Supplemental Oil and Gas Disclosures - Capitalization Cost (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Capitalized Costs Relating to Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved Properties	$ 8,928	$ 7,612
Unproved properties	1,765	1,891
Total property costs	10,693	9,503
Capitalized Costs, Accumulated Depreciation, Depletion, Amortization and Valuation Allowance Relating to Oil and Gas Producing Activities	3,491	2,542
Net capitalized costs	7,202	6,961
Equipment and facilities in support of oil and gas production excluded from capitalization	$ 350	$ 276

Amount of accumulated depreciation, depletion, amortization and valuation allowance relating to oil and gas producing activities.

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The sum of capitalized costs relating to oil and gas producing activities before accounting for accumulated depreciation.

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Net amount of capitalized costs relating to oil and gas producing activities.

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Capitalized costs of proved properties incurred for any combination mineral interests acquisitions; wells and related equipment; support equipment and facilities; and uncompleted wells and equipment and other costs not previously disclosed within this table.

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Capitalized costs of unproved properties incurred for any combination mineral interests acquisitions and other costs not previously disclosed within this table.

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The capitalized costs incurred during the period (excluded from amortization) to operate and maintain wells and related equipment and facilities, including depreciation and applicable operating costs of support equipment and facilities and other costs of operating and maintaining those wells and related equipment and facilities. They become part of the cost of oil and gas produced. Examples of production costs (sometimes called lifting costs) are: costs of labor to operate the wells and related equipment and facilities; repairs and maintenance; materials, supplies, and fuel consumed and supplies utilized in operating the wells and related equipment and facilities; property taxes and insurance applicable to proved properties and wells and related equipment and facilities; severance taxes; some support equipment or facilities may serve two or more oil and gas producing activities and may also serve transportation, refining, and marketing activities. To the extent that the support equipment and facilities are used in oil and gas producing activities, their depreciation and applicable operating costs become exploration, development or production costs, as appropriate. Depreciation, depletion, and amortization of capitalized acquisition, exploration, and development costs are not production costs but also become part of the cost of oil and gas produced along with production (lifting) costs identified above.

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