Financial Instruments Gain (Loss) Recognized on Derivatives Not Designated as Hedging Table (Details) (Not Designated as Hedging Instrument [Member], Net Gain from Investment Activities [Member], USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Derivative [Line Items]
Gain (Loss) Recognized in Income, Derivatives Not Designated as Hedging	$ (893)	[1]	$ 32	[1]	$ (1,331)	[1]	$ 70	[1]
Equity Contract [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income, Derivatives Not Designated as Hedging	(680)	[1]	28	[1]	(1,141)	[1]	37	[1]
Foreign Exchange Contract [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income, Derivatives Not Designated as Hedging	(44)	[1]	11	[1]	(19)	[1]	(2)	[1]
Credit Risk Contract [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income, Derivatives Not Designated as Hedging	1	[1]	0	[1]	1	[1]	19	[1]
Futures Index Spread [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income, Derivatives Not Designated as Hedging	0	[1]	(7)	[1]	0	[1]	16	[1]
Commodity contracts [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income, Derivatives Not Designated as Hedging	$ (170)	[1]	$ 0	[1]	$ (172)	[1]	$ 0	[1]

[1] Gains (losses) recognized on derivatives are classified in net gain from investment activities in our consolidated statements of operations.