Financial Instruments (Fair Value of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Notes to Condensed Consolidated Financial Statements [Abstract]
Derivative Asset, Fair Value	$ 98	$ 128
Derivative Liability, Fair Value	205	149
Other Assets, Current [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Asset at Fair Value	8	48
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	82	47
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Asset at Fair Value	3	30
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	5	3
Assets, Total [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Asset at Fair Value	11	78
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	87	50
Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Liability at Fair Value	53	10
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	111	136
Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Liability at Fair Value	40	1
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	1	2
Liabilities, Total [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Liability at Fair Value	93	11
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	$ 112	$ 138