Derivative Instruments and Hedging Activities - Schedule of derivatives offsetting (Details) - USD ($) $ in Thousands	May 31, 2023	May 31, 2022
Derivative [Line Items]
Derivative asset, fair value, amount not offset against collateral	$ 460,762	$ 222,042
Derivative liability, fair value, amount not offset against collateral	115,074	128,282
Interest rate swaps
Derivative [Line Items]
Derivative assets	460,762	222,042
Derivative Asset, Fair Value, Gross Liability	0	0
Derivative asset, fair value, amount not offset against collateral	460,762	222,042
Derivative, Collateral, Obligation to Return Securities	112,047	103,228
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative asset, fair value, amount offset against collateral	348,715	118,814
Derivative Liability, Fair Value, Gross Liability	115,074	128,282
Derivative Liability, Fair Value, Gross Asset	0	0
Derivative liability, fair value, amount not offset against collateral	115,074	128,282
Derivative, Collateral, Right to Reclaim Securities	112,047	103,228
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative liability, fair value, amount offset against collateral	$ 3,027	$ 25,054