Variable Interest Entities - Interest in Securitized Assets Held at Fair Value (Details 6) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Key Economic Assumptions Used to Determine Fair Value [Abstract]
Changes In Fair Value Based On Variation In Assumptions Limit First	10.00%	20.00%
Variable Interest Entity, Not Primary Beneficiary [Member] | Prime [Member]
Key Economic Assumptions Used to Determine Fair Value [Abstract]
JPMorgan Chase interests in securitized assets	553	555
Variable Interest Entity, Not Primary Beneficiary [Member] | Subprime [Member]
Key Economic Assumptions Used to Determine Fair Value [Abstract]
JPMorgan Chase interests in securitized assets	52	31
Variable Interest Entity, Not Primary Beneficiary [Member] | Option Arms
Key Economic Assumptions Used to Determine Fair Value [Abstract]
JPMorgan Chase interests in securitized assets	0	23
Variable Interest Entity, Not Primary Beneficiary [Member] | Commercial mortgage
Key Economic Assumptions Used to Determine Fair Value [Abstract]
JPMorgan Chase interests in securitized assets	1,366	1,585
Weighted-average life (in years)	6.7	1.0
Weighted-average discount rate	4.20%	59.10%
Impact of 10% adverse change	(33)	(45)
Impact of 20% adverse change	(65)	(76)