Commitments and Contingencies - Legal, Environmental or Regulatory (Details)			1 Months Ended		6 Months Ended		8 Months Ended	9 Months Ended	98 Months Ended
	Oct. 27, 2022 USD ($)	Oct. 14, 2020 USD ($)	Sep. 30, 2021 USD ($)	May 31, 2015 bbl	Jun. 30, 2023 USD ($) lawsuit	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) lawsuit	Sep. 20, 2022 USD ($)	Jun. 30, 2023 USD ($) lawsuit	Dec. 31, 2022 USD ($)	Apr. 25, 2019 USD ($)	Sep. 07, 2018 count
Line 901 Incident
Legal, Environmental or Regulatory Matters
Estimated size of release (in bbl) | bbl				2,934
Estimated size of release to reach Pacific Ocean (in bbl) | bbl				598
Recoveries from insurance carriers									$ 280,000,000
Aggregate total estimated costs					$ 740,000,000		$ 740,000,000		740,000,000
Significant costs related to legal and environmental remediation matters					0	$ 85,000,000
Total release costs probable of recovery					$ 505,000,000		$ 505,000,000		$ 505,000,000
Line 901 Incident | Civil Penalties | Judicial Ruling
Legal, Environmental or Regulatory Matters
Amount paid to plaintiff		$ 24,000,000
Line 901 Incident | Compensation for Injuries to, Destruction of, Loss of Use of, Natural Resources | Judicial Ruling
Legal, Environmental or Regulatory Matters
Amount paid to plaintiff		$ 22,325,000
Line 901 Incident | May 2016 Indictment
Legal, Environmental or Regulatory Matters
Number of felony discharges found guilty | count												1
Number of misdemeanor charges found guilty | count												8
Number of misdemeanor charges found guilty, reporting | count												1
Number of misdemeanor charges found guilty, strict liability discharge | count												1
Number of misdemeanor charges found guilty, strict liability animal takings | count												6
Number of misdemeanor charges found not guilty, strict liability animal takings | count												1
Line 901 Incident | May 2016 Indictment | Judicial Ruling
Legal, Environmental or Regulatory Matters
Fines or penalties assessed											$ 3,350,000
Line 901 Incident | May 2016 Indictment | Judicial Ruling | Maximum
Legal, Environmental or Regulatory Matters
Amount awarded to claimants by Court			$ 150,000
Line 901 Incident | Class Action Lawsuits
Legal, Environmental or Regulatory Matters
Number of cases filed | lawsuit									9
Line 901 Incident | Class Action Lawsuits | Pending Litigation
Legal, Environmental or Regulatory Matters
Number of proceedings pending | lawsuit					2		2		2
Line 901 Incident | Class Action Lawsuit Claim of Damages | Pending Litigation
Legal, Environmental or Regulatory Matters
Litigation settlement agreement amount, subject to approval								$ 230,000,000
Line 901 Incident | Class Action Lawsuit Claim of Damages | Settled Litigation
Legal, Environmental or Regulatory Matters
Payments for legal settlements	$ 230,000,000
Line 901 2015 Insurance Program
Legal, Environmental or Regulatory Matters
Recoveries from insurance carriers									$ 275,000,000
Coverage limit under insurance program					$ 500,000,000		$ 500,000,000		500,000,000
Exceeded coverage limit under insurance program					240,000,000		240,000,000		240,000,000
Claim for Reimbursement From Insurance
Legal, Environmental or Regulatory Matters
Recoveries from insurance carriers							3,600,000
Receivable for remaining portion of release costs probable of recovery from insurance					225,000,000		225,000,000		225,000,000
Denial of Insurance Coverage
Legal, Environmental or Regulatory Matters
Receivable for remaining portion of release costs probable of recovery from insurance					185,000,000		185,000,000		185,000,000
Response to Request for Reimbursement Not Received
Legal, Environmental or Regulatory Matters
Receivable for remaining portion of release costs probable of recovery from insurance					40,000,000		40,000,000		40,000,000
Arbitration Proceedings Against Insurers
Legal, Environmental or Regulatory Matters
Receivable for remaining portion of release costs probable of recovery from insurance					175,000,000		175,000,000		175,000,000
Other long-term assets, net | Line 901 Incident
Legal, Environmental or Regulatory Matters
Receivable for remaining portion of release costs probable of recovery from insurance					225,000,000		225,000,000		225,000,000
Current Liabilities | Line 901 Incident
Legal, Environmental or Regulatory Matters
Remaining undiscounted liability					98,000,000		98,000,000		98,000,000
Excluding Line 901 Incident
Legal, Environmental or Regulatory Matters
Estimated undiscounted reserve for environmental liabilities					55,000,000		55,000,000		55,000,000	$ 55,000,000
Estimated undiscounted reserve for environmental liabilities, short-term					$ 10,000,000		$ 10,000,000		$ 10,000,000	$ 10,000,000
Estimated undiscounted reserve for environmental liabilities, short-term [Extensible Enumeration]					Other current liabilities		Other current liabilities		Other current liabilities	Other current liabilities
Estimated undiscounted reserve for environmental liabilities, long-term					$ 45,000,000		$ 45,000,000		$ 45,000,000	$ 45,000,000
Estimated undiscounted reserve for environmental liabilities, long-term [Extensible Enumeration]					Other long-term liabilities and deferred credits		Other long-term liabilities and deferred credits		Other long-term liabilities and deferred credits	Other long-term liabilities and deferred credits
Amounts probable of recovery under insurance and from third parties under indemnification agreements					$ 4,000,000		$ 4,000,000		$ 4,000,000	$ 4,000,000
Excluding Line 901 Incident | Other long-term assets, net
Legal, Environmental or Regulatory Matters
Amounts probable of recovery under insurance and from third parties under indemnification agreements					$ 1,000,000		$ 1,000,000		$ 1,000,000	$ 1,000,000