Purchased Impaired Loans (Purchased Impaired Loans) (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 6,927	$ 7,780	$ 8,130
Outstanding Balance	7,947	9,723
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	162	249
Outstanding Balance	282	408
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	795	1,153
Outstanding Balance	869	1,391
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	2,810	3,024
Outstanding Balance	3,568	4,121
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	3,160	3,354
Outstanding Balance	$ 3,228	$ 3,803

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 03-3

-Paragraph 16

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6891207&loc=d3e13503-111538

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Name:	us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesOutstandingBalance
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant