2.4.0.8040702 - Disclosure - Goodwill (Schedule of Intangible Assets) (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$FROM_Apr01_2013_TO_Jun30_2013http://www.sec.gov/CIK0001326160duration2013-04-01T00:00:002013-06-30T00:00:00USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$FROM_Apr01_2012_TO_Jun30_2012http://www.sec.gov/CIK0001326160duration2012-04-01T00:00:002012-06-30T00:00:00USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$FROM_Jan01_2013_TO_Jun30_2013http://www.sec.gov/CIK0001326160duration2013-01-01T00:00:002013-06-30T00:00:00USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false USDfalsefalse$FROM_Jan01_2012_TO_Jun30_2012http://www.sec.gov/CIK0001326160duration2012-01-01T00:00:002012-06-30T00:00:00USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 4duk_EmissionAllowancesAbstractduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Emission Allowances [Abstract]2false 5us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse386000000386USD$falsetruefalse2truefalsefalse00USD$falsetruefalse3truefalsefalse386000000386USD$falsetruefalse4truefalsefalse402000000402USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Pretax impairment charge3false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5false USDtruefalse$FROM_Apr01_2013_TO_Jun30_2013_dei_LegalEntityAxis_ProgressEnergyMemberhttp://www.sec.gov/CIK0001326160duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseProgress Energy [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_ProgressEnergyMemberdei_LegalEntityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Progress Energy [Member]4true 4duk_EmissionAllowancesAbstractduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Emission Allowances [Abstract]5false 5us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse366000000366USD$falsefalsefalse2truefalsefalse00USD$falsefalsefalse3truefalsefalse366000000366USD$falsefalsefalse4truefalsefalse00USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Pretax impairment charge6false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse9false USDtruefalse$FROM_Apr01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyProgressMemberhttp://www.sec.gov/CIK0001326160duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Progress [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyProgressMemberdei_LegalEntityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Progress [Member]7true 4duk_EmissionAllowancesAbstractduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Emission Allowances [Abstract]8false 5us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse2200000022USD$falsefalsefalse2truefalsefalse00USD$falsefalsefalse3truefalsefalse2200000022USD$falsefalsefalse4truefalsefalse00USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Pretax impairment charge9false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse13false USDtruefalse$FROM_Apr01_2013_TO_Jun30_2013_dei_LegalEntityAxis_DukeEnergyFloridaMemberhttp://www.sec.gov/CIK0001326160duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseDuke Energy Florida [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiduk_DukeEnergyFloridaMemberdei_LegalEntityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Duke Energy Florida [Member]10true 4duk_EmissionAllowancesAbstractduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Emission Allowances [Abstract]11false 5us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse345000000345USD$falsefalsefalse2truefalsefalse00USD$falsefalsefalse3truefalsefalse345000000345USD$falsefalsefalse4truefalsefalse00USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Pretax impairment charge12false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse17false USDtruefalse$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$nanafalse0Duke Energy Indiana [Member]13true 4duk_EmissionAllowancesAbstractduk_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Emission Allowances [Abstract]14false 5us-gaap_AssetImpairmentChargesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse00USD$falsetruefalse2truefalsefalse00USD$falsetruefalse3truefalsefalse00USD$falsetruefalse4truefalsefalse400000000400USD$falsetruefalsexbrli: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. false2Pretax impairment chargefalseGoodwill (Schedule of Intangible Assets) (Details) (USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.duke-energy.com/role/GoodwillScheduleOfIntangibleAssetsDetails414