NET EARNINGS (LOSS) PER SHARE - Schedule of Potential Shares Not Included in the Computation of Diluted Earnings (Loss) Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares not included in the computation of diluted earnings (loss) per share	2,631	2,402	1,351
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares not included in the computation of diluted earnings (loss) per share	477	0	0
Performance share units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares not included in the computation of diluted earnings (loss) per share	1,131	1,080	799