Derivative Financial Instruments (Details Textuals) (USD $) In Millions	Aug. 31, 2011	Nov. 30, 2010
Derivative Financial Instruments (Textuals) [Abstract]
Exchange traded derivative assets	$ 308.0
Cash collateral received	32.2
Exchange traded derivative liabilities	13.7
Cash collateral pledged	342.3
Fair value of derivative instruments in a liability position	239.0	51.8
Collateral posted for derivative instruments in a liability position	221.5	44.9
Additional collateral required for derivative instruments in a liability position	$ 17.5	$ 6.5

Collateral required to be post if credit-risk-related contingent features underlying the agreements are triggered.

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Cash collateral pledged on option and swap over the counter contracts.

Cash collateral received on option and swap over the counter contracts.

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Collateral posted on credit-risk-related contingent features that are in a liability position.

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Derivative Financial Instruments.

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Exchange traded derivative assets.

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Exchange traded derivative liabilities.

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Aggregate fair value of all derivative instruments with credit-risk-related contingent features that are in a liability position.

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