LEASES - Undiscounted Cash Flows (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
2019	$ 4,914
2020	6,572
2021	5,702
2022	4,929
2023	4,702
Thereafter	5,869
Total minimum lease payments	32,688
Less: amount of lease payments representing interest	(5,199)
Present value of future minimum lease payments	27,489	$ 28,600
Less: current lease obligations	(5,063)		$ 0
Non-current lease obligations	$ 22,426		$ 0