Note 15 - Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2023	Aug. 31, 2022
Balance	$ 3,329,943	$ 4,441,366
Other comprehensive loss	3,209	(62,817)
Balance	3,401,556	4,563,182
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(46,610)	54,413
Other comprehensive loss	3,049	(56,443)
Balance	(43,561)	(2,030)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balance	0	(75,177)
Other comprehensive loss	0	(2,525)
Balance	0	(77,702)
Unrealized Loss on Available for Sale Debt Securities [Member]
Balance	(46,610)	(20,764)
Other comprehensive loss	3,049	(58,968)
Balance	$ (43,561)	$ (79,732)