v3.25.4
Regulatory Matters (Narrative) (Details)
$ in Millions
1 Months Ended 4 Months Ended 12 Months Ended
Jan. 31, 2026
USD ($)
Sep. 30, 2025
USD ($)
Jul. 31, 2025
USD ($)
Mar. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Oct. 31, 2024
USD ($)
Jul. 31, 2024
USD ($)
May 31, 2024
USD ($)
Apr. 30, 2024
USD ($)
Dec. 31, 2025
USD ($)
facility
Dec. 31, 2025
USD ($)
facility
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2016
unit
Dec. 31, 2015
unit
Dec. 31, 2013
USD ($)
Public Utilities, General Disclosures [Line Items]                                  
Regulatory assets         $ 3,569.0         $ 3,355.0 $ 3,355.0 $ 3,569.0          
Operating Revenue                     8,539.0 7,515.0 $ 7,462.0        
ASP gain                                  
Public Utilities, General Disclosures [Line Items]                                  
Gain on disposition of assets                 $ 110.0                
Amount credited to customers             $ 82.5                    
Ludington Overhaul Contract Dispute                                  
Public Utilities, General Disclosures [Line Items]                                  
Cash expenditures                     30.0            
Consumers Energy Company                                  
Public Utilities, General Disclosures [Line Items]                                  
Regulatory assets         3,569.0         $ 3,355.0 3,355.0 3,569.0          
Operating Revenue                     $ 8,132.0 7,200.0 $ 7,166.0        
Consumers Energy Company | Renewable energy grant                                  
Public Utilities, General Disclosures [Line Items]                                  
Proceeds from government grant                                 $ 69.0
Consumers Energy Company | MGP sites                                  
Public Utilities, General Disclosures [Line Items]                                  
Number of former MGPs | facility                   23 23            
Regulatory asset collection period                   10 years 10 years            
Consumers Energy Company | Gas-Fueled Electric Generation                                  
Public Utilities, General Disclosures [Line Items]                                  
Number of units retired | unit                               3  
Consumers Energy Company | Coal-Fueled Electric Generation                                  
Public Utilities, General Disclosures [Line Items]                                  
Number of units retired | unit                             7    
Consumers Energy Company | Energy Waste Reduction Plan Incentive                                  
Public Utilities, General Disclosures [Line Items]                                  
Regulatory assets         64.0         $ 64.0 $ 64.0 64.0          
Consumers Energy Company | J.H. Campbell Generating Units                                  
Public Utilities, General Disclosures [Line Items]                                  
Regulatory assets                           $ 1,300.0      
Operating Revenue                   77.0              
Rate of return on equity authorized                           9.00%      
Financial impact of emergency order                   93.0              
Consumers Energy Company | J.H. Campbell Generating Units | Subsequent Event                                  
Public Utilities, General Disclosures [Line Items]                                  
Operating Revenue $ 78.0                                
Financial impact of emergency order 42.0                                
Energy Waste Reduction Plan Incentive | Consumers Energy Company                                  
Public Utilities, General Disclosures [Line Items]                                  
Operating Revenue                     64.0            
Energy Waste Reduction Plan Incentive | Consumers Energy Company | Subsequent Event                                  
Public Utilities, General Disclosures [Line Items]                                  
Authorized recovery collection $ 64.0                                
PSCR underrecoveries | Consumers Energy Company                                  
Public Utilities, General Disclosures [Line Items]                                  
PSCR underrecoveries         0.0         $ 38.0 $ 38.0 $ 0.0   $ 401.0      
Gas Rate Case | Consumers Energy Company                                  
Public Utilities, General Disclosures [Line Items]                                  
Requested annual rate increase         $ 248.0                        
Requested annual rate increase, as a percent         10.25%                        
Amended requested annual rate increase     $ 217.0                            
Gas Rate Case | Consumers Energy Company | ASP gain                                  
Public Utilities, General Disclosures [Line Items]                                  
Gain on sale utilized as offset             $ 27.5                    
Electric Rate Case                                  
Public Utilities, General Disclosures [Line Items]                                  
Amended requested annual rate increase           $ 277.0                      
Electric Rate Case | Consumers Energy Company                                  
Public Utilities, General Disclosures [Line Items]                                  
Rate of return on equity authorized   9.80%   9.90%                          
Requested annual rate increase               $ 325.0                  
Requested annual rate increase, as a percent               10.25%                  
Surcharge for the recovery of excess distribution investments       $ 22.0                          
Additional annual rate increase authorized   $ 157.5   $ 176.0                          
Electric Rate Case, First Component | Consumers Energy Company                                  
Public Utilities, General Disclosures [Line Items]                                  
Requested annual rate increase               $ 303.0                  
Electric Rate Case, Second Component | Consumers Energy Company                                  
Public Utilities, General Disclosures [Line Items]                                  
Surcharge for the recovery of excess distribution investments               $ 22.0