UEPEP Union Electric Company (PK)

1021130000001180000004000000003000000000.0051.365140000006000000falsefalsefalse--12-31--12-31--12-31Q2Q2Q22019201920190001002910000001865400001008261450000001800000011000000700000019000000120000007000000162000000000.0150.0154000000004500000015000000040000000045000000150000000255000001021000002550000010210000003949233043293221000000100000010000001000000100000010000001000000100000000002300000023000000230000001000000100000010000001000000100000010000001000000100000010000001000000500000060000000 0001002910 aee:AmerenIllinoisCompanyMember 2019-01-01 2019-06-30 0001002910 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember 2019-07-31 0001002910 2019-07-31 0001002910 aee:UnionElectricCompanyMember 2019-07-31 0001002910 2019-04-01 2019-06-30 0001002910 us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 2018-01-01 2018-06-30 0001002910 2018-04-01 2018-06-30 0001002910 srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 2018-12-31 0001002910 2019-06-30 0001002910 2018-06-30 0001002910 2017-12-31 0001002910 us-gaap:ParentMember 2018-06-30 0001002910 us-gaap:RetainedEarningsMember 2018-04-01 2018-06-30 0001002910 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-06-30 0001002910 us-gaap:RetainedEarningsMember 2018-01-01 2018-06-30 0001002910 2018-03-31 0001002910 us-gaap:AdditionalPaidInCapitalMember 2018-03-31 0001002910 2019-03-31 0001002910 us-gaap:NoncontrollingInterestMember 2018-06-30 0001002910 us-gaap:ParentMember 2019-06-30 0001002910 us-gaap:RetainedEarningsMember 2019-06-30 0001002910 us-gaap:CommonStockMember 2018-06-30 0001002910 us-gaap:RetainedEarningsMember 2019-01-01 2019-06-30 0001002910 aee:DeferredRetirementBenefitCostsMember 2018-06-30 0001002910 aee:DeferredRetirementBenefitCostsMember 2019-04-01 2019-06-30 0001002910 us-gaap:AdditionalPaidInCapitalMember 2018-01-01 2018-06-30 0001002910 us-gaap:RetainedEarningsMember 2019-04-01 2019-06-30 0001002910 us-gaap:NoncontrollingInterestMember 2018-04-01 2018-06-30 0001002910 us-gaap:CommonStockMember 2019-06-30 0001002910 us-gaap:AdditionalPaidInCapitalMember 2019-06-30 0001002910 us-gaap:AdditionalPaidInCapitalMember 2018-12-31 0001002910 us-gaap:NoncontrollingInterestMember 2018-01-01 2018-06-30 0001002910 aee:DeferredRetirementBenefitCostsMember 2017-12-31 0001002910 us-gaap:AdditionalPaidInCapitalMember 2019-01-01 2019-06-30 0001002910 us-gaap:RetainedEarningsMember 2019-03-31 0001002910 us-gaap:NoncontrollingInterestMember 2018-12-31 0001002910 aee:DeferredRetirementBenefitCostsMember 2019-03-31 0001002910 us-gaap:NoncontrollingInterestMember 2018-03-31 0001002910 us-gaap:AdditionalPaidInCapitalMember 2018-06-30 0001002910 us-gaap:AdditionalPaidInCapitalMember 2017-12-31 0001002910 aee:DeferredRetirementBenefitCostsMember 2018-01-01 2018-06-30 0001002910 aee:DeferredRetirementBenefitCostsMember 2019-06-30 0001002910 us-gaap:AdditionalPaidInCapitalMember 2019-04-01 2019-06-30 0001002910 us-gaap:RetainedEarningsMember 2018-06-30 0001002910 us-gaap:NoncontrollingInterestMember 2019-01-01 2019-06-30 0001002910 aee:DeferredRetirementBenefitCostsMember 2018-12-31 0001002910 aee:DeferredRetirementBenefitCostsMember 2018-03-31 0001002910 aee:DeferredRetirementBenefitCostsMember 2018-04-01 2018-06-30 0001002910 us-gaap:RetainedEarningsMember 2017-12-31 0001002910 us-gaap:AdditionalPaidInCapitalMember 2018-04-01 2018-06-30 0001002910 us-gaap:RetainedEarningsMember 2018-03-31 0001002910 us-gaap:NoncontrollingInterestMember 2017-12-31 0001002910 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-06-30 0001002910 us-gaap:NoncontrollingInterestMember 2019-03-31 0001002910 us-gaap:NoncontrollingInterestMember 2019-06-30 0001002910 us-gaap:NoncontrollingInterestMember 2019-04-01 2019-06-30 0001002910 aee:DeferredRetirementBenefitCostsMember 2019-01-01 2019-06-30 0001002910 us-gaap:AdditionalPaidInCapitalMember 2019-03-31 0001002910 us-gaap:RetainedEarningsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember 2017-12-31 0001002910 aee:UnionElectricCompanyMember 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:PreferredStockNotSubjectToMandatoryRedemptionMember 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2019-03-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommonStockMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PreferredStockNotSubjectToMandatoryRedemptionMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:AdditionalPaidInCapitalMember 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2017-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2018-03-31 0001002910 aee:UnionElectricCompanyMember us-gaap:AdditionalPaidInCapitalMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommonStockMember 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:RetainedEarningsMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember 2017-12-31 0001002910 aee:AmerenIllinoisCompanyMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PreferredStockNotSubjectToMandatoryRedemptionMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommonStockMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember aee:PreferredStockNotSubjectToMandatoryRedemptionMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2017-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2017-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2019-03-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2018-03-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommonStockMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2019-03-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:RetainedEarningsMember 2018-03-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:AdditionalPaidInCapitalMember 2018-04-01 2018-06-30 0001002910 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2019-06-30 0001002910 aee:PartnershipFundingCommitmentMember 2019-06-30 0001002910 aee:PartnershipFundingCommitmentMember us-gaap:SubsequentEventMember 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:WindGenerationFacilityMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PendingFercCaseMember aee:MidwestIndependentTransmissionSystemOperatorIncMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PendingRateCaseMember us-gaap:ElectricDistributionMember aee:FEJAenergyefficiencyriderDomain 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:MinimumMember aee:PendingRateCaseMember srt:NaturalGasReservesMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreaseCustomerSalesVolumeMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:AdministrativeLawJudgeMember srt:MaximumMember aee:MidwestIndependentTransmissionSystemOperatorIncMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PendingRateCaseMember us-gaap:ElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:FinalRateOrderMember us-gaap:ElectricityMember aee:MEEIA20132016Domain 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PendingRateCaseMember srt:NaturalGasReservesMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:PendingRateCaseMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:FinalRateOrderMember srt:MaximumMember aee:MidwestIndependentTransmissionSystemOperatorIncMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:WindGenerationFacilityMember 2019-01-01 2019-06-30 0001002910 aee:MidwestIndependentTransmissionSystemOperatorIncMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:MaximumMember aee:PendingRateCaseMember srt:NaturalGasReservesMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreaseDepreciationandAmortizationMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:FinalRateOrderMember aee:MidwestIndependentTransmissionSystemOperatorIncMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:WindGenerationFacilityMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreaseNetEnergyCostsMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreaseHigherDepreciationRatesMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:AdministrativeLawJudgeMember aee:MidwestIndependentTransmissionSystemOperatorIncMember 2019-01-01 2019-06-30 0001002910 aee:PendingFercCaseMember aee:MidwestIndependentTransmissionSystemOperatorIncMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreaseOtherExpensesSubjecttoCostRecoveryMechanismsMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:AmerenTransmissionCompanyOfIllinoisMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:FinalRateOrderMember us-gaap:ElectricityMember aee:MEEIA2016Member 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreasePISAEligibleReturnonRateBaseMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:WindGenerationFacilityMember 2018-10-01 2018-12-31 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreaseReturnonRateBaseMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreaseOtherExpensesMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:UnionElectricCompanyMember aee:ComponentsofRateDecreasePISAEligibleDepreciationMember us-gaap:ElectricityMember us-gaap:SubsequentEventMember 2019-07-01 2019-09-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PendingRateCaseMember us-gaap:ElectricDistributionMember aee:IEIMAMember 2019-04-01 2019-06-30 0001002910 aee:AmerenparentDomain 2018-12-31 0001002910 aee:AmerenparentDomain 2019-06-30 0001002910 aee:AmerenparentDomain 2018-01-01 2018-06-30 0001002910 aee:AmerenparentDomain 2019-01-01 2019-06-30 0001002910 aee:AmerenparentDomain 2018-06-30 0001002910 aee:UtilitiesMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:IllinoisCreditAgreementMember 2019-06-30 0001002910 aee:UtilitiesMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:MissouriCreditAgreementMember 2019-06-30 0001002910 aee:UtilitiesMember 2018-01-01 2018-06-30 0001002910 aee:UtilitiesMember 2019-01-01 2019-06-30 0001002910 aee:CreditAgreementsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:Series1998Due2033Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:SeriesB1998Due2033Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:Series1992Due2022Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:Series1998Due2033Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:SeriesC1998Due2033Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:SeriesB1998Due2033Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:Series1992Due2022Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:SeriesC1998Due2033Member aee:EnvironmentalImprovementAndPollutionControlRevenueBondsMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:SeniorSecuredNotes6.70Due2019Member us-gaap:SecuredDebtMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:SeniorSecuredNotes6.70Due2019Member us-gaap:SecuredDebtMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:FirstMortgageBonds3.50Due2029450IssuanceMember us-gaap:SecuredDebtMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:FirstMortgageBonds3.50Due2029450IssuanceMember us-gaap:SecuredDebtMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:NondesignatedMember 2019-06-30 0001002910 us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:NondesignatedMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:NondesignatedMember 2018-12-31 0001002910 us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:NondesignatedMember 2019-06-30 0001002910 us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 us-gaap:OtherAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 us-gaap:OtherAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:NondesignatedMember 2019-06-30 0001002910 us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:NondesignatedMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:FuelOilsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentLiabilitiesMember us-gaap:NondesignatedMember aee:FuelOilsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherCurrentAssetsMember us-gaap:NondesignatedMember aee:PowerMember 2018-12-31 0001002910 aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2018-12-31 0001002910 aee:FuelOilsMember 2018-12-31 0001002910 srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:FuelOilsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:FuelOilsMember 2019-06-30 0001002910 aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:FuelOilsMember 2018-12-31 0001002910 srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:FuelOilsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:PowerMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel3Member 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member srt:NaturalGasReservesMember 2018-12-31 0001002910 us-gaap:CommodityContractMember aee:FuelOilsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember aee:PowerMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member 2019-06-30 0001002910 us-gaap:CommodityContractMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:FuelOilsMember 2018-12-31 0001002910 us-gaap:FairValueInputsLevel1Member 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:CommodityContractMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:PowerMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:FuelOilsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:FuelOilsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember aee:UsLargeCapitalizationMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:FuelOilsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:FuelOilsMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:PowerMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:FuelOilsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel1Member 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member 2018-12-31 0001002910 us-gaap:CommodityContractMember aee:PowerMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member aee:UsLargeCapitalizationMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member aee:UsLargeCapitalizationMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member aee:UsLargeCapitalizationMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member aee:UsLargeCapitalizationMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember aee:FuelOilsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel2Member 2019-06-30 0001002910 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member aee:UsLargeCapitalizationMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:PowerMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember aee:PowerMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:FuelOilsMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:FuelOilsMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel3Member 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 us-gaap:CommodityContractMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel3Member 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember aee:PowerMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel2Member 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:PowerMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member srt:NaturalGasReservesMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel1Member 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member aee:UsLargeCapitalizationMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:PowerMember 2019-06-30 0001002910 us-gaap:CommodityContractMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:PowerMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member aee:PowerMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member srt:NaturalGasReservesMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:CommodityContractMember aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member aee:UsLargeCapitalizationMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember srt:NaturalGasReservesMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel3Member 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel2Member 2018-12-31 0001002910 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member aee:UsLargeCapitalizationMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:EquitySecuritiesMember aee:UsLargeCapitalizationMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel2Member 2019-06-30 0001002910 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member aee:UsLargeCapitalizationMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member aee:UsLargeCapitalizationMember 2018-12-31 0001002910 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member aee:UsLargeCapitalizationMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:USTreasuryAndGovernmentMember 2018-12-31 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member aee:UsLargeCapitalizationMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel1Member 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member 2019-06-30 0001002910 us-gaap:EquitySecuritiesMember aee:UsLargeCapitalizationMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member aee:PowerMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CommodityContractMember 2018-12-31 0001002910 us-gaap:CommodityContractMember aee:FuelOilsMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember 2018-12-31 0001002910 us-gaap:EquitySecuritiesMember aee:UsLargeCapitalizationMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:USTreasuryAndGovernmentMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember srt:NaturalGasReservesMember 2019-06-30 0001002910 us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherDebtSecuritiesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:CommodityContractMember srt:NaturalGasReservesMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:DebtSecuritiesMember us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 us-gaap:DebtSecuritiesMember us-gaap:OtherDebtSecuritiesMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2019-04-01 2019-06-30 0001002910 aee:PowerMember 2018-01-01 2018-06-30 0001002910 aee:PowerMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2017-12-31 0001002910 aee:PowerMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2019-03-31 0001002910 aee:PowerMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2019-03-31 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2018-01-01 2018-06-30 0001002910 aee:PowerMember 2018-03-31 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2018-03-31 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2018-04-01 2018-06-30 0001002910 aee:PowerMember 2018-12-31 0001002910 aee:PowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2018-06-30 0001002910 aee:PowerMember 2017-12-31 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2018-06-30 0001002910 aee:PowerMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PowerMember 2018-03-31 0001002910 aee:UnionElectricCompanyMember aee:PowerMember 2017-12-31 0001002910 aee:PowerMember 2019-03-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001002910 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001002910 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-06-30 0001002910 srt:WeightedAverageMember aee:PowerMember aee:MeasurementInputNodalBasisMember aee:DiscountedCashFlowMember 2018-06-30 0001002910 aee:PowerMember aee:DerivativeLiabilitiesMember 2018-06-30 0001002910 srt:WeightedAverageMember aee:PowerMember us-gaap:MeasurementInputCommodityFuturePriceMember aee:FundamentalEnergyProductionModelMember 2019-06-30 0001002910 srt:WeightedAverageMember aee:PowerMember us-gaap:MeasurementInputCommodityForwardPriceMember aee:DiscountedCashFlowMember 2018-06-30 0001002910 aee:PowerMember aee:DerivativeAssetsMember 2019-06-30 0001002910 aee:PowerMember aee:DerivativeAssetsMember 2018-06-30 0001002910 srt:WeightedAverageMember aee:PowerMember aee:MeasurementInputNodalBasisMember aee:DiscountedCashFlowMember 2019-06-30 0001002910 srt:WeightedAverageMember aee:PowerMember us-gaap:MeasurementInputCommodityFuturePriceMember aee:FundamentalEnergyProductionModelMember 2018-06-30 0001002910 srt:WeightedAverageMember aee:PowerMember us-gaap:MeasurementInputQuotedPriceMember aee:DiscountedCashFlowMember 2019-06-30 0001002910 aee:PowerMember aee:DerivativeLiabilitiesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:FairValueInputsLevel1Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:FairValueInputsLevel1Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel2Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel1Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel2Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:FairValueInputsLevel2Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel1Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 us-gaap:FairValueInputsLevel1Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:FairValueInputsLevel2Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 us-gaap:FairValueInputsLevel2Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:FairValueInputsLevel1Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 us-gaap:FairValueInputsLevel2Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-06-30 0001002910 srt:MaximumMember aee:PowerMember us-gaap:MeasurementInputCommodityFuturePriceMember aee:FundamentalEnergyProductionModelMember 2019-06-30 0001002910 srt:MaximumMember aee:PowerMember us-gaap:MeasurementInputQuotedPriceMember aee:DiscountedCashFlowMember 2019-06-30 0001002910 srt:MaximumMember aee:PowerMember aee:MeasurementInputNodalBasisMember aee:DiscountedCashFlowMember 2019-06-30 0001002910 srt:MinimumMember aee:PowerMember us-gaap:MeasurementInputCommodityFuturePriceMember aee:FundamentalEnergyProductionModelMember 2019-06-30 0001002910 srt:MinimumMember aee:PowerMember us-gaap:MeasurementInputQuotedPriceMember aee:DiscountedCashFlowMember 2019-06-30 0001002910 srt:MinimumMember aee:PowerMember aee:MeasurementInputNodalBasisMember aee:DiscountedCashFlowMember 2019-06-30 0001002910 srt:MinimumMember aee:PowerMember us-gaap:MeasurementInputCommodityFuturePriceMember aee:FundamentalEnergyProductionModelMember 2018-06-30 0001002910 srt:MinimumMember aee:PowerMember us-gaap:MeasurementInputCommodityForwardPriceMember aee:DiscountedCashFlowMember 2018-06-30 0001002910 srt:MinimumMember aee:PowerMember aee:MeasurementInputNodalBasisMember aee:DiscountedCashFlowMember 2018-06-30 0001002910 srt:MaximumMember aee:PowerMember us-gaap:MeasurementInputCommodityFuturePriceMember aee:FundamentalEnergyProductionModelMember 2018-06-30 0001002910 srt:MaximumMember aee:PowerMember aee:MeasurementInputNodalBasisMember aee:DiscountedCashFlowMember 2018-06-30 0001002910 srt:MaximumMember aee:PowerMember us-gaap:MeasurementInputCommodityForwardPriceMember aee:DiscountedCashFlowMember 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:April2019ProcurementMember aee:AmerenIllinoisPowerSupplyAgreementsWithAmerenMissouriMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisPowerSupplyAgreementsWithAmerenMissouriMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisPowerSupplyAgreementsWithAmerenMissouriMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PurchasedPowerMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoistransmissionagreementswithATXIMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriPowerSupplyAgreementsWithAmerenIllinoisMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriPowerSupplyAgreementsWithAmerenIllinoisMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PurchasedPowerMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PurchasedPowerMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriPowerSupplyAgreementsWithAmerenIllinoisMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoistransmissionagreementswithATXIMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisPowerSupplyAgreementsWithAmerenMissouriMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriAndAmerenIllinoisRentAndFacilityServicesMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PurchasedPowerMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriPowerSupplyAgreementsWithAmerenIllinoisMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenServicesSupportServicesAgreementMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOtherOperationsandMaintenanceMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:TotalRelatedPartyOperatingRevenuesMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisPowerSupplyAgreementsWithAmerenMissouriMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:MoneyPoolMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:MoneyPoolMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:MoneyPoolMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoistransmissionagreementswithATXIMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:MoneyPoolMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:MoneyPoolMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoistransmissionagreementswithATXIMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:AmerenMissouriandAmerenIllinoismiscellaneoussupportservicesMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:MoneyPoolMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:MoneyPoolMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember aee:MoneyPoolMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PurchasedPowerMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:ManufacturedGasPlantMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:NewCCRRulesEstimateMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:MinimumMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:MaximumMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:MaximumMember aee:CoalCombustionResidualsEstimateMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:MinimumMember aee:ManufacturedGasPlantMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:MaximumMember aee:ManufacturedGasPlantMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:MinimumMember aee:CoalCombustionResidualsEstimateMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:RenewableEnergyCreditsMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:ZeroEmissionCreditsMember 2019-06-30 0001002910 us-gaap:PublicUtilitiesInventoryCoalMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:OtherPurchasedFuelMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:NuclearFuelMember 2019-06-30 0001002910 aee:OtherPurchasedFuelMember 2019-06-30 0001002910 aee:PurchasedPowerMember 2019-06-30 0001002910 srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:PublicUtilitiesInventoryCoalMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:NuclearFuelMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:OtherPurchasedFuelMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:PurchasedPowerMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:PublicUtilitiesInventoryCoalMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember aee:MethaneGasMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:PurchasedPowerMember 2019-06-30 0001002910 aee:MethaneGasMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember srt:NaturalGasReservesMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:MethaneGasMember 2019-06-30 0001002910 us-gaap:NuclearFuelMember 2019-06-30 0001002910 aee:NewCCRRulesEstimateMember 2019-06-30 0001002910 aee:PurchasedPowerMember 2019-01-01 2019-06-30 0001002910 srt:MinimumMember 2019-06-30 0001002910 aee:ManufacturedGasPlantMember 2019-06-30 0001002910 aee:ZeroEmissionCreditsMember 2019-06-30 0001002910 aee:RenewableEnergyCreditsMember 2019-06-30 0001002910 srt:MaximumMember 2019-06-30 0001002910 aee:ReplacementPowerNuclearElectricInsuranceLtdMember 2019-06-30 0001002910 aee:PublicLiabilityMember 2019-06-30 0001002910 aee:PublicLiabilityAndNuclearWorkerLiabilityPoolParticipationMember 2019-06-30 0001002910 aee:PublicLiabilityAndNuclearWorkerLiabilityAmericanNuclearInsurersMember 2019-06-30 0001002910 aee:PropertyDamageNuclearElectricInsuranceLtdMember 2019-06-30 0001002910 aee:ReplacementPowerNuclearElectricInsuranceLtdMember 2019-01-01 2019-06-30 0001002910 aee:RadiationEventMember 2019-01-01 2019-06-30 0001002910 aee:PublicLiabilityAndNuclearWorkerLiabilityPoolParticipationMember 2019-01-01 2019-06-30 0001002910 aee:NonradiationeventMember 2019-06-30 0001002910 aee:NonradiationeventMember 2019-01-01 2019-06-30 0001002910 aee:RadiationEventMember 2019-06-30 0001002910 aee:PropertyDamageEuropeanMutualAssociationforNuclearInsuranceMember 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-06-30 0001002910 us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-04-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2018-04-01 2018-06-30 0001002910 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-04-01 2019-06-30 0001002910 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-04-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-04-01 2018-06-30 0001002910 us-gaap:PensionPlansDefinedBenefitMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2018-04-01 2018-06-30 0001002910 us-gaap:PensionPlansDefinedBenefitMember 2019-01-01 2019-06-30 0001002910 aee:UnionElectricCompanyMember us-gaap:PensionPlansDefinedBenefitMember 2019-04-01 2019-06-30 0001002910 us-gaap:PensionPlansDefinedBenefitMember 2018-04-01 2018-06-30 0001002910 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-04-01 2018-06-30 0001002910 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-01-01 2019-06-30 0001002910 us-gaap:PerformanceSharesMember 2019-01-01 2019-06-30 0001002910 us-gaap:PerformanceSharesMember 2019-06-30 0001002910 us-gaap:RestrictedStockUnitsRSUMember 2018-12-31 0001002910 us-gaap:PerformanceSharesMember 2018-12-31 0001002910 us-gaap:RestrictedStockUnitsRSUMember 2019-01-01 2019-06-30 0001002910 us-gaap:RestrictedStockUnitsRSUMember 2019-06-30 0001002910 aee:AssetRetirementObligationBalanceMember 2019-06-30 0001002910 aee:AssetRetirementObligationBalanceMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember aee:AssetRetirementObligationBalanceMember 2018-12-31 0001002910 aee:UnionElectricCompanyMember aee:AssetRetirementObligationBalanceMember 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:CommercialMember aee:AmerenIllinoisCompanyMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:IndustrialMember aee:AmerenIllinoisCompanyMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisCompanyMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:IndustrialMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:IndustrialMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:IndustrialMember aee:AmerenIllinoisCompanyMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:OtherMember aee:AmerenIllinoisCompanyMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:CommercialMember aee:AmerenIllinoisCompanyMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:ResidentialMember aee:AmerenIllinoisCompanyMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:ResidentialMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:ResidentialMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:ResidentialMember aee:AmerenIllinoisCompanyMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:OtherMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisCompanyMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:OtherMember aee:AmerenIllinoisCompanyMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:OtherMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:IndustrialMember aee:AmerenIllinoisCompanyMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:CommercialMember aee:AmerenIllinoisCompanyMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:CommercialMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:IndustrialMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:IndustrialMember aee:AmerenIllinoisCompanyMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:IndustrialMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:OtherMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisCompanyMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:OtherMember aee:AmerenIllinoisCompanyMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:AmerenIllinoisCompanyMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:OtherMember aee:AmerenIllinoisCompanyMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:CommercialMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:CommercialMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:CommercialMember aee:AmerenIllinoisCompanyMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:ResidentialMember aee:AmerenIllinoisCompanyMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:ResidentialMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:CommercialMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:OtherMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:IntersegmentEliminationMember aee:ResidentialMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember aee:ResidentialMember aee:AmerenIllinoisCompanyMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisTransmissionMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisTransmissionMember 2018-04-01 2018-06-30 0001002910 aee:AmerenIllinoisCompanyMember us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 aee:AmerenIllinoisCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherSegmentMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherSegmentMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherSegmentMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherSegmentMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:CommercialMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:OtherMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 aee:ResidentialMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 aee:ResidentialMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 aee:IndustrialMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:IndustrialMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 aee:CommercialMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 aee:ResidentialMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 aee:IndustrialMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 aee:IndustrialMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 aee:OtherMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:IndustrialMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 aee:OtherMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:ResidentialMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 aee:CommercialMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 aee:CommercialMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 aee:IndustrialMember srt:NaturalGasReservesMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 aee:CommercialMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:CommercialMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:ResidentialMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 aee:ResidentialMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 aee:CommercialMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 aee:ResidentialMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:CommercialMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 aee:ResidentialMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 aee:OtherMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:CommercialMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 aee:OtherMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 aee:IndustrialMember srt:NaturalGasReservesMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:OtherMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2018-04-01 2018-06-30 0001002910 aee:IndustrialMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:ResidentialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:OtherMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-04-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember us-gaap:ElectricityMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2018-04-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:IndustrialMember us-gaap:ElectricityMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:UnionElectricCompanyMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenIllinoisGasMember 2019-01-01 2019-06-30 0001002910 us-gaap:IntersegmentEliminationMember aee:ResidentialMember srt:NaturalGasReservesMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2019-04-01 2019-06-30 0001002910 aee:OtherMember us-gaap:ElectricityMember 2018-04-01 2018-06-30 0001002910 aee:OtherMember us-gaap:ElectricityMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember srt:NaturalGasReservesMember aee:AmerenTransmissionMember 2018-01-01 2018-06-30 0001002910 us-gaap:IntersegmentEliminationMember srt:NaturalGasReservesMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember us-gaap:ElectricityMember aee:AmerenIllinoisElectricDistributionMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:CommercialMember srt:NaturalGasReservesMember aee:AmerenIllinoisElectricDistributionMember 2019-01-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:OtherMember us-gaap:ElectricityMember aee:UnionElectricCompanyMember 2019-04-01 2019-06-30 0001002910 us-gaap:OperatingSegmentsMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 0001002910 us-gaap:OperatingSegmentsMember aee:IndustrialMember us-gaap:ElectricityMember aee:AmerenIllinoisGasMember 2018-01-01 2018-06-30 iso4217:USD xbrli:shares iso4217:USD xbrli:shares utreg:MWh utreg:gal xbrli:pure utreg:MMBTU aee:center aee:site iso4217:USD aee:MWh iso4217:USD utreg:MMBTU iso4217:USD utreg:MWh utreg:Rate aee:waste_stream aee:scrubber aee:segment

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

 

for the Quarterly Period Ended June 30, 2019

OR

 

1901 Chouteau Avenue

St. Louis , Missouri 63103

(314) 621-3222

( Missouri Corporation)

1901 Chouteau Avenue

St. Louis , Missouri 63103

(314) 621-3222

( Illinois Corporation)

10 Executive Drive

Collinsville , Illinois 62234

(618) 343-8150

Securities Registered Pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrants: (1) have 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) have been subject to such filing requirements for the past 90 days.

 

Indicate by check mark whether each 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).

Indicate by check mark whether each registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

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 each registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

The number of shares outstanding of each registrant’s classes of common stock as of July 31, 2019, was as follows:

 

______________________________________________________________________________________________________ 

This combined Form 10-Q is separately filed by Ameren Corporation, Union Electric Company, and Ameren Illinois Company. Each registrant hereto is filing on its own behalf all of the information contained in this quarterly report that relates to such registrant. Each registrant hereto is not filing any information that does not relate to such registrant, and therefore makes no representation as to any such information.

TABLE OF CONTENTS

GLOSSARY OF TERMS AND ABBREVIATIONS

We use the words “our,” “we” or “us” with respect to certain information that relates to Ameren, Ameren Missouri, and Ameren Illinois, collectively. When appropriate, subsidiaries of Ameren Corporation are named specifically as their various business activities are discussed. Refer to the Form 10-K for a complete listing of glossary terms and abbreviations. Only new or significantly changed terms and abbreviations are included below.

Form 10-K – The combined Annual Report on Form 10-K for the year ended December 31, 2018 , filed by the Ameren Companies with the SEC.

FORWARD-LOOKING STATEMENTS

Statements in this report not based on historical facts are considered “forward-looking” and, accordingly, involve risks and uncertainties that could cause actual results to differ materially from those discussed. Although such forward-looking statements have been made in good faith and are based on reasonable assumptions, there is no assurance that the expected results will be achieved. These statements include (without limitation) statements as to future expectations, beliefs, plans, strategies, objectives, events, conditions, and financial performance. In connection with the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, we are providing this cautionary statement to identify important factors that could cause actual results to differ materially from those anticipated. The following factors, in addition to those discussed under Risk Factors in the Form 10-K and elsewhere in this report and in our other filings with the SEC, could cause actual results to differ materially from management expectations suggested in such forward-looking statements:

New factors emerge from time to time, and it is not possible for management to predict all of such factors, nor can it assess the impact of each such factor on the business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained or implied in any forward-looking statement. Given these uncertainties, undue reliance should not be placed on these forward-looking statements. Except to the extent required by the federal securities laws, we undertake no obligation to update or revise publicly any forward-looking statements to reflect new information or future events.