Fair Value Measurement - Changes in level 3 recurring measurements (Details 2) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Deposits [Member]	Mar. 31, 2012 Deposits [Member]	Mar. 31, 2013 Other borrowed funds [Member]	Mar. 31, 2012 Other borrowed funds [Member]	Mar. 31, 2013 Trading liabilities - Debt and equity instruments [Member]	Mar. 31, 2012 Trading liabilities - Debt and equity instruments [Member]	Mar. 31, 2013 Accounts payable and other liabilities [Member]	Mar. 31, 2012 Accounts payable and other liabilities [Member]	Mar. 31, 2013 Beneficial interests issued by consolidated VIEs [Member]	Mar. 31, 2012 Beneficial interests issued by consolidated VIEs [Member]	Mar. 31, 2013 Long-term debt	Mar. 31, 2012 Long-term debt	Mar. 31, 2013 Total debt and equity instruments [Member]	Mar. 31, 2012 Total debt and equity instruments [Member]	Mar. 31, 2013 Total debt instruments [Member]	Mar. 31, 2012 Total debt instruments [Member]	Mar. 31, 2013 Mortgage-backed securities	Mar. 31, 2012 Mortgage-backed securities	Mar. 31, 2013 U.S. government agencies [Member]	Mar. 31, 2012 U.S. government agencies [Member]	Mar. 31, 2013 Residential - nonagency	Mar. 31, 2012 Residential - nonagency	Mar. 31, 2013 Commercial - nonagency	Mar. 31, 2012 Commercial - nonagency	Mar. 31, 2013 Obligations of U.S. states and municipalities	Mar. 31, 2012 Obligations of U.S. states and municipalities	Mar. 31, 2013 Non-U.S. government debt securities	Mar. 31, 2012 Non-U.S. government debt securities	Mar. 31, 2013 Corporate Debt Securities	Mar. 31, 2012 Corporate Debt Securities	Mar. 31, 2013 Loans [Member]	Mar. 31, 2012 Loans [Member]	Mar. 31, 2013 Asset-backed securities [Member]	Mar. 31, 2012 Asset-backed securities [Member]	Mar. 31, 2013 Equity securities	Mar. 31, 2012 Equity securities	Mar. 31, 2013 Other equity instruments [Member]	Mar. 31, 2012 Other equity instruments [Member]	Mar. 31, 2013 Total net derivative receivables [Member]	Mar. 31, 2012 Total net derivative receivables [Member]	Mar. 31, 2013 Interest rate contract	Mar. 31, 2012 Interest rate contract	Mar. 31, 2013 Credit derivatives	Mar. 31, 2012 Credit derivatives	Mar. 31, 2013 Foreign exchange	Mar. 31, 2012 Foreign exchange	Mar. 31, 2013 Equity Contract	Mar. 31, 2012 Equity Contract	Mar. 31, 2013 Commodity Contract	Mar. 31, 2012 Commodity Contract	Mar. 31, 2013 Available-for-sale Securities	Mar. 31, 2012 Available-for-sale Securities	Mar. 31, 2013 Loans [Member]	Mar. 31, 2012 Loans [Member]	Mar. 31, 2013 Mortgage servicing rights [Member]	Mar. 31, 2012 Mortgage servicing rights [Member]	Mar. 31, 2013 Private Equity Funds [Member]	Mar. 31, 2012 Private Equity Funds [Member]	Mar. 31, 2013 All other assets [Member]	Mar. 31, 2012 All other assets [Member]	Mar. 31, 2013 Asset backed Security Available for Sale [Member]	Mar. 31, 2012 Asset backed Security Available for Sale [Member]	Mar. 31, 2013 Other Available For Sale Securities [Member]	Mar. 31, 2012 Other Available For Sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level Three Liabilities As Percentage Of Total Firm Liabilities At Fair Value	19.00%	19.00%
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings															$ (46)	$ 734	$ (91)	$ 588	$ 57	$ (57)	$ 34	$ (12)	$ 109	$ 32	$ (86)	$ (77)	$ 41	$ (7)	$ 2	$ 8	$ (83)	$ 258	$ (172)	$ 156	$ 64	$ 230	$ 1	$ (7)	$ 44	$ 153	$ 922		$ 306	$ 1,328	$ (489)	$ (2,354)	$ (116)	$ 127	$ 863	$ (720)	$ 358	$ 6	$ (18)	$ 96	$ (35)	$ 30	$ 309	$ 596	$ (269)	$ 252	$ (26)	$ (164)	$ 5	$ 3	$ (9)	$ 8
Assets
Fair Value, Beginning balance															25,639	32,967	23,662	30,910	2,368	2,640	498	86	663	796	1,207	1,758	1,436	1,619	67	104	5,308	6,373	10,787	12,209	3,696	7,965	1,114	1,177	863	880	1,893	6,238	3,322	3,561	1,873	7,732	(1,750)	(1,263)	(1,806)	(3,105)	254	(687)	28,916	25,486	2,282	1,647	7,614	7,223	7,181	6,751	4,258	4,374	28,024	24,958	892	528
Total realized/ unrealized gains/(losses)																																																					(4)	11
Purchases															6,443	4,832	6,278	4,775	827	209	391	5	299	92	137	112	1	320	301	205	2,927	2,316	1,626	901	596	824	93	22	72	35	309	592	69	109	47	78	(15)	19	197	333	11	53	400	1,349	225	127	684	573	81	111	52	356	400	1,321	0	28
Sales															(5,997)	(4,089)	(5,904)	(4,018)	(548)	(403)	(79)	0	(404)	(163)	(65)	(240)	(46)	(181)	(285)	(231)	(2,563)	(1,269)	(1,485)	(673)	(977)	(1,261)	(91)	(27)	(2)	(44)	(274)	(633)	(62)	(68)	0	(18)	(3)	(158)	(206)	(383)	(3)	(6)	(13)	(518)	(49)	0	(399)	0	(96)	(236)	(3)	(19)	0	(498)	(13)	(20)
Settlements															(1,597)	(3,338)	(1,559)	(3,294)	(96)	(47)	(25)	0	(29)	(36)	(42)	(11)	0	(4)	0	(5)	(625)	(1,967)	(703)	(945)	(135)	(326)	(9)	(13)	(29)	(31)	(1,259)	(1,742)	(858)	(1,344)	(113)	(630)	376	218	(222)	(9)	(442)	23	(72)	(527)	(359)	(119)	(259)	(353)	(66)	(139)	(296)	(150)	(39)	(452)	(33)	(75)
Transfers into and/or out of level 3															(1,739)	(767)	(1,803)	(863)	(5)	(113)	0	0	(5)	(22)	0	(91)	0	0	0	0	(112)	(248)	(21)	(504)	(1,665)	2	64	96	0	0	183	715	14	(348)	(1)	0	(8)	(3)	174	1,055	4	11	(27,260)	116	0	81	0	0	0	0	0	0	(27,260)	116	0	0
Fair Value, Ending Balance															22,703	30,339	20,583	28,098	2,603	2,229	819	79	633	699	1,151	1,451	1,432	1,747	85	81	4,852	5,463	10,032	11,144	1,579	7,434	1,172	1,248	948	993	1,774	3,557	2,791	3,238	1,317	4,808	(1,516)	(1,060)	(1,000)	(2,829)	182	(600)	1,967	25,917	2,064	1,766	7,949	8,039	6,831	6,739	3,985	4,397	1,130	25,448	837	469
Change in unrealized gains/(losses) related to financial instruments held															(82)	520	(110)	373	(8)	(61)	42	(5)	41	23	(91)	(79)	36	(9)	4	1	2	115	(192)	129	48	198	(23)	(12)	51	159	215	(2,438)	143	580	(476)	(2,228)	(194)	89	606	(880)	136	1	8	7	(40)	27	309	596	(399)	167	(27)	(177)	5	2	3	5
Liabilities
Beginning balance			1,983	1,418	1,619	1,507	205	211	36	51	925	791	8,476	10,310
Total realized/unrealized (gains)/losses			5	131	(26)	196	(8)	(15)	1	0	(34)	45	(475)	139
Purchases			0	0	0	0	(1,485)	(705)	0	0	0	0	0	0
Sales			0	0	0	0	1,552	793	0	0	0	0	0	0
Issuances			296	351	1,762	384	0	0	0	0	21	36	1,855	1,124
Settlements			(113)	(136)	(1,224)	(845)	(13)	(11)	(4)	(5)	(94)	(31)	(357)	(1,387)
Transfers into and/or out of level 3			(156)	(113)	6	(9)	0	0	0	0	0	0	(415)	(633)
Ending balance			2,015	1,651	2,137	1,233	251	273	33	46	818	841	9,084	9,553
Change in unrealized (gains)/losses related to financial instruments held			4	129	20	151	(5)	3	1	0	(34)	9	(98)	193
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)																																																					$ 14	$ (85)