PROPERTY, PLANT, AND EQUIPMENT (Details) $ in Millions	Sep. 30, 2020 USD ($)
Property, Plant and Equipment [Abstract]
Costs incurred for repairs and restorations	$ 16.8

Total costs incurred for repairs and restorations. Includes costs that were capitalized and expensed.

No definition available.

Name:	wec_CostsIncurredForRepairsAndRestorations
Namespace Prefix:	wec_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant