Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Oct. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Oct. 31, 2015 USD ($)	Oct. 31, 2016 USD ($) source	Oct. 31, 2015 USD ($)	Jan. 31, 2016 USD ($)
New Accounting Pronouncement, Early Adoption [Line Items]
Restricted cash	$ 12,734			$ 12,734		$ 7,132
Deferred commissions, current	14,298			14,298		15,703
Deferred income taxes, non-current	13,800			13,800		$ 14,300
Sales commission expenses	21,600		$ 16,500	$ 58,800	$ 38,600
Number of revenue sources | source				2
Decrease in provision for income taxes	441		751	$ 967	965
Total stock-based compensation expense	$ 28,235		$ 15,539	79,129	$ 36,198
Accounting Standards Update 2016-09, Forfeiture Rate Component | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncement, Early Adoption [Line Items]
Decrease in provision for income taxes				$ (921)
Total stock-based compensation expense		$ 864
Accounting Standards Update 2016-09, Forfeiture Rate Component | Accumulated Deficit | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncement, Early Adoption [Line Items]
Cumulative-effect adjustment, new accounting standard		$ 2,100