Income Taxes - Components of Income Before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Income Tax Disclosure [Line Items]
Income before taxes	$ 137,094	$ 46,325	$ 70,041
United States
Income Tax Disclosure [Line Items]
Income before taxes	106,059	106,850	62,878
Foreign
Income Tax Disclosure [Line Items]
Income before taxes	$ 31,035	$ (60,525)	$ 7,163