Stockholders’ Equity and Equity Incentive Plans - Summary of Stock Option Activity Under Equity Incentive Plan (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jul. 31, 2020 USD ($) $ / shares shares	Jan. 31, 2020 USD ($) $ / shares shares
Outstanding Stock Options
Beginning balance (in shares) | shares	16,833,009
Granted (in shares) | shares	0
Exercised (in shares) | shares	(4,830,752)
Cancelled/forfeited/expired (in shares) | shares	(132,739)
Ending balance (in shares) | shares	11,869,518	16,833,009
Weighted- Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 5.73
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	3.61
Cancelled/forfeited/expired (in dollars per share) | $ / shares	5.92
Ending balance (in dollars per share) | $ / shares	$ 6.59	$ 5.73
Weighted- Average Remaining Contractual Life (Years)	7 years 4 months 24 days	7 years 7 months 6 days
Options outstanding, aggregate intrinsic value | $	$ 2,935,477	$ 1,191,881
Outstanding stock options, vested and exercisable (in shares) | shares	5,021,067
Weighted average exercise price, vested and exercisable (in shares) | $ / shares	$ 3.28
Weighted-average remaining contractual life (years), vested and exercisable	6 years 9 months 18 days
Options outstanding, aggregate intrinsic value, vested and exercisable | $	$ 1,258,445