Derivative Instruments - Credit Derivatives (Details 4a) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Total credit derivatives and credit-related notes
Protection sold	$ (3,156,665)	$ (2,919,945)
Protection purchased with identical underlyings	(2,950,051)	(2,803,161)
Net protection (sold)/purchased	(206,614)	(116,784)
Other protection purchased	61,849	55,375
Credit Derivatives - supplemental information
Stockholders' equity	189,269		180,598
Total credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(3,156,155)	(2,919,203)
Protection purchased with identical underlyings	(2,950,051)	(2,803,161)
Net protection (sold)/purchased	(206,104)	(116,042)
Other protection purchased	57,692	51,431
Credit default swaps
Total credit derivatives and credit-related notes
Protection sold	(3,072,113)	(2,839,492)
Protection purchased with identical underlyings	(2,942,724)	(2,798,207)
Net protection (sold)/purchased	(129,389)	(41,285)
Other protection purchased	32,018	29,139
Other credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(84,042)	(79,711)
Protection purchased with identical underlyings	(7,327)	(4,954)
Net protection (sold)/purchased	(76,715)	(74,757)
Other protection purchased	25,674	22,292
Credit-related notes
Total credit derivatives and credit-related notes
Protection sold	(510)	(742)
Protection purchased with identical underlyings	0	0
Net protection (sold)/purchased	(510)	(742)
Other protection purchased	4,157	3,944
Credit Portfolio [Member] | Credit default swaps
Total credit derivatives and credit-related notes
Protection sold	100	131
Protection purchased with identical underlyings	$ (29,700)	$ (26,400)