Fair Value Measurement - Impact of Credit Adjustments (Details 6) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Impact of credit adjustments on earnings
Structured note credit adjustments	$ 33	$ (419)
Credit Valuation Adjustment [Member]
Impact of credit adjustments on earnings
Derivative credit adjustments	332	1,461
Debit Valuation Adjustment
Impact of credit adjustments on earnings
Derivative credit adjustments	(5)	(439)
Structured note credit adjustments	$ 131	$ (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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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