Contingent Liabilities and Guarantees (Details) (USD $)	6 Months Ended
Jun. 30, 2011
Madoff related claims
Investment losses of Austin, an investment subsidiary, max limit	$ 186,000,000
Insurance for lawsuits and arbitration proceeding allege	25,000,000
Standby letters of credit
Remaining Weighted Average Life of Standby Letters of Credit	2.1
Remaining actual life	from less than one year to as many as eight years
Recourse agreement with FNMA
Weighted average remaining term for outstanding commercial mortgage loans	5.9
Unpaid principal balance outstanding of loans sold	2,600,000,000
Potential undiscounted future payments, maximum limit	one-third of principal balance of loan outstanding
Written put options
Weighted average life of written put options	1.5
Default guarantees
Terms of default guarantees range	from less than one year to as many as eight years
Other Off-Balance Sheet Risk
Obligation for credit market disruption	51,000,000
Expiration date of liquidity facility	May 15, 2013
Aggregate amount available to be drawn of current commitments	23,000,000
Guarantees
Maximum potential undiscounted future payments	12,476,000,000
Liability recorded	179,000,000
Maximum [Member] \| Risk Level, Low [Member]
Additional Contingent Liabilities And Guarantees (Textuals) [Abstract]
Guarantee Obligations	30.00%
Maximum [Member] \| Risk Level, Medium [Member]
Additional Contingent Liabilities And Guarantees (Textuals) [Abstract]
Guarantee Obligations	70.00%
Maximum [Member] \| Risk Level, High [Member]
Additional Contingent Liabilities And Guarantees (Textuals) [Abstract]
Guarantee Obligations	100.00%
Minimum [Member] \| Risk Level, Low [Member]
Additional Contingent Liabilities And Guarantees (Textuals) [Abstract]
Guarantee Obligations	0.00%
Minimum [Member] \| Risk Level, Medium [Member]
Additional Contingent Liabilities And Guarantees (Textuals) [Abstract]
Guarantee Obligations	31.00%
Minimum [Member] \| Risk Level, High [Member]
Additional Contingent Liabilities And Guarantees (Textuals) [Abstract]
Guarantee Obligations	71.00%
Standby letters of credit [Member]
Guarantees
Maximum potential undiscounted future payments	9,913,000,000
Liability recorded	55,000,000
Recourse agreement with FNMA [Member]
Guarantees
Maximum potential undiscounted future payments	841,000,000
Liability recorded	16,000,000
Return guarantee agreement with LIHTC investors [Member]
Guarantees
Maximum potential undiscounted future payments	65,000,000
Liability recorded	65,000,000
Return guarantee agreement with LIHTC investors
Compliance period of property	15 years
Expiration of Guarantees	Extend through 2019
Written put options [Member]
Guarantees
Maximum potential undiscounted future payments	1,594,000,000
Liability recorded	41,000,000
Default guarantees [Member]
Guarantees
Maximum potential undiscounted future payments	63,000,000
Liability recorded	$ 2,000,000

Additional Contingent Liabilities And Guarantees Textuals Abstract.

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- Definition

Compliance Period Of Property.

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- Definition

Default guarantees.

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- Definition

Expiration date of liquidity facility.

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- Definition

Expiration Of Guarantees.

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- Definition

Guarantees Abstract.

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- Definition

Investment losses of institutional customer base.

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Period Type:	instant

- Definition

Madoff related claims.

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- Definition

Obligation For Credit Market Disruption.

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Balance Type:	credit
Period Type:	instant

- Definition

Other Off-Balance Sheet Risk.

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- Definition

Potential undiscounted future payments maximum limit.

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- Definition

Recourse agreement with FNMA.

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- Definition

Remaining Actual Life Letters Of Credit.

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Remaining Weighted Average Life of Standby Letters of Credit.

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- Definition

Return guarantee agreement.

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- Definition

Self insurance deductible.

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- Definition

Standby letters of credit.

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Terms of default guarantees range.

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Weighted average life of written put options.

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Weighted Average Remaining Term For Outstanding Commercial Mortgage Loans.

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- Definition

Written Put Options.

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 45
-Paragraph 13
-Subparagraph c

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- Definition

Indicates, if estimable, (as a percentage) the approximate extent to which the proceeds from liquidation of any assets held either as collateral or by third parties would be expected to cover the maximum potential amount of future payments under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 45
-Paragraph 13

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 45
-Paragraph 13
-Subparagraph b

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- Definition

The carrying amount of the long-term purchase obligation as of the balance sheet date, which equals the sum of all payments due.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 47
-Paragraph 10
-Subparagraph b

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 47
-Paragraph 6

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- Definition

The floor amount as of the balance sheet date that the entity must expend to satisfy the terms of the disclosed arrangements (excluding long-term commitments) in which the entity has agreed to expend funds to procure goods or services from a supplier, or to commit resources to supply goods or services to a customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 25
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 17
-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 19
-Article 7

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