Pension and Postretirement Benefit Plans (Components of net periodic benefit cost and other information) (Details 1) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Amounts recognized in the Consolidated Balance Sheet      
Non-current assets $ 56   $ 46
Accrued benefit cost      
Non-current liabilities (3,764)   (3,843)
Qualified and Non-qualified Pension Benefits      
Change in plan assets      
Company contributions 90    
United States Qualified and Non-qualified Pension Benefits      
Change in benefit obligation      
Service cost 73 60  
Interest cost 164 169  
International Qualified and Non-qualified Pension Benefits      
Change in benefit obligation      
Service cost 42 36  
Interest cost 55 64  
Postretirement Benefits      
Change in benefit obligation      
Service cost 21 16  
Interest cost 25 24  
Change in plan assets      
Company contributions $ 1