Restructuring Restructuring Liability (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Restructuring Reserve [Roll Forward]    
Accrual Balance Beginning Balance $ 97  
Restructuring Charges 16 21
Payments made during the period (40) (46)
Foreign currency and other (8)  
Accrual Balance Ending Balance 65  
Employee Termination Benefits Liability    
Restructuring Reserve [Roll Forward]    
Accrual Balance Beginning Balance 95  
Restructuring Charges 16  
Payments made during the period (40)  
Foreign currency and other (8)  
Accrual Balance Ending Balance 63  
Other Exit Costs Liability    
Restructuring Reserve [Roll Forward]    
Accrual Balance Beginning Balance 2  
Restructuring Charges 0  
Payments made during the period 0  
Foreign currency and other 0  
Accrual Balance Ending Balance $ 2