ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Accumulated other comprehensive loss [Abstract]      
Foreign currency translation adjustment $ (28,976) $ (19,305) $ (9,351)
Unrealized holding gain on available-for-sale securities, net of taxes of $263, $265 and $259 as of December 31, 2016, 2015 and 2014 424 434 429
Unfunded SERP liability, net of taxes of ($1,398), ($1,327) and ($1,325) as of December 31, 2016, 2015 and 2014 (2,745) (3,005) (3,026)
Accumulated other comprehensive loss (31,297) (21,876) (11,948)
Accumulated other comprehensive loss, tax [Abstract]      
Unrealized holding gains on available-for-sale securities, tax 263 265 259
Change in unfunded SERP liability, tax (1,398) (1,327) (1,325)
Changes in Accumulated Other Comprehensive (Loss) Income by Component [Roll Forward]      
Balance 233,122 224,273 228,702
Other comprehensive income (loss) before reclassifications (9,676) (10,182)  
Amounts reclassified from accumulated other comprehensive income (loss) 255 254  
Net current period other comprehensive income (loss) (9,421) (9,928) (12,593)
Balance 158,434 233,122 224,273
AOCI Attributable to Parent [Member]      
Changes in Accumulated Other Comprehensive (Loss) Income by Component [Roll Forward]      
Balance (21,876) (11,948) 645
Balance (31,297) (21,876) (11,948)
Foreign Currency Translation Adjustment [Member]      
Changes in Accumulated Other Comprehensive (Loss) Income by Component [Roll Forward]      
Balance (19,305) (9,351)  
Other comprehensive income (loss) before reclassifications (9,671) (9,954)  
Amounts reclassified from accumulated other comprehensive income (loss) 0 0  
Net current period other comprehensive income (loss) (9,671) (9,954)  
Balance (28,976) (19,305) (9,351)
Unrealized Holding Gains on Available-for-Sale Securities [Member]      
Changes in Accumulated Other Comprehensive (Loss) Income by Component [Roll Forward]      
Balance 434 429  
Other comprehensive income (loss) before reclassifications (10) 5  
Amounts reclassified from accumulated other comprehensive income (loss) 0 0  
Net current period other comprehensive income (loss) (10) 5  
Balance 424 434 429
Unfunded SERP Liability [Member]      
Changes in Accumulated Other Comprehensive (Loss) Income by Component [Roll Forward]      
Balance (3,005) (3,026)  
Other comprehensive income (loss) before reclassifications 5 (233)  
Amounts reclassified from accumulated other comprehensive income (loss) [1] 255 254  
Net current period other comprehensive income (loss) 260 21  
Balance $ (2,745) $ (3,005) $ (3,026)
[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.