Other Income And Other Expenses (Schedule of Other Interest (Expense), net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Other Income and Expenses [Abstract]
Interest income	$ 16,512	$ 6,861	$ 3,830
Foreign currency gains (losses), net	(233)	(165)	(1)
Other, net		(642)
Other, net	140		2,425
Other income (expense), net	$ 16,419	$ 6,054	$ 6,254