Summary of Significant Accounting Policies - Schedule of Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance at beginning of period	$ 256,209	$ 232,275
Other comprehensive income before reclassifications	1,844	(328)
Amounts reclassified from accumulated other comprehensive loss, net of tax of $0.3 million	(1,102)	1,473
Amounts reclassified from accumulated other comprehensive loss, tax	300	(1,000)
Net current period other comprehensive (loss) income, net	742	1,145
Balance at end of period	277,452	256,209
Accumulated other comprehensive income (loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance at beginning of period	(11,635)	(12,780)
Balance at end of period	(10,893)	(11,635)
Pension and postretirement benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance at beginning of period	(10,495)	(11,968)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss, net of tax of $0.3 million	(1,102)	1,473
Amounts reclassified from accumulated other comprehensive loss, tax	292	(1,019)
Net current period other comprehensive (loss) income, net	(1,102)	1,473
Balance at end of period	(11,597)	(10,495)
Foreign currency
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance at beginning of period	(1,140)	(812)
Other comprehensive income before reclassifications	1,844	(328)
Amounts reclassified from accumulated other comprehensive loss, net of tax of $0.3 million	0	0
Net current period other comprehensive (loss) income, net	1,844	(328)
Balance at end of period	$ 704	$ (1,140)