTransmissionSegmentMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember us-gaap:IntersegmentEliminationMember 2017-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember 2018-01-01 2018-12-31 0000783325 us-gaap:IntersegmentEliminationMember 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 wec:ElectricTransmissionSegmentMember 2018-01-01 2018-12-31 0000783325 us-gaap:IntersegmentEliminationMember 2018-01-01 2018-12-31 0000783325 wec:ElectricTransmissionSegmentMember 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:IntersegmentEliminationMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 wec:ElectricTransmissionSegmentMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 wec:ElectricTransmissionSegmentMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:CorporateAndOtherMember 2018-12-31 0000783325 wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IllinoisMember 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:WisconsinMember 2018-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember 2018-12-31 0000783325 us-gaap:IntersegmentEliminationMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 us-gaap:CorporateAndOtherMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 us-gaap:PublicUtilitiesMember wec:OtherStatesMember wec:IntersegmentTransactionsMember 2018-01-01 2018-12-31 0000783325 wec:NonUtilityEnergyInfrastructureMember wec:ExternalRevenuesMember 2018-01-01 2018-12-31 0000783325 wec:ATCHoldCoLLCMember 2019-12-31 0000783325 wec:PurchasedPowerAgreementMember 2019-12-31 0000783325 wec:PurchasedPowerAgreementMember 2019-01-01 2019-12-31 0000783325 wec:ATCMember 2018-12-31 0000783325 wec:ATCMember 2019-12-31 0000783325 wec:ATCHoldCoLLCMember 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:NonUtilityEnergyInfrastructureMember wec:PurchasedPowerMember 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:CoalSupplyAndTransportationMember 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:PurchasedPowerMember 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:NaturalGasSupplyAndTransportationMember 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:NuclearMember 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:NonUtilityEnergyInfrastructureMember wec:NaturalGasStorageandTransportationMember 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:RenewablesEfficiencyAndConservationMember stpr:WI 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember us-gaap:ElectricityUsRegulatedMember wec:RenewablesEfficiencyAndConservationMember stpr:WI 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember us-gaap:ElectricityUsRegulatedMember wec:RenewablesEfficiencyAndConservationMember stpr:WI 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:MercuryandAirToxicsMember 2018-12-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember srt:MaximumMember wec:ClimateChangeMember 2019-04-01 2019-04-30 0000783325 us-gaap:ElectricityUsRegulatedMember wec:ClimateChangeMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:RenewablesEfficiencyAndConservationMember stpr:MI 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:SteamElectricEffluentGuidelinesMember 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:ClimateChangeMember 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:ClimateChangeMember 2018-01-01 2018-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:RenewablesEfficiencyAndConservationMember stpr:WI 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:ClimateChangeMember 2019-01-01 2019-12-31 0000783325 us-gaap:ElectricityUsRegulatedMember wec:ClimateChangeMember 2019-09-01 2019-09-30 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:ManufacturedGasPlantRemediationMember 2019-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:ManufacturedGasPlantRemediationMember 2018-12-31 0000783325 us-gaap:NaturalGasUsRegulatedMember wec:ClimateChangeMember 2018-01-01 2018-12-31 0000783325 wec:BostcoLLCMember 2017-01-01 2017-12-31 0000783325 wec:BostcoLLCMember 2019-01-01 2019-12-31 0000783325 wec:BostcoLLCMember 2018-01-01 2018-12-31 0000783325 wec:MinnesotaEnergyResourcesCorporationMember wec:MinnesotaPublicUtilitiesCommissionMPUCMember wec:Rates2018Member 2018-12-01 2018-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ForwardWindEnergyCenterAcquisitionMember 2017-10-01 2017-10-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:BadgerHollowSolarFarmMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2018-05-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:IllinoisCommerceCommissionICCMember 2019-07-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2018-05-01 2018-05-31 0000783325 wec:ThePeoplesGasLightAndCokeCompanyMember wec:IllinoisCommerceCommissionICCMember 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:BadgerHollowSolarFarmAndTwoCreeksSolarProjectMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2018-05-31 0000783325 wec:WEandWGMember wec:LiquefiedNaturalGasFacilitiesMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2019-11-01 0000783325 wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:EarningsSharingMechanismsMember wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:MichiganGasUtilitiesCorporationandUpperMichiganEnergyResourcesCorporationMember wec:MichiganPublicServiceCommissionMPSCMember 2018-02-01 2018-02-28 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2021Member 2019-12-01 2019-12-31 0000783325 wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2017-09-01 2017-09-30 0000783325 wec:UpperMichiganEnergyResourcesCorporationMember 2016-08-01 2016-08-31 0000783325 wec:WisconsinGasLLCMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2017-09-01 2017-09-30 0000783325 wec:WisconsinElectricPowerCompanyWisconsinGasLLCWisconsinPublicServiceCorporationMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2017-09-01 2017-09-30 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:MinnesotaEnergyResourcesCorporationMember wec:MinnesotaPublicUtilitiesCommissionMPUCMember wec:Rates2018Member 2019-01-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:LiquefiedNaturalGasFacilitiesMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2019-11-01 0000783325 wec:WisconsinElectricPowerCompanyMember wec:BadgerHollowSolarFarmIIMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2019-08-01 0000783325 wec:WisconsinElectricPowerCompanyMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2018-05-01 2018-05-31 0000783325 wec:WisconsinGasLLCMember wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2017-09-01 2017-09-30 0000783325 wec:TaxCutsAndJobsActOf2017Member us-gaap:RegulatedOperationMember 2017-12-01 2017-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyWisconsinGasLLCWisconsinPublicServiceCorporationMember wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rate2018And2019Member 2018-05-01 2018-05-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:TaxCutsAndJobsActOf2017Member wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:MichiganPublicServiceCommissionMPSCMember 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinGasLLCMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:ElectricRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:SteamRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinPublicServiceCorporationMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinGasLLCMember wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020and2021Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:NaturalGasRateRequestMember wec:PublicServiceCommissionOfWisconsinPSCWMember wec:Rates2020Member 2019-12-01 2019-12-31 0000783325 wec:WisconsinElectricPowerCompanyMember wec:TwoCreeksSolarFarmMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2019-08-01 0000783325 wec:WisconsinElectricPowerCompanyWisconsinGasLLCWisconsinPublicServiceCorporationMember wec:MichiganNaturalGasStorageFacilityMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2017-01-01 2017-12-31 0000783325 wec:WisconsinGasLLCMember wec:LiquefiedNaturalGasFacilitiesMember wec:PublicServiceCommissionOfWisconsinPSCWMember 2019-11-01 0000783325 2018-04-01 2018-06-30 0000783325 2018-01-01 2018-03-31 0000783325 2018-10-01 2018-12-31 0000783325 2018-07-01 2018-09-30 0000783325 srt:ParentCompanyMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2019-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2019-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2017-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2017-12-31 0000783325 srt:ParentCompanyMember 2017-12-31 0000783325 srt:ParentCompanyMember 2016-12-31 0000783325 srt:ParentCompanyMember wec:SupportAgreementRelatedToWECCDebtMember wec:WisconsinEnergyCapitalCorporationMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:UpperMichiganEnergyResourcesCorporationMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:BluewaterNaturalGasHoldingLLCMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:BostcoLLCMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:BluewaterNaturalGasHoldingLLCMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:UpperMichiganEnergyResourcesCorporationMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:WisvestLLCMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:BluewaterNaturalGasHoldingLLCMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:BostcoLLCMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:WisvestLLCMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:WisvestLLCMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:UpperMichiganEnergyResourcesCorporationMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:BostcoLLCMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:WECInfrastructureLLCMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinGasLLCMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:WePowerLLCMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinGasLLCMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:WePowerLLCMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinElectricPowerCompanyMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinElectricPowerCompanyMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinGasLLCMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:ATCHoldingLLCMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinElectricPowerCompanyMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:WECInfrastructureLLCMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:ATCHoldingLLCMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:WECInfrastructureLLCMember 2017-01-01 2017-12-31 0000783325 srt:ParentCompanyMember wec:WePowerLLCMember 2018-01-01 2018-12-31 0000783325 srt:ParentCompanyMember wec:ATCHoldingLLCMember 2019-01-01 2019-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinEnergyCapitalCorporationMember 2018-12-31 0000783325 srt:ParentCompanyMember wec:WBSMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:WBSMember 2018-12-31 0000783325 srt:ParentCompanyMember wec:BluewaterGasStorageLLCMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:IntegrysHoldingIncMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:BluewaterGasStorageLLCMember 2018-12-31 0000783325 srt:ParentCompanyMember wec:WisconsinEnergyCapitalCorporationMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:IntegrysHoldingIncMember 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-12-31 0000783325 srt:ParentCompanyMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0000783325 srt:ParentCompanyMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:UpperMichiganEnergyResourcesCorporationMember 2019-12-31 0000783325 srt:ParentCompanyMember wec:WisparkLLCMember 2018-12-31 0000783325 srt:ParentCompanyMember wec:UpperMichiganEnergyResourcesCorporationMember 2018-12-31 0000783325 srt:ParentCompanyMember wec:WisparkLLCMember 2019-12-31 iso4217:USD wec:land_easement iso4217:USD xbrli:shares wec:contract wec:performance_obligations xbrli:pure iso4217:USD wec:Dekatherm xbrli:shares wec:customer wec:wind_turbines wec:period wec:solar_projects wec:extension utreg:MW wec:utility wec:number_of_interest_rate_swaps wec:change utreg:MWh utreg:gal utreg:acre utreg:MMBTU utreg:T wec:Years wec:generating_units wec:degreecelsius wec:segment wec:Assurance utreg:Bcf wec:member wec:Filings wec:vote
 
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, DC 20549

FORM 10-K

(Mark One)
ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2019

OR
TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from ________________ to ___________________

Commission
File Number
 
Registrant; State of Incorporation;
Address; and Telephone Number
 
IRS Employer
Identification No.
 
 
image0a14.jpg
 
 
001-09057
 
WEC ENERGY GROUP, INC.
 
39-1391525
(A Wisconsin Corporation)
231 West Michigan Street
P.O. Box 1331
Milwaukee, WI 53201
(414) 221-2345

Securities registered pursuant to Section 12(b) of the Act:
Title of Each Class
 
Trading Symbol(s)
 
Name of Each Exchange on Which Registered
Common Stock, $.01 Par Value
 
WEC
 
New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Yes     No

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

Yes     No




Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yes     No

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

Yes     No

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.
 
Large accelerated filer
 
Accelerated filer
 
 
Non-accelerated filer
 
Smaller reporting company
 
 
 
 
Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes     No

The aggregate market value of the common stock of WEC Energy Group, Inc. held by non-affiliates was $26.3 billion based upon the reported closing price of such securities as of June 30, 2019.

Indicate the number of shares outstanding of each of the registrant's classes of common stock, as of the latest practicable date (January 31, 2020):

Common Stock, $.01 par value, 315,434,531 shares outstanding

Documents incorporated by reference:

Portions of WEC Energy Group, Inc.'s Definitive Proxy Statement on Schedule 14A for its Annual Meeting of Shareholders, to be held on May 6, 2020, are incorporated by reference into Part III hereof.

 



Table of Contents

WEC ENERGY GROUP, INC.
ANNUAL REPORT ON FORM 10-K
For the Year Ended December 31, 2019
TABLE OF CONTENTS
 
 
 
 
 
Page
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

2019 Form 10-K
i
WEC Energy Group, Inc.


Table of Contents

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


2019 Form 10-K
ii
WEC Energy Group, Inc.


Table of Contents

GLOSSARY OF TERMS AND ABBREVIATIONS

The abbreviations and terms set forth below are used throughout this report and have the meanings assigned to them below:
Subsidiaries and Affiliates
 
 
ATC
 
American Transmission Company LLC
ATC Holdco
 
ATC Holdco LLC
ATC Holding
 
ATC Holding LLC
Bishop Hill III
 
Bishop Hill Energy III LLC
Blooming Grove
 
Blooming Grove Wind Energy Center LLC
Bluewater
 
Bluewater Natural Gas Holding, LLC
Bluewater Gas Storage
 
Bluewater Gas Storage, LLC
Bostco
 
Bostco LLC
Coyote Ridge
 
Coyote Ridge Wind, LLC
Integrys
 
Integrys Holding, Inc.
MERC
 
Minnesota Energy Resources Corporation
MGU
 
Michigan Gas Utilities Corporation
NSG
 
North Shore Gas Company
PDL
 
WPS Power Development, LLC
PELLC
 
Peoples Energy, LLC
PGL
 
The Peoples Gas Light and Coke Company
Thunderhead
 
Thunderhead Wind Energy LLC
UMERC
 
Upper Michigan Energy Resources Corporation
Upstream
 
Upstream Wind Energy LLC
WBS
 
WEC Business Services LLC
WE
 
Wisconsin Electric Power Company
We Power
 
W.E. Power, LLC
WEC Energy Group
 
WEC Energy Group, Inc.
WECC
 
Wisconsin Energy Capital Corporation
WECI
 
WEC Infrastructure LLC
WG
 
Wisconsin Gas LLC
Wispark
 
Wispark LLC
Wisvest
 
Wisvest LLC
WPS
 
Wisconsin Public Service Corporation
WRPC
 
Wisconsin River Power Company
 
 
 
Federal and State Regulatory Agencies
EPA