Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Jan. 31, 2024	Oct. 31, 2023	Jul. 31, 2023	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022	Jan. 31, 2024	Jan. 31, 2023
Computation of basic and diluted earnings per share of common stock
Net income	$ 51,905	$ 80,957	$ 86,830	$ 64,775	$ 103,153	$ 89,470	$ 219,692	$ 257,398
Basic earnings per common share:
Basic weighted average common shares outstanding (in shares)	39,864			41,578			40,360	42,119
Basic earnings per common share (in dollars per share)	$ 1.30			$ 1.56			$ 5.44	$ 6.11
Diluted earnings per common share:
Basic weighted average common shares outstanding (in shares)	39,864			41,578			40,360	42,119
Add: Common Stock Equivalents (in shares)	648			654			666	693
Diluted weighted average common shares outstanding (in shares)	40,512			42,232			41,026	42,812
Diluted earnings per common share (in dollars per share)	$ 1.28			$ 1.53			$ 5.35	$ 6.01
Shares were not included in the calculation of Diluted loss per common share
Anti-dilutive shares (in shares)	0			0			0	0