Net Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Oct. 31, 2023	Jul. 31, 2023	Oct. 31, 2022	Jul. 31, 2022	Oct. 31, 2023	Oct. 31, 2022
Earnings Per Share [Abstract]
Net income	$ 30,341	$ 37,850	$ 28,784	$ 20,070	$ 68,191	$ 48,854
Denominator for basic net earnings per common share - weighted-average shares	16,322,069		16,614,677		16,406,239	16,599,136
Effect of dilutive securities:
Stock options and restricted stock units	99,000		42,000		99,000	40,000
Diluted (in shares)	16,420,760		16,657,454		16,505,266	16,638,741
Earnings Per Share, Basic [Abstract]
Basic (in usd per share)	$ 1.86		$ 1.73		$ 4.16	$ 2.94
Earnings Per Share, Diluted [Abstract]
Diluted (in usd per share)	$ 1.85		$ 1.73		$ 4.13	$ 2.94
Stock excluded from the calculation of net earnings per share (shares)	30,780		0		43,590	0