v3.3.0.814

Variable Interest Entities (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Dec. 31, 2014
Variable Interest Entities [Line Items] |  |  |  |  |
Asset impairment charges | $ 111 | $ 1 | $ 111 | $ 81 |
Cinergy Receivables [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Minimum equity balance required by Cinergy Receivables | $ 3 |  | $ 3 |  |
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Percent of proceeds received as cash | 75.00% |  | 75.00% |  |
Percent of proceeds received as subordinated note | 25.00% |  | 25.00% |  |
Duke American Transmission Company [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Variable Interest Entity Ownership Interest |  |  | 50.00% |  |
Atlantic Coast Pipeline [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Variable Interest Entity Ownership Interest |  |  | 40.00% |  |
Sabal Trail Transmission Pipeline [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Variable Interest Entity Ownership Interest |  |  | 7.50% |  |
OVEC [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Variable Interest Entity Ownership Interest |  |  | 9.00% |  |
Duke Energy Carolinas [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Asset impairment charges |  |  |  | 3 |
Duke Energy Progress [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Asset impairment charges |  |  |  | (18) |
Duke Energy Florida [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Asset impairment charges | $ 7 | $ 1 | $ 7 | 2 |
Duke Energy Ohio [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Asset impairment charges |  |  |  | 94 |
Duke Energy Ohio [Member] | Cinergy Receivables [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Fixed interest rate added to LIBOR to compute variable rate |  |  | 1.00% |  |
Duke Energy Ohio [Member] | Other VIEs [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Asset impairment charges |  |  |  | $ 94 | $ 94
Duke Energy Indiana [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Asset impairment charges | $ 85 |  | $ 85 |  |
Duke Energy Indiana [Member] | Cinergy Receivables [Member] |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |
Fixed interest rate added to LIBOR to compute variable rate |  |  | 1.00% |  |

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