Stock Option Plan and Employee Stock Purchase Plan (Tables)

12 Months Ended

Jul. 31, 2011

Stock Option Plan and Employee Stock Purchase Plan [Abstract]

Stock Incentive Plan

	Number of Shares Underlying Stock-Based Awards	Weighted Average Exercise Price	Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding at July 31, 2008	2,519,673	$      28.87
Granted	1,066,900	38.67
Expired/canceled	(110,175)	33.88
Exercised	(411,153)	20.21
Outstanding at July 31, 2009	3,065,245	33.26
Granted	653,000	28.90
Expired/canceled	(94,100)	40.85
Exercised	(103,478)	16.15
Outstanding at July 31, 2010	3,520,667	32.75
Granted	680,750	27.64
Expired/canceled	(481,364)	35.79
Exercised	(139,885)	20.29
Outstanding at July 31, 2011	3,580,168	$      31.86	4.40	$  4,217,000
Exercisable at July 31, 2011	1,995,118	$      32.57	2.28	$  4,212,000
Vested and expected to vest at July 31, 2011	3,524,134	$      31.91	4.33	$  4,217,000