Ordinary Shares - Summary of Ordinary Shares Reserved for Issuance (Details) - shares	Apr. 30, 2020	Apr. 30, 2019
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	30,194,448	33,256,028
Stock options
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	15,260,506	22,866,438
RSUs
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	2,472,092	740,467
2012 Plan
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	12,461,850	9,649,123