Cash And Cash Equivalents (Schedule Of Cash And Cash Equivalents, Including Restricted Amounts) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 446	$ 452
Restricted cash and cash equivalents	28	24
Cash and cash equivalents, including restricted amounts	474	476	$ 524	$ 185
Consumers Energy Company
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	12	22
Restricted cash and cash equivalents	26	22
Cash and cash equivalents, including restricted amounts	$ 38	$ 44	$ 34	$ 35