Investment Securities (Schedule Of Contractual Maturities Of Debt Securities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	$ 6,453
Available for sale, 1 to 5 Years	35,808
Available for sale, 6 to 10 Years	26,678
Available for sale, Over 10 Years	36,655
Held to maturity, Under 1 Year	1,127
Held to maturity, 1 to 5 Years	1,897
Held to maturity, 6 to 10 Years	352
Held to maturity, Over 10 Years	4,431
US Treasury and Federal Agencies, Mortgage-backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, 1 to 5 Years	40
Held to maturity, 6 to 10 Years	52
Held to maturity, Over 10 Years	114
Asset-backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, 1 to 5 Years	0
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	17
Non-US Debt Securities, Mortgage-Backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, Under 1 Year	631
Held to maturity, 1 to 5 Years	63
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	3,393
Non-US Debt Securities, Asset-Backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, Under 1 Year	73
Held to maturity, 1 to 5 Years	226
Held to maturity, 6 to 10 Years	133
Held to maturity, Over 10 Years	0
Non-US Debt Securities, Government Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, Under 1 Year	3
Held to maturity, 1 to 5 Years	0
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	0
Non-US Debt Securities, Other [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, Under 1 Year	0
Held to maturity, 1 to 5 Years	152
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	14
Non U S Debt Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, Under 1 Year	707
Held to maturity, 1 to 5 Years	441
Held to maturity, 6 to 10 Years	133
Held to maturity, Over 10 Years	3,407
State And Political Subdivisions [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, Under 1 Year	50
Held to maturity, 1 to 5 Years	36
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	0
Collateralized Mortgage Obligations [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, Under 1 Year	370
Held to maturity, 1 to 5 Years	1,380
Held to maturity, 6 to 10 Years	167
Held to maturity, Over 10 Years	893
US Treasury and Federal Agencies, Direct Obligations [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, 1 to 5 Years	451
Available for sale, 6 to 10 Years	62
Available for sale, Over 10 Years	776
US Treasury and Federal Agencies, Mortgage-backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	13
Available for sale, 1 to 5 Years	1,498
Available for sale, 6 to 10 Years	10,138
Available for sale, Over 10 Years	22,500
Asset-backed Securities, Student Loans [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	217
Available for sale, 1 to 5 Years	6,141
Available for sale, 6 to 10 Years	6,877
Available for sale, Over 10 Years	3,500
Asset-backed Securities, Credit Cards [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	917
Available for sale, 1 to 5 Years	7,212
Available for sale, 6 to 10 Years	1,667
Available for sale, Over 10 Years	0
Asset-backed Securities, Sub-prime [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	135
Available for sale, 1 to 5 Years	50
Available for sale, 6 to 10 Years	5
Available for sale, Over 10 Years	1,140
Asset-backed Securities, Other [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	92
Available for sale, 1 to 5 Years	2,309
Available for sale, 6 to 10 Years	1,337
Available for sale, Over 10 Years	119
Asset-backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	1,361
Available for sale, 1 to 5 Years	15,712
Available for sale, 6 to 10 Years	9,886
Available for sale, Over 10 Years	4,759
Non-US Debt Securities, Mortgage-Backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	611
Available for sale, 1 to 5 Years	3,677
Available for sale, 6 to 10 Years	490
Available for sale, Over 10 Years	6,037
Non-US Debt Securities, Asset-Backed Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	236
Available for sale, 1 to 5 Years	3,829
Available for sale, 6 to 10 Years	1,244
Available for sale, Over 10 Years	333
Non-US Debt Securities, Government Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	1,671
Available for sale, 1 to 5 Years	150
Available for sale, 6 to 10 Years	0
Available for sale, Over 10 Years	0
Non-US Debt Securities, Other [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	1,542
Available for sale, 1 to 5 Years	2,009
Available for sale, 6 to 10 Years	122
Available for sale, Over 10 Years	0
Non-US Equity Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	4,060
Available for sale, 1 to 5 Years	9,665
Available for sale, 6 to 10 Years	1,856
Available for sale, Over 10 Years	6,370
State And Political Subdivisions [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	632
Available for sale, 1 to 5 Years	2,999
Available for sale, 6 to 10 Years	2,834
Available for sale, Over 10 Years	843
Collateralized Mortgage Obligations [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	82
Available for sale, 1 to 5 Years	2,351
Available for sale, 6 to 10 Years	922
Available for sale, Over 10 Years	1,375
Other U.S. Debt Securities [Member]
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, Under 1 Year	305
Available for sale, 1 to 5 Years	3,132
Available for sale, 6 to 10 Years	980
Available for sale, Over 10 Years	$ 32