LEASES - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease cost	$ 8,261	$ 7,834
Amortization of right-of-use assets	165	145
Interest on lease liabilities	178	141
Short-term lease cost	86	72
Variable lease cost	3,031	2,562
Less: Sublease income	(462)	(438)
Total lease cost	$ 11,259	$ 10,316