EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net income (loss)	$ 355.8	$ (120.1)	$ 599.4	$ (200.1)
Basic shares	159,900	157,900	159,200	157,800
Basic net income (loss) per share	$ 2.23	$ (0.76)	$ 3.77	$ (1.27)
Earnings Per Share, Diluted [Abstract]
Basic shares	159,900	157,900	159,200	157,800
Stock-based compensation	3,900	0	3,100	0
Diluted shares	163,800	157,900	162,300	157,800
Diluted net income (loss) per share	$ 2.17	$ (0.76)	$ 3.69	$ (1.27)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Shares	100	10,300	1,100	10,300