CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balances at Dec. 31, 2008	$ 442,534	$ 236	$ 73,460	$ 371,602	$ (2,764)
Net income	52,810			52,810
Foreign currency translation adjustment, net of tax of ($1447) in 2011, ($599) in 2010, $1,454 in 2009	(2,445)				(2,445)
Comprehensive income	50,365
Exercise of stock options	896	1	895
Tax benefit from stock based compensation	261		261
Stock granted under restricted stock plan, net		1	(1)
Stock based compensation	2,302		2,302
Shares repurchased and retired	(22,563)	(7)	(22,556)
Shares surrendered by employees to pay taxes	(192)			(192)
Cash dividends, per share $0.88 in 2011, $0.76 in 2010, $0.70 in 2009	(16,287)			(16,287)
Balances at Dec. 31, 2009	457,316	231	54,361	407,933	(5,209)
Net income	78,716			78,716
Foreign currency translation adjustment, net of tax of ($1447) in 2011, ($599) in 2010, $1,454 in 2009	1,095				1,095
Comprehensive income	79,811
Exercise of stock options	254		254
Tax benefit from stock based compensation	801		801
Stock granted under restricted stock plan, net	79		79
Stock based compensation	3,192		3,192
Shares repurchased and retired	(1,212)		(1,212)
Shares surrendered by employees to pay taxes	(692)			(692)
Cash dividends, per share $0.88 in 2011, $0.76 in 2010, $0.70 in 2009	(17,570)			(17,570)
Balances at Dec. 31, 2010	521,979	231	57,475	468,387	(4,114)
Net income	130,136			130,136
Foreign currency translation adjustment, net of tax of ($1447) in 2011, ($599) in 2010, $1,454 in 2009	249				249
Comprehensive income	130,385
Exercise of stock options	76		76
Tax benefit from stock based compensation	1,412		1,412
Stock granted under restricted stock plan, net	223		223
Stock based compensation	4,002		4,002
Shares repurchased and retired	(6,649)		(6,649)
Shares surrendered by employees to pay taxes	(901)			(901)
Cash dividends, per share $0.88 in 2011, $0.76 in 2010, $0.70 in 2009	(20,369)			(20,369)
Balances at Dec. 31, 2011	$ 630,158	$ 231	$ 56,539	$ 577,253	$ (3,865)