Investment Securities (Gains (Losses) on Sales of Securities Available for Sale) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011
Investment Securities Disclosure [Abstract]
Proceeds	$ 8,553	$ 17,564
Gross Gains	169	336
Gross Losses	(10)	(149)
Net Gains	159	187
Tax Expense	$ 56	$ 66

The net cash paid (received) associated with the acquisition or disposal of all investments, including securities and other assets.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3098-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3095-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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