Net Earnings Per Share (Schedule Of Earnings Per Share, Basic And Diluted) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 9,238	$ 6,655
Denominator for basic net earnings per common share - weighted-average shares	15,532,103	14,949,406
Stock options and restricted stock units	237,000	424,000
Denominator for diluted net earnings per common share - weighted-average shares and assumed conversions	15,768,884	15,373,260
Basic (usd per share)	$ 0.59	$ 0.45
Diluted (usd per share)	$ 0.59	$ 0.43