Net Income Per Common Share - Schedule of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Basic
Net income	$ 339,790	$ 312,900	$ 263,846
Weighted average shares outstanding-basic (shares)	37,158,898	37,092,273	36,956,115
Basic earnings per common share (in Dollars per share)	$ 9.14	$ 8.44	$ 7.14
Diluted
Net income	$ 339,790	$ 312,900	$ 263,846
Weighted average shares outstanding-basic (shares)	37,158,898	37,092,273	36,956,115
Plus effect of stock options and restricted stock units (shares)	197,800	263,865	229,713
Weighted-average shares outstanding-diluted (shares)	37,356,698	37,356,138	37,185,828
Diluted earnings per common share (in Dollars per share)	$ 9.10	$ 8.38	$ 7.10