Collateralized Agreements and Financings (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Repurchase agreements and securities borrowed and loaned transactions
Securities purchased under agreements to resell and federal funds sold (includes $141,331 and $187,789 at fair value as of December 2012 and December 2011, respectively)	$ 141,334,000,000	$ 187,789,000,000
Securities borrowed (includes $38,395 and $47,621 at fair value as of December 2012 and December 2011, respectively)	136,893,000,000	153,341,000,000
Securities sold under agreements to repurchase, at fair value	171,807,000,000	164,502,000,000
Securities loaned (includes $1,558 and $107 at fair value as of December 2012 and December 2011, respectively)	13,765,000,000	7,182,000,000
Other Secured Financings
Other Secured Financings Short Term At Fair Value	22,685,000,000	23,659,000,000
Other Secured Financings Short Term At Amortized Cost	360,000,000	5,526,000,000
Other Secured Financings Long Term At Fair Value	7,652,000,000	6,360,000,000
Other Secured Financings Long Term At Amortized Cost	1,313,000,000	1,819,000,000
Other secured financings	32,010,000,000	37,364,000,000
Other secured financings collateralized by financial instruments	30,765,000,000	35,124,000,000
Other secured financings collateralized by other assets (primarily real estate and cash)	1,245,000,000	2,240,000,000
Other Secured Financings by Maturity [Abstract]
Other secured financings, short-term	23,045,000,000	29,185,000,000
2014	4,957,000,000
2015	1,446,000,000
2016	869,000,000
2017	271,000,000
2018-thereafter	1,422,000,000
Total other secured financings (long-term)	8,965,000,000	8,179,000,000
Other secured financings	32,010,000,000	37,364,000,000
Collateral Received And Pledged [Abstract]
Fair value of financial instruments received as collateral by the firm that it was permitted to deliver or repledge	540,949,000,000	622,926,000,000
Financial instruments received as collateral which the firm delivered or repledged	397,652,000,000	454,604,000,000
Financial instruments owned at fair value pledged in connection with repurchase agreements securities lending agreements and other secured financings to counterparties that had the right to deliver or repledge	67,177,000,000	53,989,000,000
Financial instruments owned at fair value pledged in connection with repurchase agreements securities lending agreements and other secured financings to counterparties that did not have right to deliver or repledge	120,980,000,000	110,949,000,000
Other assets (primarily real estate and cash) owned and pledged in connection with other secured financings to counterparties that did not have the right to deliver or repledge	2,031,000,000	3,444,000,000
Collateralized Agreements and Financings (Textuals) [Abstract]
Securities borrowed at fair value	38,395,000,000	47,621,000,000
Securities loaned at fair value	1,558,000,000	107,000,000
Securities received under resale agreements and securities borrowed transactions segregated to satisfy certain regulatory requirements.	8,940,000,000	20,220,000,000
Nonrecourse obligations included in other secured financings	1,760,000,000	3,140,000,000
Transfers of financial assets accounted for as financings included in other secured financings	8,680,000,000	9,360,000,000
Financial assets collateralizing other secured financings related to failed sales	8,920,000,000	9,510,000,000
Other secured financings collateralized by financial instruments owned	17,240,000,000	14,330,000,000
Other secured financings collateralized by financial instruments received as collateral and repledged	13,530,000,000	20,790,000,000
U.S. Dollar [Member]
Other Secured Financings
Other Secured Financings Short Term At Fair Value	16,504,000,000	18,519,000,000
Other Secured Financings Short Term At Amortized Cost	34,000,000	155,000,000
Weighted average interest rate, after giving effect to hedging activities, on other secured financings at amortized cost (short-term)	6.18%	3.85%
Other Secured Financings Long Term At Fair Value	6,134,000,000	4,305,000,000
Other Secured Financings Long Term At Amortized Cost	577,000,000	1,024,000,000
Weighted average interest rate, after giving effect to hedging activities, on other secured financings at amortized cost (long-term)	2.61%	1.88%
Other secured financings	23,249,000,000	24,003,000,000
Other secured financings collateralized by financial instruments	22,323,000,000	22,850,000,000
Other secured financings collateralized by other assets (primarily real estate and cash)	926,000,000	1,153,000,000
Other Secured Financings by Maturity [Abstract]
Other secured financings	23,249,000,000	24,003,000,000
Non-U.S. Dollar [Member]
Other Secured Financings
Other Secured Financings Short Term At Fair Value	6,181,000,000	5,140,000,000
Other Secured Financings Short Term At Amortized Cost	326,000,000	5,371,000,000
Weighted average interest rate, after giving effect to hedging activities, on other secured financings at amortized cost (short-term)	0.10%	0.22%
Other Secured Financings Long Term At Fair Value	1,518,000,000	2,055,000,000
Other Secured Financings Long Term At Amortized Cost	736,000,000	795,000,000
Weighted average interest rate, after giving effect to hedging activities, on other secured financings at amortized cost (long-term)	2.55%	3.28%
Other secured financings	8,761,000,000	13,361,000,000
Other secured financings collateralized by financial instruments	8,442,000,000	12,274,000,000
Other secured financings collateralized by other assets (primarily real estate and cash)	319,000,000	1,087,000,000
Other Secured Financings by Maturity [Abstract]
Other secured financings	$ 8,761,000,000	$ 13,361,000,000