REGULATORY ENVIRONMENT - WI SOLAR GENERATION PROJECTS (Details) - Public Service Commission of Wisconsin (PSCW) $ in Millions	May 31, 2018 USD ($) MW
Badger Hollow Solar Farm I
Public Utilities, General Disclosures [Line Items]
Solar project output that approval was requested for from the PSCW (in megawatts)	100
Badger Hollow Solar Farm I and Two Creeks Solar Project
Public Utilities, General Disclosures [Line Items]
Solar project output that approval was requested for from the PSCW (in megawatts)	200
Estimated share of cost for solar project(s) | $	$ 256
Two Creeks Solar Project
Public Utilities, General Disclosures [Line Items]
Solar project output that approval was requested for from the PSCW (in megawatts)	100