v3.3.1.900
Retirement Benefits Plans - Change in Benefit Obligations (Details 1) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
United States pension liabilities [Member]      
Change in benefit obligations      
Balance at January 1 $ 4,047 $ 3,625  
Service cost 123 117 $ 128
Interest cost 156 162 147
Actuarial loss (gain) (179) 470  
Gross benefits paid (318) (329)  
Currency translation 0 0  
Plan amendments 0 2  
Other 0 0  
Balance at December 31 3,829 4,047 3,625
Accumulated benefit obligation 3,672 3,894  
Non-United States pension liabilities [Member]      
Change in benefit obligations      
Balance at January 1 2,337 2,127  
Service cost 71 66 62
Interest cost 72 85 80
Actuarial loss (gain) (23) 355  
Gross benefits paid (100) (106)  
Currency translation (182) (190)  
Plan amendments 0 0  
Other 0 0  
Balance at December 31 2,175 2,337 2,127
Accumulated benefit obligation 2,049 2,181  
Other postretirement liabilities [Member]      
Change in benefit obligations      
Balance at January 1 676 867  
Service cost 6 13 20
Interest cost 24 32 35
Actuarial loss (gain) (66) (36)  
Gross benefits paid (86) (91)  
Currency translation (8) (4)  
Plan amendments (1) (84)  
Other 30 (21)  
Balance at December 31 $ 575 $ 676 $ 867