Income Taxes (Schedule Of Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
CURRENT EXPENSE
Federal	$ 18,239	$ 12,663	$ 4,825
State	3,195	1,890	406
Total current expense	21,434	14,553	5,231
DEFERRED EXPENSE
Federal	10,179	3,024	6,076
State	1,450	1,311	1,902
Total deferred expense	11,629	4,335	7,978
Total expense	33,063	18,888	13,209
Other comprehensive income (loss)	(4,110)	(9,510)	3,944
Total comprehensive income tax expense	$ 28,953	$ 9,378	$ 17,153