CMS Energy Corporation Consolidated Statements of Changes in Equity - 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	Cumulative Preferred Stock	Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock outstanding (in shares)		283,374,000
Total Equity at Beginning of Period at Dec. 31, 2018	$ 4,792	$ 3	$ 5,088	$ (65)	$ (63)	$ (2)	$ (271)	$ 0	$ 0	$ 37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued (in shares)		710,000
Common stock issued			35						0
Common stock repurchased (in shares)		(181,000)
Common stock repurchased			(10)
Common stock reissued (in shares)		8,000
Common stock reissued			0
Common stock reacquired (in shares)		(47,000)
Common stock reacquired			0
Net gain (loss) arising during the period	(7)				(7)
Settlement arising during the period	0				0
Prior service credit adjustment	0				0
Amortization of net actuarial loss	3				3
Amortization of prior service credit	(2)				(2)
Unrealized gain (loss) on derivative instruments	(3)					(3)
Reclassification adjustments included in net income	1					1
Net Income	682						680			2
Dividends declared on common stock							(434)
Dividends declared on preferred stock							0
Preferred stock issued, net of issuance costs			35						0
Impact of purchase and consolidation of VIE										0
Sale of membership interest in VIE to tax equity investor										0
Contribution from noncontrolling interest										0
Distributions and other changes in noncontrolling interests										(2)
Total Equity at End of Period at Dec. 31, 2019	$ 5,055	$ 3	5,113	(73)	(69)	(4)	(25)	(51)	0	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 1.5300
Dividends declared per preferred stock Series C depositary share (in dollars per share)	$ 0
Common stock outstanding (in shares)		283,864,000
Common stock issued (in shares)		5,609,000
Common stock issued			265						0
Common stock repurchased (in shares)		(216,000)
Common stock repurchased			(13)
Common stock reissued (in shares)		12,000
Common stock reissued			1
Common stock reacquired (in shares)		(329,000)
Common stock reacquired			(1)
Net gain (loss) arising during the period	$ (15)				(15)
Settlement arising during the period	1				1
Prior service credit adjustment	(1)				(1)
Amortization of net actuarial loss	5				5
Amortization of prior service credit	(1)				(1)
Unrealized gain (loss) on derivative instruments	(4)					(4)
Reclassification adjustments included in net income	2					2
Net Income	752						755			(3)
Dividends declared on common stock							(465)
Dividends declared on preferred stock							0
Preferred stock issued, net of issuance costs			265						0
Impact of purchase and consolidation of VIE										101
Sale of membership interest in VIE to tax equity investor										417
Contribution from noncontrolling interest										31
Distributions and other changes in noncontrolling interests										(2)
Total Equity at End of Period at Dec. 31, 2020	$ 6,077	$ 3	5,365	(86)	(80)	(6)	214	$ 0	0	581
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 1.6300
Dividends declared per preferred stock Series C depositary share (in dollars per share)	$ 0
Common stock outstanding (in shares)	288,900,000	288,940,000
Common stock issued (in shares)		997,000
Common stock issued			50						224
Common stock repurchased (in shares)		(157,000)
Common stock repurchased			(9)
Common stock reissued (in shares)		0
Common stock reissued			0
Common stock reacquired (in shares)		(22,000)
Common stock reacquired			0
Net gain (loss) arising during the period	$ 19				19
Settlement arising during the period	1				1
Prior service credit adjustment	0				0
Amortization of net actuarial loss	5				5
Amortization of prior service credit	(1)				(1)
Unrealized gain (loss) on derivative instruments	2					2
Reclassification adjustments included in net income	1					1
Net Income	1,330						1,353			(23)
Dividends declared on common stock							(505)
Dividends declared on preferred stock							(5)
Preferred stock issued, net of issuance costs			50						224
Impact of purchase and consolidation of VIE										0
Sale of membership interest in VIE to tax equity investor										0
Contribution from noncontrolling interest										1
Distributions and other changes in noncontrolling interests										(2)
Total Equity at End of Period at Dec. 31, 2021	$ 7,188	$ 3	$ 5,406	$ (59)	$ (56)	$ (3)	$ 1,057		$ 224	$ 557
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in dollars per share)	$ 1.7400
Dividends declared per preferred stock Series C depositary share (in dollars per share)	$ 0.5688
Common stock outstanding (in shares)	289,800,000	289,758,000