EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net (loss) income	$ (736.8)	$ (120.1)	$ (80.0)	$ 44.2	$ (20.0)	$ 41.7	$ (936.9)	$ 65.9
Basic shares	157.9			161.9			157.8	163.7
Basic net (loss) income per share	$ (4.67)			$ 0.27			$ (5.94)	$ 0.40
Earnings Per Share, Diluted [Abstract]
Basic shares	157.9			161.9			157.8	163.7
Stock-based compensation	0.0			0.9			0.0	0.8
Diluted shares	157.9			162.8			157.8	164.5
Diluted net (loss) income per share	$ (4.67)			$ 0.27			$ (5.94)	$ 0.40
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	10.3			7.4			10.3	7.2