Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2008	$ 184,312	$ 996	$ 55,683	$ 132,064	$ (4,005)	$ (426)
Balance (shares) at Dec. 31, 2008		9,922
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18,633			18,633
Translation adjustment	6,595				6,595
Unrealized derivative gain, net of taxes	816				816
Net actuarial gain (loss) arising during period net of taxes	1,741				1,741
Total comprehensive income	27,785
Tax effect of non-qualified stock options	122		122
Stock-based compensation	543		543
Issuance of stock for acquisition	25,438	170	25,268
Issuance of stock for acquisition, shares		1,700
Exercise of stock otions	1,118	13	1,105
Exercise of stock options, shares		125
Dividends paid ($.24 per share)	(2,399)			(2,399)
Balance at Dec. 31, 2009	236,919	1,179	82,721	148,298	5,147	(426)
Balance (shares) at Dec. 31, 2009		11,747
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	21,117			21,117
Translation adjustment	(3,659)				(3,659)
Unrealized derivative gain, net of taxes	573				573
Net actuarial gain (loss) arising during period net of taxes	(528)				(528)
Total comprehensive income	17,503
Stock-based compensation	674		674
Exercise of stock otions	990	8	982
Exercise of stock options, shares		83
Dividends paid ($.24 per share)	(2,826)			(2,826)
Balance at Dec. 31, 2010	253,260	1,187	84,377	166,589	1,533	(426)
Balance (shares) at Dec. 31, 2010		11,830
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	32,070			32,070
Translation adjustment	(2,879)				(2,879)
Unrealized derivative gain, net of taxes	234				234
Net actuarial gain (loss) arising during period net of taxes	(4,512)				(4,512)
Total comprehensive income	24,913
Tax effect of non-qualified stock options	63		63
Stock-based compensation	986		986
Exercise of stock otions	281	3	278
Exercise of stock options, shares		30
Dividends paid ($.24 per share)	(2,845)			(2,845)
Balance at Dec. 31, 2011	$ 276,658	$ 1,190	$ 85,704	$ 195,814	$ (5,624)	$ (426)
Balance (shares) at Dec. 31, 2011		11,860