v3.3.1.900
Pension And Other Postretirement Benefits (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]      
Health care cost trend rate projected in 2017 4.50%    
Year that rate reaches ultimate trend rate 2017    
Effect of one-percentage-point increase on service and interest costs $ 88    
Effect of one-percentage-point increase on postretirement benefit obligation 963    
Effect of one-percentage-point decrease on service and interest costs 66    
Effect of one-percentage-point decrease on postretirement benefit obligation 764    
Costs for defined contribution plans $ 405 $ 393 $ 392
Pension Benefits - U.S. [Member] | Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Target asset allocation 40.00%    
Pension Benefits - U.S. [Member] | Debt Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Target asset allocation 60.00%    
Pension Benefits - U.S. [Member] | Venture Capital Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Target asset allocation 5.00%    
Pension Benefits - Non-U.S. [Member] | Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Target asset allocation 40.00%    
Pension Benefits - Non-U.S. [Member] | Debt Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Target asset allocation 60.00%    
Pension Benefits - Non-U.S. [Member] | Venture Capital Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Target asset allocation 3.00%