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)	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 Preferred Stock	Cumulative effect of change in accounting principle Retained Earnings (Accumulated Deficit)
Total Equity at Beginning of Period at Dec. 31, 2018	$ 4,792	$ 3	$ 5,088	$ (65)	$ (63)	$ (2)	$ (271)	$ 37	$ 6,920	$ 841	$ 4,699	$ (21)	$ (21)	$ 1,364	$ 37	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued			17
Common stock repurchased			(8)
Stockholder contribution											675
Amortization of net actuarial loss	2				2				1				1
Amortization of prior service credit	(1)				(1)
Unrealized loss on derivative instruments	(3)					(3)
Net income	307						306	1	324					324
Dividends declared on common stock							(217)							(272)
Dividends declared on preferred stock														(1)
Distributions and other changes in noncontrolling interests								(1)
Total Equity at End of Period at Jun. 30, 2019	$ 4,888	3	5,097	(67)	(62)	(5)	(182)	37	7,647	841	5,374	(20)	(20)	1,415	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 0.7650
Total Equity at Beginning of Period at Mar. 31, 2019	$ 4,895	3	5,087	(66)	(63)	(3)	(166)	37	7,324	841	5,049	(21)	(21)	1,418	37	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued			10
Common stock repurchased			0
Stockholder contribution											325
Amortization of net actuarial loss	1				1				1				1
Amortization of prior service credit	0				0
Unrealized loss on derivative instruments	(2)					(2)
Net income	94						93	1	98					98
Dividends declared on common stock							(109)							(100)
Dividends declared on preferred stock														(1)
Distributions and other changes in noncontrolling interests								(1)
Total Equity at End of Period at Jun. 30, 2019	$ 4,888	3	5,097	(67)	(62)	(5)	(182)	37	7,647	841	5,374	(20)	(20)	1,415	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 0.3825
Total Equity at Beginning of Period at Dec. 31, 2019	$ 5,055	3	5,113	(73)	(69)	(4)	(25)	37	7,737	841	5,374	(28)	(28)	1,513	37	(51)
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 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)
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
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Total Equity at Beginning 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	$ 0
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 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)
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