Earnings Per Share - CMS Energy (Basic And Diluted EPS Computations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income available to common stockholders
Income from continuing operations	$ 809	$ 728	$ 694
Loss attributable to noncontrolling interests	(24)	(23)	(3)
Preferred stock dividends	10	5	0
Income from continuing operations available to common stockholders – basic and diluted	$ 823	$ 746	$ 697
Average common shares outstanding
Weighted average shares - basic (in shares)	289.5	289.0	285.0
Dilutive nonvested stock awards (in shares)	0.3	0.5	0.7
Dilutive forward equity sale contracts (in shares)	0.2	0.0	0.6
Weighted average shares - diluted (in shares)	290.0	289.5	286.3
Income from continuing operations per average common share available to common stockholders
Basic (in dollars per share)	$ 2.84	$ 2.58	$ 2.45
Diluted (in dollars per share)	$ 2.84	$ 2.58	$ 2.44