Regulatory Matters (Schedule of Liabilities for PSCR and GCR Overrecoveries) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2022
Public Utilities, General Disclosures [Line Items]
Accrued rate refunds	$ 28	$ 38
Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Accounts receivable and accrued revenue	38	0
Accrued rate refunds	28	38
Consumers Energy Company | PSCR underrecoveries
Public Utilities, General Disclosures [Line Items]
PSCR underrecoveries	38	0	$ 401
Accrued rate refunds	0	13
Consumers Energy Company | GCR underrecoveries
Public Utilities, General Disclosures [Line Items]
Accrued rate refunds	$ 28	$ 25