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, 2013	$ 350,465	$ 1,211	$ 91,439	$ (426)	$ 255,203	$ 3,038
Balance (in shares) at Dec. 31, 2013		12,071
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	41,151				41,151
Translation adjustment	(16,331)					(16,331)
Net actuarial gain (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 (in shares)		43
Exercise of stock options	903	$ 4	899
Repurchased shares	(34,204)			(34,204)
Retirement of shares (in shares)		(850)
Retirement of shares	0	$ (85)	(569)	34,204	(33,550)
Dividends paid	(3,328)				(3,328)
Balance (in 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 gain (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 (in shares)		86
Exercise of stock options	2,023	$ 9	2,014
Dividends paid	(3,628)				(3,628)
Balance (in shares) at Dec. 31, 2015		11,350
Balance at Dec. 31, 2015	360,469	$ 1,139	96,778	(426)	299,057	(36,079)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,045				40,045
Translation adjustment	(13,156)					(13,156)
Net actuarial gain (loss) arising during period net of taxes	1,479					1,479
Tax effect of exercised non-qualified stock options	230		230
Stock-based compensation	1,414		1,414
Exercise of stock options (in shares)		70
Exercise of stock options	1,369	$ 7	1,362
Repurchased shares	(19)		(19)
Dividends paid	(4,114)				(4,114)
Balance (in shares) at Dec. 31, 2016		11,420
Balance at Dec. 31, 2016	$ 387,717	$ 1,146	$ 99,765	$ (426)	$ 334,988	$ (47,756)