Stock-Based Compensation - Summary of Stock Option Activity Under Equity Incentive Plans and Related Information (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jul. 31, 2016	Jan. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Options Outstanding, Beginning balance	15,634,518
Shares Subject to Options Outstanding, Options granted	468,136
Shares Subject to Options Outstanding, Options exercised	(1,676,632)
Shares Subject to Options Outstanding, Options forfeited/cancelled	(1,162,383)
Shares Subject to Options Outstanding, Ending balance	13,263,639	15,634,518
Shares Subject to Options Outstanding, Vested and expected to vest	13,096,353
Shares Subject to Options Outstanding, Exercisable	9,529,567
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning Balance	$ 6.92
Weighted Average Exercise Price, Options granted	11.99
Weighted Average Exercise Price, Options exercised	2.51
Weighted Average Exercise Price, Options forfeited/cancelled	13.05
Weighted Average Exercise Price, Ending Balance	7.12	$ 6.92
Weighted Average Exercise Price, Vested and expected to vest	7.06
Weighted Average Exercise Price, Exercisable	$ 5.40
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Life (Years)	6 years 9 months 4 days	7 years 1 month 13 days
Weighted Average Remaining Contractual Life (Years), Vested and expected to vest	6 years 8 months 27 days
Weighted Average Remaining Contractual Life (Years), Exercisable	6 years 3 months
Aggregate Intrinsic Value, Balance	$ 75,120	$ 82,541
Aggregate Intrinsic Value, Vested and expected to vest	74,772
Aggregate Intrinsic Value, Exercisable	$ 67,350