Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2017 |
Mar. 31, 2016 |
|
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | $ 91 | $ 91 |
| Duke Energy Carolinas [Member] | ||
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | 9 | 8 |
| Progress Energy [Member] | ||
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | 46 | 47 |
| Duke Energy Progress [Member] | ||
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | 5 | 5 |
| Duke Energy Florida [Member] | ||
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | 41 | 42 |
| Duke Energy Ohio [Member] | ||
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | 28 | 28 |
| Duke Energy Indiana [Member] | ||
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | 7 | 8 |
| Piedmont Natural Gas [Member] | ||
| Organization And Basis Of Presentation [Line Items] | ||
| Excise taxes collected | $ 1 | $ 1 |