INCOME TAXES (Components of Income Tax (Benefit) Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Current income tax (benefit) expense	$ (1.2)	$ 0.5	$ 0.8
Deferred income tax expense (benefit)	7.3	(8.8)	7.2
Total income tax expense (benefit)	$ 6.1	$ (8.3)	$ 8.0