Stockholders’ Equity and Equity Incentive Plan - Summary of Stock Option Activity Under Equity Incentive Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020
Outstanding Stock Options
Beginning balance (in shares)	16,833,009
Granted (in shares)	0
Exercised (in shares)	(3,232,991)
Cancelled/forfeited/expired (in shares)	(52,093)
Ending balance (in shares)	13,547,925	16,833,009
Weighted- Average Exercise Price
Beginning balance (in dollars per share)	$ 5.73
Granted (in dollars per share)	0
Exercised (in dollars per share)	2.97
Cancelled/forfeited/expired (in dollars per share)	4.63
Ending balance (in dollars per share)	$ 6.39	$ 5.73
Weighted- Average Remaining Contractual Life (Years)	7 years 7 months 6 days	7 years 7 months 6 days
Options outstanding, aggregate intrinsic value	$ 1,744,720	$ 1,191,881
Outstanding stock options, vested and exercisable (in shares)	5,449,596
Weighted average exercise price, vested and exercisable (in shares)	$ 2.70
Weighted-average remaining contractual life (years), vested and exercisable	7 years
Options outstanding, aggregate intrinsic value, vested and exercisable	$ 721,922