Nuclear Decommissioning Trust Funds - Schedule of Sales Proceeds, Gains, and Losses for Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Sales proceeds of NDT funds investments | $ 56 | $ 592 | $ 136 | $ 1,168 |
| Realized gains | 1 | 4 | 2 | 7 |
| Realized losses | $ (1) | $ (3) | $ (1) | $ (5) |