2.2.0.7 true Condensed Consolidated Statements Of Equity And Comprehensive Income-Carolinas (USD $) 00401 - Statement - Condensed Consolidated Statements Of Equity And Comprehensive Income-Carolinas true false In Millions false false 1 USD true false false false duk_DukeEnergyCarolinasMember dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi duk_DukeEnergyCarolinasMember dei_LegalEntityAxis explicitMember Unit13 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 2 USD true false false false duk_DukeEnergyCarolinasMember dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi duk_DukeEnergyCarolinasMember dei_LegalEntityAxis explicitMember false false us-gaap_PartnershipInterestMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_PartnershipInterestMember us-gaap_StatementEquityComponentsAxis explicitMember Unit13 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 3 USD true false false false duk_DukeEnergyCarolinasMember dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi duk_DukeEnergyCarolinasMember dei_LegalEntityAxis explicitMember false false us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember us-gaap_StatementEquityComponentsAxis explicitMember Unit13 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 4 USD true false false false duk_DukeEnergyCarolinasMember dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi duk_DukeEnergyCarolinasMember dei_LegalEntityAxis explicitMember false false duk_AccumulatedOtherChangesMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi duk_AccumulatedOtherChangesMember us-gaap_StatementEquityComponentsAxis explicitMember Unit13 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 5 USD true false false false us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember us-gaap_StatementEquityComponentsAxis explicitMember Unit13 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 6 USD true false false false duk_AccumulatedOtherChangesMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi duk_AccumulatedOtherChangesMember us-gaap_StatementEquityComponentsAxis explicitMember Unit13 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 7 USD false false Unit13 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Unit14 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Unit12 Standard http://www.xbrl.org/2003/instance pure xbrli 0 Unit1 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 5 Balance at Dec. 31, 2008 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false true false false periodstartlabel instant 2009-01-01T00:00:00 0001-01-01T00:00:00 false 1 true true false false 7316000000 7316 true false false 2 true true false false 7349000000 7349 true false false 3 true true false false -27000000 -27 true false false 4 true true false false -6000000 -6 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 6 Net income (loss) 3 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 578000000 578 true false false 2 false true false false 578000000 578 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false true false false 737000000 737 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 7 Other Comprehensive Income 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract us-gaap true na duration No definition available. false false false false false true false false false false false label false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 8 Reclassification into earnings from cash flow hedges 4 us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax us-gaap true debit duration No definition available. false false false false false false false false false false false label false 1 false true false false 3000000 3 [1] true false false 2 false false false false 0 0 true false false 3 false true false false 3000000 3 [1] true false false 4 false false false false 0 0 true false false 5 false true false false -16000000 -16 [2] true false false 6 false false false false 0 0 false false false 7 false true false false -16000000 -16 [2] false false false xbrli:monetaryItemType monetary Net of tax effect of the reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 18, 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 24 -Subparagraph b Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 31, 46 false 9 Unrealized gain (loss) on investments in auction rate securities 4 duk_UnrealizedGainLossOnInvestmentsInAuctionRateSecurities duk false credit duration Unrealized gain (loss) on investments in auction rate securities false false false false false false false false false false false terselabel false 1 false true false false -3000000 -3 [3] true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false true false false -3000000 -3 [3] true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Unrealized gain (loss) on investments in auction rate securities No authoritative reference available. false 10 Total comprehensive income (loss) 4 us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 578000000 578 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false true false false 1091000000 1091 false false false xbrli:monetaryItemType monetary The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A5 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a true 11 Advance forgiveness from parent 4 us-gaap_DebtInstrumentDecreaseForgiveness us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 3000000 3 true false false 2 false true false false 3000000 3 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Decrease for amounts of indebtedness forgiven by the holder of the debt instrument. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph f -Article 4 false 12 Capital contribution from parent 4 us-gaap_ProceedsFromContributionsFromParent us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 250000000 250 true false false 2 false true false false 250000000 250 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 false 14 Balance at Sep. 30, 2009 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false false true false periodendlabel instant 2009-09-30T00:00:00 0001-01-01T00:00:00 false 1 false true false false 8147000000 8147 true false false 2 false true false false 8180000000 8180 true false false 3 false true false false -24000000 -24 true false false 4 false true false false -9000000 -9 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 5 Balance at Jun. 30, 2009 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false true false false periodstartlabel instant 2009-07-01T00:00:00 0001-01-01T00:00:00 false 1 false false false false 0 0 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 6 Net income (loss) 3 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 265000000 265 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false true false false 106000000 106 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 7 Other Comprehensive Income 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract us-gaap true na duration No definition available. false false false false false true false false false false false label false 1 false false false false 0 0 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 14 Balance at Sep. 30, 2009 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false false true false periodendlabel instant 2009-09-30T00:00:00 0001-01-01T00:00:00 false 1 false true false false 8147000000 8147 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 5 Balance at Dec. 31, 2009 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false true false false periodstartlabel instant 2010-01-01T00:00:00 0001-01-01T00:00:00 false 1 false true false false 8271000000 8271 true false false 2 false true false false 8304000000 8304 true false false 3 false true false false -24000000 -24 true false false 4 false true false false -9000000 -9 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 6 Net income (loss) 3 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 709000000 709 true false false 2 false true false false 709000000 709 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false true false false 894000000 894 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 7 Other Comprehensive Income 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract us-gaap true na duration No definition available. false false false false false true false false false false false label false 1 false false false false 0 0 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 8 Reclassification into earnings from cash flow hedges 4 us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax us-gaap true debit duration No definition available. false false false false false false false false false false false label false 1 false true false false 2000000 2 [1] true false false 2 false false false false 0 0 true false false 3 false true false false 2000000 2 [1] true false false 4 false false false false 0 0 true false false 5 false true false false -2000000 -2 [2] true false false 6 false false false false 0 0 true false false 7 false true false false -2000000 -2 [2] false false false xbrli:monetaryItemType monetary Net of tax effect of the reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 18, 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 24 -Subparagraph b Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 31, 46 false 9 Unrealized gain (loss) on investments in auction rate securities 4 duk_UnrealizedGainLossOnInvestmentsInAuctionRateSecurities duk false credit duration Unrealized gain (loss) on investments in auction rate securities false false false false false false false false false false false terselabel false 1 false true false false 2000000 2 [3] true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false true false false 2000000 2 [3] true false false 5 false false false false 0 0 true false false 6 false true false false 8000000 8 [4] true false false 7 false true false false 8000000 8 [4] false false false xbrli:monetaryItemType monetary Unrealized gain (loss) on investments in auction rate securities No authoritative reference available. false 10 Total comprehensive income (loss) 4 us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 713000000 713 true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false true false false 971000000 971 false false false xbrli:monetaryItemType monetary The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A5 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a true 12 Capital contribution from parent 4 us-gaap_ProceedsFromContributionsFromParent us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0   true false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 false 13 Dividends to parent 4 us-gaap_CashDividendsPaidToParentCompany us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false -350000000 -350 true false false 2 false true false false -350000000 -350 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary This element represents disclosure of the total aggregate cash dividends paid to the entity by consolidated subsidiaries, by unconsolidated subsidiaries, and by 50% or less owned persons accounted for using the equity method. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph b -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 06 -Article 9 false 14 Balance at Sep. 30, 2010 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false false true false periodendlabel instant 2010-09-30T00:00:00 0001-01-01T00:00:00 false 1 false true false false 8634000000 8634 true false false 2 false true false false 8663000000 8663 true false false 3 false true false false -22000000 -22 true false false 4 false true false false -7000000 -7 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 5 Balance at Jun. 30, 2010 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false true false false periodstartlabel instant 2010-07-01T00:00:00 0001-01-01T00:00:00 false 1 false false false false 0 0 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 6 Net income (loss) 3 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 315000000 315 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false true false false 666000000 666 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 7 Other Comprehensive Income 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract us-gaap true na duration No definition available. false false false false false true false false false false false label false 1 false false false false 0 0 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 14 Balance at Sep. 30, 2010 3 duk_TotalMemberSEquity duk false credit instant Total member's equity false false false true false false false false false true false periodendlabel instant 2010-09-30T00:00:00 0001-01-01T00:00:00 false 1 true true false false 8634000000 8634 true false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false 7 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total member's equity No authoritative reference available. false 1 Net of $1 tax expense in 2010 and 2009. 2 Net of $1 tax expense in 2010 and $9 tax expense in 2009. 3 Net of $1 tax expense in 2010 and $2 tax benefit in 2009. 4 Net of $4 tax expense in 2010. 7 26 false Millions UnKnown UnKnown false true