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Financial and Derivative Instruments - Additional Information (Details) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]    
Decrease in sales and other operating revenues due to cash flow hedging contracts $ 2 $ 0
Deferred losses in accumulated other comprehensive losses due to Outstanding crude oil price hedging contracts $ 4