(LOSS) PER SHARE (Details) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended						9 Months Ended
	Feb. 29, 2020 $ / derivative shares	Sep. 30, 2021 USD ($) $ / shares $ / derivative shares	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Sep. 30, 2020 USD ($) $ / shares $ / derivative shares	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2021 USD ($) $ / shares $ / derivative shares	Sep. 30, 2020 USD ($) $ / shares $ / derivative shares
Earnings Per Share [Abstract]
Net (loss) | $		$ (56,468)	$ 37,291	$ (6,617)	$ (19,267)	$ (20,740)	$ (25,372)	$ (25,794)	$ (65,379)
Weighted-average common shares outstanding (in shares)		81,526			80,537			81,284	80,191
(Loss) per share, basic (in dollars per share) | $ / shares		$ (0.69)			$ (0.24)			$ (0.32)	$ (0.82)
Weighted-average common shares outstanding, assuming dilution (in shares)		81,526			80,537			81,284	80,191
(Loss) per share, diluted (in dollars per share) | $ / shares		$ (0.69)			$ (0.24)			$ (0.32)	$ (0.82)
Outstanding anti-dilutive stock options and RSUs (in shares)		5,815			6,622			6,136	6,166
Convertible debt (in shares)		4,400			4,400			4,400	4,400
Number of shares issuable upon conversion	4,400	4,400			4,400			4,400	4,400
Cap price (in dollars per share) | $ / derivative	196.44	196.44			196.44			196.44	196.44