Stockholders' Equity - Additional Information (Details)	Oct. 31, 2016 class $ / shares shares	Jan. 31, 2016 $ / shares shares	Oct. 31, 2015 shares
Class Of Stock [Line Items]
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Number of classes of stock | class	2
Common stock, shares authorized (in shares)	2,250,000,000	2,250,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	199,678,000	190,509,000
Common stock, shares outstanding (in shares)	199,678,000	190,509,000
Class A Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	75,319,966	28,769,000
Common stock, shares outstanding (in shares)	75,319,966	28,769,000
Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	124,357,633	161,740,000
Common stock, shares outstanding (in shares)	124,357,633	161,740,000