INCOME TAXES - Components of provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 54	$ 470
State	38	70
Total current tax	92	540
Deferred:
Federal	(22)	71
State	(78)	(68)
Total deferred tax	(100)	3
Provision for (benefit from) income taxes	$ (8)	$ 543