Derivative Instruments and Hedging Activities - Schedule of derivative instruments on consolidated balance sheets (Details) - USD ($) $ in Thousands	May 31, 2023	May 31, 2022
Derivative Asset [Abstract]
Derivative assets, fair value	$ 460,762	$ 222,042
Derivative assets, notional amount	5,405,274	4,791,699
Derivative Liability [Abstract]
Derivative liabilities, fair value	115,074	128,282
Derivative liabilities, notional amount	2,410,840	3,269,932
Interest rate swaps
Derivative Asset [Abstract]
Derivative assets, fair value	460,762	222,042
Derivative assets, notional amount	5,405,274	4,791,699
Derivative Liability [Abstract]
Derivative liabilities, fair value	115,074	128,282
Derivative liabilities, notional amount	2,410,840	3,269,932
Derivative, notional amount	7,816,114	8,061,631
Forward pay-fixed swaps
Derivative Liability [Abstract]
Derivative, notional amount	$ 195,845	$ 124,000