CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock, at Cost
Balance at Jul. 31, 2010	$ 209,405,000	$ 4,111,000	$ 92,430,000	$ 120,363,000	$ 8,045,000	$ (15,544,000)
Balance (in shares) at Jul. 31, 2010		37,949,139
Increase (Decrease) in Stockholders' Equity
Exercises of options	2,555,000	159,000	11,906,000			(9,510,000)
Exercises of options (in shares)		645,000
Repurchases of shares	(1,290,000)					(1,290,000)
Repurchases of shares (in shares)		(127,282)
Stock-based compensation	3,350,000		3,350,000
Issuance of restricted stock		41,000	(41,000)
Issuance of restricted stock (in shares)		398,362
Income tax benefit from exercises of stock options and vesting of restricted stock	695,000		695,000
Dividends on common stock	(2,063,000)			(2,063,000)
Net income	20,425,000			20,425,000
Other comprehensive income (loss)	1,238,000				1,238,000
Balance at Jul. 31, 2011	234,315,000	4,311,000	108,340,000	138,725,000	9,283,000	(26,344,000)
Balance (in shares) at Jul. 31, 2011		38,865,219
Increase (Decrease) in Stockholders' Equity
Exercises of options	2,372,000	56,000	4,200,000			(1,884,000)
Exercises of options (in shares)		562,728
Issuance for Byrne Acquisition	7,640,000	90,000	7,550,000
Issuance for Byrne Acquisition (in shares)		902,528
Stock-split fractional share adjustment	(3,000)		(3,000)
Stock-split fractional share adjustment (in shares)		(204)
Repurchases of shares	(1,904,000)					(1,904,000)
Repurchases of shares (in shares)		(133,034)
Stock-based compensation	3,840,000		3,840,000
Issuance of restricted stock		52,000	(68,000)			16,000
Issuance of restricted stock (in shares)		536,859
Cancellations of restricted stock		(9,000)	9,000
Cancellations of restricted stock (in shares)		(83,003)
Income tax benefit from exercises of stock options and vesting of restricted stock	1,970,000		1,970,000
Dividends on common stock	(2,523,000)			(2,523,000)
Net income	31,337,000			31,337,000
Other comprehensive income (loss)	(1,108,000)				(1,108,000)
Balance at Jul. 31, 2012	275,936,000	4,500,000	125,838,000	167,539,000	8,175,000	(30,116,000)
Balance (in shares) at Jul. 31, 2012	40,651,093	40,651,093
Increase (Decrease) in Stockholders' Equity
Exercises of options	1,817,000	18,000	2,606,000			(807,000)
Exercises of options (in shares)		412,279
Stock-split fractional share adjustment	(2,000)		(2,000)
Stock-split fractional share adjustment (in shares)		(92)
Repurchases of shares	(2,252,000)					(2,252,000)
Repurchases of shares (in shares)		(121,399)
Stock-based compensation	3,733,000		3,733,000
Issuance of restricted stock		1,000	(198,000)			197,000
Issuance of restricted stock (in shares)		210,484
Cancellations of restricted stock		(1,000)	1,000
Cancellations of restricted stock (in shares)		(14,244)
Income tax benefit from exercises of stock options and vesting of restricted stock	2,875,000		2,875,000
Dividends on common stock	(3,016,000)			(3,016,000)
Net income	39,239,000			39,239,000
Other comprehensive income (loss)	2,802,000				2,802,000
Balance at Jul. 31, 2013	$ 321,132,000	$ 4,518,000	$ 134,853,000	$ 203,762,000	$ 10,977,000	$ (32,978,000)
Balance (in shares) at Jul. 31, 2013	41,138,121	41,138,121