LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 3,344	$ 2,441
Finance lease cost
Amortization of leased assets	319	244
Interest on lease liabilities	55	64
Short-term lease cost	5,523	4,671
Variable lease costs (costs excluded from minimum fixed lease payments)	637	601	$ 900
Net lease cost	9,878	8,021
Accelerated rent amortization	$ 70	$ 0