Hedging Activities (Summary Of Notional Amounts And Respective Fair Values Of Derivative Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivatives Fair Value [Line Items]
Total derivatives - Notional amount	$ 3,208	$ 3,996
Asset derivatives, Fair value	166	12
Liability derivatives, Fair value	(13)	(169)
Foreign Exchange Contracts [Member]
Derivatives Fair Value [Line Items]
Derivatives designated as hedging instruments - Notional amount	719	402
Derivatives not designated as hedging instruments - Notional amount	1,939	3,094
Benchmark Interest Rate [Member]
Derivatives Fair Value [Line Items]
Derivatives designated as hedging instruments - Notional amount		500
Interest Rate Swap [Member]
Derivatives Fair Value [Line Items]
Derivatives designated as hedging instruments - Notional amount	550
Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Derivative not designated as hedging instruments - Fair value	109	6
Designated As Hedging Instrument [Member]
Derivatives Fair Value [Line Items]
Liability derivatives, Fair value		(33)
Designated As Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Asset derivatives, Fair value	57	6
Designated As Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Derivatives Fair Value [Line Items]
Liability derivatives, Fair value	(3)	(8)
Derivatives Not Designated As Hedging Instruments [Member] | Other Accrued Liabilities [Member]
Derivatives Fair Value [Line Items]
Liability derivatives, Fair value	(10)	(122)
Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Liability derivatives, Fair value		$ (6)