Financial and Derivative Instruments - Effect of Derivatives (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Pre-tax deferred losses	$ (2)	$ (2)
Commodity
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Effect of derivatives, gain (loss), net	(85)	(977)
Commodity | Sales and other operating revenues
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Effect of derivatives, gain (loss), net	(97)	(873)
Commodity | Purchased crude oil and products
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Effect of derivatives, gain (loss), net	18	(105)
Commodity | Other income
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Effect of derivatives, gain (loss), net	$ (6)	$ 1