Income Taxes - Summary of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Current:
Dutch	$ 518	$ 0	$ 0
Foreign	(560)	912	3,731
Total current tax expense	(42)	912	3,731
Deferred:
Dutch	0	(233)	0
Foreign	(1,926)	3,709	(355)
Total deferred tax expense	(1,926)	3,476	(355)
Total provision for income taxes	$ (1,968)	$ 4,388	$ 3,376