2.4.0.8040502 - Disclosure - Committments and Contingencies (Schedule of Reserves and Insurance Recoveries) (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$AS_OF_Jun30_2013http://www.sec.gov/CIK0001326160instant2013-06-30T00:00:000001-01-01T00:00:00USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$AS_OF_Dec31_2012http://www.sec.gov/CIK0001326160instant2012-12-31T00:00:000001-01-01T00:00:00USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3us-gaap_LossContingenciesLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Loss Contingencies [Line Items]2false 4us-gaap_LossContingencyAccrualAtCarryingValueus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse871000000871[1],[2]USD$falsetruefalse2truefalsefalse846000000846[1],[2]USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe carrying amount as of the balance sheet date of the combined total of loss contingency liabilities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14326-108349 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 9, 10, 11, 12 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Reserves for legal matters1Reserves are classified in the respective Condensed Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Other within Current Liabilities.2Includes reserves for asbestos-related injuries and damages claims.3Insurance recoveries are classified in the respective Condensed Consolidated Balance Sheets in Other within Investments and Other Assets and Receivables. 4Relates to recoveries associated with aforementioned asbestos-related injuries and damages claims.5Includes workers' compensation claims.falseCommittments and Contingencies (Schedule of Reserves and Insurance Recoveries) (Details) (USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.duke-energy.com/role/DisclosureCommittmentsAndContingenciesScheduleOfReservesAndInsuranceRecoveriesDetails219