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[Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseCrystal River Unit 3 [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CrystalRiverUnit3Memberus-gaap_PublicUtilityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Crystal River Unit 3 [Member]84false 4duk_InsuranceCoveragePerCompanyAtEachNuclearPlantPriorToRetirementduk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse22500000002250000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse22500000002250000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of insurance coverage provided under the Nuclear Electric Insurance Limited primary program and program for decontamination, premature decommissioning and excess property insurance before the delamination and susequent retirement of Crystal River Unit 3.No definition available.false2NEIL coverage per company at each nuclear plant, prior to retirement85false 4duk_InsuranceCoveragePerCompanyAtEachNuclearPlantCurrentduk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse10600000001060000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse10600000001060000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of insurance coverage currently provided under the Nuclear Electric Insurance Limited primary program and program for decontamination, premature decommissioning and excess property insurance.No definition available.false2NEIL coverage per company at each nuclear plant, current86false 4duk_InsuranceDeductiblePerClaimduk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1000000010000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse1000000010000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of risk retained per claim by the entity before the insurance arrangement begins to provide coverage.No definition available.false2Insurance deductible per claim87false 4duk_DecommissioningCostStudyEstimateduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse989000000989000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe cost estimate study for the decommissioning of nuclear plants that are required by the regulatory bodies of the various states.No definition available.false2Decommissioning cost study estimate88false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse44false USDtruefalse$AS_OF_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_us-gaap_PublicUtilityAxis_CrystalRiverUnit3Member_us-gaap_RangeAxis_MinimumMemberhttp://www.sec.gov/CIK0001326160instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseCrystal River Unit 3 [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CrystalRiverUnit3Memberus-gaap_PublicUtilityAxisexplicitMemberfalsefalseMinimum [Member]us-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MinimumMemberus-gaap_RangeAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | Minimum [Member]89false 4duk_RepairCostsRangeOfPossibleCostsduk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse900000000900000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse900000000900000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe estimated amount of possible repair costs for the repair of property, plant and equipment.No definition available.false2Repair costs, range of possible costs90false 4duk_IndependentReviewRepairCostsduk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse14900000001490000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse14900000001490000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of possible repair costs for the repair of property, plant and equipment as determined by an outside, independent review commissioned by the company.No definition available.false2Independent review repair costs91false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse45false USDtruefalse$AS_OF_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_us-gaap_PublicUtilityAxis_CrystalRiverUnit3Member_us-gaap_RangeAxis_MaximumMemberhttp://www.sec.gov/CIK0001326160instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseCrystal River Unit 3 [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CrystalRiverUnit3Memberus-gaap_PublicUtilityAxisexplicitMemberfalsefalseMaximum [Member]us-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | Maximum [Member]92false 4duk_RepairCostsRangeOfPossibleCostsduk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse13000000001300000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse13000000001300000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe estimated amount of possible repair costs for the repair of property, plant and equipment.No definition available.false2Repair costs, range of possible costs93false 4duk_IndependentReviewRepairCostsduk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse34300000003430000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse34300000003430000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of possible repair costs for the repair of property, plant and equipment as determined by an outside, independent review commissioned by the company.No definition available.false2Independent review repair costs94false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse46false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_FloridaPublicServiceCommissionSettlementAgreement2012Member_us-gaap_PublicUtilityAxis_CrystalRiverUnit3Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseCrystal River Unit 3 [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CrystalRiverUnit3Memberus-gaap_PublicUtilityAxisexplicitMemberfalsefalse2012 FPSC Settlement Agreement [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_FloridaPublicServiceCommissionSettlementAgreement2012Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2012 FPSC Settlement Agreement [Member]95false 4duk_RefundToCustomersRecordedAsReductionToRevenueduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse100000000100000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryDiscloses the amount of that current year revenue is being reduced for amounts to be refunded to customers as required by regulatory order.No definition available.false2Refund to customers recorded as reduction to revenue96false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse47false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_FloridaPublicServiceCommissionSettlementAgreement2013Member_us-gaap_PublicUtilityAxis_CrystalRiverUnit3Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseCrystal River Unit 3 [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CrystalRiverUnit3Memberus-gaap_PublicUtilityAxisexplicitMemberfalsefalse2013 FPSC Settlement Agreement [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_FloridaPublicServiceCommissionSettlementAgreement2013Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2013 FPSC Settlement Agreement [Member]97false 4us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse295000000295000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Impairment charges98false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse48false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_FloridaPublicServiceCommissionSettlementAgreement2013Member_duk_RegulatoryAgencyAxis_FloridaPublicServiceCommissionMember_us-gaap_PublicUtilityAxis_CrystalRiverUnit3Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseCrystal River Unit 3 [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CrystalRiverUnit3Memberus-gaap_PublicUtilityAxisexplicitMemberfalsefalse2013 FPSC Settlement Agreement [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_FloridaPublicServiceCommissionSettlementAgreement2013Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberfalsefalseFPSC [Member]duk_RegulatoryAgencyAxisxbrldihttp://xbrl.org/2006/xbrldiduk_FloridaPublicServiceCommissionMemberduk_RegulatoryAgencyAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2013 FPSC Settlement Agreement [Member] | FPSC [Member]99false 4duk_ReturnOnEquityduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.07350.0735falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureAuthorized regulatory return on equity that utility has the opportunity to earnNo definition available.false0Return on equity percentage100false 4duk_CapProjectCostOrRecoveryThatCouldBePassedOnToCustomersduk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse14660000001466000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse14660000001466000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe limitation of project cost and/or recovery that can be passed on to customers.No definition available.false2Cost Cap for customers101false 4duk_AccelerationOfCashRecoveryduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse135000000135000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAcceleration of cash receovery through the fuel clause permitted by FPSC.No definition available.false2Acceleration of cash recovery through fuel clause102false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse49false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_NeilSettlementMember_us-gaap_PublicUtilityAxis_CrystalRiverUnit3Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseCrystal River Unit 3 [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CrystalRiverUnit3Memberus-gaap_PublicUtilityAxisexplicitMemberfalsefalseNEIL Settlement [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_NeilSettlementMemberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | NEIL Settlement [Member]103false 4duk_TotalInsuranceProceedsReceivedToDateduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse835000000835000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryTotal repair and replacement costs received to date from NEIL related to the Crystal River Unit 3 delamination.No definition available.false2Total insurance proceeds received to date for Crystal River Unit 3104false 4duk_TotalInsuranceProceedsReceivedCurrentYearduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse530000000530000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryTotal repair and replacement costs received in the current year from NEIL related to the Crystal River Unit 3 delamination.No definition available.false2Current year insurance proceeds received to date for Crystal River Unit 3105false 4us-gaap_RegulatoryLiabilityNoncurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse490000000490000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse490000000490000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 11 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Regulatory liability, noncurrent106false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse50false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_FloridaPublicServiceCommissionSettlementAgreement2013Member_us-gaap_PublicUtilityAxis_LevyNuclearStationMemberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseLevy Nuclear Station [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_LevyNuclearStationMemberus-gaap_PublicUtilityAxisexplicitMemberfalsefalse2013 FPSC Settlement Agreement [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_FloridaPublicServiceCommissionSettlementAgreement2013Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member] | Levy Nuclear Station [Member] | 2013 FPSC Settlement Agreement [Member]107false 4us-gaap_PropertyPlantAndEquipmentNetus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse138000000138000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse138000000138000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAmount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Net property, plant and equipment108false 4us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse6500000065000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Impairment charges109false 4duk_NetUnrecoveredInvestmentduk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse281000000281000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse281000000281000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of unrecovered investment for a proposed nuclear station.No definition available.false2Net unrecovered investment110false 4duk_FutureCustomerCreditduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse1000000010000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryFuture customer credit required by regulatory commission as part of settlement agreement if certain conditions not met.No definition available.false2Future customer credit111false 4us-gaap_RegulatoryAssetsNoncurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse143000000143000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse143000000143000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 9, 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 false2Regulatory assets, noncurrent112false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse51false truefalseFROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_FloridaPublicServiceCommissionSettlementAgreement2013Member_us-gaap_PublicUtilityAxis_NewGenerationNeedsMemberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberfalsefalseNew Generation Needs [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_NewGenerationNeedsMemberus-gaap_PublicUtilityAxisexplicitMemberfalsefalse2013 FPSC Settlement Agreement [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_FloridaPublicServiceCommissionSettlementAgreement2013Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberMegawattStandardhttp://www.xbrl.org/2009/utrMWutr0PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0nanafalse0Duke Energy Florida [Member] | New Generation Needs [Member] | 2013 FPSC Settlement Agreement [Member]113false 4duk_CombinedCycleCapacityduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse11501150falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:powerItemTypedecimalCombined cycle capacity allowed prior to the end of 2017.No definition available.false256Combined cycle capacity, MW114false 4duk_AdditionalGenerationCapacityduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse18001800falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:powerItemTypedecimalAdditional generation capacity allowed to be placed in servie in 2018.No definition available.false256Additional generation capacity, MW115false 4duk_ReturnOnEquityduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.1050.105falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureAuthorized regulatory return on equity that utility has the opportunity to earnNo definition available.false0Return on equity percentage116false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse52false USDtruefalse$AS_OF_Jun30_2013_dei_LegalEntityAxis_DukeEnergyOhioMemberhttp://www.sec.gov/CIK0001326160instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseDuke Energy Ohio [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyOhioMemberdei_LegalEntityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Ohio [Member]117false 4us-gaap_PropertyPlantAndEquipmentNetus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse81700000008170000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse81700000008170000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse81260000008126000000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryAmount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Net property, plant and equipment118false 4us-gaap_RegulatoryAssetsNoncurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse564000000564000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse564000000564000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse579000000579000000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 9, 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 false2Regulatory assets, noncurrent119false 4us-gaap_RegulatoryLiabilityNoncurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse256000000256000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse256000000256000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse254000000254000000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 11 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Regulatory liability, noncurrent120false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse54false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyOhioMember_duk_PublicUtilitiesRegulatoryProceedingAxis_ElectricRateCaseMember_duk_RegulatoryAgencyAxis_PublicUtilitiesCommissionOfOhioMemberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Ohio [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyOhioMemberdei_LegalEntityAxisexplicitMemberfalsefalseElectric Rate Case [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_ElectricRateCaseMemberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberfalsefalsePUCO [Member]duk_RegulatoryAgencyAxisxbrldihttp://xbrl.org/2006/xbrldiduk_PublicUtilitiesCommissionOfOhioMemberduk_RegulatoryAgencyAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Ohio [Member] | Electric Rate Case [Member] | PUCO [Member]121false 4duk_ApprovedRateIncreaseAmountduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse4900000049000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryRate increase amount approved by state commission.No definition available.false2Approved rate increase amount by state commission122false 4duk_RateIncreaseBeginDateduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse005/1/2013falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalseinvest:dateStringItemTypenormalizedstringThe date that new rates go into effect after approval of the rate case.No definition available.false0Rate increase begin date123false 4duk_ReturnOnEquityduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.09840.0984falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureAuthorized regulatory return on equity that utility has the opportunity to earnNo definition available.false0Return on equity percentage124false 4duk_PercentageIncreaseInRetailRevenuesduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.0290.029falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureThe average rate of increase for the rate case.No definition available.false0Average increase in retail revenues, percentage125false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse55false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyOhioMember_duk_PublicUtilitiesRegulatoryProceedingAxis_NaturalGasRateCaseMember_duk_RegulatoryAgencyAxis_PublicUtilitiesCommissionOfOhioMemberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Ohio [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyOhioMemberdei_LegalEntityAxisexplicitMemberfalsefalseNatural Gas Rate Case [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_NaturalGasRateCaseMemberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberfalsefalsePUCO [Member]duk_RegulatoryAgencyAxisxbrldihttp://xbrl.org/2006/xbrldiduk_PublicUtilitiesCommissionOfOhioMemberduk_RegulatoryAgencyAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Ohio [Member] | Natural Gas Rate Case [Member] | PUCO [Member]126false 4duk_ReturnOnEquityduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.09840.0984falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureAuthorized regulatory return on equity that utility has the opportunity to earnNo definition available.false0Return on equity percentage127false 4duk_MgpRemediationRevenueRequirementRequestduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse6300000063000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of MGP cost remediation requested by Duke Energy Ohio to the PUCO to be recoverable through rates.No definition available.false2MGP remediation cost revenue requirement128false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse56false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyOhioMember_duk_PublicUtilitiesRegulatoryProceedingAxis_CapacityRiderFilingMemberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Ohio [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyOhioMemberdei_LegalEntityAxisexplicitMemberfalsefalseCapacity Rider Filing [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_CapacityRiderFilingMemberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Ohio [Member] | Capacity Rider Filing [Member]129false 4duk_CapacityRiderRevenuesRequestedduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse729000000729000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryDuke Energy Ohio's request to the PUCO for capacity revenues. The deferral being sought is the diffence between its costs and market-based prices for capacity.No definition available.false2Capacity rider revenues requested130false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse57false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyOhioMember_us-gaap_PublicUtilityAxis_RegionalTransmissionOrganizationRealignmentMemberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Ohio [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyOhioMemberdei_LegalEntityAxisexplicitMemberfalsefalseRTO Realignment [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_RegionalTransmissionOrganizationRealignmentMemberus-gaap_PublicUtilityAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Ohio [Member] | RTO Realignment [Member]131false 4duk_ProjectCostsApprovedduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse55000000005500000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryExcess estimated project costs, approved.No definition available.false2MVP project costs approved by MISO132false 4duk_PresentValueDiscountRateduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.0820.082falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureInterest rate used to find the present value of an amount to be paid or received in the future.No definition available.false0Future revenue requirement discount rate133false 4duk_FutureRevenueRequirementsObligationduk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse514000000514000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse514000000514000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryDuke Energy Ohio's obligation to MISO based on future revenue requirements of the proposed MVP projects.No definition available.false2MVP projects future revenue requirements obligation134false 4duk_RecoveryCostsNotSoughtduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse121000000121000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryDuke Energy Ohio's agreement to not recover a portion of PJM transmission expansion costs.No definition available.false2Recovery costs not sought135false 4us-gaap_RegulatoryAssetsNoncurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse7000000070000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse7000000070000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 9, 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 false2Regulatory assets, noncurrent136false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse58false USDtruefalse$FROM_Apr01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMemberhttp://www.sec.gov/CIK0001326160duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member]137false 4us-gaap_PropertyPlantAndEquipmentNetus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse84450000008445000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse84450000008445000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse83200000008320000000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryAmount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Net property, plant and equipment138false 4us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00USD$falsefalsefalse2truefalsefalse00USD$falsefalsefalse3truefalsefalse00USD$falsefalsefalse4truefalsefalse400000000400000000USD$falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Impairment charges139false 4duk_EnvironmentalComplianceCapitalCostsduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse395000000395000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryCosts to comply with existing and proposed EPA environmental rules and regulations.No definition available.false2EPA compliance capital costs140false 4us-gaap_RegulatoryAssetsNoncurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse769000000769000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse769000000769000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse810000000810000000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 9, 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 false2Regulatory assets, noncurrent141false 4us-gaap_RegulatoryLiabilityNoncurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse755000000755000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse755000000755000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse741000000741000000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 11 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Regulatory liability, noncurrent142false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse63false USDtruefalse$AS_OF_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_us-gaap_RegulatoryAssetAxis_RetiredGenerationFacilitiesMemberhttp://www.sec.gov/CIK0001326160instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseRetired Generation Facilities [Member]us-gaap_RegulatoryAssetAxisxbrldihttp://xbrl.org/2006/xbrldiduk_RetiredGenerationFacilitiesMemberus-gaap_RegulatoryAssetAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Retired Generation Facilities [Member]143false 4us-gaap_RegulatoryAssetsNoncurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse5900000059000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse5900000059000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 9, 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 false2Regulatory assets, noncurrent144false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse64false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_EdwardsportEventSeptember72006Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport Event September 7, 2006 [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportEventSeptember72006Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport Event September 7, 2006 [Member]145false 4duk_ApprovedEstimatedCapitalCostduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse19850000001985000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEdwardsport IGCC utility plant's original approved estimated capital cost.No definition available.false2Edwardsport IGCC original estimated and approved capital cost, including AFUDC146false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse65false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_EdwardsportEventMay12008Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport Event May 1, 2008 [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportEventMay12008Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport Event May 1, 2008 [Member]147false 4duk_EstimatedAfudcOnCapitalProjectduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse125000000125000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEstimated AFUDC on Capital ProjectNo definition available.false2Estimated AFUDC on capital project148false 4duk_RevisedEstimatedCapitalCostIncludingAfudcduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse23500000002350000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEdwardsport IGCC utility plant's revised estimated capital cost.No definition available.false2Edwardsport IGCC revised estimated capital cost, including AFUDC149false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse66false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_EdwardsportEventApril162010Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport Event April 16, 2010 [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportEventApril162010Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport Event April 16, 2010 [Member]150false 4duk_EstimatedAfudcOnCapitalProjectduk_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse160000000160000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEstimated AFUDC on Capital ProjectNo definition available.false2Estimated AFUDC on capital project151false 4duk_RevisedEstimatedCapitalCostIncludingAfudcduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse28800000002880000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEdwardsport IGCC utility plant's revised estimated capital cost.No definition available.false2Edwardsport IGCC revised estimated capital cost, including AFUDC152false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse67false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_EdwardsportEventJune272011Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport Event June 27, 2011 [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportEventJune272011Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport Event June 27, 2011 [Member]153false 4duk_RevisedEstimatedCapitalCostExcludingAfudcduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse28200000002820000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEdwardsport IGCC revised estimated capital costs, excluding AFUDCNo definition available.false2Edwardsport IGCC revised estimated capital costs, excluding AFUDC154false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse68false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_EdwardsportEventOctober192011Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport Event October 19, 2011 [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportEventOctober192011Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport Event October 19, 2011 [Member]155false 4duk_RevisedEstimatedCapitalCostExcludingAfudcduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse29800000002980000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEdwardsport IGCC revised estimated capital costs, excluding AFUDCNo definition available.false2Edwardsport IGCC revised estimated capital costs, excluding AFUDC156false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse69false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_EdwardsportEventOctober302012Memberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport Event October 30, 2012 [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportEventOctober302012Memberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport Event October 30, 2012 [Member]157false 4duk_RevisedEstimatedCapitalCostExcludingAfudcduk_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse31500000003150000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryEdwardsport IGCC revised estimated capital costs, excluding AFUDCNo definition available.false2Edwardsport IGCC revised estimated capital costs, excluding AFUDC158false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse70false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_us-gaap_PublicUtilityAxis_EdwardsportIgccPlantMemberhttp://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport IGCC Plant [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportIgccPlantMemberus-gaap_PublicUtilityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport IGCC Plant [Member]159false 4us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfIndirectDisallowanceOfCostsOfRecentlyCompletedPlantsus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse897000000897000000USD$falsefalsefalse4truefalsefalse420000000420000000USD$falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of indirect disallowance of costs of a recently completed plant. When it becomes probable that part of the cost of a recently completed plant will be disallowed for rate-making purposes and a reasonable estimate of the amount of the disallowance can be made, the estimated amount of the probable disallowance is deducted from the reported cost of the plant and recognized as a loss. If part of the cost is explicitly, but indirectly, disallowed (for example, by an explicit disallowance of return on investment on a portion of the plant), an equivalent amount of cost is deducted from the reported cost of the plant and recognized as a loss.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 35 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6500292&loc=d3e45799-110387 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 35 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6500292&loc=d3e45819-110387 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 7, 60 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Public utilities, property, plant and equipment, amount of indirect disallowance of costs of recently completed plants160false 4us-gaap_GainContingencyUnrecordedAmountus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse560000000560000000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse560000000560000000USD$falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount or range of possible amounts of gain that could be realized upon the resolution of a contingency.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 17 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6397426&loc=d3e17499-108355 false2Edwardsport damages161false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse72false USDtruefalse$AS_OF_Jun30_2013_dei_LegalEntityAxis_DukeEnergyIndianaMember_duk_PublicUtilitiesRegulatoryProceedingAxis_EdwardsportEventApril302012SettlementAgreementMember_us-gaap_PublicUtilityAxis_EdwardsportIgccPlantMemberhttp://www.sec.gov/CIK0001326160instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseDuke Energy Indiana [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyIndianaMemberdei_LegalEntityAxisexplicitMemberfalsefalseEdwardsport IGCC Plant [Member]us-gaap_PublicUtilityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportIgccPlantMemberus-gaap_PublicUtilityAxisexplicitMemberfalsefalseEdwardsport Event April 30, 2012 Settlement Agreement [Member]duk_PublicUtilitiesRegulatoryProceedingAxisxbrldihttp://xbrl.org/2006/xbrldiduk_EdwardsportEventApril302012SettlementAgreementMemberduk_PublicUtilitiesRegulatoryProceedingAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Indiana [Member] | Edwardsport IGCC Plant [Member] | Edwardsport Event April 30, 2012 Settlement Agreement [Member]162false 4duk_CapProjectCostOrRecoveryThatCouldBePassedOnToCustomersduk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse25950000002595000000USD$falsetruefalse2falsefalsefalse00falsefalsefalse3truefalsefalse25950000002595000000USD$falsetruefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe limitation of project cost and/or recovery that can be passed on to customers.No definition available.false2Cost Cap for customersfalseRegulatory Matters (Narrative) (Details) (USD $)NoRoundingUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.duke-energy.com/role/DisclosureRegulatoryMattersNarrativeDetails5162