Derivatives (Details 5) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - assets	$ 72	$ 135
Derivative instruments - liabilities	106	49
Year-on-year currency effects, including hedging impact	(103)	154
Year-on-year derivative and other transaction gains and (losses) impact	49
Derivatives designated as hedging instruments
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - assets	62	110
Derivative instruments - liabilities	86	41
Derivatives designated as hedging instruments | Foreign currency forward/option contracts | Other current assets
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - assets	39	82
Derivatives designated as hedging instruments | Foreign currency forward/option contracts | Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - liabilities	85	34
Derivatives designated as hedging instruments | Commodity price swap contracts | Other current assets
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - assets	0	0
Derivatives designated as hedging instruments | Commodity price swap contracts | Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - liabilities	1	7
Derivatives designated as hedging instruments | Interest rate swap contracts | Other assets
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - assets	23	28
Derivatives designated as hedging instruments | Interest rate swap contracts | Other liabilities
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - liabilities	0	0
Derivatives not designated as hedging instruments
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - assets	10	25
Derivative instruments - liabilities	20	8
Derivatives not designated as hedging instruments | Foreign currency forward/option contracts | Other current assets
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - assets	10	25
Derivatives not designated as hedging instruments | Foreign currency forward/option contracts | Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Derivative instruments - liabilities	$ 20	$ 8