v3.25.2
Financings and Capitalization (First Mortgage Bond Purchase) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Debt Instrument [Line Items]        
Payment for purchase of first mortgage bonds     $ 841 $ 433
Interest on long-term debt $ 199 $ 171 386 343
Consumers Energy Company        
Debt Instrument [Line Items]        
Payment for purchase of first mortgage bonds     57 15
Interest on long-term debt 131 120 253 241
First mortgage bonds        
Debt Instrument [Line Items]        
Gain on extinguishment of debt 72 48 72 70
First mortgage bonds | Consumers Energy Company | Repurchased Debt        
Debt Instrument [Line Items]        
Interest on long-term debt 7 4 13 8
First mortgage bonds | Related Party        
Debt Instrument [Line Items]        
Principal (In Millions) 184 151 184 242
Payment for purchase of first mortgage bonds $ 109 $ 100 $ 109 $ 169