NET INCOME (LOSS) PER COMMON SHARE - Disclosure of Anti-Dilutive Shares (Details) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	1,626	0	2,171	73
Price range of options: from (in dollars per share)			$ 0.40
Price range of options: to (in dollars per share)			$ 13.98
RSUs with service conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	1,411	2,464	429	2,626
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	588	609	588	609
Price range of options: from (in dollars per share)	$ 4.88	$ 3.54	$ 4.88	$ 3.54
Price range of options: to (in dollars per share)	$ 13.98	$ 13.98	$ 13.98	$ 13.98
RSUs | RSUs excluded with service and market conditions as market conditions not met
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	0	199	0	199