Financings and Capitalization (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing And Capitalization [Line Items]
Limitation on payment of stock dividends	$ 6,800,000,000
Dividends paid	$ 769,000,000
Common stock authorized (in shares)	350,000,000	350,000,000.0
Common stock, par value (in dollars per share)	$ 0.01
Preferred stock authorized (in shares)	10,000,000
Preferred stock, par value (in dollars per share)	$ 0.01
Stock offering program maximum value	$ 500,000,000
Issuance of common stock	$ 69,000,000	$ 26,000,000	$ 253,000,000
Settlement Of Forward Contracts
Financing And Capitalization [Line Items]
Settlement of forward contracts through issuance of stock (in shares)	962,354
Settlement of forward contracts through issuance of stock (in dollars per shares)	$ 57.36
Issuance of common stock	$ 55,000,000
Consumers Energy Company
Financing And Capitalization [Line Items]
Notes payable – related parties	75,000,000	$ 392,000,000
Unrestricted retained earnings	$ 1,900,000,000
Common stock authorized (in shares)	125,000,000.0	125,000,000.0
Preferred stock authorized (in shares)	7,500,000	7,500,000
Consumers Energy Company | Credit Agreement
Financing And Capitalization [Line Items]
Maximum borrowing capacity	$ 500,000,000
Notes payable – related parties	$ 75,000,000
Consumers Energy Company | Credit Agreement | Maximum
Financing And Capitalization [Line Items]
Interest rate	3.50%
Consumers Energy Company | Commercial Paper
Financing And Capitalization [Line Items]
Short-term debt authorized borrowings	$ 500,000,000
Short-term borrowings outstanding	$ 20,000,000
Interest rate	4.71%