Investment Securities (Schedule Of Gross Pre-Tax Unrealized Losses On Investment Securities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	$ 9,124	$ 25,465
Available for sale, Gross Unrealized Losses Less than 12 months	56	223
Available for sale, Fair Value 12 months or longer	15,885	17,424
Available for sale, Gross Unrealized Losses 12 months or longer	826	1,429
Available for sale, Fair Value Total	25,009	42,889
Available for sale, Gross Unrealized Losses Total	882	1,652
Held to maturity, Fair Value Less than 12 months	3,968	1,430
Held to maturity, Gross Unrealized Losses Less than 12 months	10	132
Held to maturity, Fair Value 12 months or longer	1,338	1,419
Held to maturity, Gross Unrealized Losses 12 months or longer	81	171
Held to maturity, Fair Value Total	5,306	2,849
Held to maturity, Gross Unrealized Losses Total	91	303
US Treasury and Federal Agencies, Direct Obligations [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	0	1,373
Available for sale, Gross Unrealized Losses Less than 12 months	0	1
Available for sale, Fair Value 12 months or longer	132	0
Available for sale, Gross Unrealized Losses 12 months or longer	1	0
Available for sale, Fair Value Total	132	1,373
Available for sale, Gross Unrealized Losses Total	1	1
Held to maturity, Fair Value Less than 12 months	3,792
Held to maturity, Gross Unrealized Losses Less than 12 months	8
Held to maturity, Fair Value 12 months or longer	0
Held to maturity, Gross Unrealized Losses 12 months or longer	0
Held to maturity, Fair Value Total	3,792
Held to maturity, Gross Unrealized Losses Total	8
US Treasury and Federal Agencies, Mortgage-backed Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	3,486	4,715
Available for sale, Gross Unrealized Losses Less than 12 months	18	26
Available for sale, Fair Value 12 months or longer	865	370
Available for sale, Gross Unrealized Losses 12 months or longer	8	2
Available for sale, Fair Value Total	4,351	5,085
Available for sale, Gross Unrealized Losses Total	26	28
Asset-backed Securities, Student Loans [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	625	2,992
Available for sale, Gross Unrealized Losses Less than 12 months	6	34
Available for sale, Fair Value 12 months or longer	10,241	10,356
Available for sale, Gross Unrealized Losses 12 months or longer	502	677
Available for sale, Fair Value Total	10,866	13,348
Available for sale, Gross Unrealized Losses Total	508	711
Asset-backed Securities, Credit Cards [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	888	2,581
Available for sale, Gross Unrealized Losses Less than 12 months	3	6
Available for sale, Fair Value 12 months or longer	0	1,461
Available for sale, Gross Unrealized Losses 12 months or longer	0	8
Available for sale, Fair Value Total	888	4,042
Available for sale, Gross Unrealized Losses Total	3	14
Asset-backed Securities, Sub-prime [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	0	16
Available for sale, Gross Unrealized Losses Less than 12 months	0	1
Available for sale, Fair Value 12 months or longer	1,346	1,360
Available for sale, Gross Unrealized Losses 12 months or longer	162	446
Available for sale, Fair Value Total	1,346	1,376
Available for sale, Gross Unrealized Losses Total	162	447
Asset-backed Securities, Other [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	639	1,485
Available for sale, Gross Unrealized Losses Less than 12 months	13	19
Available for sale, Fair Value 12 months or longer	989	1,119
Available for sale, Gross Unrealized Losses 12 months or longer	48	106
Available for sale, Fair Value Total	1,628	2,604
Available for sale, Gross Unrealized Losses Total	61	125
Asset-backed Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	2,152	7,074
Available for sale, Gross Unrealized Losses Less than 12 months	22	60
Available for sale, Fair Value 12 months or longer	12,576	14,296
Available for sale, Gross Unrealized Losses 12 months or longer	712	1,237
Available for sale, Fair Value Total	14,728	21,370
Available for sale, Gross Unrealized Losses Total	734	1,297
Held to maturity, Fair Value Less than 12 months		0
Held to maturity, Gross Unrealized Losses Less than 12 months		0
Held to maturity, Fair Value 12 months or longer		29
Held to maturity, Gross Unrealized Losses 12 months or longer		2
Held to maturity, Fair Value Total		29
Held to maturity, Gross Unrealized Losses Total		2
Non-US Debt Securities, Mortgage-Backed Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	670	6,126
Available for sale, Gross Unrealized Losses Less than 12 months	3	61
Available for sale, Fair Value 12 months or longer	453	1,094
Available for sale, Gross Unrealized Losses 12 months or longer	24	46
Available for sale, Fair Value Total	1,123	7,220
Available for sale, Gross Unrealized Losses Total	27	107
Held to maturity, Fair Value Less than 12 months	56	678
Held to maturity, Gross Unrealized Losses Less than 12 months	1	91
Held to maturity, Fair Value 12 months or longer	956	1,046
Held to maturity, Gross Unrealized Losses 12 months or longer	67	133
Held to maturity, Fair Value Total	1,012	1,724
Held to maturity, Gross Unrealized Losses Total	68	224
Non-US Debt Securities, Asset-Backed Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	973	2,205
Available for sale, Gross Unrealized Losses Less than 12 months	1	14
Available for sale, Fair Value 12 months or longer	53	108
Available for sale, Gross Unrealized Losses 12 months or longer	3	3
Available for sale, Fair Value Total	1,026	2,313
Available for sale, Gross Unrealized Losses Total	4	17
Held to maturity, Fair Value Less than 12 months	0	79
Held to maturity, Gross Unrealized Losses Less than 12 months	0	3
Held to maturity, Fair Value 12 months or longer	73	0
Held to maturity, Gross Unrealized Losses 12 months or longer	1	0
Held to maturity, Fair Value Total	73	79
Held to maturity, Gross Unrealized Losses Total	1	3
Non-US Debt Securities, Other [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	509	1,543
Available for sale, Gross Unrealized Losses Less than 12 months	1	13
Available for sale, Fair Value 12 months or longer	0	0
Available for sale, Gross Unrealized Losses 12 months or longer	0	0
Available for sale, Fair Value Total	509	1,543
Available for sale, Gross Unrealized Losses Total	1	13
Held to maturity, Fair Value Less than 12 months	0	0
Held to maturity, Gross Unrealized Losses Less than 12 months	0	0
Held to maturity, Fair Value 12 months or longer	156	138
Held to maturity, Gross Unrealized Losses 12 months or longer	2	17
Held to maturity, Fair Value Total	156	138
Held to maturity, Gross Unrealized Losses Total	2	17
Non U S Debt Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Held to maturity, Fair Value Less than 12 months	56	757
Held to maturity, Gross Unrealized Losses Less than 12 months	1	94
Held to maturity, Fair Value 12 months or longer	1,185	1,184
Held to maturity, Gross Unrealized Losses 12 months or longer	70	150
Held to maturity, Fair Value Total	1,241	1,941
Held to maturity, Gross Unrealized Losses Total	71	244
Non-US Equity Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	2,152	9,874
Available for sale, Gross Unrealized Losses Less than 12 months	5	88
Available for sale, Fair Value 12 months or longer	506	1,202
Available for sale, Gross Unrealized Losses 12 months or longer	27	49
Available for sale, Fair Value Total	2,658	11,076
Available for sale, Gross Unrealized Losses Total	32	137
State And Political Subdivisions [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	685	185
Available for sale, Gross Unrealized Losses Less than 12 months	9	3
Available for sale, Fair Value 12 months or longer	1,152	1,431
Available for sale, Gross Unrealized Losses 12 months or longer	58	118
Available for sale, Fair Value Total	1,837	1,616
Available for sale, Gross Unrealized Losses Total	67	121
Collateralized Mortgage Obligations [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	347	2,024
Available for sale, Gross Unrealized Losses Less than 12 months	1	43
Available for sale, Fair Value 12 months or longer	621	67
Available for sale, Gross Unrealized Losses 12 months or longer	14	10
Available for sale, Fair Value Total	968	2,091
Available for sale, Gross Unrealized Losses Total	15	53
Held to maturity, Fair Value Less than 12 months	120	673
Held to maturity, Gross Unrealized Losses Less than 12 months	1	38
Held to maturity, Fair Value 12 months or longer	153	206
Held to maturity, Gross Unrealized Losses 12 months or longer	11	19
Held to maturity, Fair Value Total	273	879
Held to maturity, Gross Unrealized Losses Total	12	57
Other U.S. Debt Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	302	220
Available for sale, Gross Unrealized Losses Less than 12 months	1	2
Available for sale, Fair Value 12 months or longer	33	58
Available for sale, Gross Unrealized Losses 12 months or longer	6	13
Available for sale, Fair Value Total	335	278
Available for sale, Gross Unrealized Losses Total	$ 7	$ 15