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. 29, 2024	Feb. 28, 2023	Feb. 29, 2024	Feb. 28, 2023
Basic earnings per share:
Net income	$ 498.6	$ 467.4	$ 1,310.5	$ 1,206.9
Weighted-average common shares outstanding	359.9	360.5	360.4	360.3
Basic earnings per share	$ 1.39	$ 1.30	$ 3.64	$ 3.35
Diluted earnings per share:
Net income	$ 498.6	$ 467.4	$ 1,310.5	$ 1,206.9
Weighted-average common shares outstanding	359.9	360.5	360.4	360.3
Dilutive effect of common share equivalents	1.8	1.8	1.8	2.0
Weighted-average common shares outstanding, assuming dilution	361.7	362.3	362.2	362.3
Diluted earnings per share	$ 1.38	$ 1.29	$ 3.62	$ 3.33
Weighted-average anti-dilutive common share equivalents	0.6	0.7	0.6	0.7