LEASES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Leases
Cumulative effect of new accounting principle	$ 100
Leased asset, cost	476,443	$ 459,006
Less: accumulated depreciation	(40,784)	(35,127)
Net book value	435,659	423,879
Interest expense
Operating lease, interest expense	22
Finance lease, interest expense,	$ 120
Operating lease, Weighted average discount rate (as a percent)	8.73%
Operating lease, Weighted average remaining lease term	5 years
Operating lease, Total discounted lease liability	$ 983
Finance leases, Weighted average discount rate (as a percent)	7.70%
Finance leases, Weighted average remaining lease term	3 years
Finance leases, Total discounted lease liability	$ 6,338	6,429
Total discounted lease liability	$ 7,321	$ 6,429
Lease, Practical Expedient, Use of Hindsight [true false]	true
Operating lease term	10 years
Finance lease term	10 years
Operating Leases
Leases
Leased asset, cost	$ 1,167
Less: accumulated depreciation	(386)
Net book value	781
Finance Leases
Leases
Leased asset, cost	6,879
Less: accumulated depreciation	(138)
Net book value	$ 6,741