Consolidated Statements Of Changes In Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income
Beginning Balance at Jul. 31, 2009	$ 397,519	$ 640	$ 70,704	$ 316,079	$ 10,096
Beginning Balance (in shares) at Jul. 31, 2009		12,808,734
Shares issued for:
Stock options exercised (in shares)		17,883
Stock options exercised	692	1	691
Restricted stock grants and cancellations, net (in shares)		46,974
Restricted stock grants and cancellations, net	(300)	4	(304)
Stock purchase plan (in shares)		11,117
Stock purchase plan	350		350
Tax benefit for share-based compensation	(147)		(147)
Share-based compensation expense	5,791		5,791
Dividends paid ($0.40 per share)	(5,044)			(5,044)
Comprehensive income:
Net income	15,555			15,555
Actuarial loss on pension plan (net of tax benefit (provision) of $885 in 2012, $395 in 2011, and ($90) in 2010)	(191)				(191)
Translation adjustments (net of tax benefit (provision) of $506 in 2012, $34 in 2011, and ($508) in 2010)	(5,183)				(5,183)
Total comprehensive income	10,181
Ending Balance at Jul. 31, 2010	409,042	645	77,085	326,590	4,722
Ending Balance (in shares) at Jul. 31, 2010		12,884,708
Shares issued for:
Stock options exercised (in shares)		26,173
Stock options exercised	1,122	1	1,121
Stock grants and vesting of restricted stock units (in shares)		14,079
Stock grants and vesting of restricted stock units	393	1	392
Restricted stock cancellations and shares traded for taxes (in shares)		(98,585)
Restricted stock cancellations and shares traded for taxes	(1,174)	(5)	(1,169)
Stock purchase plan (in shares)		8,921
Stock purchase plan	368		368
Tax benefit for share-based compensation	(184)		(184)
Share-based compensation expense	9,638		9,638
Repurchase of common stock (in shares)		(300,289)
Repurchase of common stock	(15,187)	(15)	(1,844)	(13,328)
Dividends paid ($0.40 per share)	(5,154)			(5,154)
Comprehensive income:
Net income	17,833			17,833
Actuarial loss on pension plan (net of tax benefit (provision) of $885 in 2012, $395 in 2011, and ($90) in 2010)	(793)				(793)
Translation adjustments (net of tax benefit (provision) of $506 in 2012, $34 in 2011, and ($508) in 2010)	7,568				7,568
Total comprehensive income	24,608
Ending Balance at Jul. 31, 2011	423,472	627	85,407	325,941	11,497
Ending Balance (in shares) at Jul. 31, 2011	12,535,007	12,535,007
Shares issued for:
Stock options exercised (in shares)		35,922
Stock options exercised	1,626	2	1,624
Stock grants and vesting of restricted stock units (in shares)		53,094
Stock grants and vesting of restricted stock units	2,477	2	2,475
Restricted stock cancellations and shares traded for taxes (in shares)		(45,075)
Restricted stock cancellations and shares traded for taxes	(473)	(2)	(471)
Stock purchase plan (in shares)		7,757
Stock purchase plan	375		375
Tax benefit for share-based compensation	67		67
Share-based compensation expense	13,396		13,396
Repurchase of common stock (in shares)		(423,981)
Repurchase of common stock	(23,260)	(21)	(2,651)	(20,588)
Dividends paid ($0.40 per share)	(5,238)			(5,238)
Comprehensive income:
Net income	43,071			43,071
Unrealized gain on foreign currency forward contracts (net of tax benefit (provision) of ($24) in 2012)	43				43
Actuarial loss on pension plan (net of tax benefit (provision) of $885 in 2012, $395 in 2011, and ($90) in 2010)	(1,632)				(1,632)
Translation adjustments (net of tax benefit (provision) of $506 in 2012, $34 in 2011, and ($508) in 2010)	(7,605)				(7,605)
Total comprehensive income	33,877
Ending Balance at Jul. 31, 2012	$ 446,319	$ 608	$ 100,222	$ 343,186	$ 2,303
Ending Balance (in shares) at Jul. 31, 2012	12,162,724	12,162,724