Earnings Per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019
Basic Earnings per Share from Continuing Operations
Income from continuing operations	$ 234,520	$ 200,923	$ 731,775	$ 656,464
Less: income from continuing operations allocated to participating securities	2,193	2,783	6,864	8,977
Income from continuing operations available to common shareholders	$ 232,327	$ 198,140	$ 724,911	$ 647,487
Basic weighted average common shares outstanding (in shares)	104,245	105,080	103,840	106,147
Basic earnings per share from continuing operations (in dollars per share)	$ 2.23	$ 1.89	$ 6.98	$ 6.10
Diluted Earnings per Share from Continuing Operations
Income from continuing operations	$ 234,520	$ 200,923	$ 731,775	$ 656,464
Less: income from continuing operations allocated to participating securities	2,193	2,783	6,864	8,977
Income from continuing operations available to common shareholders	$ 232,327	$ 198,140	$ 724,911	$ 647,487
Basic weighted average common shares outstanding (in shares)	104,245	105,080	103,840	106,147
Effect of dilutive securities - employee stock options (in shares)	3,343	3,082	3,440	3,436
Diluted weighted average common shares outstanding (in shares)	107,588	108,162	107,280	109,583
Diluted earnings per share from continuing operations (in dollars per share)	$ 2.16	$ 1.83	$ 6.76	$ 5.91