Investment Securities (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Schedule of Available for Sale Securities by Type
Cost	$ 9,029	$ 13,937
Gross Unrealized Gains	345	444
Gross Unrealized Losses	(105)	(371)
Investment securities	9,269	14,010
U.S. States and Political Subdivisions Debt Securities [Member]
Schedule of Available for Sale Securities by Type
Cost	5,205	6,140
Gross Unrealized Gains	82	24
Gross Unrealized Losses	(102)	(367)
Investment securities	5,185	5,797
U.S. Government agency obligations [Member]
Schedule of Available for Sale Securities by Type
Cost	352	3,402
Gross Unrealized Gains	3	12
Gross Unrealized Losses	0	(1)
Investment securities	355	3,413
U.S. Government treasury obligations [Member]
Schedule of Available for Sale Securities by Type
Cost	1,932	2,450
Gross Unrealized Gains	11	6
Gross Unrealized Losses	0	0
Investment securities	1,943	2,456
Corporate debt securities [Member]
Schedule of Available for Sale Securities by Type
Cost	1,006	1,431
Gross Unrealized Gains	11	15
Gross Unrealized Losses	(3)	(1)
Investment securities	1,014	1,445
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available for Sale Securities by Type
Cost	272	272
Gross Unrealized Gains	16	6
Gross Unrealized Losses	0	(2)
Investment securities	288	276
Equity securities [Member]
Schedule of Available for Sale Securities by Type
Cost	98	98
Gross Unrealized Gains	215	377
Gross Unrealized Losses	0	0
Investment securities	313	475
Foreign government bonds and obligations [Member]
Schedule of Available for Sale Securities by Type
Cost	107	95
Gross Unrealized Gains	6	4
Gross Unrealized Losses	0	0
Investment securities	113	99
Availabe For Sale Securities Other [Member]
Schedule of Available for Sale Securities by Type
Cost	57	49
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	0
Investment securities	$ 58	$ 49

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15E

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 22

-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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-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 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-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 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

-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 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 14

-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 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-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 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6379932&loc=d3e22054-111558

+ Details