Fair Value Measurement - Changes in level 3 recurring measurements (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Deposits [Member]
Liabilities
Beginning balance	$ 1,418		$ 773
Total realized/unrealized (gains)/losses	131	(11)
Purchases	0	0
Sales	0	0
Issuances	351	59
Settlements	(136)	(66)
Transfers into and/or out of level 3	(113)	(1)
Ending balance	1,651	754	773
Change in unrealized (gains)/losses related to financial instruments held	129	(4)
Other borrowed funds [Member]
Liabilities
Beginning balance	1,507		1,384
Total realized/unrealized (gains)/losses	196	(31)
Purchases	0	0
Sales	0	0
Issuances	384	577
Settlements	(845)	(88)
Transfers into and/or out of level 3	(9)	2
Ending balance	1,233	1,844	1,384
Change in unrealized (gains)/losses related to financial instruments held	151	58
Trading liabilities - Debt and equity instruments [Member]
Liabilities
Beginning balance	211		54
Total realized/unrealized (gains)/losses	(15)	0
Purchases	(705)	0
Sales	793	119
Issuances	0	0
Settlements	(11)	0
Transfers into and/or out of level 3	0	0
Ending balance	273	173	54
Change in unrealized (gains)/losses related to financial instruments held	3	0
Accounts payable and other liabilities [Member]
Liabilities
Beginning balance	51		236
Total realized/unrealized (gains)/losses	0	(37)
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	(5)	(53)
Transfers into and/or out of level 3	0	0
Ending balance	46	146	236
Change in unrealized (gains)/losses related to financial instruments held	0	4
Beneficial interests issued by consolidated VIEs [Member]
Liabilities
Beginning balance	791		873
Total realized/unrealized (gains)/losses	45	(6)
Purchases	0	0
Sales	0	0
Issuances	36	11
Settlements	(31)	(290)
Transfers into and/or out of level 3	0	0
Ending balance	841	588	873
Change in unrealized (gains)/losses related to financial instruments held	9	(7)
Long-term debt
Liabilities
Beginning balance	10,310		13,044
Total realized/unrealized (gains)/losses	139	62
Purchases	0	0
Sales	0	0
Issuances	1,124	653
Settlements	(1,387)	(971)
Transfers into and/or out of level 3	(633)	239
Ending balance	9,553	13,027	13,044
Change in unrealized (gains)/losses related to financial instruments held	193	258
Total debt and equity instruments [Member]
Assets
Fair Value, Beginning balance	32,967		34,554
Total realized/ unrealized gains/(losses)	734	761
Purchases	4,832	4,717
Sales	4,089	(4,600)
Settlements	3,338	(1,285)
Transfers into and/or out of level 3	(767)	101
Fair Value, Ending Balance	30,339	34,248	34,554
Change in unrealized gains/(losses) related to financial instruments held	520	449
Total debt instruments [Member]
Assets
Fair Value, Beginning balance	30,910		31,939
Total realized/ unrealized gains/(losses)	588	656
Purchases	4,775	4,675
Sales	4,018	(4,525)
Settlements	3,294	(929)
Transfers into and/or out of level 3	(863)	122
Fair Value, Ending Balance	28,098	31,938	31,939
Change in unrealized gains/(losses) related to financial instruments held	373	331
Total mortgage-backed securities [Member]
Assets
Fair Value, Beginning balance	2,640		2,930
Total realized/ unrealized gains/(losses)	(57)	104
Purchases	209	626
Sales	403	(671)
Settlements	47	(131)
Transfers into and/or out of level 3	(113)	0
Fair Value, Ending Balance	2,229	2,858	2,930
Change in unrealized gains/(losses) related to financial instruments held	(61)	4
U.S. government agencies [Member]
Assets
Fair Value, Beginning balance	86		174
Total realized/ unrealized gains/(losses)	(12)	17
Purchases	5	21
Sales	0	(21)
Settlements	0	0
Transfers into and/or out of level 3	0	0
Fair Value, Ending Balance	79	191	174
Change in unrealized gains/(losses) related to financial instruments held	(5)	(1)
Residential - nonagency [Member]
Assets
Fair Value, Beginning balance	796		687
Total realized/ unrealized gains/(losses)	32	71
Purchases	92	259
Sales	(163)	(168)
Settlements	(36)	(67)
Transfers into and/or out of level 3	(22)	0
Fair Value, Ending Balance	699	782	687
Change in unrealized gains/(losses) related to financial instruments held	23	27
Commercial - nonagency [Member]
Assets
Fair Value, Beginning balance	1,758		2,069
Total realized/ unrealized gains/(losses)	(77)	16
Purchases	112	346
Sales	(240)	(482)
Settlements	(11)	(64)
Transfers into and/or out of level 3	(91)	0
Fair Value, Ending Balance	1,451	1,885	2,069
Change in unrealized gains/(losses) related to financial instruments held	(79)	(22)
Obligations of U.S. states and municipalities [Member]
Assets
Fair Value, Beginning balance	1,619		2,257
Total realized/ unrealized gains/(losses)	(7)	(14)
Purchases	320	284
Sales	(181)	(555)
Settlements	(4)	(1)
Transfers into and/or out of level 3	0	0
Fair Value, Ending Balance	1,747	1,971	2,257
Change in unrealized gains/(losses) related to financial instruments held	(9)	(14)
Non-U.S. government debt securities [Member]
Assets
Fair Value, Beginning balance	104		202
Total realized/ unrealized gains/(losses)	8	3
Purchases	205	130
Sales	(231)	(143)
Settlements	(5)	(5)
Transfers into and/or out of level 3	0	(74)
Fair Value, Ending Balance	81	113	202
Change in unrealized gains/(losses) related to financial instruments held	1	4
Corporate debt securities [Member]
Assets
Fair Value, Beginning balance	6,373		4,946
Total realized/ unrealized gains/(losses)	258	32
Purchases	2,316	1,629
Sales	(1,269)	(1,075)
Settlements	(1,967)	(6)
Transfers into and/or out of level 3	(248)	97
Fair Value, Ending Balance	5,463	5,623	4,946
Change in unrealized gains/(losses) related to financial instruments held	115	34
Loans [Member]
Assets
Fair Value, Beginning balance	12,209		13,144
Total realized/ unrealized gains/(losses)	156	131
Purchases	901	888
Sales	(673)	(1,024)
Settlements	(945)	(729)
Transfers into and/or out of level 3	(504)	80
Fair Value, Ending Balance	11,144	12,490	13,144
Change in unrealized gains/(losses) related to financial instruments held	129	12
Asset-backed securities [Member]
Assets
Fair Value, Beginning balance	7,965		8,460
Total realized/ unrealized gains/(losses)	230	400
Purchases	824	1,118
Sales	(1,261)	(1,057)
Settlements	(326)	(57)
Transfers into and/or out of level 3	2	19
Fair Value, Ending Balance	7,434	8,883	8,460
Change in unrealized gains/(losses) related to financial instruments held	198	291
Equity securities [Member]
Assets
Fair Value, Beginning balance	1,177		1,685
Total realized/ unrealized gains/(losses)	(7)	70
Purchases	22	37
Sales	(27)	(74)
Settlements	(13)	(330)
Transfers into and/or out of level 3	96	(21)
Fair Value, Ending Balance	1,248	1,367	1,685
Change in unrealized gains/(losses) related to financial instruments held	(12)	83
Other equity instruments [Member]
Assets
Fair Value, Beginning balance	880		930
Total realized/ unrealized gains/(losses)	153	35
Purchases	35	5
Sales	(44)	(1)
Settlements	(31)	(26)
Transfers into and/or out of level 3	0	0
Fair Value, Ending Balance	993	943	930
Change in unrealized gains/(losses) related to financial instruments held	159	35
Total net derivative receivables [Member]
Assets
Fair Value, Beginning balance	6,238		4,357
Total realized/ unrealized gains/(losses)	(1,613)	501
Purchases	592	335
Sales	633	(480)
Settlements	1,742	(1,432)
Transfers into and/or out of level 3	715	(144)
Fair Value, Ending Balance	3,557	3,137	4,357
Change in unrealized gains/(losses) related to financial instruments held	(2,438)	(552)
Interest rate
Assets
Fair Value, Beginning balance	3,561		2,836
Total realized/ unrealized gains/(losses)	1,328	519
Purchases	109	128
Sales	(68)	(83)
Settlements	(1,344)	(915)
Transfers into and/or out of level 3	(348)	(15)
Fair Value, Ending Balance	3,238	2,470	2,836
Change in unrealized gains/(losses) related to financial instruments held	580	184
Credit derivatives
Assets
Fair Value, Beginning balance	7,732		5,386
Total realized/ unrealized gains/(losses)	(2,354)	(853)
Purchases	78	1
Sales	(18)	0
Settlements	(630)	(146)
Transfers into and/or out of level 3	0	(15)
Fair Value, Ending Balance	4,808	4,373	5,386
Change in unrealized gains/(losses) related to financial instruments held	(2,228)	(1,068)
Foreign exchange
Assets
Fair Value, Beginning balance	(1,263)		(614)
Total realized/ unrealized gains/(losses)	127	61
Purchases	19	25
Sales	(158)	0
Settlements	218	482
Transfers into and/or out of level 3	(3)	48
Fair Value, Ending Balance	(1,060)	2	(614)
Change in unrealized gains/(losses) related to financial instruments held	89	69
Equity Contract
Assets
Fair Value, Beginning balance	(3,105)		(2,446)
Total realized/ unrealized gains/(losses)	(720)	179
Purchases	333	95
Sales	(383)	(330)
Settlements	(9)	(429)
Transfers into and/or out of level 3	1,055	88
Fair Value, Ending Balance	(2,829)	(2,843)	(2,446)
Change in unrealized gains/(losses) related to financial instruments held	(880)	54
Commodity
Assets
Fair Value, Beginning balance	(687)		(805)
Total realized/ unrealized gains/(losses)	6	595
Purchases	53	86
Sales	(6)	(67)
Settlements	23	(424)
Transfers into and/or out of level 3	11	(250)
Fair Value, Ending Balance	(600)	(865)	(805)
Change in unrealized gains/(losses) related to financial instruments held	1	209
Available-for-sale Securities [Member]
Assets
Fair Value, Beginning balance	25,486		14,287
Total realized/ unrealized gains/(losses)	11	487
Purchases	1,349	1,109
Sales	518	(7)
Settlements	527	(351)
Transfers into and/or out of level 3	116	0
Fair Value, Ending Balance	25,917	15,525	14,287
Change in unrealized gains/(losses) related to financial instruments held	7	482
Asset backed security [Member]
Assets
Fair Value, Beginning balance	24,958		13,775
Total realized/ unrealized gains/(losses)	3	478
Purchases	1,321	1,109
Sales	(498)	(4)
Settlements	(452)	(342)
Transfers into and/or out of level 3	116	0
Fair Value, Ending Balance	25,448	15,016	13,775
Change in unrealized gains/(losses) related to financial instruments held	2	475
Other available-for-sale securities [Member]
Assets
Fair Value, Beginning balance	528		512
Total realized/ unrealized gains/(losses)	8	9
Purchases	28	0
Sales	(20)	(3)
Settlements	(75)	(9)
Transfers into and/or out of level 3	0	0
Fair Value, Ending Balance	469	509	512
Change in unrealized gains/(losses) related to financial instruments held	5	7
Loans [Member]
Assets
Fair Value, Beginning balance	1,647		1,466
Total realized/ unrealized gains/(losses)	30	120
Purchases	127	84
Sales	0	0
Settlements	(119)	(283)
Transfers into and/or out of level 3	81	(16)
Fair Value, Ending Balance	1,766	1,371	1,466
Change in unrealized gains/(losses) related to financial instruments held	27	108
Mortgage servicing rights [Member]
Assets
Fair Value, Beginning balance	7,223		13,649
Total realized/ unrealized gains/(losses)	596	(751)
Purchases	573	758
Sales	0	0
Settlements	(353)	(563)
Transfers into and/or out of level 3	0	0
Fair Value, Ending Balance	8,039	13,093	13,649
Change in unrealized gains/(losses) related to financial instruments held	596	(751)
Private Equity Funds [Member]
Assets
Fair Value, Beginning balance	6,751		7,862
Total realized/ unrealized gains/(losses)	252	905
Purchases	111	328
Sales	(236)	(139)
Settlements	(139)	(103)
Transfers into and/or out of level 3	0	0
Fair Value, Ending Balance	6,739	8,853	7,862
Change in unrealized gains/(losses) related to financial instruments held	167	845
All other assets [Member]
Assets
Fair Value, Beginning balance	4,374		4,179
Total realized/ unrealized gains/(losses)	(164)	60
Purchases	356	409
Sales	(19)	(3)
Settlements	(150)	(86)
Transfers into and/or out of level 3	0	1
Fair Value, Ending Balance	4,397	4,560	4,179
Change in unrealized gains/(losses) related to financial instruments held	$ (177)	$ 60