Net Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Jan. 31, 2025	Oct. 31, 2024	Jul. 31, 2024	Jan. 31, 2024	Oct. 31, 2023	Jul. 31, 2023	Jan. 31, 2025	Jan. 31, 2024
Earnings Per Share [Abstract]
Net income	$ 16,571	$ 27,686	$ 29,633	$ 21,227	$ 30,341	$ 37,850	$ 73,890	$ 89,418
Denominator for basic net earnings per common share - weighted-average shares	15,051,630			15,991,520			15,309,779	16,267,999
Effect of dilutive securities:
Stock options and restricted stock units	107,000			132,000			120,000	113,000
Diluted (in shares)	15,159,442			16,124,198			15,430,164	16,380,756
Earnings Per Share, Basic [Abstract]
Basic (in usd per share)	$ 1.10			$ 1.33			$ 4.83	$ 5.50
Earnings Per Share, Diluted [Abstract]
Diluted (in usd per share)	$ 1.09			$ 1.32			$ 4.79	$ 5.46
Stock excluded from the calculation of net earnings per share (shares)	0						0	40,170
Document Period End Date							Jan. 31, 2025