Derivative Instruments - Credit Derivatives, Protection Sold, Notional and Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Protection sold credit derivatives and credit related notes ratings/maturity profile
Protection sold credit derivatives and credit related notes ratings/maturity profile - less than one year	$ (417,674)	$ (480,679)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from one to five years	(1,304,231)	(1,515,091)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than five years	(94,082)	(104,533)
Total notional amount	(1,815,987)	(2,100,303)
Net fair value	18,268	17,675
Investment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Protection sold credit derivatives and credit related notes ratings/maturity profile - less than one year	(291,246)	(323,398)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from one to five years	(958,426)	(1,118,293)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than five years	(65,049)	(79,486)
Total notional amount	(1,314,721)	(1,521,177)
Net fair value	14,818	19,453
Noninvestment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Protection sold credit derivatives and credit related notes ratings/maturity profile - less than one year	(126,428)	(157,281)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from one to five years	(345,805)	(396,798)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than five years	(29,033)	(25,047)
Total notional amount	(501,266)	(579,126)
Net fair value	3,450	(1,778)
Trading assets
Protection sold credit derivatives and credit related notes ratings/maturity profile
Fair value of receivables	35,741	46,444
Trading assets | Investment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Fair value of receivables	18,552	25,767
Trading assets | Noninvestment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Fair value of receivables	17,189	20,677
Trading liabilities
Protection sold credit derivatives and credit related notes ratings/maturity profile
Fair value of payables	(17,473)	(28,769)
Trading liabilities | Investment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Fair value of payables	(3,734)	(6,314)
Trading liabilities | Noninvestment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Fair value of payables	$ (13,739)	$ (22,455)