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Other, Net -Summary Of Other Expenses (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Other Expenses [Abstract]      
Asset retirement obligation accretion $ 20 $ 21 $ 26
Severance tax refunds (40)   (5)
Other (14) (17) (28)
Total $ (34) $ 4 $ (7)