1.0.0.3 false Statement Of Financial Position Classified (USD $) In Millions false 1 $ false false Shares Standard http://www.xbrl.org/2003/instance shares 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDperShareItemType Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 false 2 $ false false Shares Standard http://www.xbrl.org/2003/instance shares 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDperShareItemType Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 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 706000000 706 false false 2 true true 986000000 986 false false No definition available. No authoritative reference available. false 8 Short-term investments 5 us-gaap_ShortTermInvestments us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 4000000 4 false false 2 false true 51000000 51 false false No definition available. No authoritative reference available. false 9 Receivables (net of allowance for doubtful accounts of $46 at June 30, 2009 and $42 at December 31, 2008) 5 us-gaap_ReceivablesNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1511000000 1511 false false 2 false true 1653000000 1653 false false No definition available. No authoritative reference available. false 10 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 1368000000 1368 false false 2 false true 1135000000 1135 false false No definition available. No authoritative reference available. false 11 Other 5 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1802000000 1802 false false 2 false true 1448000000 1448 false false No definition available. No authoritative reference available. false 12 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 5391000000 5391 false false 2 false true 5273000000 5273 false false No definition available. No authoritative reference available. true 13 Investments and Other Assets 4 duk_InvestmentsAndOtherAssetsAbstract duk 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 No definition available. false 14 Investments in equity method unconsolidated affiliates 5 us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 466000000 466 false false 2 false true 473000000 473 false false No definition available. No authoritative reference available. false 15 Nuclear decommissioning trust funds 5 us-gaap_DecommissioningFundInvestments us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1513000000 1513 false false 2 false true 1436000000 1436 false false No definition available. No authoritative reference available. false 16 Goodwill 5 us-gaap_Goodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 4741000000 4741 false false 2 false true 4720000000 4720 false false No definition available. No authoritative reference available. false 17 Intangibles, net 5 us-gaap_IntangibleAssetsNetExcludingGoodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 621000000 621 false false 2 false true 680000000 680 false false No definition available. No authoritative reference available. false 18 Notes receivable 5 us-gaap_NotesAndLoansReceivableNetNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 135000000 135 false false 2 false true 134000000 134 false false No definition available. No authoritative reference available. false 19 Other 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 2598000000 2598 false false 2 false true 2577000000 2577 false false No definition available. No authoritative reference available. false 20 Total investments and other assets 5 duk_InvestmentsAndOtherAssets duk false debit instant monetary No definition available. false false false false false false false false false 1 false true 10074000000 10074 false false 2 false true 10020000000 10020 false false No definition available. No authoritative reference available. true 21 Property, Plant and Equipment 4 us-gaap_PropertyPlantAndEquipmentNetAbstract 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 Cost 5 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 52356000000 52356 false false 2 false true 50304000000 50304 false false No definition available. No authoritative reference available. false 23 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 16927000000 16927 false false 2 false true 16268000000 16268 false false No definition available. No authoritative reference available. false 24 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 35429000000 35429 false false 2 false true 34036000000 34036 false false No definition available. No authoritative reference available. true 25 Regulatory Assets and Deferred Debits 4 duk_TotalRegulatoryAssetsAndDeferredDebitsAbstract duk 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 No definition available. false 26 Deferred debt expense 5 us-gaap_UnamortizedDebtIssuanceExpense us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 256000000 256 false false 2 false true 257000000 257 false false No definition available. No authoritative reference available. false 27 Regulatory assets related to income taxes 5 us-gaap_RegulatoryAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 664000000 664 false false 2 false true 625000000 625 false false No definition available. No authoritative reference available. false 28 Other 5 duk_OtherlRegulatoryAssetsAndDeferredDebits duk false debit instant monetary No definition available. false false false false false false false false false 1 false true 2895000000 2895 false false 2 false true 2866000000 2866 false false No definition available. No authoritative reference available. false 29 Total regulatory assets and deferred debits 5 duk_TotalRegulatoryAssetsAndDeferredDebits duk false debit instant monetary No definition available. false false false false false false false false false 1 false true 3815000000 3815 false false 2 false true 3748000000 3748 false false No definition available. No authoritative reference available. true 30 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 54709000000 54709 false false 2 false true 53077000000 53077 false false No definition available. No authoritative reference available. true 32 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 33 Accounts payable 5 us-gaap_AccountsPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1015000000 1015 false false 2 false true 1477000000 1477 false false No definition available. No authoritative reference available. false 34 Notes payable and commercial paper 5 us-gaap_ShortTermBorrowings us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 399000000 399 false false 2 false true 543000000 543 false false No definition available. No authoritative reference available. false 35 Taxes accrued 5 us-gaap_AccruedIncomeTaxesPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 360000000 360 false false 2 false true 362000000 362 false false No definition available. No authoritative reference available. false 36 Interest accrued 5 us-gaap_InterestPayable 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 187000000 187 false false No definition available. No authoritative reference available. false 37 Current maturities of long-term debt 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 901000000 901 false false 2 false true 646000000 646 false false No definition available. No authoritative reference available. false 38 Other 5 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1251000000 1251 false false 2 false true 1130000000 1130 false false No definition available. No authoritative reference available. false 39 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 4141000000 4141 false false 2 false true 4345000000 4345 false false No definition available. No authoritative reference available. true 40 Long-term Debt 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 14433000000 14433 false false 2 false true 13250000000 13250 false false No definition available. No authoritative reference available. false 41 Deferred Credits and Other Liabilities 4 duk_TotalDeferredCreditsAndOtherLiabilitiesAbstract duk 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 No definition available. false 42 Deferred income taxes 5 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5895000000 5895 false false 2 false true 5117000000 5117 false false No definition available. No authoritative reference available. false 43 Investment tax credits 5 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 142000000 142 false false 2 false true 148000000 148 false false No definition available. No authoritative reference available. false 44 Asset retirement obligations 5 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2657000000 2657 false false 2 false true 2567000000 2567 false false No definition available. No authoritative reference available. false 45 Other 5 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6081000000 6081 false false 2 false true 6499000000 6499 false false No definition available. No authoritative reference available. false 46 Total deferred credits and other liabilities 5 duk_TotalDeferredCreditsAndOtherLiabilities duk false credit instant monetary No definition available. false false false false false false false false false 1 false true 14775000000 14775 false false 2 false true 14331000000 14331 false false No definition available. No authoritative reference available. true 47 Commitments and Contingencies 5 us-gaap_CommitmentsAndContingencies us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 48 Equity 4 duk_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract duk 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 No definition available. false 49 Common Stock, $0.001 par value, 2 billion shares authorized; 1,294 million and 1,272 million shares outstanding at June 30, 2009 and December 31, 2008, respectively 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 1000000 1 false false 2 false true 1000000 1 false false No definition available. No authoritative reference available. false 50 Additional paid-in capital 5 us-gaap_AdditionalPaidInCapitalCommonStock us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 20425000000 20425 false false 2 false true 20106000000 20106 false false No definition available. No authoritative reference available. false 51 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 1321000000 1321 false false 2 false true 1607000000 1607 false false No definition available. No authoritative reference available. false 52 Accumulated other comprehensive loss 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 -521000000 -521 false false 2 false true -726000000 -726 false false No definition available. No authoritative reference available. false 53 Total Duke Energy Corporation shareholders' 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 21226000000 21226 false false 2 false true 20988000000 20988 false false No definition available. No authoritative reference available. true 54 Noncontrolling Interests 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 134000000 134 false false 2 false true 163000000 163 false false No definition available. No authoritative reference available. false 55 Total equity 5 duk_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest duk false credit instant monetary No definition available. false false false false false false false false false 1 false true 21360000000 21360 false false 2 false true 21151000000 21151 false false No definition available. No authoritative reference available. true 56 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 54709000000 54709 false false 2 true true 53077000000 53077 false false No definition available. No authoritative reference available. true false 2 50 false Millions UnKnown UnKnown false true