v3.25.2
Financial Instruments (Schedule of Carrying Amounts and Fair Values of Financial Instruments) (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Liabilities    
Current accounts receivable and notes receivable $ 3 $ 4
Current portion of long-term debt 1,100 1,200
Current portion of long-term payables 1 2
Carrying Amount    
Assets    
Long-term receivables 7 9
Liabilities    
Long-term debt 17,901 16,386
Long-term payables 8 9
Fair Value    
Assets    
Long-term receivables 7 8
Liabilities    
Long-term debt 16,678 14,876
Long-term payables 8 9
Consumers Energy Company    
Liabilities    
Current accounts receivable and notes receivable 3 4
Current portion of long-term debt 570 452
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 92 94
Liabilities    
Long-term payables 3 4
Consumers Energy Company | Carrying Amount | Nonrelated Party    
Liabilities    
Long-term debt 12,151 11,270
Consumers Energy Company | Carrying Amount | Related Party    
Liabilities    
Long-term debt 1,004 823
Consumers Energy Company | Fair Value    
Assets    
Long-term receivables 7 8
Notes receivable related party 92 94
Liabilities    
Long-term payables 3 4
Consumers Energy Company | Fair Value | Nonrelated Party    
Liabilities    
Long-term debt 11,067 9,940
Consumers Energy Company | Fair Value | Related Party    
Liabilities    
Long-term debt 662 549
Level 1 | Fair Value    
Assets    
Long-term receivables 0 0
Liabilities    
Long-term debt 1,981 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 12,768 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 9,138 8,034
Level 2 | Consumers Energy Company | Fair Value | Related Party    
Liabilities    
Long-term debt 662 549
Level 3 | Fair Value    
Assets    
Long-term receivables 7 8
Liabilities    
Long-term debt 1,929 1,906
Long-term payables 8 9
Level 3 | Consumers Energy Company | Fair Value    
Assets    
Long-term receivables 7 8
Notes receivable related party 92 94
Liabilities    
Long-term payables 3 4
Level 3 | Consumers Energy Company | Fair Value | Nonrelated Party    
Liabilities    
Long-term debt 1,929 1,906
Level 3 | Consumers Energy Company | Fair Value | Related Party    
Liabilities    
Long-term debt $ 0 $ 0