1.0.0.3 false CONSOLIDATED STATEMENTS OF INCOME (LOSS) (Constellation Energy Group, Inc. and Subsidiaries) (USD $) In Millions, except Per Share data false 1 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 2 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 3 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 3 Revenues 1 us-gaap_RevenuesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 4 Nonregulated revenues 2 us-gaap_SalesRevenueFromEnergyCommoditiesAndServices us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 12024300000 12024.3 false false 2 true true 16057600000 16057.6 false false 3 true true 17786500000 17786.5 false false No definition available. No authoritative reference available. false 5 Regulated electric revenues 2 us-gaap_ElectricDomesticRegulatedRevenue us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 2820700000 2820.7 false false 2 false true 2679500000 2679.5 false false 3 false true 2455600000 2455.6 false false No definition available. No authoritative reference available. false 6 Regulated gas revenues 2 us-gaap_GasDomesticRegulatedRevenue us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 753800000 753.8 false false 2 false true 1004800000 1004.8 false false 3 false true 943000000 943.0 false false No definition available. No authoritative reference available. false 7 Total revenues 2 us-gaap_Revenues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 15598800000 15598.8 false false 2 false true 19741900000 19741.9 false false 3 false true 21185100000 21185.1 false false No definition available. No authoritative reference available. true 8 Expenses 1 us-gaap_CostsAndExpensesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 9 Fuel and purchased energy expenses 2 us-gaap_CostOfGoodsAndServicesEnergyCommoditiesAndServices us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 11135600000 11135.6 false false 2 false true 15521300000 15521.3 false false 3 false true 16473900000 16473.9 false false No definition available. No authoritative reference available. false 10 Operating expenses 2 us-gaap_OperatingExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 2228000000 2228.0 false false 2 false true 2378800000 2378.8 false false 3 false true 2447400000 2447.4 false false No definition available. No authoritative reference available. false 11 Merger termination and strategic alternatives costs 2 ceg_MergerAndStrategicAlternativesCosts ceg false debit duration monetary Amount of costs related to a merger and our pursuit of other strategic alternatives to the merger that were charged to... false false false false false false false false false 1 false true 145800000 145.8 false false 2 false true 1204400000 1204.4 false false 3 false false 0 0 false false Amount of costs related to a merger and our pursuit of other strategic alternatives to the merger that were charged to expense during the period. No authoritative reference available. false 12 Impairment losses and other costs 2 us-gaap_AssetImpairmentCharges us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 124700000 124.7 false false 2 false true 741800000 741.8 false false 3 false true 20200000 20.2 false false No definition available. No authoritative reference available. false 13 Workforce reduction costs 2 us-gaap_SeveranceCosts us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 12600000 12.6 false false 2 false true 22200000 22.2 false false 3 false true 2300000 2.3 false false No definition available. No authoritative reference available. false 14 Depreciation, depletion, and amortization 2 us-gaap_DepreciationAndAmortization us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 589100000 589.1 false false 2 false true 583200000 583.2 false false 3 false true 557800000 557.8 false false No definition available. No authoritative reference available. false 15 Accretion of asset retirement obligations 2 us-gaap_AssetRetirementObligationAccretionExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 62300000 62.3 false false 2 false true 68400000 68.4 false false 3 false true 68300000 68.3 false false No definition available. No authoritative reference available. false 16 Taxes other than income taxes 2 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 290400000 290.4 false false 2 false true 301800000 301.8 false false 3 false true 288900000 288.9 false false No definition available. No authoritative reference available. false 17 Total expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 14588500000 14588.5 false false 2 false true 20821900000 20821.9 false false 3 false true 19858800000 19858.8 false false No definition available. No authoritative reference available. true 18 Equity Investment (Losses) Earnings 1 us-gaap_IncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -6100000 -6.1 false false 2 false true 76400000 76.4 false false 3 false true 8100000 8.1 false false No definition available. No authoritative reference available. false 19 Gain on Sale of Interest in CENG 1 ceg_GainLossOnSaleOfInterestInCENG ceg false credit duration monetary Gain on sale of 49.99% membership interest in CENG. false false false false false false false false false 1 false true 7445600000 7445.6 false false 2 false false 0 0 false false 3 false false 0 0 false false Gain on sale of 49.99% membership interest in CENG. No authoritative reference available. false 20 Net (Loss) Gain on Divestitures 1 us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -468800000 -468.8 false false 2 false true 25500000 25.5 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 21 Income (Loss) from Operations 1 us-gaap_OperatingIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 7981000000 7981.0 false false 2 false true -978100000 -978.1 false false 3 false true 1334400000 1334.4 false false No definition available. No authoritative reference available. true 22 Gain on Sales of CEP LLC Equity 1 us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 63300000 63.3 false false No definition available. No authoritative reference available. false 23 Other (Expense) Income 1 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -140700000 -140.7 false false 2 false true -69500000 -69.5 false false 3 false true 157400000 157.4 false false No definition available. No authoritative reference available. false 24 Fixed Charges 1 ceg_FixedChargesAbstract ceg false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 25 Interest expense 2 us-gaap_InterestCostsIncurred us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 437200000 437.2 false false 2 false true 399100000 399.1 false false 3 false true 311800000 311.8 false false No definition available. No authoritative reference available. false 26 Interest capitalized and allowance for borrowed funds used during construction 2 ceg_InterestCapitalizedAndAllowanceForBorrowedFundsUsedDuringConstruction ceg false credit duration monetary The balance consists of interest capitalized during the period for the nonregulated business and the allowance for borrowed... false false false false false false false false false 1 false true -87100000 -87.1 false false 2 false true -50000000 -50.0 false false 3 false true -19400000 -19.4 false false The balance consists of interest capitalized during the period for the nonregulated business and the allowance for borrowed funds used during construction in the regulated business during the period, which may be reflected as a reduction of interest expense. No authoritative reference available. false 27 Total fixed charges 2 ceg_FixedCharges ceg false debit duration monetary The aggregate interest expense incurred on all borrowings, net of capitalized interest and allowance for borrowed funds used... false false false false false false false false false 1 false true 350100000 350.1 false false 2 false true 349100000 349.1 false false 3 false true 292400000 292.4 false false The aggregate interest expense incurred on all borrowings, net of capitalized interest and allowance for borrowed funds used during construction. No authoritative reference available. true 28 Income (Loss) from Continuing Operations Before Income Taxes 1 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 7490200000 7490.2 false false 2 false true -1396700000 -1396.7 false false 3 false true 1262700000 1262.7 false false No definition available. No authoritative reference available. true 29 Income Tax Expense (Benefit) 1 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 2986800000 2986.8 false false 2 false true -78300000 -78.3 false false 3 false true 428300000 428.3 false false No definition available. No authoritative reference available. false 30 Income (Loss) from Continuing Operations 1 us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 4503400000 4503.4 false false 2 false true -1318400000 -1318.4 false false 3 false true 834400000 834.4 false false No definition available. No authoritative reference available. true 31 Loss from discontinued operations, net of income taxes of $1.5 1 us-gaap_DiscontinuedOperationAmountOfAdjustmentToPriorPeriodGainLossOnDisposalNetOfTax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -900000 -0.9 false false No definition available. No authoritative reference available. false 32 Net Income (Loss) 1 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 4503400000 4503.4 false false 2 false true -1318400000 -1318.4 false false 3 false true 833500000 833.5 false false No definition available. No authoritative reference available. true 33 Net Income (Loss) Attributable to Noncontrolling Interests and BGE Preference Stock Dividends 1 ceg_NetIncomeLossAttributableToNoncontrollingInterestAndPreferredStockDividendsAndOtherAdjustments ceg false debit duration monetary The portion of net income (loss) attributable to the noncontrolling interest (if any) deducted in order to derive the portion... false false false false false false false false false 1 false true 60000000 60.0 false false 2 false true -4000000 -4.0 false false 3 false true 12000000 12.0 false false The portion of net income (loss) attributable to the noncontrolling interest (if any) deducted in order to derive the portion attributable to the parent combined with the aggregate value of preferred stock dividends and other adjustments necessary to derive net income apportioned to common stockholders. No authoritative reference available. false 34 Net Income (Loss) Attributable to Common Stock 1 us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 4443400000 4443.4 false false 2 true true -1314400000 -1314.4 false false 3 true true 821500000 821.5 false false No definition available. No authoritative reference available. true 35 Average Shares of Common Stock Outstanding - Basic (in shares) 1 us-gaap_WeightedAverageNumberOfSharesOutstandingBasic us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 199300000 199.3 false false 2 false true 179100000 179.1 false false 3 false true 180200000 180.2 false false No definition available. No authoritative reference available. false 36 Average Shares of Common Stock Outstanding - Diluted (in shares) 1 us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 200300000 200.3 false false 2 false true 179100000 179.1 false false 3 false true 182500000 182.5 false false No definition available. No authoritative reference available. false 37 Earnings (Loss) Per Common Share from Continuing Operations - Basic (in dollars per share) 1 us-gaap_IncomeLossFromContinuingOperationsPerBasicShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 22.29 22.29 false false 2 true true -7.34 -7.34 false false 3 true true 4.56 4.56 false false No definition available. No authoritative reference available. false 38 Loss from discontinued operations (in dollars per share) 1 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 false false 0 0 false false 2 false false 0 0 false false 3 true true -0.01 -0.01 false false No definition available. No authoritative reference available. false 39 Earnings (Loss) Per Common Share - Basic (in dollars per share) 1 us-gaap_EarningsPerShareBasic us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 22.29 22.29 false false 2 true true -7.34 -7.34 false false 3 true true 4.55 4.55 false false No definition available. No authoritative reference available. true 40 Earnings (Loss) Per Common Share from Continuing Operations - Diluted (in dollars per share) 1 us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 22.19 22.19 false false 2 true true -7.34 -7.34 false false 3 true true 4.51 4.51 false false No definition available. No authoritative reference available. false 41 Loss from discontinued operations (in dollars per share) 1 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 false false 0 0 false false 2 false false 0 0 false false 3 true true -0.01 -0.01 false false No definition available. No authoritative reference available. false 42 Earnings (Loss) Per Common Share - Diluted (in dollars per share) 1 us-gaap_EarningsPerShareDiluted us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 22.19 22.19 false false 2 true true -7.34 -7.34 false false 3 true true 4.50 4.50 false false No definition available. No authoritative reference available. true 43 Dividends Declared Per Common Share (in dollars per share) 1 us-gaap_CommonStockDividendsPerShareDeclared us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 0.96 0.96 false false 2 true true 1.91 1.91 false false 3 true true 1.74 1.74 false false No definition available. No authoritative reference available. false false 3 41 false HundredThousands HundredThousands Hundreds false true