Income Taxes - Components of Income Before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2019
Income before income taxes for continuing operations consists of the following components:
U.S. operations	$ 1,221,690	$ 1,035,902	$ 1,061,505
Foreign operations	66,059	22,389	40,894
Income before income taxes from continuing operations	$ 1,287,749	$ 1,058,291	$ 1,102,399