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, 2023	Dec. 31, 2022	Dec. 31, 2021
Income available to common stockholders
Income from continuing operations	$ 807	$ 809	$ 728
Loss attributable to noncontrolling interests	(79)	(24)	(23)
Preferred stock dividends	10	10	5
Income from continuing operations available to common stockholders – basic and diluted	$ 876	$ 823	$ 746
Average common shares outstanding
Weighted average shares - basic (in shares)	291.2	289.5	289.0
Dilutive nonvested stock awards (in shares)	0.5	0.3	0.5
Dilutive forward equity sale contracts (in shares)	0.0	0.2	0.0
Weighted average shares - diluted (in shares)	291.7	290.0	289.5
Income from continuing operations per average common share available to common stockholders
Basic (in dollars per share)	$ 3.01	$ 2.84	$ 2.58
Diluted (in dollars per share)	$ 3.01	$ 2.84	$ 2.58