Earnings Per Share - CMS Energy (Basic And Diluted EPS Computations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income available to common stockholders
Income from continuing operations	$ 247	$ 173	$ 692	$ 556
Loss attributable to noncontrolling interests	(6)	(3)	(46)	(21)
Preferred stock dividends	2	2	7	7
Income from continuing operations available to common stockholders – basic and diluted	$ 251	$ 174	$ 731	$ 570
Average common shares outstanding
Weighted average shares - basic (in shares)	298.0	291.0	297.5	290.9
Dilutive nonvested stock awards (in shares)	0.8	0.4	0.7	0.4
Weighted average shares - diluted (in shares)	298.8	291.4	298.2	291.3
Income from continuing operations per average common share available to common stockholders
Basic (in dollars per share)	$ 0.84	$ 0.60	$ 2.45	$ 1.96
Diluted (in dollars per share)	$ 0.84	$ 0.60	$ 2.45	$ 1.96