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	$ 139,436
BBB- to BBB+	15,949
BB+ or lower	353,564
Unrated	197,264
Total OTC derivative assets included in Financial instruments owned, at fair value	$ 706,213

Fair value of OTC derivatives assets, counterparty credit quality A- or higher.

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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+.

No definition available.

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

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OTC Derivative Assets Included In Financial Instruments Owned.

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