v3.19.3.a.u2
Leases (Future Minimum Maturities of Lease Liabilities) (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Operating Leases [Abstract]    
2020 $ 4,723  
2021 4,349  
2022 4,028  
2023 3,611  
2024 3,078  
Thereafter 11,366  
Total lease payments 31,155  
Less: imputed interest (5,900)  
Total 25,255  
Finance Leases [Abstract]    
2020 340  
2021 305  
2022 289  
2023 274  
2024 258  
Thereafter 1,649  
Total lease payments 3,115  
Less: inputed interest (1,081)  
Total $ 2,034 $ 1,911