ACQUISITIONS ACQUISITIONS - COYOTE RIDGE (Details) - Coyote Ridge Wind $ in Millions	1 Months Ended	3 Months Ended
	Dec. 31, 2018 USD ($) MW	Mar. 31, 2019 USD ($) Years
Business Acquisition [Line Items]
WEC's ownership interest in Coyote Ridge Wind, LLC	80.00%
Capacity of Coyote Ridge | MW	97.5
Acquisition purchase price	$ 61.6
Duration of offtake agreement for the sale of energy produced	12 years
Total expected investment		$ 145.0
Bonus depreciation percentage		100.00%
Percent of tax benefits entitled to		99.00%
Years Entitled to 99 Percent of Tax Benefits | Years		11