Earnings Per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Aug. 31, 2022	Aug. 31, 2021
Basic earnings per share:
Net income	$ 351,689	$ 331,179
Less: income allocated to participating securities	1,520	1,765
Income available to common shareholders	$ 350,169	$ 329,414
Basic weighted average common shares outstanding (in shares)	101,428	103,295
Basic earnings per share (in dollars per share)	$ 3.45	$ 3.19
Diluted earnings per share:
Net income	$ 351,689	$ 331,179
Less: income allocated to participating securities	1,520	1,765
Income available to common shareholders	$ 350,169	$ 329,414
Basic weighted average common shares outstanding (in shares)	101,428	103,295
Effect of dilutive securities - employee stock options (in shares)	1,909	2,649
Diluted weighted average common shares outstanding (in shares)	103,337	105,944
Diluted earnings per share (in dollars per share)	$ 3.39	$ 3.11