Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Components of income tax expense (benefit)
Current federal	$ 12,537	$ 11,858	$ 30,827
Current foreign	1,624	13,739
Current state	7,857	5,929	6,409
Total current	22,018	31,526	37,236
Deferred federal	8,986	453	(14,796)
Deferred foreign	(7,347)	(16,931)
Deferred state	(713)	(1,009)	(1,557)
Total deferred	926	(17,487)	(16,353)
Total provision for income taxes	$ 22,944	$ 14,039	$ 20,883