Stock-Based Compensation - Summary of Stock Option Activity Under Equity Incentive Plans and Related Information (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Apr. 30, 2017 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Options Outstanding, Beginning balance | shares	12,318,800
Shares Subject to Options Outstanding, Options granted | shares	1,030,000
Shares Subject to Options Outstanding, Options exercised | shares	(531,910)
Shares Subject to Options Outstanding, Options forfeited/cancelled | shares	(65,575)
Shares Subject to Options Outstanding, Ending balance | shares	12,751,315
Shares Subject to Options Outstanding, Vested and expected to vest | shares	12,600,593
Shares Subject to Options Outstanding, Exercisable | shares	9,160,781
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 7.44
Weighted Average Exercise Price, Options granted | $ / shares	16.67
Weighted Average Exercise Price, Options exercised | $ / shares	4.62
Weighted Average Exercise Price, Options forfeited/cancelled | $ / shares	15.15
Weighted Average Exercise Price, Ending Balance | $ / shares	8.27
Weighted Average Exercise Price, Vested and expected to vest | $ / shares	8.19
Weighted Average Exercise Price, Exercisable | $ / shares	$ 5.91
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Life (Years)	6 years 6 months
Weighted Average Remaining Contractual Life (Years), Vested and expected to vest	6 years 5 months 20 days
Weighted Average Remaining Contractual Life (Years), Exercisable	5 years 8 months 8 days
Aggregate Intrinsic Value, Balance | $	$ 115,138
Aggregate Intrinsic Value, Vested and expected to vest | $	114,682
Aggregate Intrinsic Value, Exercisable | $	$ 104,276