Divestitures and Other Transactions - Summary of Revenues and Costs from Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Costs and other deductions
Net income of Algeria operations, after taxes	$ (445)	$ 0
Algeria Africa Assets | Disposal Group, Not Discontinued Operations
Revenues and other income
Net sales		203
Costs and other deductions
Oil and gas lease operating expense		23
Transportation expense		7
Taxes other than on income		43
Depreciation, depletion and amortization		67
Other		6
Total costs and other deductions		146
Income before income taxes		57
Income tax expense		(57)
Net income of Algeria operations, after taxes		$ 0