Investment Securities (Schedule Of Gross Pre-Tax Unrealized Losses On Investment Securities) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	$ 6,718	$ 25,040
Available for sale, Gross Unrealized Losses Less than 12 months	56	206
Available for sale, Fair Value 12 months or longer	17,084	17,849
Available for sale, Gross Unrealized Losses 12 months or longer	1,034	1,446
Available for sale, Fair Value Total	23,802	42,889
Available for sale, Gross Unrealized Losses Total	1,090	1,652
Held to maturity, Fair Value Less than 12 months	178	999
Held to maturity, Gross Unrealized Losses Less than 12 months	2	39
Held to maturity, Fair Value 12 months or longer	1,360	1,850
Held to maturity, Gross Unrealized Losses 12 months or longer	108	264
Held to maturity, Fair Value Total	1,538	2,849
Held to maturity, Gross Unrealized Losses Total	110	303
Asset-backed Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
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]
Held to maturity, Fair Value Less than 12 months	178	341
Held to maturity, Gross Unrealized Losses Less than 12 months	2	6
Held to maturity, Fair Value 12 months or longer	973	1,382
Held to maturity, Gross Unrealized Losses 12 months or longer	91	218
Held to maturity, Fair Value Total	1,151	1,723
Held to maturity, Gross Unrealized Losses Total	93	224
Non-US Debt Securities, Asset-Backed Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Held to maturity, Fair Value Less than 12 months	0	9
Held to maturity, Gross Unrealized Losses Less than 12 months	0	1
Held to maturity, Fair Value 12 months or longer	81	70
Held to maturity, Gross Unrealized Losses 12 months or longer	2	2
Held to maturity, Fair Value Total	81	79
Held to maturity, Gross Unrealized Losses Total	2	3
Non-US Debt Securities, Other [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
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	151	138
Held to maturity, Gross Unrealized Losses 12 months or longer	3	17
Held to maturity, Fair Value Total	151	138
Held to maturity, Gross Unrealized Losses Total	3	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	178	350
Held to maturity, Gross Unrealized Losses Less than 12 months	2	7
Held to maturity, Fair Value 12 months or longer	1,205	1,590
Held to maturity, Gross Unrealized Losses 12 months or longer	96	237
Held to maturity, Fair Value Total	1,383	1,940
Held to maturity, Gross Unrealized Losses Total	98	244
Collateralized Mortgage Obligations [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Held to maturity, Fair Value Less than 12 months	0	649
Held to maturity, Gross Unrealized Losses Less than 12 months	0	32
Held to maturity, Fair Value 12 months or longer	155	231
Held to maturity, Gross Unrealized Losses 12 months or longer	12	25
Held to maturity, Fair Value Total	155	880
Held to maturity, Gross Unrealized Losses Total	12	57
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		1,373
Available for sale, Gross Unrealized Losses Less than 12 months		1
Available for sale, Fair Value 12 months or longer	140
Available for sale, Gross Unrealized Losses 12 months or longer	1
Available for sale, Fair Value Total	140	1,373
Available for sale, Gross Unrealized Losses Total	1	1
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	3,440	4,714
Available for sale, Gross Unrealized Losses Less than 12 months	21	26
Available for sale, Fair Value 12 months or longer	570	370
Available for sale, Gross Unrealized Losses 12 months or longer	3	2
Available for sale, Fair Value Total	4,010	5,084
Available for sale, Gross Unrealized Losses Total	24	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	619	2,642
Available for sale, Gross Unrealized Losses Less than 12 months	4	23
Available for sale, Fair Value 12 months or longer	11,012	10,706
Available for sale, Gross Unrealized Losses 12 months or longer	587	688
Available for sale, Fair Value Total	11,631	13,348
Available for sale, Gross Unrealized Losses Total	591	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	660	2,581
Available for sale, Gross Unrealized Losses Less than 12 months	4	6
Available for sale, Fair Value 12 months or longer	109	1,461
Available for sale, Gross Unrealized Losses 12 months or longer	0	8
Available for sale, Fair Value Total	769	4,042
Available for sale, Gross Unrealized Losses Total	4	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	1,341	1,360
Available for sale, Gross Unrealized Losses 12 months or longer	242	446
Available for sale, Fair Value Total	1,341	1,376
Available for sale, Gross Unrealized Losses Total	242	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	769	1,482
Available for sale, Gross Unrealized Losses Less than 12 months	21	19
Available for sale, Fair Value 12 months or longer	1,072	1,122
Available for sale, Gross Unrealized Losses 12 months or longer	65	106
Available for sale, Fair Value Total	1,841	2,604
Available for sale, Gross Unrealized Losses Total	86	125
Asset-backed Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	2,048	6,721
Available for sale, Gross Unrealized Losses Less than 12 months	29	49
Available for sale, Fair Value 12 months or longer	13,534	14,649
Available for sale, Gross Unrealized Losses 12 months or longer	894	1,248
Available for sale, Fair Value Total	15,582	21,370
Available for sale, Gross Unrealized Losses Total	923	1,297
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	146	6,069
Available for sale, Gross Unrealized Losses Less than 12 months	1	55
Available for sale, Fair Value 12 months or longer	714	1,151
Available for sale, Gross Unrealized Losses 12 months or longer	29	52
Available for sale, Fair Value Total	860	7,220
Available for sale, Gross Unrealized Losses Total	30	107
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	467	2,205
Available for sale, Gross Unrealized Losses Less than 12 months	1	14
Available for sale, Fair Value 12 months or longer	65	108
Available for sale, Gross Unrealized Losses 12 months or longer	3	3
Available for sale, Fair Value Total	532	2,313
Available for sale, Gross Unrealized Losses Total	4	17
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	209	1,543
Available for sale, Gross Unrealized Losses Less than 12 months	1	13
Available for sale, Fair Value 12 months or longer	25	0
Available for sale, Gross Unrealized Losses 12 months or longer	0	0
Available for sale, Fair Value Total	234	1,543
Available for sale, Gross Unrealized Losses Total	1	13
Non-US Equity Securities [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	822	9,817
Available for sale, Gross Unrealized Losses Less than 12 months	3	82
Available for sale, Fair Value 12 months or longer	804	1,259
Available for sale, Gross Unrealized Losses 12 months or longer	32	55
Available for sale, Fair Value Total	1,626	11,076
Available for sale, Gross Unrealized Losses Total	35	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	163	171
Available for sale, Gross Unrealized Losses Less than 12 months	1	3
Available for sale, Fair Value 12 months or longer	1,371	1,446
Available for sale, Gross Unrealized Losses 12 months or longer	80	118
Available for sale, Fair Value Total	1,534	1,617
Available for sale, Gross Unrealized Losses Total	81	121
Collateralized Mortgage Obligations [Member]
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	245	2,024
Available for sale, Gross Unrealized Losses Less than 12 months	2	43
Available for sale, Fair Value 12 months or longer	633	68
Available for sale, Gross Unrealized Losses 12 months or longer	16	10
Available for sale, Fair Value Total	878	2,092
Available for sale, Gross Unrealized Losses Total	18	53
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	0	220
Available for sale, Gross Unrealized Losses Less than 12 months	0	2
Available for sale, Fair Value 12 months or longer	32	57
Available for sale, Gross Unrealized Losses 12 months or longer	8	13
Available for sale, Fair Value Total	32	277
Available for sale, Gross Unrealized Losses Total	$ 8	$ 15