1.0.0.3 false CONSOLIDATED BALANCE SHEETS (USD $) In Millions 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 6 Current Assets 4 us-gaap_AssetsCurrentAbstract 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 No definition available. false 7 Cash and cash equivalents 5 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 true true 1208000000 1208 false false 2 true true 1807000000 1807 false false No definition available. No authoritative reference available. false 8 Short-term investments 5 us-gaap_HeldToMaturitySecuritiesCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2000000 2 false false 2 false true 4000000 4 false false No definition available. No authoritative reference available. false 9 Accounts receivable - trade 5 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 191000000 191 false false 2 false true 241000000 241 false false No definition available. No authoritative reference available. false 10 Receivables from affiliates 5 us-gaap_DueFromAffiliateCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 138000000 138 false false 2 false true 18000000 18 false false No definition available. No authoritative reference available. false 11 Inventory 5 us-gaap_InventoryNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 217000000 217 false false 2 false true 189000000 189 false false No definition available. No authoritative reference available. false 12 Derivative assets 5 us-gaap_DerivativeAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 208000000 208 false false 2 false true 170000000 170 false false No definition available. No authoritative reference available. false 13 Restricted cash 5 us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 148000000 148 false false 2 false false 0 0 false false No definition available. No authoritative reference available. false 14 Margin and collateral deposits 5 us-gaap_GoodFaithAndMarginDepositsWithBrokerDealers us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 206000000 206 false false 2 false true 88000000 88 false false No definition available. No authoritative reference available. false 15 Prepaid expenses and other 5 eme_PrepaidExpensesAndOtherCurrentAssets eme false debit instant monetary Sum of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of... false false false false false false false false false 1 false true 103000000 103 false false 2 false true 144000000 144 false false Sum of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or the normal operating cycle, if longer, combined with the aggregate carrying amount, as of the balance sheet date, of current assets not separately disclosed in the balance sheet due to materiality considerations. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). No authoritative reference available. false 16 Total current assets 5 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2421000000 2421 false false 2 false true 2661000000 2661 false false No definition available. No authoritative reference available. true 17 Investments in Unconsolidated Affiliates 4 us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 389000000 389 false false 2 false true 362000000 362 false false No definition available. No authoritative reference available. false 18 Property, Plant and Equipment 4 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5782000000 5782 false false 2 false true 5643000000 5643 false false No definition available. No authoritative reference available. false 19 Less accumulated depreciation and amortization 5 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1411000000 1411 false false 2 false true 1241000000 1241 false false No definition available. No authoritative reference available. false 20 Net property, plant and equipment 5 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 4371000000 4371 false false 2 false true 4402000000 4402 false false No definition available. No authoritative reference available. true 21 Other Assets 4 us-gaap_OtherAssetsNoncurrentAbstract 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 No definition available. false 22 Deferred financing costs 5 us-gaap_DeferredFinanceCostsNoncurrentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 45000000 45 false false 2 false true 36000000 36 false false No definition available. No authoritative reference available. false 23 Long-term derivative assets 5 us-gaap_DerivativeAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 107000000 107 false false 2 false true 170000000 170 false false No definition available. No authoritative reference available. false 24 Restricted deposits 5 us-gaap_RestrictedCashAndInvestmentsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 40000000 40 false false 2 false true 43000000 43 false false No definition available. No authoritative reference available. false 25 Rent payments in excess of levelized rent expense under plant operating leases 5 eme_RentPaymentsInExcessOfLevelizedRentExpenseUnderPlantOperatingLeases eme false debit instant monetary Represents prepaid rent, which is the excess of cash rent payments over the amount of rent expense levelized over the term of... false false false false false false false false false 1 false true 1039000000 1039 false false 2 false true 878000000 878 false false Represents prepaid rent, which is the excess of cash rent payments over the amount of rent expense levelized over the term of each plant operating lease. To the extent that cash rent payments are less than the amount levelized, prepaid rent is reduced. No authoritative reference available. false 26 Other long-term assets 5 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 796000000 796 false false 2 false true 528000000 528 false false No definition available. No authoritative reference available. false 27 Total other assets 5 eme_TotalOtherAssetsNoncurrent eme false debit instant monetary Sum of the carrying amounts as of the balance sheet date of all other assets that are expected to be realized in cash, sold... false false false false false false false false false 1 false true 2027000000 2027 false false 2 false true 1655000000 1655 false false Sum of the carrying amounts as of the balance sheet date of all other assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. No authoritative reference available. true 28 Total Assets 4 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 9208000000 9208 false false 2 false true 9080000000 9080 false false No definition available. No authoritative reference available. true 30 Current Liabilities 4 us-gaap_LiabilitiesCurrentAbstract 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 No definition available. false 31 Accounts payable 5 us-gaap_AccountsPayableCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 103000000 103 false false 2 false true 95000000 95 false false No definition available. No authoritative reference available. false 32 Payables to affiliates 5 us-gaap_DueToAffiliateCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 14000000 14 false false 2 false true 18000000 18 false false No definition available. No authoritative reference available. false 33 Accrued liabilities 5 us-gaap_AccruedLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 215000000 215 false false 2 false true 380000000 380 false false No definition available. No authoritative reference available. false 34 Derivative liabilities 5 us-gaap_DerivativeLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5000000 5 false false 2 false true 22000000 22 false false No definition available. No authoritative reference available. false 35 Interest payable 5 us-gaap_InterestPayableCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 101000000 101 false false 2 false true 30000000 30 false false No definition available. No authoritative reference available. false 36 Deferred taxes 5 us-gaap_DeferredTaxLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 47000000 47 false false 2 false true 66000000 66 false false No definition available. No authoritative reference available. false 37 Current portion of long-term obligations 5 us-gaap_LongTermDebtCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 502000000 502 false false 2 false true 24000000 24 false false No definition available. No authoritative reference available. false 38 Total current liabilities 5 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 987000000 987 false false 2 false true 635000000 635 false false No definition available. No authoritative reference available. true 39 Long-term obligations net of current portion 4 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 3940000000 3940 false false 2 false true 4638000000 4638 false false No definition available. No authoritative reference available. false 40 Deferred taxes and tax credits 4 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 831000000 831 false false 2 false true 541000000 541 false false No definition available. No authoritative reference available. false 41 Deferred revenues 4 us-gaap_DeferredRevenueAndCreditsNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 65000000 65 false false 2 false true 63000000 63 false false No definition available. No authoritative reference available. false 42 Long-term derivative liabilities 4 us-gaap_DerivativeLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 20000000 20 false false 2 false true 5000000 5 false false No definition available. No authoritative reference available. false 43 Other long-term liabilities 4 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 499000000 499 false false 2 false true 434000000 434 false false No definition available. No authoritative reference available. false 44 Total Liabilities 4 us-gaap_Liabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6342000000 6342 false false 2 false true 6316000000 6316 false false No definition available. No authoritative reference available. true 46 Equity 4 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract 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 No definition available. false 47 Common stock, par value $0.01 per share; 10,000 shares authorized; 100 shares issued and outstanding as of September 30, 2009 and December 31, 2008 5 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 64000000 64 false false 2 false true 64000000 64 false false No definition available. No authoritative reference available. false 48 Additional paid-in capital 5 us-gaap_AdditionalPaidInCapital us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1338000000 1338 false false 2 false true 1335000000 1335 false false No definition available. No authoritative reference available. false 49 Retained earnings 5 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1232000000 1232 false false 2 false true 1085000000 1085 false false No definition available. No authoritative reference available. false 50 Accumulated other comprehensive income 5 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 154000000 154 false false 2 false true 200000000 200 false false No definition available. No authoritative reference available. false 51 Total EME common shareholder's equity 5 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2788000000 2788 false false 2 false true 2684000000 2684 false false No definition available. No authoritative reference available. true 52 Noncontrolling Interest 5 us-gaap_MinorityInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 78000000 78 false false 2 false true 80000000 80 false false No definition available. No authoritative reference available. false 53 Total Equity 5 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2866000000 2866 false false 2 false true 2764000000 2764 false false No definition available. No authoritative reference available. true 54 Total Liabilities and Equity 4 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 9208000000 9208 false false 2 true true 9080000000 9080 false false No definition available. No authoritative reference available. true false 2 47 false Millions UnKnown UnKnown false true