Financings and Capitalization (Narrative) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Financing And Capitalization [Line Items]
Notes payable	$ 0	$ 20,000,000
Limitation on payment of stock dividends	6,900,000,000
Dividends paid	$ 305,000,000
Consumers Energy Company
Financing And Capitalization [Line Items]
Supplier financing program, payment period	60 days
Supplier financing program, termination period	30 days
Payables under supplier finance program	$ 23,000,000	1,000,000
Unrestricted retained earnings	2,000,000,000
Consumers Energy Company | Related Party
Financing And Capitalization [Line Items]
Notes payable	6,000,000	75,000,000
Consumers Energy Company | Credit Agreement | Related Party
Financing And Capitalization [Line Items]
Maximum borrowing capacity		$ 500,000,000
Notes payable	0
Consumers Energy Company | Credit Agreement | Subsidiaries
Financing And Capitalization [Line Items]
Maximum borrowing capacity	40,000,000
Notes payable	$ 6,000,000
Interest rate at period end	6.924%
Consumers Energy Company | Credit Agreement | Subsidiaries | SOFR
Financing And Capitalization [Line Items]
Basis spread on variable rate	1.75%
Consumers Energy Company | Commercial Paper
Financing And Capitalization [Line Items]
Short-term debt authorized borrowings	$ 500,000,000
Short-term borrowings outstanding	$ 0