STOCKHOLDERS' EQUITY - Stock based expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Total stock-based compensation expenses	$ 22,468	$ 14,414	$ 44,733	$ 31,355
Research and development
Total stock-based compensation expenses	13,940	8,585	27,591	17,787
General and administrative
Total stock-based compensation expenses	$ 8,528	$ 5,829	$ 17,142	$ 13,568