v3.25.4
Financial Instruments (Schedule of Carrying Amounts and Fair Values of Financial Instruments) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Liabilities    
Current accounts receivable and notes receivable $ 3 $ 4
Current portion of long-term debt 950 1,192
Current portion of long-term payables 2 2
Carrying Amount    
Assets    
Long-term receivables 7 9
Liabilities    
Long-term debt 18,757 16,386
Long-term payables 7 9
Fair Value    
Assets    
Long-term receivables 6 8
Liabilities    
Long-term debt 17,645 14,876
Long-term payables 7 9
Consumers Energy Company    
Liabilities    
Current accounts receivable and notes receivable 3 4
Current portion of long-term debt 573 452
Consumers Energy Company | Related Party    
Liabilities    
Notes receivable 7 7
Consumers Energy Company | Carrying Amount    
Assets    
Long-term receivables 7 9
Notes receivable related party 90 94
Liabilities    
Long-term payables 2 4
Consumers Energy Company | Carrying Amount | Nonrelated Party    
Liabilities    
Long-term debt 12,097 11,270
Consumers Energy Company | Carrying Amount | Related Party    
Liabilities    
Long-term debt 1,005 823
Consumers Energy Company | Fair Value    
Assets    
Long-term receivables 6 8
Notes receivable related party 90 94
Liabilities    
Long-term payables 2 4
Consumers Energy Company | Fair Value | Nonrelated Party    
Liabilities    
Long-term debt 11,031 9,940
Consumers Energy Company | Fair Value | Related Party    
Liabilities    
Long-term debt 657 549
Level 1 | Fair Value    
Assets    
Long-term receivables 0 0
Liabilities    
Long-term debt 2,042 1,018
Long-term payables 0 0
Level 1 | Consumers Energy Company | Fair Value    
Assets    
Long-term receivables 0 0
Notes receivable related party 0 0
Liabilities    
Long-term payables 0 0
Level 1 | Consumers Energy Company | Fair Value | Nonrelated Party    
Liabilities    
Long-term debt 0 0
Level 1 | Consumers Energy Company | Fair Value | Related Party    
Liabilities    
Long-term debt 0 0
Level 2 | Fair Value    
Assets    
Long-term receivables 0 0
Liabilities    
Long-term debt 13,663 11,952
Long-term payables 0 0
Level 2 | Consumers Energy Company | Fair Value    
Assets    
Long-term receivables 0 0
Notes receivable related party 0 0
Liabilities    
Long-term payables 0 0
Level 2 | Consumers Energy Company | Fair Value | Nonrelated Party    
Liabilities    
Long-term debt 9,091 8,034
Level 2 | Consumers Energy Company | Fair Value | Related Party    
Liabilities    
Long-term debt 657 549
Level 3 | Fair Value    
Assets    
Long-term receivables 6 8
Liabilities    
Long-term debt 1,940 1,906
Long-term payables 7 9
Level 3 | Consumers Energy Company | Fair Value    
Assets    
Long-term receivables 6 8
Notes receivable related party 90 94
Liabilities    
Long-term payables 2 4
Level 3 | Consumers Energy Company | Fair Value | Nonrelated Party    
Liabilities    
Long-term debt 1,940 1,906
Level 3 | Consumers Energy Company | Fair Value | Related Party    
Liabilities    
Long-term debt $ 0 $ 0