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, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Basic earnings per share:
Net income	$ 430.7	$ 350.5	$ 1,096.4	$ 834.5
Weighted-average common shares outstanding	360.9	360.6	360.6	359.8
Basic earnings per share	$ 1.19	$ 0.97	$ 3.04	$ 2.32
Diluted earnings per share:
Net income	$ 430.7	$ 350.5	$ 1,096.4	$ 834.5
Weighted-average common shares outstanding	360.9	360.6	360.6	359.8
Dilutive effect of common share equivalents	2.5	2.2	2.5	2.2
Weighted-average common shares outstanding, assuming dilution	363.4	362.8	363.1	362.0
Diluted earnings per share	$ 1.19	$ 0.97	$ 3.02	$ 2.31
Weighted-average anti-dilutive common share equivalents	0.3		0.3	0.7