Leases and Palisades Financing - Schedule of Lease Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Operating lease costs	$ 8	$ 9
Finance lease costs
Amortization of right-of-use assets	7	6
Interest on lease liabilities	16	17
Variable lease costs	90	94
Short-term lease costs	22	17
Total lease costs	143	143
Consumers Energy Company
Lessee, Lease, Description [Line Items]
Operating lease costs	8	9
Finance lease costs
Amortization of right-of-use assets	7	6
Interest on lease liabilities	16	17
Variable lease costs	90	94
Short-term lease costs	21	16
Total lease costs	$ 142	$ 142