REGULATORY ENVIRONMENT - 2022 Rates (Details) - 2022 Rates - Public Service Commission of Wisconsin (PSCW)	Mar. 30, 2021 utility
Public Utilities, General Disclosures [Line Items]
Period to forego filing a rate case	1 year
Number of Companies Entering into Agreement	3
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%