Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings
Beginning Balance (shares) at Apr. 30, 2022		37,111,667
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
Share-based compensation (net of tax withholding on employee share-based awards)	707	$ 707
Ending Balance (shares) at Jul. 31, 2022		37,249,799
Ending Balance at Jul. 31, 2022	2,380,046	$ 80,119	2,299,927
Beginning Balance (shares) at Apr. 30, 2022		37,111,667
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
Ending Balance at Oct. 31, 2022	2,512,816	$ 89,669	2,423,147
Beginning Balance (shares) at Jul. 31, 2022		37,249,799
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
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
Ending Balance at Oct. 31, 2022	2,512,816	$ 89,669	2,423,147
Beginning Balance (shares) at Apr. 30, 2023		37,263,248
Beginning Balance at Apr. 30, 2023	2,660,666	$ 110,037	2,550,629
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	169,237		169,237
Dividends declared	(16,214)		(16,214)
Repurchase of common stock		(123,569)
Repurchase of common stock	(29,893)	$ (29,893)
Share-based compensation (net of tax withholding on employee share-based awards) (shares)		126,774
Share-based compensation (net of tax withholding on employee share-based awards)	(7,501)	$ (7,501)
Ending Balance (shares) at Jul. 31, 2023		37,266,453
Ending Balance at Jul. 31, 2023	2,776,295	$ 72,643	2,703,652
Beginning Balance (shares) at Apr. 30, 2023		37,263,248
Beginning Balance at Apr. 30, 2023	2,660,666	$ 110,037	2,550,629
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	328,019
Ending Balance (shares) at Oct. 31, 2023		37,164,195
Ending Balance at Oct. 31, 2023	2,897,391	$ 51,117	2,846,274
Beginning Balance (shares) at Jul. 31, 2023		37,266,453
Beginning Balance at Jul. 31, 2023	2,776,295	$ 72,643	2,703,652
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	158,782		158,782
Dividends declared	(16,160)		(16,160)
Repurchase of common stock		(110,481)
Repurchase of common stock	(30,391)	$ (30,391)
Share-based compensation (net of tax withholding on employee share-based awards) (shares)		8,223
Share-based compensation (net of tax withholding on employee share-based awards)	8,865	$ 8,865
Ending Balance (shares) at Oct. 31, 2023		37,164,195
Ending Balance at Oct. 31, 2023	$ 2,897,391	$ 51,117	$ 2,846,274