Derivatives (Details 4) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
CounterParties
Dec. 31, 2014
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets $ 561 $ 256
Fair Value of Derivative Instruments, Liabilities 73 43
Year-on-year currency effects impact on pre-tax net income, including hedging impact (90)  
Year-on-year derivative and other transaction gains and (losses) pre-tax impact 40  
Number of primary derivative counterparties 1  
Number of master netting agreements supported by primary counterparty's parent guarantee 16  
Number of credit support agreements by primary counterparty 15  
Derivatives designated as hedging instruments    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 441 190
Fair Value of Derivative Instruments, Liabilities 6 10
Derivatives designated as hedging instruments | Foreign currency forward/option contracts | Other current assets    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 310 116
Derivatives designated as hedging instruments | Foreign currency forward/option contracts | Other assets    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 100 47
Derivatives designated as hedging instruments | Foreign currency forward/option contracts | Other current liabilities    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Liabilities 6 2
Derivatives designated as hedging instruments | Foreign currency forward/option contracts | Other liabilities    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Liabilities 0 1
Derivatives designated as hedging instruments | Commodity price swap contracts | Other current assets    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets   0
Derivatives designated as hedging instruments | Commodity price swap contracts | Other current liabilities    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Liabilities   4
Derivatives designated as hedging instruments | Interest rate swap contracts | Other assets    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 31 27
Derivatives designated as hedging instruments | Interest rate swap contracts | Other liabilities    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Liabilities 0 3
Derivatives not designated as hedging instruments    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 120 66
Fair Value of Derivative Instruments, Liabilities 67 33
Derivatives not designated as hedging instruments | Foreign currency forward/option contracts | Other current assets    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 118 66
Derivatives not designated as hedging instruments | Foreign currency forward/option contracts | Other assets    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 1  
Derivatives not designated as hedging instruments | Foreign currency forward/option contracts | Other current liabilities    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Liabilities 62 33
Derivatives not designated as hedging instruments | Foreign currency forward/option contracts | Other liabilities    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Liabilities 1  
Derivatives not designated as hedging instruments | Commodity price swap contracts | Other current assets    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Assets 1  
Derivatives not designated as hedging instruments | Commodity price swap contracts | Other current liabilities    
Location and Fair Value Amount of Derivative Instruments    
Fair Value of Derivative Instruments, Liabilities $ 4