Securities - Impairment (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	$ 101,248	$ 37,687
Less than 12 months, Gross unrealized losses	2,755	104
12 months or more, Fair Value	3,319	11,028
12 months or more, Gross unrealized losses	178	146
Total fair value	104,567	48,715
Total gross unrealized losses	2,933	250
Held-to-maturity Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	20,745	0
Less than 12 months, Gross unrealized losses	317	0
12 months or more, Fair value	0	0
12 months or more, Gross unrealized losses	0	0
Total fair value	20,745	0
Total gross unrealized losses	317	0
Debt securities [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	80,503	37,687
Less than 12 months, Gross unrealized losses	2,438	104
12 months or more, Fair Value	3,319	11,028
12 months or more, Gross unrealized losses	178	146
Total fair value	83,822	48,715
Total gross unrealized losses	2,616	250
Mortgage-backed securities [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	25,486	6,259
Less than 12 months, Gross unrealized losses	949	29
12 months or more, Fair Value	1,308	1,122
12 months or more, Gross unrealized losses	83	29
Total fair value	26,794	7,381
Total gross unrealized losses	1,032	58
U.S. government agencies [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	20,293	2,440
Less than 12 months, Gross unrealized losses	895	13
12 months or more, Fair Value	1,150	0
12 months or more, Gross unrealized losses	82	0
Total fair value	21,443	2,440
Total gross unrealized losses	977	13
Commercial mortgage [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	3,980	1,159
Less than 12 months, Gross unrealized losses	26	8
12 months or more, Fair Value	0	312
12 months or more, Gross unrealized losses	0	5
Total fair value	3,980	1,471
Total gross unrealized losses	26	13
U.S. Treasury and government agencies [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	6,293	4,198
Less than 12 months, Gross unrealized losses	250	8
12 months or more, Fair Value	237	0
12 months or more, Gross unrealized losses	56	0
Total fair value	6,530	4,198
Total gross unrealized losses	306	8
Obligations of U.S. states and municipalities [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	15,387	907
Less than 12 months, Gross unrealized losses	975	10
12 months or more, Fair Value	55	0
12 months or more, Gross unrealized losses	12	0
Total fair value	15,442	907
Total gross unrealized losses	987	10
Certificates of deposit [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	988	741
Less than 12 months, Gross unrealized losses	1	2
12 months or more, Fair Value	0	0
12 months or more, Gross unrealized losses	0	0
Total fair value	988	741
Total gross unrealized losses	1	2
Non-U.S. government debt securities [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	11,286	14,527
Less than 12 months, Gross unrealized losses	110	21
12 months or more, Fair Value	821	1,927
12 months or more, Gross unrealized losses	12	4
Total fair value	12,107	16,454
Total gross unrealized losses	122	25
Corporate debt securities [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	1,580	2,651
Less than 12 months, Gross unrealized losses	21	10
12 months or more, Fair Value	505	5,641
12 months or more, Gross unrealized losses	8	74
Total fair value	2,085	8,292
Total gross unrealized losses	29	84
Collateralized loan obligations [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	18,369	6,328
Less than 12 months, Gross unrealized losses	129	17
12 months or more, Fair Value	393	2,063
12 months or more, Gross unrealized losses	7	35
Total fair value	18,762	8,391
Total gross unrealized losses	136	52
Other debt obligations [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	1,114	2,076
Less than 12 months, Gross unrealized losses	3	7
12 months or more, Fair Value	0	275
12 months or more, Gross unrealized losses	0	4
Total fair value	1,114	2,351
Total gross unrealized losses	3	11
Equity securities [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	0	0
Less than 12 months, Gross unrealized losses	0	0
12 months or more, Fair Value	0	0
12 months or more, Gross unrealized losses	0	0
Total fair value	0	0
Total gross unrealized losses	0	0
Residential mortgage-backed securities [Member] | Prime and Alt-A [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	1,061	218
Less than 12 months, Gross unrealized losses	27	2
12 months or more, Fair Value	0	76
12 months or more, Gross unrealized losses	0	1
Total fair value	1,061	294
Total gross unrealized losses	27	3
Residential mortgage-backed securities [Member] | Subprime [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	152	0
Less than 12 months, Gross unrealized losses	1	0
12 months or more, Fair Value	0	0
12 months or more, Gross unrealized losses	0	0
Total fair value	152	0
Total gross unrealized losses	1	0
Residential mortgage-backed securities [Member] | Non- U.S. [Member]
Available-for-sale Securities, Securities with Gross Unrealized Losses:
Less than 12 months, Fair value	0	2,442
Less than 12 months, Gross unrealized losses	0	6
12 months or more, Fair Value	158	734
12 months or more, Gross unrealized losses	1	23
Total fair value	158	3,176
Total gross unrealized losses	$ 1	$ 29