Earnings Per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Basic earnings per share:
Net income	$ 324,293	$ 294,669	$ 675,982	$ 625,848
Less: net income allocated to participating securities	1,372	1,495	2,859	3,179
Net income available to common shareholders	$ 322,921	$ 293,174	$ 673,123	$ 622,669
Basic weighted average common shares outstanding (in shares)	101,637	103,646	101,530	103,463
Basic earnings per share (in dollars per share)	$ 3.18	$ 2.83	$ 6.63	$ 6.02
Diluted earnings per share:
Net income	$ 324,293	$ 294,669	$ 675,982	$ 625,848
Less: net income allocated to participating securities	1,372	1,495	2,859	3,179
Net income available to common shareholders	$ 322,921	$ 293,174	$ 673,123	$ 622,669
Basic weighted average common shares outstanding (in shares)	101,637	103,646	101,530	103,463
Effect of dilutive securities - employee stock options (in shares)	1,719	2,476	1,813	2,563
Diluted weighted average common shares outstanding (in shares)	103,356	106,122	103,343	106,026
Diluted earnings per share (in dollars per share)	$ 3.12	$ 2.76	$ 6.51	$ 5.87