Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	$ 628	$ 553
Incurred	1	71
Settled	(39)	(53)
Accretion	28	24
Cash Flow Revisions	128	33
ARO Liability, end of period	746	628
Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	605	530
Incurred	1	71
Settled	(39)	(53)
Accretion	27	24
Cash Flow Revisions	128	33
ARO Liability, end of period	722	605
Renewable generation assets
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	23	23
Incurred	0	0
Settled	0	0
Accretion	1	0
Cash Flow Revisions	0	0
ARO Liability, end of period	24	23
Renewable generation assets | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	93	74
Incurred	0	16
Settled	0	0
Accretion	2	3
Cash Flow Revisions	0	0
ARO Liability, end of period	95	93
Coal ash disposal areas | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	157	148
Incurred	0	0
Settled	(20)	(34)
Accretion	7	5
Cash Flow Revisions	128	38
ARO Liability, end of period	272	157
Gas distribution cut, purge, and cap | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	282	240
Incurred	1	39
Settled	(11)	(10)
Accretion	15	13
Cash Flow Revisions	0	0
ARO Liability, end of period	287	282
Asbestos abatement | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	38	36
Incurred	0	0
Settled	(1)	0
Accretion	2	2
Cash Flow Revisions	0	0
ARO Liability, end of period	39	38
Gas wells plug and abandon | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	35	32
Incurred	0	16
Settled	(7)	(9)
Accretion	1	1
Cash Flow Revisions	0	(5)
ARO Liability, end of period	$ 29	$ 35