Derivatives and Hedging (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2012
Interest Rate Risk Management
Collateral received from counterparties	6
Cash flow hedges
Foreign Exchange Risk Management
Foreign currency exposures, maximum average hedging period	2 years
Foreign currency exposures, maximum hedging period	5 years
Interest Rate Risk Management
Interest rate fluctuations, maximum hedging period	2 years
Net investment hedges
Foreign Exchange Risk Management
Foreign currency exposures, maximum hedging period	2 years
Not designated as hedging instrument
Foreign Exchange Risk Management
Foreign currency exposures, maximum hedging period	1 year

Maximum average contract period for foreign currency exchange rate derivatives.

No definition available.

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- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future exchange rates on its net investments in foreign operations.

+ References

No definition available.

+ Details

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- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future exchange rates using instruments not designated as accounting hedges.

+ References

No definition available.

+ Details

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- Definition

Fair value of financial instrument held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions where counterparty does not have the right to re-pledge such.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 17

-Subparagraph a(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6862952&loc=SL6226653-111729

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS140-4/FIN46(R)-8

-Paragraph B6

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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- Details

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- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph b(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6887037&loc=d3e80748-113994

+ Details

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- Definition

+ References

+ Details

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