Derivative Instruments - Credit Derivatives (Details 4a) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Total credit derivatives and credit-related notes
Protection sold	$ (3,129,341)	$ (2,755,024)
Protection purchased with identical underlyings	3,014,861	2,662,329
Net protection (sold)/purchased	(114,480)	(92,695)
Other protection purchased	58,561	60,428
Total credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(3,128,145)	(2,753,016)
Protection purchased with identical underlyings	3,014,861	2,662,329
Net protection (sold)/purchased	(113,284)	(90,687)
Other protection purchased	54,835	57,101
Credit default swaps
Total credit derivatives and credit-related notes
Protection sold	(3,033,703)	(2,659,240)
Protection purchased with identical underlyings	2,997,157	2,652,313
Net protection (sold)/purchased	(36,546)	(6,927)
Other protection purchased	30,305	32,867
Other credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(94,442)	(93,776)
Protection purchased with identical underlyings	17,704	10,016
Net protection (sold)/purchased	(76,738)	(83,760)
Other protection purchased	24,530	24,234
Credit-related notes
Total credit derivatives and credit-related notes
Protection sold	(1,196)	(2,008)
Protection purchased with identical underlyings	0	0
Net protection (sold)/purchased	(1,196)	(2,008)
Other protection purchased	$ 3,726	$ 3,327