Net Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jul. 31, 2023	Jul. 31, 2022
Earnings Per Share [Abstract]
Net income	$ 37,850	$ 20,070
Denominator for basic net earnings per common share - weighted-average shares	16,490,408	16,583,595
Effect of dilutive securities:
Stock options and restricted stock units	99,000	36,000
Diluted (in shares)	16,589,481	16,619,916
Earnings Per Share, Basic [Abstract]
Basic (in usd per share)	$ 2.30	$ 1.21
Earnings Per Share, Diluted [Abstract]
Diluted (in usd per share)	$ 2.28	$ 1.21
Stock excluded from the calculation of net earnings per share (shares)	0