Cash and Cash Equivalents (Schedule Of Cash And Cash Equivalents, Including Restricted Amounts) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 77	$ 452
Restricted cash and cash equivalents	19	24
Cash and cash equivalents, including restricted amounts	96	476	$ 292	$ 185
Consumers Energy Company
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	8	22
Restricted cash and cash equivalents	18	22
Cash and cash equivalents, including restricted amounts	$ 26	$ 44	$ 68	$ 35