Financial Instruments (Details 1) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	$ 557	$ 628
Fair Value of Derivative, Liability	68	61
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	23,583	20,446
U.S. Dollar Notional	23,583	20,446
Basis adjustments on debt for discontinued interest rate swaps	139
Designated As Hedging Instrument [Member] | Foreign exchange contract [Member] | Deferred income taxes and other current assets [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	91	167
Fair Value of Derivative, Liability	0	0
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	3,696	2,344
U.S. Dollar Notional	3,696	2,344
Designated As Hedging Instrument [Member] | Foreign exchange contract [Member] | Deferred income taxes and noncurrent liabilities [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	0	0
Fair Value of Derivative, Liability	3	6
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	113	503
U.S. Dollar Notional	113	503
Designated As Hedging Instrument [Member] | Foreign exchange contract [Member] | Accrued and other current liabilities [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	0	0
Fair Value of Derivative, Liability	40	18
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	1,825	1,505
U.S. Dollar Notional	1,825	1,505
Designated As Hedging Instrument [Member] | Foreign exchange contract [Member] | Other Assets [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	288	310
Fair Value of Derivative, Liability	0	0
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	4,469	3,720
U.S. Dollar Notional	4,469	3,720
Derivatives not designated in a hedging relationship [Member] | Foreign exchange contract [Member] | Deferred income taxes and other current assets [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	106	95
Fair Value of Derivative, Liability	0	0
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	7,894	6,295
U.S. Dollar Notional	7,894	6,295
Derivatives not designated in a hedging relationship [Member] | Foreign exchange contract [Member] | Accrued and other current liabilities [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	0	0
Fair Value of Derivative, Liability	25	30
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	3,736	4,229
U.S. Dollar Notional	3,736	4,229
Designated As Hedging Instrument [Member] | Interest rate swap contract [Member] | Deferred income taxes and other current assets [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	6	0
Fair Value of Derivative, Liability	0	0
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	250	0
U.S. Dollar Notional	250	0
Designated As Hedging Instrument [Member] | Interest rate swap contract [Member] | Deferred income taxes and noncurrent liabilities [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	0	0
Fair Value of Derivative, Liability	0	7
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	0	850
U.S. Dollar Notional	0	850
Designated As Hedging Instrument [Member] | Interest rate swap contract [Member] | Other Assets [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	66	56
Fair Value of Derivative, Liability	0	0
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	1,600	1,000
U.S. Dollar Notional	1,600	1,000
Due 2015 [Member] | Swap One [Member]
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional, Interest Rate Swaps	750
Due 2016 [Member] | Swap One [Member]
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional, Interest Rate Swaps	125
Due 2015 [Member] | Swap Two [Member]
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional, Interest Rate Swaps	150
Designated As Hedging Instrument [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	451	533
Fair Value of Derivative, Liability	43	31
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	11,953	9,922
U.S. Dollar Notional	11,953	9,922
Derivatives not designated in a hedging relationship [Member]
Fair value of derivatives segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments
Fair Value of Derivative, Asset	106	95
Fair Value of Derivative, Liability	25	30
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional	11,630	10,524
U.S. Dollar Notional	11,630	10,524
Due 2011 [Member]
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional, Interest Rate Swaps	125
Due 2016 [Member]
Derivatives Designated as Hedging Instruments
U.S. Dollar Notional, Interest Rate Swaps	$ 850