LEASES - Components of Lease Cost and Other Operating Lease Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Lease, Cost [Abstract]
Operating lease cost	$ 1,829	$ 2,685	$ 5,897	$ 7,556
Short-term lease cost	6	28	25	90
Variable lease cost	$ 336	$ 406	1,224	1,378
Cash payments included in operating cash flows from lease arrangements			6,417	6,629
Right-of-use assets obtained in exchange for new operating lease liabilities			$ 5,132	$ 17,238
Weighted-average remaining lease term - operating leases	5 years 7 months 17 days		5 years 7 months 17 days		5 years 10 months 9 days
Weighted-average discount rate - operating leases	7.00%		7.00%		8.00%