NET INCOME (LOSS) PER COMMON SHARE - Basic and Diluted Net Income (loss) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic Income (Loss) Per Share
Net income (loss)	$ (4,761)	$ 1,426	$ (21,648)	$ (16,878)	$ (53,811)	$ (9,138)	$ (24,982)	$ (79,827)
Basic weighted average shares outstanding (in shares)	135,893,823			134,735,075			135,857,127	134,753,276
Net income (loss) per share - Basic (in dollars per share)	$ (0.04)			$ (0.13)			$ (0.18)	$ (0.59)
Diluted Income (Loss) Per Share
Net income (loss)	$ (4,761)	$ 1,426	$ (21,648)	$ (16,878)	$ (53,811)	$ (9,138)	$ (24,982)	$ (79,827)
Basic weighted average shares outstanding (in shares)	135,893,823			134,735,075			135,857,127	134,753,276
Effect of RSUs and options under the treasury stock method (in shares)	0			0			0	0
Diluted weighted average shares outstanding (in shares)	135,893,823			134,735,075			135,857,127	134,753,276
Net income (loss) per share - Diluted (in dollars per share)	$ (0.04)			$ (0.13)			$ (0.18)	$ (0.59)