Leases (Schedule of Lessee Cash Flows) (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Cash paid for amounts included in the measurement of lease liabilities | ||
| Cash used in operating activities for operating leases | $ 4 | $ 6 |
| Cash used in operating activities for finance leases | 17 | 15 |
| Cash used in financing activities for finance leases | 5 | 6 |
| Lease liabilities arising from obtaining right-of-use assets | ||
| Operating leases | 1 | 3 |
| Finance leases | 22 | 55 |
| Consumers Energy Company | ||
| Cash paid for amounts included in the measurement of lease liabilities | ||
| Cash used in operating activities for operating leases | 4 | 5 |
| Cash used in operating activities for finance leases | 14 | 13 |
| Cash used in financing activities for finance leases | 6 | 5 |
| Lease liabilities arising from obtaining right-of-use assets | ||
| Operating leases | 1 | 1 |
| Finance leases | $ 22 | $ 34 |