Consumers Energy Company Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Other Paid-in Capital	Accumulated Other Comprehensive Loss	Retirement benefits liability	Retained Earnings	Cumulative Preferred Stock	Consumers Energy Company	Consumers Energy Company Common Stock	Consumers Energy Company Other Paid-in Capital	Consumers Energy Company Accumulated Other Comprehensive Loss	Consumers Energy Company Retirement benefits liability	Consumers Energy Company Retained Earnings	Consumers Energy Company Cumulative Preferred Stock
Total Equity at Beginning of Period at Dec. 31, 2023	$ 8,125	$ 3	$ 5,705		$ (46)	$ 1,658	$ 224	$ 10,800	$ 841	$ 7,759		$ (15)	$ 2,178	$ 37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										320
Return of stockholder contribution										(320)
Amortization of net actuarial loss	1				1			1				1
Net Income	738							726					726
Dividends declared on common stock						(461)							(544)
Dividends declared on preferred stock						(7)							(1)
Total Equity at End of Period at Sep. 30, 2024	8,641	3	6,001	$ (45)		1,928	224	10,982	841	7,759	$ (14)		2,359	37
Total Equity at Beginning of Period at Jun. 30, 2024	8,541	3	5,991		(45)	1,830	224	10,893	841	7,759		(15)	2,271	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										0
Return of stockholder contribution										0
Amortization of net actuarial loss	0				0			1				1
Net Income	253							273					273
Dividends declared on common stock						(153)							(185)
Dividends declared on preferred stock						(2)							0
Total Equity at End of Period at Sep. 30, 2024	8,641	3	6,001	(45)		1,928	224	10,982	841	7,759	(14)		2,359	37
Total Equity at Beginning of Period at Dec. 31, 2024	8,748	3	6,009		(41)	2,035	224	11,431	841	8,174		(11)	2,390	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										695
Return of stockholder contribution										0
Amortization of net actuarial loss	1				1			0				0
Net Income	782							848					848
Dividends declared on common stock						(487)							(649)
Dividends declared on preferred stock						(7)							(1)
Total Equity at End of Period at Sep. 30, 2025	9,431	3	6,355	(41)		2,323	224	12,324	841	8,869	(11)		2,588	37
Total Equity at Beginning of Period at Jun. 30, 2025	8,971	3	5,998		(41)	2,210	224	11,698	841	8,324		(11)	2,507	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										545
Return of stockholder contribution										0
Amortization of net actuarial loss	1				$ 1			0				$ 0
Net Income	277							314					314
Dividends declared on common stock						(162)							(233)
Dividends declared on preferred stock						(2)							0
Total Equity at End of Period at Sep. 30, 2025	$ 9,431	$ 3	$ 6,355	$ (41)		$ 2,323	$ 224	$ 12,324	$ 841	$ 8,869	$ (11)		$ 2,588	$ 37