Stockholders' Equity - Additional Information (Detail) - $ / shares	Apr. 29, 2015	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Class of Stock [Line Items]
Common stock, shares authorized	1,000,000,000	1,000,000,000	1,000,000,000	30,263,157
Common stock, par value		$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	200,000,000	200,000,000	200,000,000
Convertible preferred stock, par value	$ 0.001	$ 0.001	$ 0.001
IPO [Member]
Class of Stock [Line Items]
Convertible preferred stock converted into shares of common stock	19,818,172