Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Income Tax Contingency [Line Items] | ||
| Unrecognized tax benefits | $ 88 | $ 100 |
| Offsetting receivable | 5,196 | 4,755 |
| Constellation Energy Corp | ||
| Income Tax Contingency [Line Items] | ||
| Unrecognized tax benefits | 20 | 31 |
| Offsetting receivable | 20 | 31 |
| Pepco Holdings LLC | ||
| Income Tax Contingency [Line Items] | ||
| Unrecognized tax benefits | 54 | 48 |
| Delmarva Power and Light Company | ||
| Income Tax Contingency [Line Items] | ||
| Unrecognized tax benefits | $ 18 | $ 11 |