Leases - Minimum Annual Rental Commitments (Details) $ in Millions	Dec. 31, 2022 USD ($)
Operating Leases
2023	$ 5
2024	5
2025	3
2026	2
2027	2
2028 and thereafter	31
Total minimum lease payments	48
Less discount	17
Present value of minimum lease payments	31
Finance Leases
2023	23
2024	19
2025	16
2026	17
2027	15
2028 and thereafter	106
Total minimum lease payments	196
Less discount	119
Present value of minimum lease payments	77
Consumers Energy Company
Operating Leases
2023	5
2024	4
2025	3
2026	2
2027	1
2028 and thereafter	26
Total minimum lease payments	41
Less discount	14
Present value of minimum lease payments	27
Finance Leases
2023	22
2024	18
2025	15
2026	15
2027	14
2028 and thereafter	47
Total minimum lease payments	131
Less discount	77
Present value of minimum lease payments	54
Pipelines and PPAs
Finance Leases
2023	15
2024	13
2025	13
2026	13
2027	13
2028 and thereafter	39
Total minimum lease payments	106
Less discount	75
Present value of minimum lease payments	31
Pipelines and PPAs | Consumers Energy Company
Finance Leases
2023	15
2024	13
2025	13
2026	13
2027	13
2028 and thereafter	39
Total minimum lease payments	106
Less discount	75
Present value of minimum lease payments	31
Other
Finance Leases
2023	8
2024	6
2025	3
2026	4
2027	2
2028 and thereafter	67
Total minimum lease payments	90
Less discount	44
Present value of minimum lease payments	46
Other | Consumers Energy Company
Finance Leases
2023	7
2024	5
2025	2
2026	2
2027	1
2028 and thereafter	8
Total minimum lease payments	25
Less discount	2
Present value of minimum lease payments	$ 23