Suspended Wells and Exploration Expenses (Aging of Suspended Well Cost) (Details) $ in Millions	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Suspended Wells and Exploration Expenses [Abstract]
Exploratory well costs capitalized for a period of one year or less	$ 4	$ 156	$ 206
Exploratory well costs capitalized for a period greater than one year	656	526	814
Ending balance	$ 660	$ 682	$ 1,020	$ 856
Number of projects with exploratory well costs capitalized for a period greater than one year	22	22	23
Capitalized Exploratory Well Costs [Line Items]
Capitalized cost of suspended wells	$ 660	$ 682	$ 1,020	$ 856
Australia [Member]
Suspended Wells and Exploration Expenses [Abstract]
Ending balance			313
Capitalized Exploratory Well Costs [Line Items]
Capitalized cost of suspended wells			$ 313