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 5 Operating Revenues 3 us-gaap_ElectricalGenerationRevenue us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 593000000 593 false false 2 true true 814000000 814 false false 3 true true 1762000000 1762 false false 4 true true 2146000000 2146 false false No definition available. No authoritative reference available. false 6 Operating Expenses 3 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 7 Fuel 4 us-gaap_FuelCosts us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 228000000 228 false false 2 false true 220000000 220 false false 3 false true 587000000 587 false false 4 false true 564000000 564 false false No definition available. No authoritative reference available. false 8 Plant operations 4 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 131000000 131 false false 2 false true 135000000 135 false false 3 false true 426000000 426 false false 4 false true 466000000 466 false false No definition available. No authoritative reference available. false 9 Plant operating leases 4 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 132000000 132 false false 4 false true 132000000 132 false false No definition available. No authoritative reference available. false 10 Depreciation and amortization 4 us-gaap_DepreciationAndAmortization us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 62000000 62 false false 2 false true 50000000 50 false false 3 false true 174000000 174 false false 4 false true 140000000 140 false false No definition available. No authoritative reference available. false 11 (Gain) on buyout of contract and (gain) loss on sale of assets 4 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 12 Administrative and general 4 us-gaap_GeneralAndAdministrativeExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 48000000 48 false false 2 false true 57000000 57 false false 3 false true 143000000 143 false false 4 false true 155000000 155 false false No definition available. No authoritative reference available. false 13 Total operating expenses 4 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 513000000 513 false false 2 false true 506000000 506 false false 3 false true 1463000000 1463 false false 4 false true 1441000000 1441 false false No definition available. No authoritative reference available. true 14 Operating income 3 us-gaap_OperatingIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 80000000 80 false false 2 false true 308000000 308 false false 3 false true 299000000 299 false false 4 false true 705000000 705 false false No definition available. No authoritative reference available. true 15 Other Income (Expense) 3 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 16 Equity in income from unconsolidated affiliates 4 us-gaap_IncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 60000000 60 false false 2 false true 74000000 74 false false 3 false true 86000000 86 false false 4 false true 123000000 123 false false No definition available. No authoritative reference available. false 17 Dividend income 4 us-gaap_OtherInterestAndDividendIncome 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 false 0 0 false false 3 false true 11000000 11 false false 4 false true 10000000 10 false false No definition available. No authoritative reference available. false 18 Interest income 4 us-gaap_InvestmentIncomeInterest 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 true 4000000 4 false false 3 false true 6000000 6 false false 4 false true 19000000 19 false false No definition available. No authoritative reference available. false 19 Interest expense 4 us-gaap_InterestExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -78000000 -78 false false 2 false true -67000000 -67 false false 3 false true -225000000 -225 false false 4 false true -204000000 -204 false false No definition available. No authoritative reference available. false 20 Other income (expense), net 4 us-gaap_OtherNonoperatingIncomeExpense 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 true 4000000 4 false false 3 false true 2000000 2 false false 4 false true 9000000 9 false false No definition available. No authoritative reference available. false 21 Total other income (expense) 4 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -17000000 -17 false false 2 false true 15000000 15 false false 3 false true -120000000 -120 false false 4 false true -43000000 -43 false false No definition available. No authoritative reference available. true 22 Income from continuing operations before income taxes 3 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 63000000 63 false false 2 false true 323000000 323 false false 3 false true 179000000 179 false false 4 false true 662000000 662 false false Sum of operating profit and non operating income (expense) before income taxes and noncontrolling interest. No authoritative reference available. true 23 Provision for income taxes 3 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 10000000 10 false false 2 false true 121000000 121 false false 3 false true 27000000 27 false false 4 false true 237000000 237 false false No definition available. No authoritative reference available. false 24 Income From Continuing Operations 3 us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 53000000 53 false false 2 false true 202000000 202 false false 3 false true 152000000 152 false false 4 false true 425000000 425 false false No definition available. No authoritative reference available. true 25 Income (loss) from operations of discontinued subsidiaries, net of tax (Note 6) 3 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax 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 6000000 6 false false 3 false true -5000000 -5 false false 4 false false 0 0 false false No definition available. No authoritative reference available. false 26 Net Income 3 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 52000000 52 false false 2 false true 208000000 208 false false 3 false true 147000000 147 false false 4 false true 425000000 425 false false No definition available. No authoritative reference available. true 27 Net Loss Attributable to Noncontrolling Interest 3 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 true 1000000 1 false false 3 false true 2000000 2 false false 4 false true 1000000 1 false false No definition available. No authoritative reference available. false 28 Net Income Attributable to Common Shareholders of EME 3 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 53000000 53 false false 2 true true 209000000 209 false false 3 true true 149000000 149 false false 4 true true 426000000 426 false false No definition available. No authoritative reference available. true false 4 24 false Millions UnKnown UnKnown false true