Nuclear Decommissioning Trust Funds - Schedule of Sales Proceeds, Gains, and Losses for Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Investments, Debt and Equity Securities [Abstract] | ||
| Sales proceeds of NDT funds investments | $ 80 | $ 576 |
| Realized gains | 1 | 3 |
| Realized losses | $ 0 | $ (2) |