Schedule I - Condensed Financial Information of Registrant (Condensed Statements of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Expenses
Other operating expense	$ (1,669)	$ (1,610)	$ (1,280)
Total operating expenses	(7,372)	(6,183)	(5,188)
Operating income (loss)	1,224	1,146	1,230
Other Income (Expense)
Non-operating retirement benefits, net	205	165	118
Interest income – related parties	0	0	7
Other income	19	30	28
Other expense	(27)	(18)	(62)
Total other income	197	177	84
Interest Charges
Interest on long-term debt	509	481	483
Intercompany interest expense and other	0	10	12
Total interest charges	519	500	505
Income Before Income Taxes	902	823	809
Income tax expense (benefit)	93	95	115
Income From Continuing Operations	809	728	694
Income (Loss) From Discontinued Operations, Net of Tax	4	602	58
Net Income Attributable to CMS Energy	837	1,353	755
Preferred Stock Dividends	10	5	0
Net Income Available to Common Stockholders	827	1,348	755
CMS Energy
Operating Expenses
Other operating expense	(7)	(7)	(6)
Total operating expenses	(7)	(7)	(6)
Operating income (loss)	(7)	(7)	(6)
Other Income (Expense)
Equity earnings of subsidiaries	980	1,482	909
Non-operating retirement benefits, net	(1)	(1)	(1)
Interest income	2	0	0
Interest income – related parties	2	1	1
Other income	1	1	1
Other expense	(1)	0	(19)
Total other income	983	1,483	891
Interest Charges
Interest on long-term debt	181	183	178
Intercompany interest expense and other	8	7	7
Total interest charges	189	190	185
Income Before Income Taxes	787	1,286	700
Income tax expense (benefit)	(50)	(60)	(55)
Income From Continuing Operations	837	1,346	755
Income (Loss) From Discontinued Operations, Net of Tax	0	7	0
Net Income Attributable to CMS Energy	837	1,353	755
Preferred Stock Dividends	10	5	0
Net Income Available to Common Stockholders	$ 827	$ 1,348	$ 755