Financings and Capitalization (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2024	Jan. 31, 2024	Dec. 31, 2023	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Oct. 31, 2024
Financing And Capitalization [Line Items]
Principal (In Millions)	$ 1,300			$ 1,300	$ 1,300
Payment for purchase of first mortgage bonds					789	$ 1,846
Notes payable	0		$ 93	0	0		$ 93
Limitation on payment of stock dividends	7,900			7,900	7,900
Dividends paid					544
Stock offering program maximum value							1,000
Issuance of common stock					283	10
First mortgage bonds
Financing And Capitalization [Line Items]
Gain on extinguishment of debt				20	90
Settlement Of Forward Contracts
Financing And Capitalization [Line Items]
Settlement of forward contracts through issuance of stock (in dollars per share)		$ 70.31
Issuance of common stock		$ 266
Senior notes | Delayed Draw Unsecured Term Loan Credit Facility
Financing And Capitalization [Line Items]
Maximum borrowing capacity	$ 400			400	400
Basis spread on variable rate	0.85%
Senior notes | Subsequent Event | Delayed Draw Unsecured Term Loan Credit Facility
Financing And Capitalization [Line Items]
Amount borrowed								$ 175
Interest rate at period end								5.694%
Consumers Energy Company
Financing And Capitalization [Line Items]
Principal (In Millions)	$ 1,300			1,300	1,300
Payment for purchase of first mortgage bonds					322	$ 1,639
Notes payable	0		93	0	0		93
Unrestricted retained earnings	2,300			2,300	2,300
Consumers Energy Company | Variable Rate Revenue Bonds | Subsequent Event
Financing And Capitalization [Line Items]
Principal (In Millions)								$ 75
Interest rate								3.35%
Consumers Energy Company | Related Party | First mortgage bonds
Financing And Capitalization [Line Items]
Principal (In Millions)	311			311	311
Payment for purchase of first mortgage bonds					218
Consumers Energy Company | Credit Agreement | Related Party
Financing And Capitalization [Line Items]
Maximum borrowing capacity			$ 500				$ 500
Basis spread on variable rate			(0.10%)
Notes payable	0			0	0
Consumers Energy Company | Commercial Paper
Financing And Capitalization [Line Items]
Short-term debt authorized borrowings					500
Short-term borrowings outstanding	$ 0			$ 0	$ 0