Earnings Per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Basic earnings per share:
Net income	$ 325,827	$ 315,448	$ 1,001,809	$ 941,296
Less: net income allocated to participating securities	1,351	1,581	4,155	4,706
Net income available to common shareholders	$ 324,476	$ 313,867	$ 997,654	$ 936,590
Basic weighted average common shares outstanding (in shares)	101,714	103,388	101,589	103,438
Basic earnings per share (in dollars per share)	$ 3.19	$ 3.04	$ 9.82	$ 9.05
Diluted earnings per share:
Net income	$ 325,827	$ 315,448	$ 1,001,809	$ 941,296
Less: net income allocated to participating securities	1,351	1,581	4,155	4,706
Net income available to common shareholders	$ 324,476	$ 313,867	$ 997,654	$ 936,590
Basic weighted average common shares outstanding (in shares)	101,714	103,388	101,589	103,438
Effect of dilutive securities - employee stock options (in shares)	1,704	2,253	1,774	2,458
Diluted weighted average common shares outstanding (in shares)	103,418	105,641	103,363	105,896
Diluted earnings per share (in dollars per share)	$ 3.14	$ 2.97	$ 9.65	$ 8.84