Financial Instruments Owned, at Fair Value and Financial Instruments Sold, But Not Yet Purchased, at Fair Value (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	$ 407,011,000,000	$ 364,206,000,000
Financial instruments sold, but not yet purchased, at fair value	126,644,000,000	145,013,000,000
Gains and Losses from Market Making and Other Principal Transactions
Trading Activity, Gains and Losses, Net	17,213,000,000	10,794,000,000	20,610,000,000
Trading Activity, Gains and Losses, On Sale Of Business	500,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Available-for-sale securities held within the firm's insurance subsidiaries included in Other Assets, at Fair Value	9,070,000,000
Available-for-sale securities substantially all of which is held within the firm's insurance subsidiaries included in Total Financial Instruments Owned, at Fair Value		4,860,000,000
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	407,011,000,000	364,206,000,000
Commercial paper, certificates of deposit, time deposits and other money market instruments [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	6,057,000,000	13,440,000,000
Financial instruments sold, but not yet purchased, at fair value	0	0
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	6,057,000,000	13,440,000,000
U.S. government and federal agency obligations [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	93,241,000,000	87,040,000,000
Financial instruments sold, but not yet purchased, at fair value	15,905,000,000	21,006,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	93,241,000,000	87,040,000,000
Non-U.S. government and agency obligations [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	62,250,000,000	49,205,000,000
Financial instruments sold, but not yet purchased, at fair value	32,361,000,000	34,886,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	62,250,000,000	49,205,000,000
Loans and securities backed by commercial real estate [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	9,805,000,000	6,699,000,000
Financial instruments sold, but not yet purchased, at fair value	0	27,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	9,805,000,000	6,699,000,000
Loans and securities backed by residential real estate [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	8,216,000,000	7,592,000,000
Financial instruments sold, but not yet purchased, at fair value	4,000,000	3,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	8,216,000,000	7,592,000,000
Bank loans and bridge loans [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	22,407,000,000	19,745,000,000
Financial instruments sold, but not yet purchased, at fair value	1,779,000,000	2,756,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	22,407,000,000	19,745,000,000
Corporate Debt Securities [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	20,981,000,000	22,131,000,000
Financial instruments sold, but not yet purchased, at fair value	5,761,000,000	6,553,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	20,981,000,000	22,131,000,000
State and municipal obligations [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	2,477,000,000	3,089,000,000
Financial instruments sold, but not yet purchased, at fair value	1,000,000	3,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	2,477,000,000	3,089,000,000
Other debt obligations [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	2,251,000,000	4,362,000,000
Financial instruments sold, but not yet purchased, at fair value	0	0
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	2,251,000,000	4,362,000,000
Equities and convertible debentures [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	96,454,000,000	65,113,000,000
Financial instruments sold, but not yet purchased, at fair value	20,406,000,000	21,326,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	96,454,000,000	65,113,000,000
Commodities [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	11,696,000,000	5,762,000,000
Financial instruments sold, but not yet purchased, at fair value	0	0
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	11,696,000,000	5,762,000,000
Derivative [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	71,176,000,000	80,028,000,000
Financial instruments sold, but not yet purchased, at fair value	50,427,000,000	58,453,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	71,176,000,000	80,028,000,000
Commodities Accounted for As Collateralized Financings [Member]
Fair Value of Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	4,290,000,000	2,490,000,000
Trading Assets and Trading Liabilities (Textuals) [Abstract]
Financial instruments owned, at fair value (includes $67,177 and $53,989 pledged as collateral as of December 2012 and December 2011, respectively)	4,290,000,000	2,490,000,000
Interest Rates [Member]
Gains and Losses from Market Making and Other Principal Transactions
Trading Activity, Gains and Losses, Net	4,366,000,000	1,557,000,000	(2,042,000,000)
Credit [Member]
Gains and Losses from Market Making and Other Principal Transactions
Trading Activity, Gains and Losses, Net	5,506,000,000	2,715,000,000	8,679,000,000
Foreign Exchange [Member]
Gains and Losses from Market Making and Other Principal Transactions
Trading Activity, Gains and Losses, Net	(1,004,000,000)	901,000,000	3,219,000,000
Equity [Member]
Gains and Losses from Market Making and Other Principal Transactions
Trading Activity, Gains and Losses, Net	5,802,000,000	2,788,000,000	6,862,000,000
Commodity [Member]
Gains and Losses from Market Making and Other Principal Transactions
Trading Activity, Gains and Losses, Net	575,000,000	1,588,000,000	1,567,000,000
Other Trading [Member]
Gains and Losses from Market Making and Other Principal Transactions
Trading Activity, Gains and Losses, Net	$ 1,968,000,000	$ 1,245,000,000	$ 2,325,000,000