Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Balance, shares at Dec. 31, 2012		30,938,000				350,000
Balance at Dec. 31, 2012	$ 476,822	$ 309	$ 240,107	$ 242,082	$ (1,575)	$ (4,101)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(5,633)			(5,633)
Foreign currency translation adjustment	(2,108)				(2,108)
Adjustment to retirement benefit liability, net of tax	53				53
Adjustment to post-retirement healthcare benefit liability, net of taxes	45				45
Unrealized loss on cash flow hedges, net of tax	0
Stock compensation expense	2,564		2,564
Excess tax benefit from stock compensation	72		72
Net settlement of restricted stock units, shares		120,000				45,000
Net settlement of restricted stock units	$ (714)	$ 2	(2)			$ (714)
Issuance of restricted stock, shares		13,000
Stock options exercised, shares	59,750	60,000
Stock options exercised	$ 648		648
Balance, shares at Dec. 31, 2013		31,131,000				395,000
Balance at Dec. 31, 2013	471,749	$ 311	243,389	236,449	(3,585)	$ (4,815)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(81,824)			(81,824)
Foreign currency translation adjustment	(4,364)				(4,364)
Adjustment to retirement benefit liability, net of tax	(24)				(24)
Adjustment to post-retirement healthcare benefit liability, net of taxes	(1,435)				(1,435)
Unrealized loss on cash flow hedges, net of tax	143				143
Stock compensation expense	3,150		3,150
Excess tax benefit from stock compensation	100		100
Net settlement of restricted stock units, shares		136,000				34,000
Net settlement of restricted stock units	$ (575)	$ 1	(1)			$ (575)
Issuance of restricted stock, shares		22,000
Stock options exercised, shares	52,805	53,000
Stock options exercised	$ 595	$ 1	594
Balance, shares at Dec. 31, 2014		31,342,000				429,000
Balance at Dec. 31, 2014	387,229	$ 313	247,232	154,625	(9,551)	$ (5,390)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	23,448			23,448
Foreign currency translation adjustment	(6,228)				(6,228)
Adjustment to retirement benefit liability, net of tax	49				49
Adjustment to post-retirement healthcare benefit liability, net of taxes	171				171
Unrealized loss on cash flow hedges, net of tax	(143)				(143)
Stock compensation expense	3,891		3,891
Excess tax benefit from stock compensation	537		537
Net settlement of restricted stock units, shares		297,000				55,000
Net settlement of restricted stock units	$ (956)	$ 3	(3)			$ (956)
Issuance of restricted stock, shares		21,000
Stock options exercised, shares	119,096	119,000
Stock options exercised	$ 1,802	$ 1	1,801
Balance, shares at Dec. 31, 2015		31,779,000				484,000
Balance at Dec. 31, 2015	$ 410,086	$ 317	$ 253,458	$ 178,073	$ (15,416)	$ (6,346)