Schedule I - Condensed Financial Information of Registrant (Condensed Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current Assets
Cash and cash equivalents	$ 227	$ 164
Prepayments and other current assets	80	113
Total current assets	2,839	3,433
Other Non‑current Assets
Investments in subsidiaries	76	71	$ 71
Other	357	310
Total other non‑current assets	5,606	5,207
Total Assets	33,517	31,353	$ 28,753
Current Liabilities
Current portion of long-term debt	975	1,090
Accrued interest, including intercompany	142	122
Accrued taxes	612	538
Other current liabilities	149	166
Total current liabilities	2,895	2,985
Non‑current Liabilities
Long-term debt	14,508	13,122
Postretirement benefits	106	108
Other non‑current liabilities	415	397
Total non‑current liabilities	22,497	20,773
Equity
Common stock	3	3
Total common stockholders’ equity	7,320	6,791
Preferred stock	224	224
Total stockholders’ equity	7,544	7,015
Total Liabilities and Equity	33,517	31,353
CMS Energy
Current Assets
Cash and cash equivalents	149	36
Taxes receivable	11	45
Prepayments and other current assets	0	1
Total current assets	229	197
Other Non‑current Assets
Deferred income taxes	137	105
Other investments	8	6
Other	24	11
Total other non‑current assets	12,166	11,003
Total Assets	12,395	11,200
Current Liabilities
Current portion of long-term debt	250	0
Accrued interest, including intercompany	37	33
Other current liabilities	9	9
Total current liabilities	371	116
Non‑current Liabilities
Long-term debt	4,471	3,930
Notes payable – intercompany	105	109
Postretirement benefits	15	15
Other non‑current liabilities	18	15
Total non‑current liabilities	4,609	4,069
Equity
Common stock	3	3
Other stockholders' equity	7,188	6,788
Total common stockholders’ equity	7,191	6,791
Preferred stock	224	224
Total stockholders’ equity	7,415	7,015
Total Liabilities and Equity	12,395	11,200
CMS Energy | Intercompany
Current Assets
Notes and accrued interest receivable – intercompany	60	107
Other Non‑current Assets
Investments in subsidiaries	11,701	10,881
Investment in debt securities – intercompany	296	0
Current Liabilities
Accounts and notes payable – intercompany	75	74
CMS Energy | Intercompany and related parties
Current Assets
Accounts receivable – intercompany and related parties	$ 9	$ 8