Income Taxes - Summary of Income Tax Expense/(Benefit) from Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2018
Current:
Federal	$ 2,356	$ 8,356	$ 693
State	302	1,085	149
Foreign	3	4	4
Total current	2,661	9,445	846
Deferred:
Deferred federal	5,958	(3,222)	(11,266)
Deferred state	725	(336)	(1,233)
Total deferred	6,683	(3,558)	(12,499)
Total income tax expense/(benefit)	$ 9,344	$ 5,887	$ (11,653)	$ (11,653)