Fair Value Measurement - Schedule of Net Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Financial Assets [Abstract]
Investment in Cenovus Energy	$ 0	$ 1,117
Carrying Amount
Financial Assets [Abstract]
Investment in Cenovus Energy	0	1,117
Investments in debt securities	1,210	479
Loans and advances—related parties	59	114
Financial Liabilities [Abstract]
Total debt, excluding finance leases	15,687	18,673
Carrying Amount \| Commodity Contract
Financial Assets [Abstract]
Commodity derivatives	750	593
Financial Liabilities [Abstract]
Commodity derivatives	706	537
Estimate of Fair Value Measurement
Financial Assets [Abstract]
Investment in Cenovus Energy	0	1,117
Investments in debt securities	1,210	479
Loans and advances—related parties	59	114
Financial Liabilities [Abstract]
Total debt, excluding finance leases	16,547	22,451
Estimate of Fair Value Measurement \| Commodity Contract
Financial Assets [Abstract]
Commodity derivatives	750	593
Financial Liabilities [Abstract]
Commodity derivatives	$ 706	$ 537

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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