Earnings Per Share - CMS Energy (Basic And Diluted EPS Computations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income available to common stockholders
Income from continuing operations	$ 194	$ 341
Loss attributable to noncontrolling interests	(10)	(8)
Preferred stock dividends	2	2
Income from continuing operations available to common stockholders – basic and diluted	$ 202	$ 347
Average common shares outstanding
Weighted average shares - basic (in shares)	290.7	289.3
Dilutive nonvested stock awards (in shares)	0.5	0.5
Dilutive forward equity sale contracts (in shares)	0.0	0.1
Weighted average shares - diluted (in shares)	291.2	289.9
Income from continuing operations per average common share available to common stockholders
Basic (in dollars per share)	$ 0.69	$ 1.20
Diluted (in dollars per share)	$ 0.69	$ 1.20