Defined contribution plan employers vesting percent.

No definition available.

Name:	cop_DefinedContributionPlanVestingPercent
Namespace Prefix:	cop_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition.

+ References

No definition available.

+ Details

Name:	cop_Definedcontributionplanemployersvestingperiod
Namespace Prefix:	cop_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage Potential company discretionary cash contribution to eligible participants in savings plan.

+ References

No definition available.

+ Details

Name:	cop_EmployerMatchingDiscretionaryContributionPercent
Namespace Prefix:	cop_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of investment funds in which employee can contribute in the defined contribution plan.

+ References

No definition available.

+ Details

Name:	cop_NumberOfInvestmentFundsInWhichEmployeeCanContribute
Namespace Prefix:	cop_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum term of the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6409961&loc=d3e20487-108367

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualMaximumContractualTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_PlanNameAxis=cop_TwentyFourteenOmnibusStockAndPerformanceIncentivePlanOfConocoPhillipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=cop_IncentiveStockOptionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=cop_DefinedContributionPlanCompanyRetirementContributionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=us-gaap_ForeignPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Employee Benefit Plans - Other Plan Narrative (Details) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Share-based Compensation Plan
Defined Benefit Plan Disclosure [Line Items]
Share Based Compensation Plan, number of shares authorized \| shares	79
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Share-based Compensation Plan
Defined Benefit Plan Disclosure [Line Items]
Deferred Compensation Arrangement with Individual, Maximum Contractual Term	10 years
U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan Maximum Annual Contributions Per Employee Percent	75.00%
Number Of Investment Funds In Which Employee Can Contribute [Member]	(17)
Defined Contribution Plan, Employer Matching Contribution, Percent	1.00%
Defined Contribution Plan Employer Matching Contribution Percent Of Match	6.00%
Employer Matching Discretionary Contribution Percent	6.00%
Company contributions charged to expense for defined contribution plan \| $	$ 82	$ 82	$ 77
U.S. \| cop_IncentiveStockOptionsMember [Member]
Defined Benefit Plan Disclosure [Line Items]
Share Based Compensation Plan, number of shares authorized \| shares	40
U.S. \| Company Retirement Contribution (CRC)
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan Employer Matching Contribution Percent Of Match	6.00%
Defined Contribution Plan Employers Vesting Period	3 years
Defined contribution plan employers vesting percent	100.00%
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Company contributions charged to expense for defined contribution plan \| $	$ 30	$ 31	$ 35