Fair Value Measurement - Carrying Value and Estimated Fair Value (Details 7) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Financial assets
Federal funds sold and securities purchased under resale agreements (included $22.2 and $20.3 at fair value)	$ 248,042,000,000		$ 248,042,000,000			$ 222,554,000,000
Mortgage servicing rights at fair value	7,833,000,000	10,305,000,000	7,833,000,000	10,305,000,000	12,243,000,000	13,649,000,000	11,853,000,000	15,531,000,000
Financial liabilities
Net appreciation	3,000,000,000		3,000,000,000			300,000,000
Long-term advances from Federal Home Loan Banks						23,000,000,000
Asset and Liability Parenthetical Fair Values [Abstract]
Federal funds sold and securities purchased under resale agreements, at fair value	248,042,000,000		248,042,000,000			222,554,000,000
Securities borrowed, at fair value	131,561,000,000		131,561,000,000			123,587,000,000
Other assets, at fair value	109,310,000,000		109,310,000,000			105,291,000,000
Deposits, at fair value	1,092,708,000,000		1,092,708,000,000			930,369,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements, at fair value	238,585,000,000		238,585,000,000			276,644,000,000
Other borrowed funds, at fair value	29,318,000,000		29,318,000,000			34,325,000,000
Beneficial interest liability, at fair value	65,971,000,000		65,971,000,000			77,649,000,000
Trading assets and liabilities average balances Abstract
Trading assets - debt and equity instruments	377,840,000,000	347,990,000,000	405,861,000,000	340,181,000,000
Trading assets - derivative receivables	96,612,000,000	92,857,000,000	88,344,000,000	83,702,000,000
Trading liabilities - debt and equity instruments	85,541,000,000	79,838,000,000	84,246,000,000	76,104,000,000
Trading liabilities - derivative payables	75,828,000,000	69,350,000,000	71,058,000,000	63,688,000,000
Fair Value, Measurements, Recurring [Member] | Other Assets [Member] | Fair value
Asset and Liability Parenthetical Fair Values [Abstract]
Other assets, at fair value	16,131,000,000		16,131,000,000			18,201,000,000
Fair Value, Measurements, Recurring [Member] | Fair value
Financial assets
Federal funds sold and securities purchased under resale agreements (included $22.2 and $20.3 at fair value)	22,192,000,000		22,192,000,000			20,299,000,000
Loans (included $2.0 and $2.0 at fair value)	1,997,000,000		1,997,000,000			1,976,000,000
Asset and Liability Parenthetical Fair Values [Abstract]
Federal funds sold and securities purchased under resale agreements, at fair value	22,192,000,000		22,192,000,000			20,299,000,000
Securities borrowed, at fair value	14,648,000,000		14,648,000,000			13,961,000,000
Securities, at fair value	339,336,000,000		339,336,000,000			316,318,000,000
Loans, at fair value	1,997,000,000		1,997,000,000			1,976,000,000
Deposits, at fair value	4,816,000,000		4,816,000,000			4,369,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements, at fair value	7,011,000,000		7,011,000,000			4,060,000,000
Other borrowed funds, at fair value	9,381,000,000		9,381,000,000			9,931,000,000
Accounts payable and other liabilities, at fair value	68,000,000		68,000,000			236,000,000
Beneficial interest liability, at fair value	905,000,000		905,000,000			1,495,000,000
Long term debt borrowings, at fair value	35,865,000,000		35,865,000,000			38,839,000,000
Contractual principal outstanding
Financial assets
Assets for which fair value approximates carrying value	185,600,000,000		185,600,000,000			49,200,000,000
Accrued interest and accounts receivable	72,100,000,000		72,100,000,000			70,100,000,000
Federal funds sold and securities purchased under resale agreements (included $22.2 and $20.3 at fair value)	248,000,000,000		248,000,000,000			222,600,000,000
Securities borrowed (included $14.6 and $14.0 at fair value)	131,600,000,000		131,600,000,000			123,600,000,000
Trading assets	461,500,000,000		461,500,000,000			489,900,000,000
Securities (included $339.3 and $316.3 at fair value)	339,300,000,000		339,300,000,000			316,300,000,000
Loans (included $2.0 and $2.0 at fair value)	668,500,000,000		668,500,000,000			660,700,000,000
Mortgage servicing rights at fair value	7,800,000,000		7,800,000,000			13,600,000,000
Other (included $16.1 and $18.2 at fair value)	68,100,000,000		68,100,000,000			64,900,000,000
Total financial assets	2,182,500,000,000		2,182,500,000,000			2,010,900,000,000
Financial liabilities
Deposits (included $4.8 and $4.4 at fair value)	1,092,700,000,000		1,092,700,000,000			930,400,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $7.0 and $4.1 at fair value)	238,600,000,000		238,600,000,000			276,600,000,000
Commercial paper	51,100,000,000		51,100,000,000			35,400,000,000
Other borrowed funds (included $9.4 and $9.9 at fair value)	29,300,000,000		29,300,000,000			34,300,000,000
Trading liabilities	155,800,000,000		155,800,000,000			146,200,000,000
Accounts payable and other liabilities (included $0.1 and $0.2 at fair value)	164,900,000,000		164,900,000,000			138,200,000,000
Beneficial interests issued by consolidated VIEs (included $0.9 and $1.5 at fair value)	66,000,000,000		66,000,000,000			77,600,000,000
Long-term debt and junior subordinated deferrable interest debentures (included $35.9 and $38.8 at fair value)	273,700,000,000		273,700,000,000			270,700,000,000
Total financial liabilities	2,072,100,000,000		2,072,100,000,000			1,909,400,000,000
Asset and Liability Parenthetical Fair Values [Abstract]
Federal funds sold and securities purchased under resale agreements, at fair value	248,000,000,000		248,000,000,000			222,600,000,000
Loans, at fair value	668,500,000,000		668,500,000,000			660,700,000,000
The Carrying Value and estimated fair value of the Firm's wholesale lending- related commitments [Abstract]
Wholesale lending related commitments	700,000,000		700,000,000			700,000,000
Appreciation/(depreciation)
Financial assets
Assets for which fair value approximates carrying value	0		0			0
Accrued interest and accounts receivable	0		0			0
Federal funds sold and securities purchased under resale agreements (included $22.2 and $20.3 at fair value)	0		0			0
Securities borrowed (included $14.6 and $14.0 at fair value)	0		0			0
Trading assets	0		0			0
Securities (included $339.3 and $316.3 at fair value)	0		0			0
Loans (included $2.0 and $2.0 at fair value)	800,000,000		800,000,000			2,800,000,000
Mortgage servicing rights at fair value	0		0			0
Other (included $16.1 and $18.2 at fair value)	500,000,000		500,000,000			100,000,000
Total financial assets	1,300,000,000		1,300,000,000			2,900,000,000
Financial liabilities
Deposits (included $4.8 and $4.4 at fair value)	(700,000,000)		(700,000,000)			(1,100,000,000)
Federal funds purchased and securities loaned or sold under repurchase agreements (included $7.0 and $4.1 at fair value)	0		0			0
Commercial paper	0		0			0
Other borrowed funds (included $9.4 and $9.9 at fair value)	0		0			0
Trading liabilities	0		0			0
Accounts payable and other liabilities (included $0.1 and $0.2 at fair value)	100,000,000		100,000,000			0
Beneficial interests issued by consolidated VIEs (included $0.9 and $1.5 at fair value)	(300,000,000)		(300,000,000)			(300,000,000)
Long-term debt and junior subordinated deferrable interest debentures (included $35.9 and $38.8 at fair value)	2,600,000,000		2,600,000,000			(1,200,000,000)
Total financial liabilities	1,700,000,000		1,700,000,000			(2,600,000,000)
Asset and Liability Parenthetical Fair Values [Abstract]
Federal funds sold and securities purchased under resale agreements, at fair value	0		0			0
Loans, at fair value	800,000,000		800,000,000			2,800,000,000
Estimate of Fair Value
Financial assets
Assets for which fair value approximates carrying value	185,600,000,000		185,600,000,000			49,200,000,000
Accrued interest and accounts receivable	72,100,000,000		72,100,000,000			70,100,000,000
Federal funds sold and securities purchased under resale agreements (included $22.2 and $20.3 at fair value)	248,000,000,000		248,000,000,000			222,600,000,000
Securities borrowed (included $14.6 and $14.0 at fair value)	131,600,000,000		131,600,000,000			123,600,000,000
Trading assets	461,500,000,000		461,500,000,000			489,900,000,000
Securities (included $339.3 and $316.3 at fair value)	339,300,000,000		339,300,000,000			316,300,000,000
Loans (included $2.0 and $2.0 at fair value)	669,300,000,000		669,300,000,000			663,500,000,000
Mortgage servicing rights at fair value	7,800,000,000		7,800,000,000			13,600,000,000
Other (included $16.1 and $18.2 at fair value)	68,600,000,000		68,600,000,000			65,000,000,000
Total financial assets	2,183,800,000,000		2,183,800,000,000			2,013,800,000,000
Financial liabilities
Deposits (included $4.8 and $4.4 at fair value)	1,093,400,000,000		1,093,400,000,000			931,500,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $7.0 and $4.1 at fair value)	238,600,000,000		238,600,000,000			276,600,000,000
Commercial paper	51,100,000,000		51,100,000,000			35,400,000,000
Other borrowed funds (included $9.4 and $9.9 at fair value)	29,300,000,000		29,300,000,000			34,300,000,000
Trading liabilities	155,800,000,000		155,800,000,000			146,200,000,000
Accounts payable and other liabilities (included $0.1 and $0.2 at fair value)	164,800,000,000		164,800,000,000			138,200,000,000
Beneficial interests issued by consolidated VIEs (included $0.9 and $1.5 at fair value)	66,300,000,000		66,300,000,000			77,900,000,000
Long-term debt and junior subordinated deferrable interest debentures (included $35.9 and $38.8 at fair value)	271,100,000,000		271,100,000,000			271,900,000,000
Total financial liabilities	2,070,400,000,000		2,070,400,000,000			1,912,000,000,000
Asset and Liability Parenthetical Fair Values [Abstract]
Federal funds sold and securities purchased under resale agreements, at fair value	248,000,000,000		248,000,000,000			222,600,000,000
Loans, at fair value	669,300,000,000		669,300,000,000			663,500,000,000
The Carrying Value and estimated fair value of the Firm's wholesale lending- related commitments [Abstract]
Wholesale lending related commitments	3,300,000,000		3,300,000,000			900,000,000
Fair Value, Measurements, Recurring [Member]
Financial assets
Trading assets	461,531,000,000		461,531,000,000			489,892,000,000
Mortgage servicing rights at fair value	7,833,000,000		7,833,000,000			13,649,000,000
Financial liabilities
Trading liabilities	155,841,000,000		155,841,000,000			146,166,000,000
Total financial liabilities	$ 213,887,000,000		$ 213,887,000,000			$ 205,096,000,000