Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income
Balance at Dec. 31, 2012	$ 310,286	$ 1,203	$ 88,660	$ (426)	$ 222,480	$ (1,631)
Balance (shares) at Dec. 31, 2012		11,986
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	36,094				36,094
Translation adjustment	479					479
Net actuarial loss arising during period net of taxes	4,190					4,190
Stock-based compensation	1,501		1,501
Exercise of stock options, shares		85
Exercise of stock options	1,286	$ 8	1,278
Dividends paid	(3,371)				(3,371)
Balance (shares) at Dec. 31, 2013		12,071
Balance at Dec. 31, 2013	350,465	$ 1,211	91,439	(426)	255,203	3,038
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	41,151				41,151
Translation adjustment	(16,331)					(16,331)
Net actuarial loss arising during period net of taxes	(3,066)					(3,066)
Tax effect of exercised non-qualified stock options	94		94
Stock-based compensation	1,986		1,986
Exercise of stock options, shares		43
Exercise of stock options	903	$ 4	899
Repurchased shares	(34,204)			(34,204)
Retirement of shares (shares)		(850)
Retirement of shares	0	$ (85)	(569)	34,204	(33,550)
Dividends paid	(3,328)				(3,328)
Balance (shares) at Dec. 31, 2014		11,264
Balance at Dec. 31, 2014	337,670	$ 1,130	93,849	(426)	259,476	(16,359)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	43,209				43,209
Translation adjustment	(20,112)					(20,112)
Net actuarial loss arising during period net of taxes	392					392
Tax effect of exercised non-qualified stock options	(142)		(142)
Stock-based compensation	1,057		1,057
Exercise of stock options, shares		86
Exercise of stock options	2,023	$ 9	2,014
Dividends paid	(3,628)				(3,628)
Balance (shares) at Dec. 31, 2015		11,350
Balance at Dec. 31, 2015	$ 360,469	$ 1,139	$ 96,778	$ (426)	$ 299,057	$ (36,079)