Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income (loss)	$ (5,603)	$ 1,615
Other comprehensive income (loss):
Adjustment to pension liability	870	1,345
Tax expense	(348)	(538)
Adjustment to pension liability, net of tax	522	807
Foreign currency translation adjustment	(470)	(1,487)
Total other comprehensive loss, net of tax	52	(680)
Comprehensive income (loss)	(5,551)	935
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance	140,316	326,676
Other comprehensive income (loss), net of tax, before reclassifications	(470)	(1,487)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	522	807
Total other comprehensive income (loss), net of tax	52	(680)
Balance	129,409	322,415
Defined Benefit Pension Items
Other comprehensive income (loss):
Total other comprehensive loss, net of tax	522	807
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance	(43,915)	(49,560)
Other comprehensive income (loss), net of tax, before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	522	807
Total other comprehensive income (loss), net of tax	522	807
Balance	(43,393)	(48,753)
Foreign Currency Items
Other comprehensive income (loss):
Total other comprehensive loss, net of tax	(470)	(1,487)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance	355	2,331
Other comprehensive income (loss), net of tax, before reclassifications	(470)	(1,487)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Total other comprehensive income (loss), net of tax	(470)	(1,487)
Balance	(115)	844
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance	(43,560)	(47,229)
Balance	$ (43,508)	$ (47,909)