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			117
Common stock repurchased			(13)
Stockholder contribution												650
Amortization of net actuarial loss	2				2					0				0
Amortization of prior service credit	(1)				(1)
Unrealized gain (loss) on derivative instruments	(4)					(4)
Net Income	380						379		1	395					395
Dividends declared on common stock							(233)								(276)
Dividends declared on preferred stock															(1)
Contribution from noncontrolling interest									0
Distributions and other changes in noncontrolling interests									(1)
Total Equity at End of Period at Jun. 30, 2020	$ 5,251	3	5,217	(76)	(68)	(8)	70		37	8,505	841	6,024	(28)	(28)	1,631	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 0.8150
Total Equity at Beginning of Period at Mar. 31, 2020	$ 5,222	3	5,207	(76)	(68)	(8)	51	0	37	8,103	841	5,724	(28)	(28)	1,529	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued			11
Common stock repurchased			(1)
Stockholder contribution												300
Amortization of net actuarial loss	1				1					0				0
Amortization of prior service credit	(1)				(1)
Unrealized gain (loss) on derivative instruments	0					0
Net Income	137						136		1	160					160
Dividends declared on common stock							(117)								(57)
Dividends declared on preferred stock															(1)
Contribution from noncontrolling interest									0
Distributions and other changes in noncontrolling interests									(1)
Total Equity at End of Period at Jun. 30, 2020	$ 5,251	3	5,217	(76)	(68)	(8)	70		37	8,505	841	6,024	(28)	(28)	1,631	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			33
Common stock repurchased			(9)
Stockholder contribution												275
Amortization of net actuarial loss	4				4					1				1
Amortization of prior service credit	(1)				(1)
Unrealized gain (loss) on derivative instruments	1					1
Net Income	513						525		(12)	526					526
Dividends declared on common stock							(252)								(380)
Dividends declared on preferred stock															(1)
Contribution from noncontrolling interest									1
Distributions and other changes in noncontrolling interests									(1)
Total Equity at End of Period at Jun. 30, 2021	$ 6,366	3	5,389	(82)	(77)	(5)	487		569	8,977	841	6,299	(35)	(35)	1,835	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 0.8700
Total Equity at Beginning of Period at Mar. 31, 2021	$ 6,302	3	5,371	(84)	(79)	(5)	437	$ 0	575	8,766	841	6,174	(36)	(36)	1,750	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued			18
Common stock repurchased			0
Stockholder contribution												125
Amortization of net actuarial loss	3				3					1				1
Amortization of prior service credit	(1)				(1)
Unrealized gain (loss) on derivative instruments	0					0
Net Income	171						176		(5)	190					190
Dividends declared on common stock							(126)								(104)
Dividends declared on preferred stock															(1)
Contribution from noncontrolling interest									0
Distributions and other changes in noncontrolling interests									(1)
Total Equity at End of Period at Jun. 30, 2021	$ 6,366	$ 3	$ 5,389	$ (82)	$ (77)	$ (5)	$ 487		$ 569	$ 8,977	$ 841	$ 6,299	$ (35)	$ (35)	$ 1,835	$ 37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 0.4350