Derivative Instruments - Impact on Statements of Income, Risk Management Derivatives (Details 2d) (Not Designated as Hedging Instrument [Member], Risk Management Activities [Member], USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Risk management derivatives gains and losses [Abstract]
Income statement impact	$ 5,246	$ 2,433	$ 6,647	$ 6,109
Foreign exchange
Risk management derivatives gains and losses [Abstract]
Income statement impact	(110)	(30)	(208)	(50)
Credit derivatives
Risk management derivatives gains and losses [Abstract]
Income statement impact	99	(148)	36	(207)
Commodity
Risk management derivatives gains and losses [Abstract]
Income statement impact	13	(1)	13	(48)
Interest rate contract
Risk management derivatives gains and losses [Abstract]
Income statement impact	$ 5,244	$ 2,612	$ 6,806	$ 6,414