Investment Securities (Schedule of Gross Pre-Tax Unrealized Losses on Investment Securities) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	$ 27,220	$ 9,124
Available for sale, Gross Unrealized Losses Less than 12 months	580	56
Available for sale, Fair Value 12 months or longer	13,764	15,885
Available for sale, Gross Unrealized Losses 12 months or longer	567	826
Available for sale, Fair Value Total	40,984	25,009
Available for sale, Gross Unrealized Losses Total	1,147	882
Held to maturity, Fair Value Less than 12 months	7,813	3,968
Held to maturity, Gross Unrealized Losses Less than 12 months	480	10
Held to maturity, Fair Value 12 months or longer	1,068	1,338
Held to maturity, Gross Unrealized Losses 12 months or longer	54	81
Held to maturity, Fair Value Total	8,881	5,306
Held to maturity, Gross Unrealized Losses Total	534	91
Asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	7,540	2,152
Available for sale, Gross Unrealized Losses Less than 12 months	58	22
Available for sale, Fair Value 12 months or longer	9,002	12,576
Available for sale, Gross Unrealized Losses 12 months or longer	365	712
Available for sale, Fair Value Total	16,542	14,728
Available for sale, Gross Unrealized Losses Total	423	734
Held to maturity, Fair Value Less than 12 months	1,649
Held to maturity, Gross Unrealized Losses Less than 12 months	11
Held to maturity, Fair Value 12 months or longer	29
Held to maturity, Gross Unrealized Losses 12 months or longer	1
Held to maturity, Fair Value Total	1,678
Held to maturity, Gross Unrealized Losses Total	12
US Treasury and federal agencies, direct obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	182	0
Available for sale, Gross Unrealized Losses Less than 12 months	1	0
Available for sale, Fair Value 12 months or longer	113	132
Available for sale, Gross Unrealized Losses 12 months or longer	1	1
Available for sale, Fair Value Total	295	132
Available for sale, Gross Unrealized Losses Total	2	1
Held to maturity, Fair Value Less than 12 months	4,571	3,792
Held to maturity, Gross Unrealized Losses Less than 12 months	448	8
Held to maturity, Fair Value 12 months or longer	0	0
Held to maturity, Gross Unrealized Losses 12 months or longer	0	0
Held to maturity, Fair Value Total	4,571	3,792
Held to maturity, Gross Unrealized Losses Total	448	8
US Treasury and federal agencies, mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	10,562	3,486
Available for sale, Gross Unrealized Losses Less than 12 months	316	18
Available for sale, Fair Value 12 months or longer	2,389	865
Available for sale, Gross Unrealized Losses 12 months or longer	76	8
Available for sale, Fair Value Total	12,951	4,351
Available for sale, Gross Unrealized Losses Total	392	26
Asset-backed securities, student loans
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	1,930	625
Available for sale, Gross Unrealized Losses Less than 12 months	16	6
Available for sale, Fair Value 12 months or longer	7,252	10,241
Available for sale, Gross Unrealized Losses 12 months or longer	252	502
Available for sale, Fair Value Total	9,182	10,866
Available for sale, Gross Unrealized Losses Total	268	508
Held to maturity, Fair Value Less than 12 months	1,352
Held to maturity, Gross Unrealized Losses Less than 12 months	10
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	1,352
Held to maturity, Gross Unrealized Losses Total	10
Asset-backed securities, credit cards
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	3,714	888
Available for sale, Gross Unrealized Losses Less than 12 months	30	3
Available for sale, Fair Value 12 months or longer	161	0
Available for sale, Gross Unrealized Losses 12 months or longer	11	0
Available for sale, Fair Value Total	3,875	888
Available for sale, Gross Unrealized Losses Total	41	3
Asset-backed securities, sub-prime
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	0	0
Available for sale, Gross Unrealized Losses Less than 12 months	0	0
Available for sale, Fair Value 12 months or longer	1,150	1,346
Available for sale, Gross Unrealized Losses 12 months or longer	91	162
Available for sale, Fair Value Total	1,150	1,346
Available for sale, Gross Unrealized Losses Total	91	162
Asset-backed securities, other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	1,896	639
Available for sale, Gross Unrealized Losses Less than 12 months	12	13
Available for sale, Fair Value 12 months or longer	439	989
Available for sale, Gross Unrealized Losses 12 months or longer	11	48
Available for sale, Fair Value Total	2,335	1,628
Available for sale, Gross Unrealized Losses Total	23	61
Held to maturity, Fair Value Less than 12 months	297
Held to maturity, Gross Unrealized Losses Less than 12 months	1
Held to maturity, Fair Value 12 months or longer	29
Held to maturity, Gross Unrealized Losses 12 months or longer	1
Held to maturity, Fair Value Total	326
Held to maturity, Gross Unrealized Losses Total	2
Total non-U.S. debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	3,074	2,152
Available for sale, Gross Unrealized Losses Less than 12 months	12	5
Available for sale, Fair Value 12 months or longer	424	506
Available for sale, Gross Unrealized Losses 12 months or longer	10	27
Available for sale, Fair Value Total	3,498	2,658
Available for sale, Gross Unrealized Losses Total	22	32
Held to maturity, Fair Value Less than 12 months		56
Held to maturity, Gross Unrealized Losses Less than 12 months		1
Held to maturity, Fair Value 12 months or longer		1,185
Held to maturity, Gross Unrealized Losses 12 months or longer		70
Held to maturity, Fair Value Total		1,241
Held to maturity, Gross Unrealized Losses Total		71
Non-U.S. debt securities, mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	868	670
Available for sale, Gross Unrealized Losses Less than 12 months	2	3
Available for sale, Fair Value 12 months or longer	258	453
Available for sale, Gross Unrealized Losses 12 months or longer	7	24
Available for sale, Fair Value Total	1,126	1,123
Available for sale, Gross Unrealized Losses Total	9	27
Held to maturity, Fair Value Less than 12 months	834	56
Held to maturity, Gross Unrealized Losses Less than 12 months	3	1
Held to maturity, Fair Value 12 months or longer	878	956
Held to maturity, Gross Unrealized Losses 12 months or longer	45	67
Held to maturity, Fair Value Total	1,712	1,012
Held to maturity, Gross Unrealized Losses Total	48	68
Non-U.S. debt securities, asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	551	973
Available for sale, Gross Unrealized Losses Less than 12 months	1	1
Available for sale, Fair Value 12 months or longer	16	53
Available for sale, Gross Unrealized Losses 12 months or longer	1	3
Available for sale, Fair Value Total	567	1,026
Available for sale, Gross Unrealized Losses Total	2	4
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		73
Held to maturity, Gross Unrealized Losses 12 months or longer		1
Held to maturity, Fair Value Total		73
Held to maturity, Gross Unrealized Losses Total		1
Non-U.S. debt securities, other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	1,655	509
Available for sale, Gross Unrealized Losses Less than 12 months	9	1
Available for sale, Fair Value 12 months or longer	150	0
Available for sale, Gross Unrealized Losses 12 months or longer	2	0
Available for sale, Fair Value Total	1,805	509
Available for sale, Gross Unrealized Losses Total	11	1
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		156
Held to maturity, Gross Unrealized Losses 12 months or longer		2
Held to maturity, Fair Value Total		156
Held to maturity, Gross Unrealized Losses Total		2
State and political subdivisions
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	3,242	685
Available for sale, Gross Unrealized Losses Less than 12 months	113	9
Available for sale, Fair Value 12 months or longer	1,268	1,152
Available for sale, Gross Unrealized Losses 12 months or longer	85	58
Available for sale, Fair Value Total	4,510	1,837
Available for sale, Gross Unrealized Losses Total	198	67
Collateralized mortgage obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	1,581	347
Available for sale, Gross Unrealized Losses Less than 12 months	55	1
Available for sale, Fair Value 12 months or longer	510	621
Available for sale, Gross Unrealized Losses 12 months or longer	21	14
Available for sale, Fair Value Total	2,091	968
Available for sale, Gross Unrealized Losses Total	76	15
Held to maturity, Fair Value Less than 12 months	759	120
Held to maturity, Gross Unrealized Losses Less than 12 months	18	1
Held to maturity, Fair Value 12 months or longer	161	153
Held to maturity, Gross Unrealized Losses 12 months or longer	8	11
Held to maturity, Fair Value Total	920	273
Held to maturity, Gross Unrealized Losses Total	26	12
Other U.S.debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, Fair Value Less than 12 months	1,039	302
Available for sale, Gross Unrealized Losses Less than 12 months	25	1
Available for sale, Fair Value 12 months or longer	58	33
Available for sale, Gross Unrealized Losses 12 months or longer	9	6
Available for sale, Fair Value Total	1,097	335
Available for sale, Gross Unrealized Losses Total	$ 34	$ 7