Schedule I - Condensed Financial Information of Registrant (Condensed Statements Of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Flows from Operating Activities
Net cash provided by operating activities	$ 855	$ 1,819	$ 1,276
Cash Flows from Investing Activities
Net cash used in investing activities	(2,476)	(1,233)	(2,867)
Cash Flows from Financing Activities
Proceeds from issuance of debt	1,899	335	3,179
Issuance of common stock	69	26	253
Issuance of preferred stock, net of issuance costs	0	224	0
Retirement of long-term debt	(106)	(235)	(2,010)
Debt prepayment costs	0	0	(59)
Payment of dividends on common and preferred stock	(546)	(509)	(467)
Net cash provided by (used in) financing activities	1,327	(295)	1,619
Net Increase (Decrease) in Cash and Cash Equivalents, Including Restricted Amounts	(294)	291	28
Cash and Cash Equivalents, Including Restricted Amounts, Beginning of Period	476	185	157
Cash and Cash Equivalents, Including Restricted Amounts, End of Period	182	476	185
CMS Energy
Cash Flows from Operating Activities
Net cash provided by operating activities	565	1,549	507
Cash Flows from Investing Activities
Investment in subsidiaries	(796)	(581)	(657)
Decrease (increase) in notes receivable – intercompany	286
Decrease (increase) in notes receivable – intercompany		(83)	(307)
Net cash used in investing activities	(510)	(664)	(964)
Cash Flows from Financing Activities
Proceeds from issuance of debt	0	0	1,225
Issuance of common stock	69	26	253
Issuance of preferred stock, net of issuance costs	0	224	0
Retirement of long-term debt	0	(200)	(425)
Debt prepayment costs	0	0	(16)
Payment of dividends on common and preferred stock	(544)	(507)	(465)
Debt issuance costs and financing fees	(11)	(10)	(10)
Change in notes payable – intercompany	77	(28)	(105)
Net cash provided by (used in) financing activities	(409)	(495)	457
Net Increase (Decrease) in Cash and Cash Equivalents, Including Restricted Amounts	(354)	390	0
Cash and Cash Equivalents, Including Restricted Amounts, Beginning of Period	390	0	0
Cash and Cash Equivalents, Including Restricted Amounts, End of Period	$ 36	$ 390	$ 0