Equity Incentive Plans - Summary of Equity Awards Available for Grant (Details) - shares	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Equity Awards, Outstanding [Roll Forward]
Available at beginning of fiscal year (in shares)	9,649,123	2,061,282
Awards authorized (in shares)	3,683,754	12,000,000
Options granted (in shares)	(172,031)	(4,722,404)
Options cancelled (in shares)	1,181,482	976,130
Options repurchased (in shares)	0	43,630
Available at end of fiscal year (in shares)	12,461,850	9,649,123
RSUs
Equity Awards, Outstanding [Roll Forward]
RSUs granted (in shares)	(2,101,271)	(732,701)
RSUs cancelled (in shares)	216,208	23,186
RSAs
Equity Awards, Outstanding [Roll Forward]
RSAs repurchased (in shares)	4,585	0