Income Taxes (Schedule Of Income Tax Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Current Expense (Benefit) [Abstract]
Federal	$ 4,825	$ 1,031	$ (36)
State	406	162	(176)
Total current expense (benefit)	5,231	1,193	(212)
Deferred Benefit [Abstract]
Federal	6,076	4,859	(10,115)
State	1,902	930	(2,175)
Total deferred expense (benefit)	7,978	5,789	(12,290)
Total expense (benefit)	13,209	6,982	(12,502)
Other comprehensive income (loss)	3,944	(2,905)	(3,624)
Total comprehensive income tax expense (benefit)	$ 17,153	$ 4,077	$ (16,126)