v3.25.4
Related party Transactions - Consumers (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Consumers Energy Company      
Related Party Transaction [Line Items]      
Purchased power – related parties $ 94 $ 71 $ 75
Consumers Energy Company | Related Party      
Related Party Transaction [Line Items]      
Due to related parties 19 20  
Accounts receivable related parties 13 15  
Interest payable 9 $ 7  
Consumers Energy Company | Credit Agreement | Related Party      
Related Party Transaction [Line Items]      
Maximum borrowing capacity $ 500    
CMS Energy Note Payable      
Related Party Transaction [Line Items]      
Interest Rate (%) 4.10%    
CMS Energy Note Payable | Consumers Energy Company      
Related Party Transaction [Line Items]      
Interest Rate (%) 4.10%