XML 19 R152.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Regulatory Environment - WI 2018 and 2019 Rates (Details) - 2018 and 2019 rates - Public Service Commission of Wisconsin (PSCW)
$ in Millions
1 Months Ended 12 Months Ended
Sep. 30, 2017
USD ($)
utility
Dec. 31, 2019
USD ($)
WE    
Public Utilities, General Disclosures [Line Items]    
Approved return on equity (as a percent) 10.20%  
Income statement impact of flow through of repair-related deferred tax liabilities   $ 0.0
WG    
Public Utilities, General Disclosures [Line Items]    
Approved return on equity (as a percent) 10.00%  
WPS    
Public Utilities, General Disclosures [Line Items]    
Approved return on equity (as a percent) 10.30%  
Authorized Revenue Requirement For ReACT $ 275.0  
WE, WG, and WPS    
Public Utilities, General Disclosures [Line Items]    
Number of utilities with earnings sharing mechanism | utility 3  
Percentage of first 50 basis points of additional utility earnings shared with customers 50.00%  
Return on equity in excess of authorized amount (as a percent) 0.50%