Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Oct. 31, 2015	Sep. 30, 2015	Jan. 31, 2015
Class Of Stock [Line Items]
Preferred stock, shares authorized	20,000,000		0
Preferred stock, par value	$ 0.0001		$ 0.0001
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0		0
Common stock, shares authorized	2,250,000,000		230,812,000
Common stock, shares issued	189,980,000		36,465,000
Common stock, shares outstanding	189,980,000		36,465,000
Class A Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	2,000,000,000		1,000
Common stock, par value per share	$ 0.0001		$ 0.0001
Common stock, shares issued	28,750,000
Common stock, shares outstanding	28,750,000
Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	250,000,000		230,811,000
Common stock, par value per share	$ 0.0001		$ 0.0001
Common stock, shares issued	161,229,673		36,465,000
Common stock, shares outstanding	161,229,673		36,465,000
Class B Common Stock | Pure Good Foundation
Class Of Stock [Line Items]
Common stock, shares issued		700,000
Non cash general and administrative expense	$ 11.9