Equity Incentive Plans and Employee Stock Purchase Plan - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2020	Jan. 31, 2019	Jan. 31, 2020
Shares
Balance - beginning of period (in shares)	6,178,999
Stock options exercised (in shares)	(373,394)
Stock options forfeited and expired (in shares)	(16,389)
Balance - end of period (in shares)	5,789,216
Vested and exercisable (in shares)	4,635,511		4,693,273
Weighted- Average Exercise Price Per Share
Balance - beginning of period (in dollars per share)	$ 7.60
Stock options exercised (in dollars per share)	8.03
Stock options forfeited and expired (in dollars per share)	10.06
Balance - end of period (in dollars per share)	7.56
Vested and exercisable (in dollars per share)	$ 7.11		$ 7.08
Weighted- Average Remaining Contractual Term (In Years)
Balance	5 years 6 months	5 years 8 months 12 days
Vested and exercisable	5 years 2 months 12 days	5 years 4 months 24 days
Aggregate Intrinsic Value
Balance	$ 894,828		$ 965,860
Vested and exercisable	$ 718,616		$ 736,034