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

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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