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, 2025	Mar. 31, 2024
Income available to common stockholders
Income from continuing operations	$ 295	$ 263
Loss attributable to noncontrolling interests	(9)	(24)
Preferred stock dividends	2	2
Income from continuing operations available to common stockholders – basic and diluted	$ 302	$ 285
Average common shares outstanding
Weighted average shares - basic (in shares)	298.2	296.5
Dilutive nonvested stock awards (in shares)	0.9	0.7
Weighted average shares - diluted (in shares)	299.1	297.2
Income from continuing operations per average common share available to common stockholders
Basic (in dollars per share)	$ 1.01	$ 0.96
Diluted (in dollars per share)	$ 1.01	$ 0.96