Condensed Statements of Consolidated Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Shares	Additional Capital	Retained Income	Accumulated Other Comprehensive Income (Loss)
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	185.0			185.0
Other comprehensive income (loss)	2.4				2.4
Comprehensive income (loss)	187.4
Purchase of treasury shares	(2.6)	$ 0.0	(3.2)	0.6
Purchase of treasury shares, shares		(22,748)
Stock plans	5.4	$ 0.1	4.5	0.8
Stock plans, shares		236,997
Cash dividends declared	(114.6)			(114.6)
Balance at Jul. 31, 2024	7,769.5	$ 26.6	5,715.2	2,259.9	(232.2)
Balance, shares at Jul. 31, 2024		106,408,530
Balance at Apr. 30, 2025	$ 6,082.6	$ 26.6	5,738.7	501.8	(184.5)
Balance, shares at Apr. 30, 2025	106,400,000	106,425,081
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (43.9)			(43.9)
Other comprehensive income (loss)	2.0				2.0
Comprehensive income (loss)	(41.9)
Purchase of treasury shares	(4.6)	$ 0.0	(5.8)	1.2
Purchase of treasury shares, shares		(47,688)
Stock plans	6.5	$ 0.1	5.3	1.1
Stock plans, shares		309,721
Cash dividends declared	(116.7)			(116.7)
Balance at Jul. 31, 2025	$ 5,925.9	$ 26.7	$ 5,738.2	$ 343.5	$ (182.5)
Balance, shares at Jul. 31, 2025	106,700,000	106,687,114