ACCUMULATED OTHER COMPREHENSIVE LOSS, Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				$ 157,960
Other comprehensive income before reclassifications				(3,436)
Amount reclassified from accumulated other comprehensive loss				145
Net current period other comprehensive income		$ (7,363)	$ 5,734	(3,291)	$ 7,427
Balance		163,297		163,297
Accumulated Other Comprehensive Income (Loss) [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				(19,625)
Balance		(22,916)		(22,916)
Foreign Currency Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				(16,537)
Other comprehensive income before reclassifications				(3,431)
Amount reclassified from accumulated other comprehensive loss				0
Net current period other comprehensive income				(3,431)
Balance		(19,968)		(19,968)
Unrealized Holding Gains on Available-for-Sale Securities [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				145
Other comprehensive income before reclassifications				(31)
Amount reclassified from accumulated other comprehensive loss				0
Net current period other comprehensive income				(31)
Balance		114		114
Unfunded SERP Liability [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Balance				(3,233)
Other comprehensive income before reclassifications				26
Amount reclassified from accumulated other comprehensive loss	[1]			145
Net current period other comprehensive income				171
Balance		$ (3,062)		$ (3,062)

[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.