Exploratory Well Costs (Details) $ in Millions		12 Months Ended
		Dec. 31, 2021 USD ($) well	Dec. 31, 2020 USD ($) well		Dec. 31, 2019 USD ($) well
Capitalized Exploratory Well Costs [Abstract]
Balance at January 1		$ 29	$ 26		$ 4
Additions Pending the Determination of Proved Reserves		73	108		83
Reclassifications to Proved Properties		(41)	(81)		(39)
Costs Charged to Expense (1)	[1]	(54)	(24)		(22)
Balance at December 31		$ 7	$ 29		$ 26
Projects that have Exploratory Well Costs that have been Capitalized for Period Greater than One Year, Number of Projects | well		0	1		0
Capitalized Exploratory Well Costs that Have Been Capitalized for Period of One Year or Less		$ 7	$ 26		$ 26
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year		$ 0	$ 3	[2]	$ 0

[1] Includes capitalized exploratory well costs charged to either dry hole costs or impairments.

[2] (1)    Consists of costs related to a project in the United States at December 31, 2020.