REGULATORY ENVIRONMENT - WI 2018 AND 2019 RATES (Details) - Public Service Commission of Wisconsin (PSCW) - 2018 and 2019 rates $ in Millions	1 Months Ended	24 Months Ended
	Sep. 30, 2017 USD ($) utility	Dec. 31, 2019 USD ($)
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%
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
WPS
Public Utilities, General Disclosures [Line Items]
Approved return on equity (as a percent)	10.00%
Authorized revenue requirement for ReACT	$ 275.0
WG
Public Utilities, General Disclosures [Line Items]
Approved return on equity (as a percent)	10.30%