Income Taxes (Significant Components Of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current income taxes
Federal	$ 6	$ (1)	$ (35)
State and local	0	1	(2)
Total current income tax expense	6	0	(37)
Deferred income taxes
Federal	4	49	100
State and local	65	49	57
Total deferred income tax expense	69	98	157
Deferred income tax credit	18	(3)	(5)
Income tax expense	93	95	115
Consumers Energy Company
Current income taxes
Federal	(2)	(13)	3
State and local	8	15	(7)
Total current income tax expense	6	2	(4)
Deferred income taxes
Federal	50	103	115
State and local	66	54	67
Total deferred income tax expense	116	157	182
Deferred income tax credit	18	(3)	(5)
Income tax expense	$ 140	$ 156	$ 173