v3.25.4
Asset Retirement Obligations (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period $ 728 $ 771
Incurred 31 1
Settled (73) (69)
Accretion 33 35
Cash Flow Revisions 73 (10)
ARO Liability, end of period 792 728
Consumers Energy Company    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 694 739
Incurred 27 1
Settled (73) (69)
Accretion 32 33
Cash Flow Revisions 73 (10)
ARO Liability, end of period 753 694
Renewable generation assets    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 34 32
Incurred 4 0
Settled 0 0
Accretion 1 2
Cash Flow Revisions 0 0
ARO Liability, end of period 39 34
Renewable generation assets | Consumers Energy Company    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 105 102
Incurred 17 0
Settled 0 0
Accretion 3 3
Cash Flow Revisions 0 0
ARO Liability, end of period 125 105
Coal ash disposal areas | Consumers Energy Company    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 230 268
Incurred 0 1
Settled (37) (51)
Accretion 10 12
Cash Flow Revisions 60 0
ARO Liability, end of period 263 230
Gas distribution cut, purge, and cap | Consumers Energy Company    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 295 290
Incurred 10 0
Settled (13) (9)
Accretion 15 15
Cash Flow Revisions 0 (1)
ARO Liability, end of period 307 295
Asbestos abatement | Consumers Energy Company    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 37 51
Incurred 0 0
Settled (2) (7)
Accretion 2 2
Cash Flow Revisions 0 (9)
ARO Liability, end of period 37 37
Generating plant water intake line | Consumers Energy Company    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 0  
Incurred 0  
Settled 0  
Accretion 1  
Cash Flow Revisions 18  
ARO Liability, end of period 19 0
Gas wells plug and abandon | Consumers Energy Company    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
ARO Liability, at beginning of period 27 28
Incurred 0 0
Settled (21) (2)
Accretion 1 1
Cash Flow Revisions (5) 0
ARO Liability, end of period $ 2 $ 27