Income Taxes (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Apr. 30, 2024	Jun. 30, 2024	Jun. 30, 2023
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits		$ 79	$ 71
Consumers Energy Company
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits		76	$ 73
Consumers Energy Company | Renewable Energy Tax Credit
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits	$ 37
Adjustment for production		$ 51