Variable Interest Entities - Interest in Securitized Assets Held at Fair Value (Details 6) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Key economic assumptions used to determine the fair value of certain of the Firm's retained interests, other than MSRs [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 the fair value of certain of the Firm's retained interests, other than MSRs [Abstract]
JPMorgan Chase interests in securitized assets	579	555
Variable Interest Entity, Not Primary Beneficiary [Member] | Subprime [Member]
Key economic assumptions used to determine the fair value of certain of the Firm's retained interests, other than MSRs [Abstract]
JPMorgan Chase interests in securitized assets	50	31
Variable Interest Entity, Not Primary Beneficiary [Member] | Option Arms
Key economic assumptions used to determine the fair value of certain of the Firm's retained interests, other than MSRs [Abstract]
JPMorgan Chase interests in securitized assets	25	23
Variable Interest Entity, Not Primary Beneficiary [Member] | Commercial mortgage [Member]
Key economic assumptions used to determine the fair value of certain of the Firm's retained interests, other than MSRs [Abstract]
JPMorgan Chase interests in securitized assets	3,666	3,663
Weighted-average life (in years)	5.4	3.0
Weighted-average constant prepayment rate	0.00%	0.00%
Impact of 10% adverse change	0	0
Impact of 20% adverse change	0	0
Weighted-average loss assumption	0.40%	0.20%
Impact of 10% adverse change	6	(61)
Impact of 20% adverse change	(51)	(119)
Weighted-average discount rate	3.80%	28.20%
Impact of 10% adverse change	(54)	(75)
Impact of 20% adverse change	(105)	(136)