Investments in Debt and Equity Securities (Realized Gains and Losses) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| FV-NI: | ||||
| Realized gains | $ 41 | $ 127 | $ 167 | $ 195 |
| Realized losses | 40 | 27 | 81 | 45 |
| AFS: | ||||
| Realized gains | 10 | 2 | 20 | 12 |
| Realized losses | 17 | 22 | 37 | 36 |
| Duke Energy Carolinas | ||||
| FV-NI: | ||||
| Realized gains | 22 | 72 | 104 | 125 |
| Realized losses | 19 | 15 | 41 | 21 |
| AFS: | ||||
| Realized gains | 8 | 1 | 15 | 5 |
| Realized losses | 9 | 11 | 23 | 17 |
| Progress Energy | ||||
| FV-NI: | ||||
| Realized gains | 19 | 55 | 63 | 70 |
| Realized losses | 21 | 12 | 40 | 24 |
| AFS: | ||||
| Realized gains | 2 | 1 | 5 | 7 |
| Realized losses | 8 | 11 | 14 | 19 |
| Duke Energy Progress | ||||
| FV-NI: | ||||
| Realized gains | 17 | 55 | 61 | 70 |
| Realized losses | 21 | 12 | 40 | 24 |
| AFS: | ||||
| Realized gains | 2 | 1 | 5 | 7 |
| Realized losses | $ 7 | $ 10 | $ 13 | $ 18 |