v2.4.0.6

Commitments And Contingencies (Narrative) (Details) (USD $) | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2009
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Loss exposure in excess of accrual, high estimate | $ 84,000,000 |  |  |  |
Probable insurance recoveries | 781,000,000 | [1],[2] | 781,000,000 | [1],[2] |
Reserves for legal matters | 834,000,000 | [3],[4] | 846,000,000 | [3],[4] |
Minimum [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Estimated cost of complying with recently issued and proposed EPA regulations | 5,000,000,000 |  |  |  |
Maximum [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Estimated cost of complying with recently issued and proposed EPA regulations | 6,000,000,000 |  |  |  |
Alaskan Global Warming Lawsuit [Member] | Minimum [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Amount of claim(s) | 95,000,000 |  |  |  |
Alaskan Global Warming Lawsuit [Member] | Maximum [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Amount of claim(s) | 400,000,000 |  |  |  |
Brazil Expansion Lawsuit [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Obligation to expand installed generation capacity, percent | 15.00% |  |  |  |
Crescent Litigation [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Amount of claim(s) | 1,200,000,000 |  |  |  |
Duke Energy Carolinas [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Loss exposure in excess of accrual, high estimate | 29,000,000 |  |  |  |
New Source Review maximum civil penalties per day for each violation | 37,500 |  |  |  |
Probable insurance recoveries | 781,000,000 | [1],[2] | 781,000,000 | [1],[2] |
Reserves for legal matters | 743,000,000 | [3],[4] | 751,000,000 | [3],[4] |
Duke Energy Carolinas [Member] | Asbestos Issue [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Number of nonmalignant asbestos related claims | 99 |  |  |  |
Cumulative relief sought for nonmalignant asbestos related claims | 18,000,000 |  |  |  |
Number of malignant asbestos related claims | 46 |  |  |  |
Cumulative relief sought for malignant asbestos related claims | 15,000,000 |  |  |  |
Asbestos-related injuries and damages reserves | 743,000,000 |  | 751,000,000 |  |
Asbestos related injuries and damages self insured retention | 476,000,000 |  |  |  |
Policy limit for potential future insurance recoveries for indemnification and medical cost claim payments in excess of self insured limit | 935,000,000 |  |  |  |
Progress Energy [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Loss exposure in excess of accrual, high estimate | 7,000,000 |  |  |  |
Reserves for legal matters | 75,000,000 | [3] | 79,000,000 | [3] |
Progress Energy [Member] | Spent Nuclear Fuels [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Gain contingency asserted damage | 113,000,000 |  |  |  |
Progress Energy [Member] | Synthetic Fuels [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Judgment payment |  |  |  |  | 154,000,000
Damages awarded to plaintiff | 90,000,000 |  |  |  |
Gain recognized in period |  |  | 63,000,000 |  |
Duke Energy Progress [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Loss exposure in excess of accrual, high estimate | 3,000,000 |  |  |  |
Reserves for legal matters | 11,000,000 | [3] | 12,000,000 | [3] |
Duke Energy Progress [Member] | Spent Nuclear Fuels [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Gain contingency asserted damage | 90,000,000 |  |  |  |
Duke Energy Florida [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Loss exposure in excess of accrual, high estimate | 4,000,000 |  |  |  |
Reserves for legal matters | 44,000,000 | [3],[5] | 47,000,000 | [3],[5] |
Duke Energy Florida [Member] | Spent Nuclear Fuels [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Gain contingency asserted damage | 23,000,000 |  |  |  |
Duke Energy Ohio [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Loss exposure in excess of accrual, high estimate | 43,000,000 |  |  |  |
Duke Energy Indiana [Member] |  |  |  |  |
Valuation and Qualifying Accounts [Abstract] |  |  |  |  |
Loss exposure in excess of accrual, high estimate | 5,000,000 |  |  |  |
Reserves for legal matters | $ 7,000,000 | [3] | $ 8,000,000 | [3] |
[1] | Insurance recoveries are classified in the respective Condensed Consolidated Balance Sheets in Other within Investments and Other Assets and Receivables.
[2] | Relates to recoveries associated with aforementioned asbestos-related injuries and damages claims.
[3] | Reserves are classified in the respective Condensed Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Other within Current Liabilities.
[4] | Includes reserves for aforementioned asbestos-related injuries and damages claims.
[5] | Includes workers' compensation claims.

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- Definition Cumulative relief sought for malignant asbestos related claims + References No definition available. + Details
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- Definition The maximum per daily value (monetary amount) of the cival penalty the U.S. Department of Justice seeks for complaints and notices of violations under New Source Review (NSR) provisions of the Clean Air Act (CAA). + References No definition available. + Details
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- Definition Amount of gain recognized in the period that had been disclosed in prior periods as a contingent gain. + References Reference 1: 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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 17 -Subparagraph b -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. + Details
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- Definition Carrying amount as of the balance sheet date of reserves for the costs of settling insured claims and costs incurred in the claims settlement process attributable to asbestos and environmental claims, before estimated recoveries from reinsurers. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-PLI -Paragraph 132, 133, 135, 136, 137 -IssueDate 2006-09-01 -Chapter 4 -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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 94-5 -Paragraph 11, 12 -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. + Details
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