EARNINGS PER SHARE - Reconciliation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net (loss) income attributable to common shareholders	$ (62)	$ (9)	$ (238)	$ 64
Shares for basic (loss) earnings per share (in shares)	41,200	43,400	41,300	44,500
Basic (loss) earnings per share (in usd per share)	$ (1.51)	$ (0.21)	$ (5.76)	$ 1.44
Employee stock options and SARs (in shares)	0	0	0	300
Restricted stock units (in shares)	0	0	0	300
Shares for diluted earnings per share (in shares)	41,200	43,400	41,300	45,100
Diluted (loss) earnings per share (in usd per share)	$ (1.51)	$ (0.21)	$ (5.76)	$ 1.43
Performance shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of diluted earnings per share (in shares)		401