Financings and Capitalization (Summary of Long-Term Debt) (Details) - USD ($) $ in Millions			12 Months Ended
	Dec. 01, 2030	Jun. 01, 2030	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Total principal amount outstanding			$ 14,362	$ 12,568
Current amounts			(1,090)	(373)
Unamortized discounts			(30)	(31)
Unamortized issuance costs			(120)	(118)
Long-term debt			13,122	12,046
Consumers Energy Company
Debt Instrument [Line Items]
Total principal amount outstanding			10,277	8,505
Current amounts			(991)	(365)
Unamortized discounts			(27)	(28)
Unamortized issuance costs			(67)	(62)
Long-term debt			$ 9,192	8,050
Term loan facility | Consumers Energy Company | Term Loan Facility Due 2024
Debt Instrument [Line Items]
Weighted average interest rate			4.975%
Total principal amount outstanding			$ 1,000	0
Term loan facility | Consumers Energy Company | Term Loan Facility Due 2024 | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate			0.65%
First mortgage bonds | Consumers Energy Company
Debt Instrument [Line Items]
Total principal amount outstanding			$ 8,997	8,197
First mortgage bonds | Consumers Energy Company | 0.350% First Mortgage Bonds Due 2023
Debt Instrument [Line Items]
Interest rate			0.35%
Total principal amount outstanding			$ 300	300
First mortgage bonds | Consumers Energy Company | 3.375% First Mortgage Bonds Due 2023
Debt Instrument [Line Items]
Interest rate			3.375%
Total principal amount outstanding			$ 325	325
First mortgage bonds | Consumers Energy Company | 3.125% First Mortgage Bonds Due 2024
Debt Instrument [Line Items]
Interest rate			3.125%
Total principal amount outstanding			$ 250	250
First mortgage bonds | Consumers Energy Company | 3.190% First Mortgage Bonds Due 2024
Debt Instrument [Line Items]
Interest rate			3.19%
Total principal amount outstanding			$ 52	52
First mortgage bonds | Consumers Energy Company | 3.680% First Mortgage Bonds Due 2027
Debt Instrument [Line Items]
Interest rate			3.68%
Total principal amount outstanding			$ 100	100
First mortgage bonds | Consumers Energy Company | 3.390 % First Mortgage Bonds Due 2027
Debt Instrument [Line Items]
Interest rate			3.39%
Total principal amount outstanding			$ 35	35
First mortgage bonds | Consumers Energy Company | 3.800% First Mortgage Bonds Due 2028
Debt Instrument [Line Items]
Interest rate			3.80%
Total principal amount outstanding			$ 300	300
First mortgage bonds | Consumers Energy Company | 3.600% First Mortgage Bonds Due 2032
Debt Instrument [Line Items]
Interest rate			3.60%
Total principal amount outstanding			$ 350	0
First mortgage bonds | Consumers Energy Company | 3.180% First Mortgage Bonds Due 2032
Debt Instrument [Line Items]
Interest rate			3.18%
Total principal amount outstanding			$ 100	100
First mortgage bonds | Consumers Energy Company | 5.800 % First Mortgage Bonds Due 2035
Debt Instrument [Line Items]
Interest rate			5.80%
Total principal amount outstanding			$ 175	175
First mortgage bonds | Consumers Energy Company | 3.520% First Mortgage Bonds Due 2037
Debt Instrument [Line Items]
Interest rate			3.52%
Total principal amount outstanding			$ 335	335
First mortgage bonds | Consumers Energy Company | 4.010% First Mortgage Bonds Due 2038
Debt Instrument [Line Items]
Interest rate			4.01%
Total principal amount outstanding			$ 215	215
First mortgage bonds | Consumers Energy Company | 6.170% First Mortgage Bonds Due 2040
Debt Instrument [Line Items]
Interest rate			6.17%
Total principal amount outstanding			$ 50	50
First mortgage bonds | Consumers Energy Company | 4.970% First Mortgage Bonds Due 2040
Debt Instrument [Line Items]
Interest rate			4.97%
Total principal amount outstanding			$ 50	50
First mortgage bonds | Consumers Energy Company | 4.310% First Mortgage Bonds Due 2042
Debt Instrument [Line Items]
Interest rate			4.31%
Total principal amount outstanding			$ 263	263
First mortgage bonds | Consumers Energy Company | 3.950% First Mortgage Bonds Due 2043
Debt Instrument [Line Items]
Interest rate			3.95%
Total principal amount outstanding			$ 425	425
First mortgage bonds | Consumers Energy Company | 4.100% First Mortgage Bonds Due 2045
Debt Instrument [Line Items]
Interest rate			4.10%
Total principal amount outstanding			$ 250	250
First mortgage bonds | Consumers Energy Company | 3.250% First Mortgage Bonds Due 2046
Debt Instrument [Line Items]
Interest rate			3.25%
Total principal amount outstanding			$ 450	450
First mortgage bonds | Consumers Energy Company | 3.950% First Mortgage Bonds Due 2047
Debt Instrument [Line Items]
Interest rate			3.95%
Total principal amount outstanding			$ 350	350
First mortgage bonds | Consumers Energy Company | 4.050% First Mortgage Bonds Due 2048
Debt Instrument [Line Items]
Interest rate			4.05%
Total principal amount outstanding			$ 550	550
First mortgage bonds | Consumers Energy Company | 4.350% First Mortgage Bonds Due 2049
Debt Instrument [Line Items]
Interest rate			4.35%
Total principal amount outstanding			$ 550	550
First mortgage bonds | Consumers Energy Company | 3.750% First Mortgage Bonds Due 2050
Debt Instrument [Line Items]
Interest rate			3.75%
Total principal amount outstanding			$ 300	300
First mortgage bonds | Consumers Energy Company | 3.100% First Mortgage Bonds Due 2050
Debt Instrument [Line Items]
Interest rate			3.10%
Total principal amount outstanding			$ 550	550
First mortgage bonds | Consumers Energy Company | 3.500% First Mortgage Bonds Due 2051
Debt Instrument [Line Items]
Interest rate			3.50%
Total principal amount outstanding			$ 575	575
First mortgage bonds | Consumers Energy Company | 2.650% First Mortgage Bonds Due 2052
Debt Instrument [Line Items]
Interest rate			2.65%
Total principal amount outstanding			$ 300	300
First mortgage bonds | Consumers Energy Company | 4.200% First Mortgage Bonds Due 2052
Debt Instrument [Line Items]
Interest rate			4.20%
Total principal amount outstanding			$ 450	0
First mortgage bonds | Consumers Energy Company | 3.860% First Mortgage Bonds Due 2052
Debt Instrument [Line Items]
Interest rate			3.86%
Total principal amount outstanding			$ 50	50
First mortgage bonds | Consumers Energy Company | 4.280% First Mortgage Bonds Due 2057
Debt Instrument [Line Items]
Interest rate			4.28%
Total principal amount outstanding			$ 185	185
First mortgage bonds | Consumers Energy Company | 2.500% First Mortgage Bonds Due 2060
Debt Instrument [Line Items]
Interest rate			2.50%
Total principal amount outstanding			$ 525	525
First mortgage bonds | Consumers Energy Company | 4.350% First Mortgage Bonds Due 2064
Debt Instrument [Line Items]
Interest rate			4.35%
Total principal amount outstanding			$ 250	250
First mortgage bonds | Consumers Energy Company | Variable Rate First Mortgage Bonds Due 2069
Debt Instrument [Line Items]
Total principal amount outstanding			$ 76	76
Interest rate at period end			4.469%
First mortgage bonds | Consumers Energy Company | Variable Rate First Mortgage Bonds Due 2070
Debt Instrument [Line Items]
Total principal amount outstanding			$ 134	134
Interest rate at period end			4.375%
First mortgage bonds | Consumers Energy Company | Variable Rate First Mortgage Bonds Due 2070
Debt Instrument [Line Items]
Total principal amount outstanding			$ 127	$ 127
Interest rate at period end			3.484%
First mortgage bonds | Consumers Energy Company | Variable Rate First Mortgage Bonds
Debt Instrument [Line Items]
Interest rate at period end				0.00%
First mortgage bonds | Consumers Energy Company | Variable Rate First Mortgage Bonds | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			0.30%
Tax-exempt revenue bonds | Consumers Energy Company
Debt Instrument [Line Items]
Total principal amount outstanding			$ 110	$ 110
Tax-exempt revenue bonds | Consumers Energy Company | 0.875% Tax Exempt Revenue Bonds Due 2035
Debt Instrument [Line Items]
Interest rate			0.875%
Total principal amount outstanding			$ 35	35
Tax-exempt revenue bonds | Consumers Energy Company | 1.800% Tax Exempt Revenue Bonds Due 2049
Debt Instrument [Line Items]
Interest rate			1.80%
Total principal amount outstanding			$ 75	$ 75
Securitization bonds | Consumers Energy Company | Securitization Bonds
Debt Instrument [Line Items]
Weighted average interest rate			3.343%	3.29%
Total principal amount outstanding			$ 170	$ 198
CMS Energy
Debt Instrument [Line Items]
Total principal amount outstanding			3,985	3,985
Long-term debt			3,930	3,928
CMS Energy | Senior notes
Debt Instrument [Line Items]
Total principal amount outstanding			$ 1,975	1,975
CMS Energy | Senior notes | 3.875% Senior Notes Due 2024
Debt Instrument [Line Items]
Interest rate			3.875%
Total principal amount outstanding			$ 250	250
CMS Energy | Senior notes | 3.600% Senior Notes Due 2025
Debt Instrument [Line Items]
Interest rate			3.60%
Total principal amount outstanding			$ 250	250
CMS Energy | Senior notes | 3.000% Senior Notes Due 2026
Debt Instrument [Line Items]
Interest rate			3.00%
Total principal amount outstanding			$ 300	300
CMS Energy | Senior notes | 2.950% Senior Notes Due 2027
Debt Instrument [Line Items]
Interest rate			2.95%
Total principal amount outstanding			$ 275	275
CMS Energy | Senior notes | 3.450% Senior Notes Due 2027
Debt Instrument [Line Items]
Interest rate			3.45%
Total principal amount outstanding			$ 350	350
CMS Energy | Senior notes | 4.700% Senior Notes Due 2043
Debt Instrument [Line Items]
Interest rate			4.70%
Total principal amount outstanding			$ 250	250
CMS Energy | Senior notes | 4.875% Senior Notes Due 2044
Debt Instrument [Line Items]
Interest rate			4.875%
Total principal amount outstanding			$ 300	300
CMS Energy | Junior subordinated notes
Debt Instrument [Line Items]
Total principal amount outstanding			$ 2,010	2,010
CMS Energy | Junior subordinated notes | 4.750% Junior Subordinated Notes Due 2050
Debt Instrument [Line Items]
Interest rate			4.75%
Total principal amount outstanding			$ 500	500
CMS Energy | Junior subordinated notes | 3.750% Junior Subordinated Notes Due 2050
Debt Instrument [Line Items]
Interest rate			3.75%
Total principal amount outstanding			$ 400	400
CMS Energy | Junior subordinated notes | 5.625% Junior Subordinated Notes Due 2078
Debt Instrument [Line Items]
Interest rate			5.625%
Total principal amount outstanding			$ 200	200
CMS Energy | Junior subordinated notes | 5.875% Junior Subordinated Notes Due 2078
Debt Instrument [Line Items]
Interest rate			5.875%
Total principal amount outstanding			$ 280	280
CMS Energy | Junior subordinated notes | 5.875% Junior Subordinated Notes Due 2079
Debt Instrument [Line Items]
Interest rate			5.875%
Total principal amount outstanding			$ 630	630
NorthStar Clean Energy, Including Subsidiaries
Debt Instrument [Line Items]
Unamortized issuance costs			(1)
NorthStar Clean Energy, Including Subsidiaries | Term loan facility | Term Loan Facility Due 2025
Debt Instrument [Line Items]
Total principal amount outstanding			$ 0	78
NorthStar Clean Energy, Including Subsidiaries | Term loan facility | Term Loan Facility Due 2023
Debt Instrument [Line Items]
Interest rate			5.423%
Total principal amount outstanding			$ 100	$ 0
NorthStar Clean Energy, Including Subsidiaries | Term loan facility | Term Loan Facility Due 2023 | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.00%
Forecast | CMS Energy | Junior subordinated notes | 4.750% Junior Subordinated Notes Due 2050 | US Treasury (UST) Interest Rate
Debt Instrument [Line Items]
Basis spread on variable rate		4.116%
Forecast | CMS Energy | Junior subordinated notes | 3.750% Junior Subordinated Notes Due 2050 | US Treasury (UST) Interest Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.90%