CMS Energy Corporation Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 1,330	$ 752	$ 682
Retirement Benefits Liability
Net loss arising during the period, net of tax	19	(15)	(7)
Settlement arising during the period, net of tax	1	1	0
Prior service credit adjustment	0	(1)	0
Amortization of net actuarial loss, net of tax	5	5	3
Amortization of prior service credit	(1)	(1)	(2)
Derivatives
Unrealized loss on derivative instruments, net of tax	2	(4)	(3)
Reclassification adjustments included in net income, net of tax	1	2	1
Other Comprehensive Income (Loss)	27	(13)	(8)
Comprehensive Income	1,357	739	674
Comprehensive Income (Loss) Attributable to Noncontrolling Interests	(23)	(3)	2
Comprehensive Income Attributable to CMS Energy	$ 1,380	$ 742	$ 672