Segment Information - Schedule of Long-Lived Assets, Including Property and Equipment, Net and Operating Lease Right-of-Use Assets (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 38,281	$ 40,543
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	27,701	30,373
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	6,369	5,854
The Netherlands
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	3,147	3,529
Rest of world
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 1,064	$ 787