Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2023	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022	Apr. 30, 2022	Jan. 31, 2022	Oct. 31, 2021	Jul. 31, 2021	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Earnings Per Share [Abstract]
Net income	$ 75,593	$ 64,775	$ 103,153	$ 89,470	$ 76,496	$ 61,383	$ 74,361	$ 61,202	$ 332,991	$ 273,442	$ 105,560
Basic earnings per common share:
Basic weighted average common shares outstanding (in shares)	41,239	41,578	42,232	42,549	42,977	43,094	43,135	43,089	41,904	43,075	42,765
Basic earnings per common share (in dollars per share)	$ 1.83	$ 1.56	$ 2.44	$ 2.10	$ 1.78	$ 1.42	$ 1.72	$ 1.42	$ 7.95	$ 6.35	$ 2.47
Diluted earnings per common share:
Basic weighted average common shares outstanding (in shares)	41,239	41,578	42,232	42,549	42,977	43,094	43,135	43,089	41,904	43,075	42,765
Add: Common Stock Equivalents									688	823	578
Diluted weighted average common shares outstanding (in shares)	41,913	42,232	42,887	43,317	43,776	43,945	43,894	43,972	42,592	43,898	43,343
Diluted earnings per common share (in dollars per share)	$ 1.80	$ 1.53	$ 2.41	$ 2.07	$ 1.75	$ 1.40	$ 1.69	$ 1.39	$ 7.82	$ 6.23	$ 2.44
Shares were not included in the calculation of Diluted loss per common share
Anti-dilutive shares (in shares)									400		300