Plant, Property, and Equipment (Schedule of Finance Leases and Other Financing Obligations) (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Finance Leases and Other Financing Obligations, Rollforward [Roll Forward] | ||
| Balance at beginning of period | $ 176 | $ 136 |
| Additions | 53 | 55 |
| Net retirements and other adjustments | (36) | (15) |
| Balance at end of period | 193 | 176 |
| Consumers Energy Company | ||
| Finance Leases and Other Financing Obligations, Rollforward [Roll Forward] | ||
| Balance at beginning of period | 131 | 112 |
| Additions | 22 | 34 |
| Net retirements and other adjustments | (15) | (15) |
| Balance at end of period | $ 138 | $ 131 |