Income Taxes - Reconciliation of Income Taxes at the U.S. Statutory Federal Income Tax Rate (Parenthetical) (Details) - USD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Effective Income Tax Computation [Line Items] | ||
| Production tax credit | $ 50 | $ 27 |
| Virginia Electric And Power Company [Member] | ||
| Effective Income Tax Computation [Line Items] | ||
| Production tax credit | $ 40 | |