Earnings Per Share (Schedule Of Earnings (Loss) Per Share, Basic And Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Earnings Per Share [Abstract]
Net income (loss)	$ 93,723	$ (29,722)	$ 61,193
Denominator for basic earnings per common share - weighted-average shares	16,614	16,592	16,970
Stock options and restricted stock units	71	0	67
Denominator for diluted earnings (loss) per common share - weighted-average shares and assumed conversions	16,685	16,592	17,037
Net earnings (loss) per share, Basic (usd per share)	$ 5.64	$ (1.79)	$ 3.61
Net earnings (loss) per share, Diluted (usd per share)	$ 5.62	$ (1.79)	$ 3.59