Stockholder's Equity (Details Textuals) - $ / shares	Jul. 31, 2016	Jul. 31, 2015
Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract]
Common stock, shares authorized	180,000,000	180,000,000
Common stock par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares outstanding	110,122,060	120,156,340
Common stock, reserved for issuance of stock options	20,812,967	22,682,820
Common stock, shares issued	110,122,060	120,156,340
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Employee Stock Purchase Plan (ESPP)
Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract]
Common stock, reserved for issuance of stock options	989,811	1,097,943