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, 2024	Dec. 31, 2023	Dec. 31, 2022
Income available to common stockholders
Income from continuing operations	$ 947	$ 807	$ 809
Loss attributable to noncontrolling interests	(56)	(79)	(24)
Preferred stock dividends	10	10	10
Income from continuing operations available to common stockholders – basic and diluted	$ 993	$ 876	$ 823
Average common shares outstanding
Weighted average shares - basic (in shares)	297.6	291.2	289.5
Dilutive nonvested stock awards (in shares)	0.7	0.5	0.3
Dilutive forward equity sale contracts (in shares)	0.0	0.0	0.2
Weighted average shares - diluted (in shares)	298.3	291.7	290.0
Income from continuing operations per average common share available to common stockholders
Basic (in dollars per share)	$ 3.34	$ 3.01	$ 2.84
Diluted (in dollars per share)	$ 3.33	$ 3.01	$ 2.84