Derivatives Offsetting (Details) - USD ($) $ in Thousands	Nov. 30, 2019	May 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Asset, Fair Value, Gross Asset	$ 53,174	$ 41,179
Derivative Asset, Fair Value, Gross Liability	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	53,174	41,179
Derivative, Collateral, Obligation to Return Securities	53,174	41,176
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	3
Derivative liabilities	591,027	391,724
Derivative Liability, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	591,027	391,724
Derivative, Collateral, Right to Reclaim Securities	53,174	41,176
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 537,853	$ 350,548

Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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