Statements of Consolidated Shareholders' Equity - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	$ 8,140.1	$ 8,124.8	$ 8,190.9
Balance, shares	106,458,317
Net income (loss)	$ (91.3)	631.7	876.3
Other comprehensive income (loss)	(1.8)	40.0	101.6
Comprehensive Income (Loss)	(93.1)	671.7	977.9
Purchase of treasury shares	(371.1)	(270.4)	(678.4)
Stock plans	46.1	39.9	34.6
Cash dividends declared	(431.2)	(425.9)	(400.2)
Other			0.0
Balance	$ 7,290.8	$ 8,140.1	8,124.8
Balance, shares	104,398,618	106,458,317
Common Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	$ 26.6	$ 27.1	$ 29.0
Balance, shares	106,458,317	108,339,057	114,072,726
Purchase of treasury shares	$ (0.6)	$ (0.5)	$ (1.5)
Purchase of treasury shares, shares	(2,423,196)	(2,059,083)	(5,834,904)
Stock plans	$ 0.1	$ 0.0	$ 0.1
Stock plans, shares	363,497	178,343	101,235
Other			$ (0.5)
Balance	$ 26.1	$ 26.6	$ 27.1
Balance, shares	104,398,618	106,458,317	108,339,057
Additional Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	$ 5,457.9	$ 5,527.6	$ 5,794.1
Purchase of treasury shares	(132.2)	(109.6)	(301.5)
Stock plans	46.1	39.9	34.5
Other			0.5
Balance	5,371.8	5,457.9	5,527.6
Retained Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	2,893.0	2,847.5	2,746.8
Net income (loss)	(91.3)	631.7	876.3
Purchase of treasury shares	(238.3)	(160.3)	(375.4)
Stock plans	(0.1)
Cash dividends declared	(431.2)	(425.9)	(400.2)
Other			0.0
Balance	2,132.1	2,893.0	2,847.5
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	(237.4)	(277.4)	(379.0)
Other comprehensive income (loss)	(1.8)	40.0	101.6
Balance	$ (239.2)	$ (237.4)	$ (277.4)