Securities - Impairment (Details 2) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	$ 62,375	$ 88,153
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	1,268	1,515
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	35,758	9,094
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	1,254	510
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	98,133	97,247
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	2,522	2,025
Equity securities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	355	0
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	1	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	0	2
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	0	6
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	355	2
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	1	6
Debt Securities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	62,020	88,153
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	1,267	1,515
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	35,758	9,092
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	1,254	504
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	97,778	97,245
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	2,521	2,019
Mortgage-backed securities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	24,476	49,753
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	236	690
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	23,635	2,284
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	549	283
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	48,111	52,037
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	785	973
U.S. government agencies [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	2,769	14,039
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	1	297
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	11	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	1	0
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	2,780	14,039
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	2	297
Commercial mortgage [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	2,118	548
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	77	14
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	0	11
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	0	3
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	2,118	559
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	77	17
Prime and Alt A [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	591	0
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	2	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	1,061	1,193
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	174	250
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	1,652	1,193
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	176	250
Subprime [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	0	0
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	0	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	0	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	0	0
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	0	0
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	0	0
Non-U.S. [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	18,998	35,166
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	156	379
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	22,563	1,080
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	374	30
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	41,561	36,246
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	530	409
U.S. Treasury and government agencies [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	0	921
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	0	28
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	0	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	0	0
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	0	921
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	0	28
Obligations of U.S. states and municipalities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	712	6,890
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	28	330
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	25	20
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	5	8
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	737	6,910
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	33	338
Certificates of Deposit [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	0	1,771
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	0	2
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	0	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	0	0
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	0	1,771
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	0	2
Non-U.S. government debt securities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	7,945	6,960
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	35	28
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	298	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	17	0
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	8,243	6,960
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	52	28
Corporate Debt Securities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	21,146	18,783
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	887	418
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	7,845	90
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	575	1
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	28,991	18,873
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	1,462	419
Credit card receivables, Asset Backed Securities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	0	0
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	0	0
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	0	345
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	0	5
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	0	345
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	0	5
Collateralized loan obligations
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	5,335	460
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	58	10
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	3,726	6,321
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	106	200
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	9,061	6,781
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	164	210
Other, Debt Securities [Member]
Fair value and gross unrealized loss, securities impairment [Abstract]
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Fair Value	2,406	2,615
Available-for-sale Securities, with gross unrealized losses, Less than 12 Months, Gross unrealized losses	23	9
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Fair Value	229	32
Available-for-sale Securities, with gross unrealized losses, 12 Months or Longer, Gross unrealized losses	2	7
Available-for-sale securities, with gross unrealized losses, Fair Value, Total	2,635	2,647
Available-for-sale Securities, with gross unrealized losses, Gross Unrealized Losses	$ 25	$ 16