ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Summary of components of accumulated other comprehensive (loss) income (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		$ (18,102)	$ (17,969)
Change during the period:
Before-tax amount		18	678
Tax benefit		9	5
Reclassification adjustment, net of taxes:
Amortization of net loss	[1]	135	127
Total activity for the period		162	810
Balance		(17,940)	(17,159)
Pension Adjustment
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		(15,503)	(14,715)
Change during the period:
Before-tax amount
Tax benefit
Reclassification adjustment, net of taxes:
Amortization of net loss	[1]	135	127
Total activity for the period		135	127
Balance		(15,368)	(14,588)
Unrealized Gain (Loss) On Securities
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		39	36
Change during the period:
Before-tax amount		(24)	(14)
Tax benefit		9	5
Reclassification adjustment, net of taxes:
Amortization of net loss
Total activity for the period		(15)	(9)
Balance		24	27
Foreign Currency Translation
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		(2,638)	(3,290)
Change during the period:
Before-tax amount		42	692
Tax benefit
Reclassification adjustment, net of taxes:
Amortization of net loss
Total activity for the period		42	692
Balance		$ (2,596)	$ (2,598)

[1] Reported as part of selling, general and administrative expenses.