v3.20.4
Debt (Debt Maturing Within One Year) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Debt Disclosure [Abstract]    
Current maturities of long-term debt $ 3,470 $ 11,834
Bank borrowings 0 4
Total $ 3,470 $ 11,838