Schedule I - Condensed Financial Information of Registrant (Condensed Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Current Assets
Cash and cash equivalents	$ 103	$ 227
Prepayments and other current assets	103	80
Total current assets	2,790	2,839
Other Non‑current Assets
Construction work in progress	2,098	944
Investments in subsidiaries	64	74
Other	384	357
Total other non‑current assets	5,669	5,606
Total Assets	35,920	33,517
Current Liabilities
Current portion of long-term debt	1,192	975
Accrued interest, including intercompany	156	142
Accrued taxes	654	612
Other current liabilities	209	149
Total current liabilities	3,521	2,895
Non‑current Liabilities
Long-term debt	15,194	14,508
Postretirement benefits	96	106
Other non‑current liabilities	407	415
Total non‑current liabilities	23,651	22,497
Equity
Common stock	3	3
Total common stockholders’ equity	8,006	7,320
Cumulative preferred stock	224	224
Total stockholders’ equity	8,230	7,544
Total Liabilities and Equity	35,920	33,517
CMS Energy
Current Assets
Cash and cash equivalents	4	149
Taxes receivable	0	11
Prepayments and other current assets	1	0
Total current assets	53	229
Other Non‑current Assets
Construction work in progress	1	0
Deferred income taxes	150	137
Other investments	9	8
Other	21	24
Total other non‑current assets	13,172	12,166
Total Assets	13,225	12,395
Current Liabilities
Current portion of long-term debt	740	250
Accrued interest, including intercompany	34	37
Accrued taxes	16	0
Other current liabilities	6	9
Total current liabilities	870	371
Non‑current Liabilities
Long-term debt	4,226	4,471
Notes payable – intercompany	100	105
Postretirement benefits	14	15
Other non‑current liabilities	17	18
Total non‑current liabilities	4,357	4,609
Equity
Common stock	3	3
Other stockholders’ equity	7,771	7,188
Total common stockholders’ equity	7,774	7,191
Cumulative preferred stock	224	224
Total stockholders’ equity	7,998	7,415
Total Liabilities and Equity	13,225	12,395
CMS Energy | Intercompany
Current Assets
Notes receivable	40	60
Other Non‑current Assets
Investments in subsidiaries	12,400	11,701
Investment in debt securities – intercompany	591	296
Current Liabilities
Accounts and notes payable – intercompany	74	75
CMS Energy | Intercompany and related parties
Current Assets
Accounts receivable – intercompany and related parties	$ 8	$ 9