Value of commodity inventory received and sold as partial settlement of litigation during the current period.

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Offset to settlement agreement for counter claim.

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Cash and nonmonetary proceeds received for the settlement of litigation during the current period.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Amount awarded from other party in judgment or settlement of litigation.

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Amount awarded to other party in judgment or settlement of litigation.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Description of the terms of a settlement agreement which resolved the legal matter, including the nature of the consideration, timing of payment, and the nature of rights obtained or lost (for example, but not limited to, patent, trademark, copyright, license and franchise rights).

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Cash received for the settlement of litigation during the current period.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Contingencies and Commitments (Details) - USD ($)	1 Months Ended			12 Months Ended
Contingencies and Commitments (Details) - USD ($)	Apr. 30, 2018	Dec. 31, 2017	Feb. 28, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Long-Term Throughput Agreements and Take-or-Pay Agreements [Abstract]
Payments under Long-Term Throughput Agreements And Take-or-Pay Agreements, Due Within One Year				$ 7,000,000
Payments under Long-Term Throughput Agreements And Take-or-Pay Agreements, Due in Second Year				7,000,000
Payments under Long-Term Throughput Agreements And Take-or-Pay Agreements, Due in Third Year				7,000,000
Payments under Long-Term Throughput Agreements And Take-or-Pay Agreements, Due in Fourth Year				7,000,000
Payments under Long-Term Throughput Agreements And Take-or-Pay Agreements, Due in Fifth Year				7,000,000
Payments under Long-Term Throughput Agreements And Take-or-Pay Agreements, Due after Fifth Year				61,000,000
Total payments under Long-Term Throughput Agreements and Take-or-Pay Agreements		$ 43,000,000		39,000,000	$ 43,000,000	$ 42,000,000
Burlington Resources Inc Vs The Republic Of Ecuador [Member]
Loss Contingencies [Line Items]
Cash Proceeds from Legal Settlements				$ 262,000,000	75,000,000
Burlington Resources Inc Vs The Republic Of Ecuador [Member] \| Burlington Resources Inc [Member] \| Ecuador
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded from Other Party			$ 380,000,000		$ 337,000,000
Litigation Settlement, Amount Awarded to Other Party			$ 42,000,000
Offset For Counter Claim	$ 24,000,000
Loss Contingency Settlement Agreement Terms				two installments
Cash Proceeds from Legal Settlements		$ 75,000,000
Conoco Phillips Vs Petroleos de Venezuela SA [Member]
Loss Contingencies [Line Items]
Cash Proceeds from Legal Settlements				$ 200,000,000
Conoco Phillips Vs Petroleos de Venezuela SA [Member] \| Venezuela
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded from Other Party	$ 2,000,000,000
Loss Contingency Settlement Agreement Terms				initial payments totaling approximately $500 million within a period of 90 days from the time of signing of the settlement agreement. The balance of the settlement is to be paid quarterly over a period of four and a half years.
Cash Proceeds from Legal Settlements				$ 200,000,000
Inventory Received For Settlement				230,000,000
Total cash and noncash proceeds From Legal Settlement				430,000,000
Performance Guarantee [Member]
Loss Contingencies [Line Items]
Letters of Credit Outstanding, Amount				$ 323,000,000