COMMITMENTS AND CONTINGENCIES - SCHEDULE OF COMPONENTS OF LEASE EXPENSE, OTHER INFORMATION AND CASH FLOWS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Lease, Cost [Abstract]
Fixed operating lease costs	$ 7,115	$ 2,971	$ 15,905	$ 8,034
Variable operating lease costs	1,232	791	3,684	2,218
Short-term lease costs	457	266	1,067	579
Total lease costs	$ 8,804	$ 4,028	$ 20,656	10,831
Weighted Average Remaining Lease Term and Discount Rate [Abstract]
Weighted-average remaining lease term	7 years 5 months 15 days		7 years 5 months 15 days		5 years 4 months 28 days
Weighted-average discount rate	6.27%		6.27%		7.02%
Operating cash flows:
Payments for operating lease liabilities			$ 240	11,238
Supplemental cash flow data:
Lease liabilities arising from obtaining right-of-use assets			$ 96,519	$ 14,991