Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for uncollectible accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 27	$ 20	$ 29
Charged to Expense	34	50	22
Charged to Other Accounts	0	0	0
Deductions	40	43	31
Balance at End of Period	21	27	20
Allowance for uncollectible accounts | Consumers Energy Company
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	27	20	29
Charged to Expense	34	50	22
Charged to Other Accounts	0	0	0
Deductions	40	43	31
Balance at End of Period	21	27	20
Deferred tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	2	2	1
Charged to Expense	0	0	1
Charged to Other Accounts	0	0	0
Deductions	0	0	0
Balance at End of Period	$ 2	$ 2	$ 2