1.0.0.3 false CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions false 1 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 2 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 3 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 4 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 4 Operating Revenues 2 us-gaap_ElectricalGenerationRevenue us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 557000000 557 false false 2 true true 613000000 613 false false 3 true true 1169000000 1169 false false 4 true true 1332000000 1332 false false No definition available. No authoritative reference available. false 5 Operating Expenses 2 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 4 false false 0 0 false false No definition available. false 6 Fuel 3 us-gaap_FuelCosts us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 172000000 172 false false 2 false true 157000000 157 false false 3 false true 359000000 359 false false 4 false true 344000000 344 false false No definition available. No authoritative reference available. false 7 Plant operations 3 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 146000000 146 false false 2 false true 195000000 195 false false 3 false true 295000000 295 false false 4 false true 331000000 331 false false No definition available. No authoritative reference available. false 8 Plant operating leases 3 us-gaap_SaleLeasebackTransactionRentExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 44000000 44 false false 2 false true 44000000 44 false false 3 false true 88000000 88 false false 4 false true 88000000 88 false false No definition available. No authoritative reference available. false 9 Depreciation and amortization 3 us-gaap_DepreciationAndAmortization us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 56000000 56 false false 2 false true 46000000 46 false false 3 false true 112000000 112 false false 4 false true 90000000 90 false false No definition available. No authoritative reference available. false 10 (Gain) on buyout of contract and (gain) loss on sale of assets 3 us-gaap_GainLossOnContractTermination 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 1000000 1 false false 4 false true -16000000 -16 false false No definition available. No authoritative reference available. false 11 Administrative and general 3 us-gaap_GeneralAndAdministrativeExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 51000000 51 false false 2 false true 50000000 50 false false 3 false true 95000000 95 false false 4 false true 98000000 98 false false No definition available. No authoritative reference available. false 12 Total operating expenses 3 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 469000000 469 false false 2 false true 492000000 492 false false 3 false true 950000000 950 false false 4 false true 935000000 935 false false No definition available. No authoritative reference available. true 13 Operating income 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 88000000 88 false false 2 false true 121000000 121 false false 3 false true 219000000 219 false false 4 false true 397000000 397 false false No definition available. No authoritative reference available. true 14 Other Income (Expense) 2 us-gaap_NonoperatingIncomeExpenseAbstract 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 4 false false 0 0 false false No definition available. false 15 Equity in income from unconsolidated affiliates 3 us-gaap_IncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 20000000 20 false false 2 false true 37000000 37 false false 3 false true 26000000 26 false false 4 false true 49000000 49 false false No definition available. No authoritative reference available. false 16 Dividend income 3 us-gaap_OtherInterestAndDividendIncome us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 9000000 9 false false 2 false true 9000000 9 false false 3 false true 10000000 10 false false 4 false true 10000000 10 false false No definition available. No authoritative reference available. false 17 Interest income 3 us-gaap_InvestmentIncomeInterest us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 3000000 3 false false 2 false true 7000000 7 false false 3 false true 6000000 6 false false 4 false true 15000000 15 false false No definition available. No authoritative reference available. false 18 Interest expense 3 us-gaap_InterestExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -73000000 -73 false false 2 false true -66000000 -66 false false 3 false true -147000000 -147 false false 4 false true -137000000 -137 false false No definition available. No authoritative reference available. false 19 Other income (expense), net 3 us-gaap_OtherNonoperatingIncomeExpense us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 1000000 1 false false 2 false true -1000000 -1 false false 3 false true 2000000 2 false false 4 false true 5000000 5 false false No definition available. No authoritative reference available. false 20 Total other income (expense) 3 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -40000000 -40 false false 2 false true -14000000 -14 false false 3 false true -103000000 -103 false false 4 false true -58000000 -58 false false No definition available. No authoritative reference available. true 21 Income from continuing operations before income taxes 2 eme_IncomeFromContinuingOperationsBeforeIncomeTaxes eme false credit duration monetary Sum of operating profit and non operating income (expense) before income taxes and noncontrolling interest. false false false false false false false false false 1 false true 48000000 48 false false 2 false true 107000000 107 false false 3 false true 116000000 116 false false 4 false true 339000000 339 false false Sum of operating profit and non operating income (expense) before income taxes and noncontrolling interest. No authoritative reference available. true 22 Provision for income taxes 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 2000000 2 false false 2 false true 34000000 34 false false 3 false true 17000000 17 false false 4 false true 116000000 116 false false No definition available. No authoritative reference available. false 23 Income From Continuing Operations 2 us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 46000000 46 false false 2 false true 73000000 73 false false 3 false true 99000000 99 false false 4 false true 223000000 223 false false No definition available. No authoritative reference available. true 24 Loss from operations of discontinued subsidiaries, net of tax (Note 6) 2 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -7000000 -7 false false 2 false true -1000000 -1 false false 3 false true -4000000 -4 false false 4 false true -6000000 -6 false false No definition available. No authoritative reference available. false 25 Net Income 2 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 39000000 39 false false 2 false true 72000000 72 false false 3 false true 95000000 95 false false 4 false true 217000000 217 false false No definition available. No authoritative reference available. true 26 Net Loss Attributable to Noncontrolling Interest 2 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 1000000 1 false false 2 false false 0 0 false false 3 false true 1000000 1 false false 4 false false 0 0 false false No definition available. No authoritative reference available. false 27 Net Income Attributable to Common Shareholders of EME 2 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 40000000 40 false false 2 true true 72000000 72 false false 3 true true 96000000 96 false false 4 true true 217000000 217 false false No definition available. No authoritative reference available. true false 4 24 false Millions UnKnown UnKnown false true