Ordinary Shares - Summary of Ordinary Shares Reserved for Issuance (Details) - shares	Oct. 31, 2020	Apr. 30, 2020
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	29,988,385	30,194,448
Stock options
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	10,757,903	15,260,506
RSUs
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	2,617,676	2,472,092
2012 Plan
Class of Stock [Line Items]
Total ordinary shares reserved (in shares)	16,612,806	12,461,850