ACCUMULATED OTHER COMPREHENSIVE LOSS, Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				$ 157,960
Other comprehensive (loss) income before reclassifications				(4,455)
Amount reclassified from accumulated other comprehensive loss				47
Net current period other comprehensive (loss) income		$ (1,117)	$ 3,504	(4,408)	$ 10,931
Balance		173,311		173,311
Accumulated Other Comprehensive Income (Loss) [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				(19,625)
Balance		(24,033)		(24,033)
Foreign Currency Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				(16,537)
Other comprehensive (loss) income before reclassifications				(4,463)
Amount reclassified from accumulated other comprehensive loss				0
Net current period other comprehensive (loss) income				(4,463)
Balance		(21,000)		(21,000)
Unrealized Holding Gains (Losses) on Available-for-Sale Securities [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				145
Other comprehensive (loss) income before reclassifications				(31)
Amount reclassified from accumulated other comprehensive loss				(170)
Net current period other comprehensive (loss) income				(201)
Balance		(56)		(56)
Unfunded SERP Liability [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				(3,233)
Other comprehensive (loss) income before reclassifications				39
Amount reclassified from accumulated other comprehensive loss	[1]			217
Net current period other comprehensive (loss) income				256
Balance		$ (2,977)		$ (2,977)

[1] This reclassification relates to the amortization of prior service costs and gains/losses associated with the Company's SERP plan. This expense is allocated between cost of sales and selling, general and administrative expense based upon the employment classification of the plan participants.