Goodwill and Other Intangible Assets - Key Economic Assumptions (Details 5) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
Sep. 30, 2012	Dec. 31, 2011
Key economic assumptions used to determine the fair value of the Firm's Mortgage Servicing Rights (MSRs) [Abstract]
Weighted-average prepayment speed assumption (CPR)	15.60%	18.07%
Impact on fair value of 10% adverse change	$ (543)	$ (585)
Impact on fair value of 20% adverse change	(1,040)	(1,118)
Weighted-average option adjusted spread	7.82%	7.83%
Impact on fair value of 100 basis points adverse change	(270)	(269)
Impact on fair value of 200 basis points adverse change	$ (521)	$ (518)

The hypothetical financial impact of a 10 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

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The hypothetical financial impact of a 20 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

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- Definition

A specified percentage variance in the prepayment speed assumption in the determination of fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities).

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