Fair Value Measurement - Impact of Credit Adjustments (Details 6) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Impact of credit adjustments on earnings [Abstract]
Structured note credit adjustments	$ (835)	$ 927	$ 400
Credit Valuation Adjustment [Member]
Impact of credit adjustments on earnings [Abstract]
Derivative credit adjustments	2,698	(2,574)	(665)
Debit Valuation Adjustment [Member]
Impact of credit adjustments on earnings [Abstract]
Derivative credit adjustments	(590)	538	41
Structured note credit adjustments	$ (340)	$ 899	$ 468

This item represents the estimated amount of gains and losses from fair value changes included in earnings that are attributable to changes in the instrument-specific credit risk of liabilities with fair values that have been significantly affected during the reporting period by changes in the instrument-specific credit risk.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 30

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 19

-Subparagraph d(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Name:	us-gaap_FairValueOptionCreditRiskGainsLossesOnLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration