ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Summary of components of accumulated other comprehensive (loss) income (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2018		Sep. 30, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		$ (16,702)	[1]	$ (18,102)
Change during the period:
Before-tax amount		(44)		565
Reclassification adjustment, net of taxes:
Reclassification adjustment, net of taxes				7
Amortization of net loss	[2]	485		405
Total activity for the period		441		977
Balance		(16,261)		(17,125)
Pension Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		(14,470)		(15,503)
Change during the period:
Before-tax amount		0		0
Reclassification adjustment, net of taxes:
Reclassification adjustment, net of taxes				0
Amortization of net loss	[2]	485		405
Total activity for the period		485		405
Balance		(13,985)		(15,098)
Unrealized Gain (Loss) On Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		15		39
Change during the period:
Before-tax amount		(15)		(19)
Reclassification adjustment, net of taxes:
Reclassification adjustment, net of taxes				7
Amortization of net loss	[2]	0		0
Total activity for the period		(15)		(12)
Balance		0		27
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		(2,247)		(2,638)
Change during the period:
Before-tax amount		(29)		584
Reclassification adjustment, net of taxes:
Reclassification adjustment, net of taxes				0
Amortization of net loss	[2]	0		0
Total activity for the period		(29)		584
Balance		$ (2,276)		$ (2,054)

[1] (Note 1)

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