Fair Value Option (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Other Financial Assets Measured on Recurring Basis, Gain (Loss) Included in Market Making Revenue	$ 119	$ 54
Fair Value, Other Financial Assets Measured on Recurring Basis, Gain (Loss) Included in Other Principal Transactions Revenue	(3)	2
Fair Value, Other Financial Assets Measured on Recurring Basis, Gain (Loss) Included in Interest Income	10
Fair Value, Other Financial Liabilities Measured on Recurring Basis, Gain (Loss) Included in Market Making Revenue	(1,370)	(766)
Fair Value, Other Financial Liabilities Measured on Recurring Basis, Gain (Loss) Included in Other Principal Transactions Revenue	(113)	(7)
Fair Value, Other Financial Liabilities Measured on Recurring Basis, Gain (Loss) Included in Interest Expense	(15)	(8)
Cash Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	34,685	32,207
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	905	446
Net Realized Gains / (Losses)	1,691	1,807
Net Unrealized Gains / (Losses) Relating to Instruments Still Held at Period-End	2,013	(92)
Purchases	11,996	13,677
Sales	(6,696)	(7,590)
Sales	366	475
Settlements	(6,415)	(4,626)
Transfers Into Level 3	2,790
Transfers Into Level 3	63
Transfers Out Of Level 3	(4,315)
Transfers Out Of Level 3	(134)
Net transfers in and/or (out) of level 3		(698)
Net Realized (Gains) / Losses	(19)	(27)
Net Unrealized (Gains) / Losses Relating to Instruments Still Held at Period-End	(54)	218
Purchases	(530)	(491)
Settlements	45	272
Net transfers in and/or (out) of level 3		12
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	35,749	34,685
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	642	905
Net Unrealized Gains / (Losses) Relating to Instruments Still Held at the Reporting Date	2,070	(310)
Derivatives Net [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Derivative Contracts Net Value, Beginning Balance	5,734	7,562
Net Realized Gains / (Losses)	78	131
Purchases	348	907
Settlements	(1,096)	(1,374)
Net transfers in and/or (out) of level 3		(889)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Derivative Contracts Net Value, Ending Balance	4,356	5,734
Securities purchased under agreements to resell at fair value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	557	100
Net Realized Gains / (Losses)	7	2
Purchases	116	620
Settlements	(402)	(165)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	278	557
Deposits At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	13	0
Transfers Into Level 3	16
Net Unrealized (Gains) / Losses Relating to Instruments Still Held at Period-End	5
Issuances	326	13
Settlements	(1)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	359	13
Receivables from customers and counterparties at fair value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	795	298
Net Unrealized Gains / (Losses) Relating to Instruments Still Held at Period-End	37	54
Purchases	199	468
Settlements	(17)	(25)
Transfers Out Of Level 3	(373)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	641	795
Other Assets At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	0
Net Unrealized Gains / (Losses) Relating to Instruments Still Held at Period-End	82
Settlements	(23)
Transfers Into Level 3	448
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	507
Securities Sold Under Agreements To Repurchase At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	2,181	2,060
Issuances		299
Settlements	(254)	(178)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	1,927	2,181
Other Secured Financings At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	1,752	8,349
Net Realized (Gains) / Losses	12	8
Net Unrealized (Gains) / Losses Relating to Instruments Still Held at Period-End	(51)	3
Issuances	854	483
Settlements	(1,155)	(4,062)
Net transfers in and/or (out) of level 3		(3,029)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	1,412	1,752
Unsecured Short-Term Borrowings Including Current Portion Of Unsecured Long-Term Borrowings At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	3,294	3,476
Sales
Transfers Into Level 3	240
Transfers Out Of Level 3	(684)
Net Realized (Gains) / Losses	(13)	(15)
Net Unrealized (Gains) / Losses Relating to Instruments Still Held at Period-End	204	(340)
Purchases	(13)	(5)
Issuances	762	815
Settlements	(1,206)	(1,080)
Net transfers in and/or (out) of level 3		443
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	2,584	3,294
Unsecured Long-term Borrowings At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	2,191	2,104
Transfers Into Level 3	225
Transfers Out Of Level 3	(801)
Net Realized (Gains) / Losses	31	25
Net Unrealized (Gains) / Losses Relating to Instruments Still Held at Period-End	286	5
Issuances	329	441
Settlements	(344)	(193)
Net transfers in and/or (out) of level 3		(191)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	1,917	2,191
Other Liabilities And Accrued Expenses At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	8,996	2,409
Sales
Transfers Into Level 3	2
Net Realized (Gains) / Losses	78
Net Unrealized (Gains) / Losses Relating to Instruments Still Held at Period-End	941	1,095
Purchases	1,617	5,840
Settlements	(360)	(348)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	11,274	8,996
Other Financial Assets and Liabilities At Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	1,352	398
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance	18,427	18,398
Net Realized Gains / (Losses)	7	2
Net Unrealized Gains / (Losses) Relating to Instruments Still Held at Period-End	119	54
Purchases	315	1,088
Sales
Settlements	(442)	(190)
Transfers Into Level 3	448
Transfers Into Level 3	483
Transfers Out Of Level 3	(373)
Transfers Out Of Level 3	(1,485)
Net Realized (Gains) / Losses	108	18
Net Unrealized (Gains) / Losses Relating to Instruments Still Held at Period-End	1,385	763
Purchases	1,604	5,835
Issuances	2,271	2,051
Settlements	(3,320)	(5,861)
Net transfers in and/or (out) of level 3		(2,777)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	1,426	1,352
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance	19,473	18,427
Net Unrealized Gains / (Losses) Relating to Instruments Still Held at the Reporting Date		$ (709)