Basic and Diluted Earnings Per Share (Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Basic earnings per share:
Net income	$ 467.4	$ 430.7	$ 1,206.9	$ 1,096.4
Weighted-average common shares outstanding	360.5	360.9	360.3	360.6
Basic earnings per share	$ 1.30	$ 1.19	$ 3.35	$ 3.04
Diluted earnings per share:
Net income	$ 467.4	$ 430.7	$ 1,206.9	$ 1,096.4
Weighted-average common shares outstanding	360.5	360.9	360.3	360.6
Dilutive effect of common share equivalents	1.8	2.5	2.0	2.5
Weighted-average common shares outstanding, assuming dilution	362.3	363.4	362.3	363.1
Diluted earnings per share	$ 1.29	$ 1.19	$ 3.33	$ 3.02
Weighted-average anti-dilutive common share equivalents	0.7	0.3	0.7	0.3