Variable Interest Entities - Municipal Bond Vehicle VIEs (Details 2a) (USD $)															3 Months Ended	12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011		Mar. 31, 2012 Standby Letters of Credit, and Other Financial Guarantees [Member]	Dec. 31, 2011 Standby Letters of Credit, and Other Financial Guarantees [Member]	Mar. 31, 2012 Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2011 Variable Interest Entity, Primary Beneficiary [Member]	Mar. 31, 2012 Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2012 JPMorgan Chase & Co Municipal Bonds [Member]	Dec. 31, 2011 JPMorgan Chase & Co Municipal Bonds [Member]	Mar. 31, 2012 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] years	Dec. 31, 2011 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] years	Mar. 31, 2012 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade AAA to AAA-	Dec. 31, 2011 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade AAA to AAA-	Mar. 31, 2012 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade AAplus to AA-	Dec. 31, 2011 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade AAplus to AA-	Mar. 31, 2012 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade Aplus to A-	Dec. 31, 2011 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade Aplus to A-	Mar. 31, 2012 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade BBB to BBB-	Dec. 31, 2011 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Investment Grade BBB to BBB-	Mar. 31, 2012 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Noninvestment-grade	Dec. 31, 2011 Nonconsolidated Municipal Bond Vehicles Municipal Bonds [Member] Noninvestment-grade
Firm's exposure to nonconsolidated municipal bond VIEs [Abstract]
Fair value of non-consolidated assets held by VIEs	$ 2,320,164,000,000	[1]	$ 2,265,792,000,000	[1]	$ 2,198,161,000,000	[1]			$ 98,100,000,000	$ 101,500,000,000					$ 13,800,000,000	$ 13,500,000,000	$ 1,500,000,000	$ 1,500,000,000	$ 11,500,000,000	$ 11,200,000,000	$ 700,000,000	$ 700,000,000	$ 0	$ 0	$ 100,000,000	$ 100,000,000
Variable Interest Entity Weighted Average Expected Life Of Assets Unconsolidated V I E															6.3	6.6
Liquidity facilities provided by Firm serving as liquidity provider															7,900,000,000	7,900,000,000
Excess/ (deficit)															5,900,000,000	5,600,000,000
Maximum exposure											23,400,000,000	25,400,000,000	7,900,000,000	7,900,000,000
Total lending related commitments	$ 997,503,000,000		$ 975,662,000,000		$ 985,934,000,000		$ 102,014,000,000	$ 101,899,000,000

[1] (a)The following table presents information on assets and liabilities related to VIEs that are consolidated by the Firm at March 31, 2012, and December 31, 2011. The difference between total VIE assets and liabilities represents the Firm’s interests in those entities, which were eliminated in consolidation.