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 |