NET LOSS PER SHARE - Basic and diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
NET LOSS PER SHARE
Net income /(loss) (numerator), Basic (in dollars)	$ (41,131)	$ (22,937)	$ (69,199)	$ 10,476
Net income /(loss) (numerator), Diluted (in dollars)	$ (41,131)	$ (22,937)	$ (69,199)	$ 10,476
Weighted-average shares (denominator), basic (in shares)	43,718,748	43,569,482	43,713,967	42,724,813
Basic net income / (loss) per share (in dollars per share)	$ (0.94)	$ (0.53)	$ (1.58)	$ 0.25
Weighted-average shares (denominator), diluted (in shares)	43,718,748	43,569,482	43,713,967	45,080,419
Diluted net income / (loss) per share (in dollars per share)	$ (0.94)	$ (0.53)	$ (1.58)	$ 0.23