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Risk Management, Derivative Instruments And Hedging Activities (Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified | Mar. 31, 2013 | Dec. 31, 2012
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | $ 309 |  | $ 264 |
Location and fair value amounts of derivatives (Liability) | 845 |  | 917 |
Designated As Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 3 |  | 9 |
Location and fair value amounts of derivatives (Liability) | 102 |  | 119 |
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 2 |  | 2 |
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Investments And Other Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 3 |  | 7 |
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | (2) |  |  |
Location and fair value amounts of derivatives (Liability) | 70 |  | 81 |
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 30 |  | 35 |
Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 1 |  | 2 |
Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 1 |  | 1 |
Nondesignated [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 306 |  | 255 |
Location and fair value amounts of derivatives (Liability) | 743 |  | 798 |
Nondesignated [Member] | Interest Rate Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 57 |  | 76 |
Nondesignated [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 6 |  | 8 |
Nondesignated [Member] | Commodity Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 52 |  | 41 |
Location and fair value amounts of derivatives (Liability) | 9 |  | 2 |
Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 32 |  | 106 |
Location and fair value amounts of derivatives (Liability) | 6 |  | 50 |
Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 151 |  | 106 |
Location and fair value amounts of derivatives (Liability) | 372 |  | 407 |
Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 71 |  | 2 |
Location and fair value amounts of derivatives (Liability) | 293 |  | 255 |
Duke Energy Carolinas [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 5 |  | 12 |
Duke Energy Carolinas [Member] | Nondesignated [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 5 |  | 12 |
Duke Energy Carolinas [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 2 |  | 6 |
Duke Energy Carolinas [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 3 |  | 6 |
Progress Energy [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 47 |  | 11 |
Location and fair value amounts of derivatives (Liability) | 301 |  | 440 |
Progress Energy [Member] | Designated As Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) |  |  | 3 |
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 2 |  |  |
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 1 |  | 2 |
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 1 |  | 1 |
Progress Energy [Member] | Nondesignated [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 47 |  | 11 |
Location and fair value amounts of derivatives (Liability) | 299 |  | 437 |
Progress Energy [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) |  |  | 11 |
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 13 |  | 3 |
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 2 |  | 8 |
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 20 |  |  |
Location and fair value amounts of derivatives (Liability) | 140 |  | 231 |
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 12 |  |  |
Location and fair value amounts of derivatives (Liability) | 159 |  | 195 |
Duke Energy Progress [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 14 |  | 2 |
Location and fair value amounts of derivatives (Liability) | 108 |  | 166 |
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 2 |  | 2 |
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 1 |  | 1 |
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 1 |  | 1 |
Duke Energy Progress [Member] | Nondesignated [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 14 |  | 2 |
Location and fair value amounts of derivatives (Liability) | 106 |  | 164 |
Duke Energy Progress [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) |  |  | 11 |
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 4 | [1] | 1 | [1]
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) |  |  | 1 | [1]
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 8 | [1] |  |
Location and fair value amounts of derivatives (Liability) | 52 | [1] | 85 | [1]
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 2 | [1] |  |
Location and fair value amounts of derivatives (Liability) | 54 | [1] | 68 | [1]
Duke Energy Florida [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 33 |  | 9 |
Location and fair value amounts of derivatives (Liability) | 190 |  | 270 |
Duke Energy Florida [Member] | Designated As Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) |  |  | 1 |
Duke Energy Florida [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) |  |  | 1 |
Duke Energy Florida [Member] | Nondesignated [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 33 |  | 9 |
Location and fair value amounts of derivatives (Liability) | 190 |  | 269 |
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 8 | [1] | 2 | [1]
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 2 | [1] | 7 | [1]
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 13 | [1] |  |
Location and fair value amounts of derivatives (Liability) | 89 | [1] | 146 | [1]
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 10 | [1] |  |
Location and fair value amounts of derivatives (Liability) | 101 | [1] | 123 | [1]
Duke Energy Ohio [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 244 |  | 220 |
Location and fair value amounts of derivatives (Liability) | 319 |  | 199 |
Duke Energy Ohio [Member] | Designated As Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 2 |  | 2 |
Duke Energy Ohio [Member] | Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 2 |  | 2 |
Duke Energy Ohio [Member] | Nondesignated [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 242 |  | 218 |
Location and fair value amounts of derivatives (Liability) | 319 |  | 199 |
Duke Energy Ohio [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 1 |  | 1 |
Duke Energy Ohio [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 6 |  | 7 |
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 42 |  | 31 |
Location and fair value amounts of derivatives (Liability) | 32 |  | 4 |
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 13 |  | 81 |
Location and fair value amounts of derivatives (Liability) | 7 |  | 51 |
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 130 |  | 106 |
Location and fair value amounts of derivatives (Liability) | 182 |  | 132 |
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 57 |  |  |
Location and fair value amounts of derivatives (Liability) | 91 |  | 4 |
Duke Energy Indiana [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 5 |  | 10 |
Location and fair value amounts of derivatives (Liability) | 55 |  | 63 |
Duke Energy Indiana [Member] | Nondesignated [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | 5 |  | 10 |
Location and fair value amounts of derivatives (Liability) | 55 |  | 63 |
Duke Energy Indiana [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Current Liabilities Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Liability) | 55 |  | 63 |
Duke Energy Indiana [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets Other [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Location and fair value amounts of derivatives (Asset) | $ 5 |  | $ 10 |
[1] | Substantially all of these contracts receive regulatory treatment.

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- Definition Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -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 Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -Clause 1 -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 FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959 + Details
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- Definition Fair value of derivative liability, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -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 Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -Clause 1 -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 FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959 + Details
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