Business Overview - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2015	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Organization And Description Of Business [Line Items]
Net proceeds from initial public offering		$ 459,425	$ 0	$ 0
Conversion of preferred stock	122,280,679
IPO
Organization And Description Of Business [Line Items]
Net proceeds from initial public offering	$ 459,400
Underwriting discounts and commissions	29,300
Offering costs incurred	$ 4,500
IPO | Class A Common Stock
Organization And Description Of Business [Line Items]
Shares issued	28,750,000
Issue price per share	$ 17.00
IPO | Class B Common Stock
Organization And Description Of Business [Line Items]
Conversion of preferred stock	122,280,679