Consolidated Statements of Changes In Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Other Paid-in Capital	Accumulated Other Comprehensive Loss	Retirement benefits liability	Derivative instruments	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjustment	Noncontrolling Interests	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 (Accumulated Deficit)	Consumers Energy Company Cumulative Preferred Stock
Total Equity at Beginning of Period at Dec. 31, 2019	$ 5,055	$ 3	$ 5,113	$ (73)	$ (69)	$ (4)	$ (25)	$ (51)	$ 37	$ 7,737	$ 841	$ 5,374	$ (28)	$ (28)	$ 1,513	$ 37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued			106
Common stock repurchased			(12)
Stockholder contribution												350
Amortization of net actuarial loss	1				1					0
Unrealized gain (loss) on derivative instruments	(4)					(4)
Net Income	243						243		0	235					235
Dividends declared on common stock							(116)								(219)
Contribution from noncontrolling interest									0
Total Equity at End of Period at Mar. 31, 2020	$ 5,222	3	5,207	(76)	(68)	(8)	51		37	8,103	841	5,724	(28)	(28)	1,529	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 0.4075
Total Equity at Beginning of Period at Dec. 31, 2020	$ 6,077	3	5,365	(86)	(80)	(6)	214	$ 0	581	8,556	841	6,024	(36)	(36)	1,690	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued			15
Common stock repurchased			(9)
Stockholder contribution												150
Amortization of net actuarial loss	1				1					0
Unrealized gain (loss) on derivative instruments	1					1
Net Income	342						349		(7)	336					336
Dividends declared on common stock							(126)								(276)
Contribution from noncontrolling interest									1
Total Equity at End of Period at Mar. 31, 2021	$ 6,302	$ 3	$ 5,371	$ (84)	$ (79)	$ (5)	$ 437		$ 575	$ 8,766	$ 841	$ 6,174	$ (36)	$ (36)	$ 1,750	$ 37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 0.4350