Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Oct. 31, 2024	Jul. 31, 2024	Oct. 31, 2023	Jul. 31, 2023	Oct. 31, 2024	Oct. 31, 2023
Computation of basic and diluted earnings per share of common stock
Net income	$ 53,536	$ 57,248	$ 80,957	$ 86,830	$ 110,784	$ 167,787
Basic earnings per common share:
Basic weighted average common shares outstanding (in shares)	39,126		40,466		39,334	40,608
Basic earnings per common share (in dollars per share)	$ 1.37		$ 2.00		$ 2.82	$ 4.13
Diluted earnings per common share:
Basic weighted average common shares outstanding (in shares)	39,126		40,466		39,334	40,608
Add: Common Stock Equivalents (in shares)	577		622		630	674
Diluted weighted average common shares outstanding (in shares)	39,703		41,088		39,964	41,282
Diluted earnings per common share (in dollars per share)	$ 1.35		$ 1.97		$ 2.77	$ 4.06
Shares were not included in the calculation of Diluted loss per common share
Anti-dilutive shares (in shares)	0		0		0	0