CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY (USD $) In Thousands	Total	Common Stock Issued	Common Stock in Treasury	Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Beginning balance at Dec. 31, 2009	$ 169,730	$ 191	$ (79,826)	$ 128,913	$ 1,463	$ 118,989
Beginning balance, shares at Dec. 31, 2009		19,140	(5,450)
Net income	15,081					15,081
Currency translation adjustment	(1,952)				(1,952)
Shares issued for employee benefit plan and compensation, shares		156
Shares issued for employee benefit plan and compensation	566	2		564
Shares issued for purchase of Enson, shares		1,460
Shares issued for purchase of Enson	30,763	15		30,748
Purchase of treasury shares, shares	(506)		(506)
Purchase of treasury shares	(10,145)		(10,145)
Stock options exercised, shares	121	121
Stock options exercised	1,964	1		1,963
Shares Issued to Directors, shares			30
Shares Issued to Directors, value	0		445	(445)
Stock-based compensation expense	4,966			4,966
Tax benefit from exercise of non-qualified stock options and vested restricted stock	231			231
Ending balance at Dec. 31, 2010	211,204	209	(89,526)	166,940	(489)	134,070
Ending balance, shares at Dec. 31, 2010		20,877	(5,926)
Net income	19,946					19,946
Currency translation adjustment	1,427				1,427
Shares issued for employee benefit plan and compensation, shares		164
Shares issued for employee benefit plan and compensation	729	1		728
Purchase of treasury shares, shares	(457)		(457)
Purchase of treasury shares	(9,785)		(9,785)
Stock options exercised, shares	102	102
Stock options exercised	1,677	1		1,676
Shares Issued to Directors, shares			30
Shares Issued to Directors, value	0		434	(434)
Stock-based compensation expense	4,511			4,511
Tax benefit from exercise of non-qualified stock options and vested restricted stock	280			280
Ending balance at Dec. 31, 2011	229,989	211	(98,877)	173,701	938	154,016
Ending balance, shares at Dec. 31, 2011		21,143	(6,353)
Net income	16,553					16,553
Currency translation adjustment	114				114
Shares issued for employee benefit plan and compensation, shares		159
Shares issued for employee benefit plan and compensation	749	2		747
Purchase of treasury shares, shares	(201)		(201)
Purchase of treasury shares	(3,451)		(3,451)
Stock options exercised, shares	189	189
Stock options exercised	2,204	2		2,202
Shares Issued to Directors, shares			38
Shares Issued to Directors, value	0		535	(535)
Stock-based compensation expense	4,575			4,575
Tax benefit from exercise of non-qualified stock options and vested restricted stock	(83)			(83)
Ending balance at Dec. 31, 2012	$ 250,650	$ 215	$ (101,793)	$ 180,607	$ 1,052	$ 170,569
Ending balance, shares at Dec. 31, 2012		21,491	(6,516)