Stock-Based Compensation Overview (Details) - shares	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
2000 Stock Incentive Plan [Member]
2000 Stock Incentive Plan
Aggregate maximum number of shares of common stock which may be issued under stock option plan	8,962,500
Aggregate net number of stock-based awards granted	7,456,622
Aggregate number of stock based awards expired and canceled	2,833,834
Aggregate number of stock-based awards exercised	5,112,774
Stock-Based Awards Outstanding By Award Type (In Shares)
Number of total stock-based awards outstanding	2,343,848
2000 Stock Incentive Plan [Member] | Stock options [Member]
2000 Stock Incentive Plan
Maximum term for grants of incentive and non-qualified stock-based awards, excluding incentive stock-based awards granted to stockholders who own more than 10% of the voting power	10 years
Maximum term for incentive stock-based awards granted to stockholders who own more than 10% of the voting power	5 years
Percentage of a stockholder's voting power that limits the contractual term of an incentive stock-based award	10.00%
Stock-Based Awards Outstanding By Award Type (In Shares)
Number of stock-based awards outstanding at period end	2,119,683
2000 Stock Incentive Plan [Member] | Performance Shares [Member]
Stock-Based Awards Outstanding By Award Type (In Shares)
Number of stock-based awards outstanding at period end	170,841
2000 Stock Incentive Plan [Member] | RSUs and restricted stock [Member]
Stock-Based Awards Outstanding By Award Type (In Shares)
Number of stock-based awards outstanding at period end	44,821
2000 Stock Incentive Plan [Member] | Share units [Member]
Stock-Based Awards Outstanding By Award Type (In Shares)
Number of stock-based awards outstanding at period end	8,503
2000 Stock Incentive Plan [Member] | Stock appreciation rights (SARs) [Member]
Stock-Based Awards Outstanding By Award Type (In Shares)
Number of stock-based awards outstanding at period end	0	0
2001 Employee Stock Purchase Plan [Member] | Employee Stock Purchase Plan - ESPP [Member]
2001 Employee Stock Purchase Plan
Total number of common shares reserved for issuance under employee stock purchase plan	675,000
Discount rate from market value, on purchase date, offered to employees participating in the Employee Stock Purchase Plan (ESPP)	85.00%
Total number of shares of common stock issued to employees under employee stock purchase plan and through the end of the reporting period	589,053