Nuclear Decommissioning Trust Funds - Schedule of Sales Proceeds, Gains, and Losses for Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Sales proceeds of NDT funds investments | $ 162 | $ 433 | $ 298 | $ 1,601 |
| Realized gains | 1 | 2 | 3 | 9 |
| Realized losses | $ (9) | $ 0 | $ (10) | $ (5) |