LEASES - Components of lease expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
LEASES
Operating lease cost	$ 4,169	$ 4,053	$ 13,123	$ 10,831
Variable lease cost	1,666	1,484	3,882	3,772
Short-term lease cost	38	26	115	101
Total lease cost	5,873	5,563	17,120	14,704
Cash paid for amounts included in the measurement of lease liabilities included in operating cashflows	3,188	3,605	10,261	8,439
Tenant improvement allowance received for amounts included in the measurement of lease liabilities included in Operating cash flows	1,232		6,432
Right-of-use assets obtained from entering new leases		16,999	553	17,617
Increase / (decrease) in right-of-use assets from lease modifications	$ 171	$ 5,853	$ 7,664	$ 7,796
Weighted-average remaining lease terms (years)	13 years 11 months 23 days	15 years 3 months	13 years 11 months 23 days	15 years 3 months
Weighted-average discount rates	7.30%	7.20%	7.30%	7.20%