Net Earnings Per Share (Schedule Of Earnings Per Share, Basic And Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
Earnings Per Share [Abstract]
Net income	$ 15,158	$ 9,238
Denominator for basic net earnings per common share - weighted-average shares	16,180,860	15,532,103
Stock options and restricted stock units	240,000	237,000
Denominator for diluted net earnings per common share - weighted-average shares and assumed conversions	16,421,230	15,768,884
Basic (usd per share)	$ 0.94	$ 0.59
Diluted (usd per share)	$ 0.92	$ 0.59