INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
INCOME TAXES
Deferred tax assets, net of valuation allowance	$ 4,674
Net operating loss (NOL) carryforwards	5,900
Tax credit carryforwards	$ 1,700
Expiration period from date of origination for net operating loss carryforwards	20 years
Annual limitation for usage of NOL	$ 1,404
Annual limitation for usage of tax credits	476
Deferred tax expense	$ 408	$ 889