Schedule 1 - Condensed Financial Information of Registrant (Condensed Statements of Income - Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Condensed Income Statements, Captions [Line Items]
Tax effect of discontinued operations	$ 170	$ 18	$ 16
CMS Energy
Condensed Income Statements, Captions [Line Items]
Tax effect of discontinued operations	$ (5)	$ 0	$ 0

Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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+ Details