SPECIAL PURPOSE ENTITIES (Details) $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2018 USD ($)	Jan. 31, 2020 USD ($)	Jan. 31, 2019 USD ($) item project
VIE
Variable Interest Entity
Gain on grant of utility easement		$ 2.2
Cost of property, plant and equipment		6.9	$ 2.1
Total amounts of notes receivable due from VIE		$ 6.0	$ 2.1
GPS
Variable Interest Entity
Number of natural gas-fired power plants | project			2
Number of joint ventures | item			2
Final cash distributions to joint ventures	$ 0.1