Derivative Financial Instruments - Counterparty Credit Quality with Respect to Fair Value of OTC Derivatives Assets (Details) $ in Thousands	Aug. 31, 2020 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
A- or higher	$ 113,989
BBB- to BBB	15,949
BB or lower	353,564
Unrated	197,264
Total OTC derivative assets included in Financial instruments owned	$ 680,766

Fair value of OTC derivatives assets, counterparty credit quality BB or lower.

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Fair value of OTC derivatives assets, counterparty credit quality BBB- to BBB.

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Fair value of OTC derivatives assets, counterparty credit quality unrated.

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Fair Value Of Over Counter Derivatives Assets Counterparty Credit QualityA Or Higher

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OTC Derivative Assets Included In Financial Instruments Owned.

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