Derivative Financial Instruments (Summary Of Aggregate Contractual Or Notional Amounts And Gross Estimated Fair Values Related To Derivative Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Designated As Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Contractual/Notional Amount	$ 300	$ 1,095
Estimated Fair Value Asset	3
Estimated Fair Value (Liability)	(3)	(75)
Designated As Hedging Instrument [Member] | Commodities Forwards - Short [Member]
Derivative [Line Items]
Contractual/Notional Amount	268	487
Estimated Fair Value Asset	64	70
Estimated Fair Value (Liability)	(22)	(24)
Designated As Hedging Instrument [Member] | Currency Forwards - Short [Member]
Derivative [Line Items]
Contractual/Notional Amount	154	140
Estimated Fair Value Asset	1	4
Estimated Fair Value (Liability)	(8)
Not Designated As Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Contractual/Notional Amount	100	5
Estimated Fair Value Asset	1
Estimated Fair Value (Liability)	(1)	(1)
Not Designated As Hedging Instrument [Member] | Currency Forwards - Short [Member]
Derivative [Line Items]
Contractual/Notional Amount	330
Estimated Fair Value (Liability)	(2)
Not Designated As Hedging Instrument [Member] | Equity Options - Purchased [Member]
Derivative [Line Items]
Contractual/Notional Amount	286	207
Estimated Fair Value Asset	33	30
Not Designated As Hedging Instrument [Member] | Equity Options - Written [Member]
Derivative [Line Items]
Contractual/Notional Amount	398	340
Estimated Fair Value (Liability)	(23)	(10)
Not Designated As Hedging Instrument [Member] | Equity Swaps And Warrants - Long [Member]
Derivative [Line Items]
Contractual/Notional Amount	63
Estimated Fair Value Asset	16
Not Designated As Hedging Instrument [Member] | Credit Default Swaps - Purchased Protection [Member]
Derivative [Line Items]
Contractual/Notional Amount	145	20
Estimated Fair Value Asset	8
Estimated Fair Value (Liability)	(1)	(2)
Not Designated As Hedging Instrument [Member] | Credit Default Swaps - Sold Protection [Member]
Derivative [Line Items]
Contractual/Notional Amount	28	8
Estimated Fair Value Asset		1
Estimated Fair Value (Liability)	(2)
Not Designated As Hedging Instrument [Member] | Currency Forwards - Long [Member]
Derivative [Line Items]
Contractual/Notional Amount	203
Estimated Fair Value Asset	$ 4