Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Components of income tax expense (benefit)
Current federal	$ 11,858	$ 30,827	$ 37,164
Current foreign	13,739
Current state	5,929	6,409	5,875
Total current	31,526	37,236	43,039
Deferred federal	453	(14,796)	(19,011)
Deferred foreign	(16,931)
Deferred state	(1,009)	(1,557)	(1,374)
Total deferred	(17,487)	(16,353)	(20,385)
Total provision for income taxes	$ 14,039	$ 20,883	$ 22,654