Income Taxes (Schedule of Reconciliation of Uncertain Tax Benefits) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Balance at beginning of period | $ 24 | $ 26 | $ 28 |
| Additions for current-year tax positions | 2 | 1 | 1 |
| Additions for prior-year tax positions | 7 | 2 | 0 |
| Reductions for lapse of statute of limitations | (4) | (5) | (3) |
| Balance at end of period | 29 | 24 | 26 |
| Consumers Energy Company | |||
| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Balance at beginning of period | 32 | 36 | 36 |
| Additions for current-year tax positions | 1 | 6 | 1 |
| Additions for prior-year tax positions | 7 | 1 | 2 |
| Reductions for lapse of statute of limitations | (4) | (11) | (3) |
| Balance at end of period | $ 36 | $ 32 | $ 36 |