Earnings Per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020
Basic earnings per share:
Income from continuing operations	$ 258,384	$ 234,520	$ 843,246	$ 731,775
Less: income from continuing operations allocated to participating securities	1,894	2,193	5,908	6,864
Income from continuing operations available to common shareholders	$ 256,490	$ 232,327	$ 837,338	$ 724,911
Basic weighted average common shares outstanding (in shares)	105,264	104,245	104,782	103,840
Basic earnings per share from continuing operations (in dollars per share)	$ 2.44	$ 2.23	$ 7.99	$ 6.98
Diluted earnings per share:
Income from continuing operations	$ 258,384	$ 234,520	$ 843,246	$ 731,775
Less: income from continuing operations allocated to participating securities	1,894	2,193	5,908	6,864
Income from continuing operations available to common shareholders	$ 256,490	$ 232,327	$ 837,338	$ 724,911
Basic weighted average common shares outstanding (in shares)	105,264	104,245	104,782	103,840
Effect of dilutive securities - employee stock options (in shares)	2,732	3,343	2,914	3,440
Diluted weighted average common shares outstanding (in shares)	107,996	107,588	107,696	107,280
Diluted earnings per share from continuing operations (in dollars per share)	$ 2.37	$ 2.16	$ 7.78	$ 6.76