Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2015 |
Sep. 30, 2014 |
|
| Organization And Basis Of Presentation [Line Items] | ||||
| Excise taxes collected | $ 109 | $ 101 | $ 308 | $ 416 |
| Duke Energy Carolinas [Member] | ||||
| Organization And Basis Of Presentation [Line Items] | ||||
| Excise taxes collected | 9 | 4 | 27 | 93 |
| Progress Energy [Member] | ||||
| Organization And Basis Of Presentation [Line Items] | ||||
| Excise taxes collected | 67 | 63 | 174 | 214 |
| Duke Energy Progress [Member] | ||||
| Organization And Basis Of Presentation [Line Items] | ||||
| Excise taxes collected | 4 | 12 | 56 | |
| Duke Energy Florida [Member] | ||||
| Organization And Basis Of Presentation [Line Items] | ||||
| Excise taxes collected | 63 | 63 | 162 | 158 |
| Duke Energy Ohio [Member] | ||||
| Organization And Basis Of Presentation [Line Items] | ||||
| Excise taxes collected | 24 | 24 | 80 | 80 |
| Duke Energy Indiana [Member] | ||||
| Organization And Basis Of Presentation [Line Items] | ||||
| Excise taxes collected | $ 9 | $ 10 | $ 27 | $ 29 |