EARNINGS PER SHARE - Reconciliation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net (loss) income attributable to common shareholders	$ (70)	$ 49	$ (176)	$ 73
Shares for basic (loss) earnings per share (in shares)	41,200	44,700	41,400	45,100
Basic (loss) earnings per share (in usd per share)	$ (1.68)	$ 1.11	$ (4.25)	$ 1.62
Employee stock options and SARs (in shares)	0	300	0	300
Restricted stock units (in shares)	0	200	0	200
Shares for diluted earnings per share (in shares)	41,200	45,200	41,400	45,600
Diluted (loss) earnings per share (in usd per share)	$ (1.68)	$ 1.10	$ (4.25)	$ 1.61
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)		452