LEASES - Leases Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
LEASES
Operating lease cost	$ 814	$ 789	$ 1,615	$ 1,572
Variable lease cost	498	385	959	773
Sublease income	(100)	(100)	(199)	(199)
Lease costs, net	$ 1,212	$ 1,074	$ 2,375	$ 2,146