Income Taxes (Schedule Of Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2016
CURRENT EXPENSE
Federal	$ 8,668	$ 23,638	$ 18,239
State	1,290	4,189	3,195
Foreign	257	0	0
Total current expense	10,215	27,827	21,434
DEFERRED EXPENSE
Federal	17,833	8,607	10,179
State	3,642	1,292	1,450
Deferred Foreign Income Tax Expense (Benefit)	(71)	0	0
Total deferred expense	21,404	9,899	11,629
Total expense	31,619	37,726	33,063
Other comprehensive income (loss)	50	4,391	(4,110)
Total comprehensive income tax expense	$ 31,669	$ 42,117	$ 28,953