Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings
Beginning Balance (shares) at Apr. 30, 2021		36,949,878,000
Beginning Balance at Apr. 30, 2021	$ 1,932,679	$ 58,951	$ 1,873,728
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	119,159		119,159
Dividends declared	(12,680)		(12,680)
Exercise of stock options (in shares)		3,000,000
Exercise of stock options	133	$ 133
Share-based compensation (net of tax withholding on employee share-based awards) (shares)		149,368,000
Share-based compensation (net of tax withholding on employee share-based awards)	(8,626)	$ (8,626)
Ending Balance (shares) at Jul. 31, 2021		37,102,246,000
Ending Balance at Jul. 31, 2021	2,030,665	$ 50,458	1,980,207
Beginning Balance (shares) at Apr. 30, 2021		36,949,878,000
Beginning Balance at Apr. 30, 2021	1,932,679	$ 58,951	1,873,728
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	215,990
Ending Balance (shares) at Oct. 31, 2021		37,108,803,000
Ending Balance at Oct. 31, 2021	2,123,134	$ 59,214	2,063,920
Beginning Balance (shares) at Jul. 31, 2021		37,102,246,000
Beginning Balance at Jul. 31, 2021	2,030,665	$ 50,458	1,980,207
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	96,831		96,831
Dividends declared	(13,118)		(13,118)
Share-based compensation (net of tax withholding on employee share-based awards) (shares)		6,557,000
Share-based compensation (net of tax withholding on employee share-based awards)	8,756	$ 8,756
Ending Balance (shares) at Oct. 31, 2021		37,108,803,000
Ending Balance at Oct. 31, 2021	2,123,134	$ 59,214	2,063,920
Beginning Balance (shares) at Apr. 30, 2022		37,111,667,000
Beginning Balance at Apr. 30, 2022	2,240,838	$ 79,412	2,161,426
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	152,932		152,932
Dividends declared	(14,431)		(14,431)
Share-based compensation (net of tax withholding on employee share-based awards) (shares)		138,132,000
Share-based compensation (net of tax withholding on employee share-based awards)	707	$ 707
Ending Balance (shares) at Jul. 31, 2022		37,249,799,000
Ending Balance at Jul. 31, 2022	2,380,046	$ 80,119	2,299,927
Beginning Balance (shares) at Apr. 30, 2022		37,111,667,000
Beginning Balance at Apr. 30, 2022	2,240,838	$ 79,412	2,161,426
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	290,487
Ending Balance (shares) at Oct. 31, 2022		37,258,622,000
Ending Balance at Oct. 31, 2022	2,512,816	$ 89,669	2,423,147
Beginning Balance (shares) at Jul. 31, 2022		37,249,799,000
Beginning Balance at Jul. 31, 2022	2,380,046	$ 80,119	2,299,927
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	137,555		137,555
Dividends declared	(14,335)		(14,335)
Share-based compensation (net of tax withholding on employee share-based awards) (shares)		8,823,000
Share-based compensation (net of tax withholding on employee share-based awards)	9,550	$ 9,550
Ending Balance (shares) at Oct. 31, 2022		37,258,622,000
Ending Balance at Oct. 31, 2022	$ 2,512,816	$ 89,669	$ 2,423,147