Statements of Consolidated Shareholders' Equity - USD ($) $ in Millions	Total	Common Shares	Additional Capital	Retained Income	Accumulated Other Comprehensive Income (Loss)
Balance at Apr. 30, 2022	$ 8,140.1	$ 26.6	$ 5,457.9	$ 2,893.0	$ (237.4)
Balance, shares at Apr. 30, 2022		106,458,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(91.3)			(91.3)
Other comprehensive income (loss)	(1.8)				(1.8)
Comprehensive income (loss)	(93.1)
Purchase of treasury shares	(371.1)	$ (0.6)	(132.2)	(238.3)
Purchase of treasury shares, shares		(2,423,196)
Stock plans	46.1	$ 0.1	46.1	(0.1)
Stock plans, shares		363,497
Cash dividends declared	(431.2)			(431.2)
Balance at Apr. 30, 2023	7,290.8	$ 26.1	5,371.8	2,132.1	(239.2)
Balance, shares at Apr. 30, 2023		104,398,618
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	744.0			744.0
Other comprehensive income (loss)	4.6				4.6
Comprehensive income (loss)	748.6
Purchase of treasury shares	(376.4)	$ (0.7)	(132.8)	(242.9)
Purchase of treasury shares, shares		(2,416,945)
Issuance of shares for acquisition	450.2	$ 1.0	449.2
Issuance of shares for acquisition, shares		3,989,915
Stock plans	24.7	$ 0.1	25.7	(1.1)
Stock plans, shares		222,693
Cash dividends declared	(444.0)			(444.0)
Balance at Apr. 30, 2024	$ 7,693.9	$ 26.5	5,713.9	2,188.1	(234.6)
Balance, shares at Apr. 30, 2024	106,194,281	106,194,281
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (1,230.8)			(1,230.8)
Other comprehensive income (loss)	50.1				50.1
Comprehensive income (loss)	(1,180.7)
Purchase of treasury shares	(2.9)	$ 0.0	(3.7)	0.8
Purchase of treasury shares, shares		(29,747)
Stock plans	29.4	$ 0.1	28.5	0.8
Stock plans, shares		260,547
Cash dividends declared	(457.1)			(457.1)
Balance at Apr. 30, 2025	$ 6,082.6	$ 26.6	$ 5,738.7	$ 501.8	$ (184.5)
Balance, shares at Apr. 30, 2025	106,425,081	106,425,081