Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Narrative (Details)

v3.10.0.1
Employee Benefit Plans - Narrative (Details) - USD ($)
shares in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 23,475,000,000 $ 25,675,000,000  
Increase (decrease) from change in weighted average discount rates (1,300,000,000) 1,100,000,000  
Defined Contribution Plan:      
Cost recognized $ 1,000,000,000.0 $ 1,000,000,000 $ 1,000,000,000
Number of common stock shares held in plan (in shares) 212 218  
Dividend payments to the plan $ 115,000,000 $ 86,000,000 60,000,000
U.S. | Pension Plan | Qualified      
Defined Benefit Plan Disclosure [Line Items]      
Company contributions 0 0  
Fair value of plan assets $ 18,178,000,000 19,708,000,000 18,239,000,000
Percentage of prior years market gains (losses) recognized at next measurement date 60.00%    
Percentage of prior years market gains (losses) recognized equally over four year period 40.00%    
U.S. | Pension Plan | Qualified | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Amount of employer and related party securities included in plan assets $ 221,000,000 $ 261,000,000  
Actual plan asset allocations 1.22% 1.33%  
U.S. | Other Pension Plan      
Defined Benefit Plan Disclosure [Line Items]      
Company contributions $ 0 $ 0  
U.S. | Other Pension Plan | Nonqualified      
Defined Benefit Plan Disclosure [Line Items]      
Company contributions 91,000,000 98,000,000  
Fair value of plan assets 2,584,000,000 2,724,000,000 2,744,000,000
Estimated future employer contributions in next fiscal year 91,000,000    
U.S. | Postretirement Health and Life Plans      
Defined Benefit Plan Disclosure [Line Items]      
Company contributions 43,000,000 393,000,000  
Fair value of plan assets 252,000,000 300,000,000 0
Estimated future employer contributions in next fiscal year $ 15,000,000    
Percentage of unrecognized gain (loss) recognized during the period 50.00%    
Health care cost trend rate assumed for next fiscal year 6.50%    
Ultimate health care cost trend rate 5.00%    
Non-U.S. | Pension Plan      
Defined Benefit Plan Disclosure [Line Items]      
Company contributions $ 22,000,000 23,000,000  
Fair value of plan assets 2,461,000,000 $ 2,943,000,000 $ 2,789,000,000
Estimated future employer contributions in next fiscal year $ 21,000,000