Stock-Based Compensation - Summary of Stock Option Activity Under Equity Incentive Plans and Related Information (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2015	Jan. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Outstanding Options, Beginning balance	17,465,571
Shares Subject to Outstanding Options, Options granted	1,898,700
Shares Subject to Outstanding Options, Options exercised	(1,734,155)
Shares Subject to Outstanding Options, Options forfeited/cancelled	(1,289,083)
Shares Subject to Outstanding Options, Ending balance	16,341,033	17,465,571
Shares Subject to Outstanding Options, Vested and expected to vest	16,081,099
Shares Subject to Outstanding Options, Exercisable	9,321,360
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning Balance	$ 5.67
Weighted Average Exercise Price, Options granted	15.62
Weighted Average Exercise Price, Options exercised	3.05
Weighted Average Exercise Price, Options forfeited/cancelled	8.14
Weighted Average Exercise Price, Ending Balance	6.90	$ 5.67
Weighted Average Exercise Price, Vested and expected to vest	6.83
Weighted Average Exercise Price, Exercisable	$ 4.02
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Life (Years)	7 years 4 months 13 days	7 years 9 months 18 days
Weighted Average Remaining Contractual Life (Years), Vested and expected to vest	7 years 4 months 6 days
Weighted Average Remaining Contractual Life (Years), Exercisable	6 years 7 months 21 days
Aggregate Intrinsic Value, Beginning Balance	$ 229,713
Aggregate Intrinsic Value, Ending Balance	106,264	$ 229,713
Aggregate Intrinsic Value, Vested and expected to vest	105,566
Aggregate Intrinsic Value, Exercisable	$ 82,215