Earnings Per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2023	Nov. 30, 2022	Nov. 30, 2023	Nov. 30, 2022
Basic earnings per share:
Net income	$ 374,613	$ 324,293	$ 759,698	$ 675,982
Less: net income allocated to participating securities	1,460	1,372	2,957	2,859
Net income available to common shareholders	$ 373,153	$ 322,921	$ 756,741	$ 673,123
Basic weighted average common shares outstanding (in shares)	101,667	101,637	101,781	101,530
Basic earnings per share (in dollars per share)	$ 3.67	$ 3.18	$ 7.43	$ 6.63
Diluted earnings per share:
Net income	$ 374,613	$ 324,293	$ 759,698	$ 675,982
Less: net income allocated to participating securities	1,460	1,372	2,957	2,859
Net income available to common shareholders	$ 373,153	$ 322,921	$ 756,741	$ 673,123
Basic weighted average common shares outstanding (in shares)	101,667	101,637	101,781	101,530
Effect of dilutive securities - employee stock options (in shares)	1,599	1,719	1,637	1,813
Diluted weighted average common shares outstanding (in shares)	103,266	103,356	103,418	103,343
Diluted earnings per share (in dollars per share)	$ 3.61	$ 3.12	$ 7.32	$ 6.51