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Commitments and Contingencies Personal Injury (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Sep. 30, 2019
Loss Contingency Accrual [Roll Forward]        
Beginning balance $ 120      
Ending balance 115 $ 120    
Personal Injury        
Loss Contingency Accrual [Roll Forward]        
Beginning balance 308 307 $ 367  
Accruals / changes in estimates 80 76 (1)  
Payments (113) (75) (59)  
Ending balance 275 308 307  
Current portion of ending balance $ 75 $ 80 $ 85  
Personal Injury | Minimum        
Loss Contingency Accrual [Roll Forward]        
Future costs to settle claims and associated liability       $ 235
Personal Injury | Maximum        
Loss Contingency Accrual [Roll Forward]        
Future costs to settle claims and associated liability       $ 330