Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	$ (8,801)	$ (16,926)
Other Comprehensive Income (Loss), before Tax	(315)	(1,180)
Balance at end of period	(5,336)	(8,801)	$ (16,926)
Tax (Benefit) Expense
Balance at beginning of period	(1,080)	(1,510)
Minimum pension and post retirement health care plan adjustments	110	430
Balance at end of period	(970)	(1,080)	(1,510)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(7,721)	(15,416)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	205	750
Other Comprehensive Income (Loss), Net of Tax	(3,355)	(7,695)	5,865
Balance at end of period	(4,366)	(7,721)	(15,416)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	(5,848)	(12,793)
Other Comprehensive Income (Loss), before Tax	3,150	6,945
Balance at end of period	(2,698)	(5,848)	(12,793)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	3,150	6,945
Accumulated Defined Benefit Plans Adjustment | Minimum Pension Liability Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	197	118
Other Comprehensive Income (Loss), before Tax	26	(79)
Balance at end of period	171	197	118
Accumulated Defined Benefit Plans Adjustment | Unamortized Post-Retirement Health Care Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	(3,150)	(4,251)
Other Comprehensive Income (Loss), before Tax	(341)	(1,101)
Balance at end of period	$ (2,809)	$ (3,150)	$ (4,251)