CMS Energy Corporation Consolidated Statements of Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Income Statement [Abstract]
Impairment	$ 0	$ (102)	$ 0

Net Income (Loss) Attributable to Noncontrolling Interest, Impairment Charges

No definition available.

Name:	cms_NetIncomeLossAttributableToNoncontrollingInterestImpairmentCharges
Namespace Prefix:	cms_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration