v3.26.1
REGULATORY ENVIRONMENT - 2027 AND 2028 RATE CASE (Details) - Public Service Commission of Wisconsin (PSCW)
$ in Millions
Apr. 01, 2026
USD ($)
2027 Rates | Electric  
Public Utilities, General Disclosures [Line Items]  
Requested Rate Increase, Amount $ 86.1
Requested Rate Increase, Percentage 6.30%
2027 Rates | Natural gas  
Public Utilities, General Disclosures [Line Items]  
Requested Rate Increase, Amount $ 21.7
Requested Rate Increase, Percentage 4.90%
2028 Rates | Electric  
Public Utilities, General Disclosures [Line Items]  
Requested Rate Increase, Amount $ 50.8
Requested Rate Increase, Percentage 3.50%
2028 Rates | Natural gas  
Public Utilities, General Disclosures [Line Items]  
Requested Rate Increase, Amount $ 6.9
Requested Rate Increase, Percentage 1.50%
2027 and 2028 Rate Case  
Public Utilities, General Disclosures [Line Items]  
Requested return on equity (as a percent) 9.90%
Requested common equity component average (as a percent) 55.00%
Percentage of first 15 basis points of additional earnings retained by the utility 100.00%
Return on equity in excess of authorized amount (as a percent) 0.15%
Percentage of additional earnings between 15 and 75 basis points refunded to customers 50.00%
Return on equity in excess of first 15 basis points above authorized amount (as a percent) 0.60%
Percentage of earnings in excess of 75 basis points refunded to customers 100.00%