Investment Securities (Schedule Of Contractual Maturities Of Debt Securities) (Details) (USD $) In Millions	Sep. 30, 2011
Available for sale, Under 1 Year	$ 9,153
Available for sale, 1 to 5 Years	25,824
Available for sale, 6 to 10 Years	30,080
Available for sale, Over 10 Years	30,721
Held to maturity, Under 1 Year	1,710
Held to maturity, 1 to 5 Years	2,938
Held to maturity, 6 to 10 Years	699
Held to maturity, Over 10 Years	4,671
Asset-Backed Securities [Member] \| U.S. Treasury And Federal Agencies [Member]
Held to maturity, Over 10 Years	38
Sub-Prime [Member] \| U.S. Treasury And Federal Agencies [Member]
Available for sale, Under 1 Year	781
Available for sale, 1 to 5 Years	153
Available for sale, 6 to 10 Years	10
Available for sale, Over 10 Years	542
U.S. Treasury And Federal Agencies [Member]
Available for sale, Under 1 Year	3,009
Available for sale, 1 to 5 Years	12,892
Available for sale, 6 to 10 Years	11,251
Available for sale, Over 10 Years	4,700
U.S. Treasury And Federal Agencies [Member] \| Direct Obligations [Member]
Available for sale, Under 1 Year	1,966
Available for sale, 1 to 5 Years	1,095
Available for sale, 6 to 10 Years	1,589
Available for sale, Over 10 Years	715
U.S. Treasury And Federal Agencies [Member] \| Student Loans [Member]
Available for sale, Under 1 Year	134
Available for sale, 1 to 5 Years	4,715
Available for sale, 6 to 10 Years	7,883
Available for sale, Over 10 Years	3,801
U.S. Treasury And Federal Agencies [Member] \| Credit Cards [Member]
Available for sale, Under 1 Year	1,961
Available for sale, 1 to 5 Years	6,294
Available for sale, 6 to 10 Years	2,240
U.S. Treasury And Federal Agencies [Member] \| Other Asset-Backed Securities [Member]
Available for sale, Under 1 Year	133
Available for sale, 1 to 5 Years	1,730
Available for sale, 6 to 10 Years	1,118
Available for sale, Over 10 Years	357
U.S. Treasury And Federal Agencies [Member] \| Mortgage-Backed Securities [Member]
Available for sale, Under 1 Year	3
Available for sale, 1 to 5 Years	1,672
Available for sale, 6 to 10 Years	10,407
Available for sale, Over 10 Years	15,944
Held to maturity, 1 to 5 Years	67
Held to maturity, 6 to 10 Years	73
Held to maturity, Over 10 Years	159
Asset-Backed Securities [Member] \| Non-U.S. Debt Securities [Member]
Available for sale, Under 1 Year	53
Available for sale, 1 to 5 Years	949
Available for sale, 6 to 10 Years	2,320
Available for sale, Over 10 Years	459
Held to maturity, Under 1 Year	47
Held to maturity, 1 to 5 Years	292
Held to maturity, 6 to 10 Years	235
Non-U.S. Debt Securities [Member]
Held to maturity, Under 1 Year	1,295
Held to maturity, 1 to 5 Years	1,026
Held to maturity, 6 to 10 Years	279
Held to maturity, Over 10 Years	3,344
Non-U.S. Debt Securities [Member] \| Non-U.S. Debt Securities [Member]
Available for sale, Under 1 Year	3,398
Available for sale, 1 to 5 Years	3,848
Available for sale, 6 to 10 Years	2,704
Available for sale, Over 10 Years	7,336
Non-U.S. Debt Securities [Member] \| Other Non-U.S. Debt Securities [Member]
Available for sale, Under 1 Year	38
Available for sale, 1 to 5 Years	942
Available for sale, 6 to 10 Years	118
Available for sale, Over 10 Years	1
Held to maturity, 1 to 5 Years	176
Held to maturity, Over 10 Years	17
Non-U.S. Debt Securities [Member] \| Government Securities [Member]
Available for sale, Under 1 Year	3,014
Held to maturity, Under 1 Year	3
Non-U.S. Debt Securities [Member] \| Mortgage-Backed Securities [Member]
Available for sale, Under 1 Year	293
Available for sale, 1 to 5 Years	1,957
Available for sale, 6 to 10 Years	266
Available for sale, Over 10 Years	6,876
Held to maturity, Under 1 Year	1,245
Held to maturity, 1 to 5 Years	558
Held to maturity, 6 to 10 Years	44
Held to maturity, Over 10 Years	3,327
State And Political Subdivisions [Member]
Available for sale, Under 1 Year	467
Available for sale, 1 to 5 Years	2,742
Available for sale, 6 to 10 Years	2,743
Available for sale, Over 10 Years	944
Held to maturity, Under 1 Year	57
Held to maturity, 1 to 5 Years	56
Collateralized Mortgage Obligations [Member]
Available for sale, Under 1 Year	68
Available for sale, 1 to 5 Years	1,419
Available for sale, 6 to 10 Years	562
Available for sale, Over 10 Years	1,043
Held to maturity, Under 1 Year	358
Held to maturity, 1 to 5 Years	1,789
Held to maturity, 6 to 10 Years	347
Held to maturity, Over 10 Years	1,130
Other U.S. Debt Securities [Member]
Available for sale, Under 1 Year	242
Available for sale, 1 to 5 Years	2,156
Available for sale, 6 to 10 Years	824
Available for sale, Over 10 Years	$ 39

This item represents the fair value of debt securities which are expected to mature after five years and through ten years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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+ References

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-Publisher FASB

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This item represents the fair value of debt securities which are expected to mature after ten years from the balance sheet date which are categorized neither as held-to-maturity nor trading securities.

+ References

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 20

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-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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This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

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-Publisher FASB

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-Name Statement of Financial Accounting Standard (FAS)

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-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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+ References

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-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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This item represents the fair value of debt securities which are expected to mature after ten years from the balance sheet date which are categorized as held-to-maturity.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-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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This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and which are categorized as held-to-maturity.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 20

-Subparagraph a

-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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