Segment Disclosures and Related Information (Capital Expenditures and Investments and Interest Income and Expense) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	$ 5,324	$ 4,715	$ 6,636
Interest income	33	100	166
Interest and debt expense	884	806	778
Alaska [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	982	1,038	1,513
Interest income	0	0	0
Lower 48 [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	3,129	1,881	3,394
Interest income	0	0	0
Canada [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	203	651	368
Interest income	0	0	0
Europe, Middle East and North Africa [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	534	600	708
Interest income	2	5	11
Asia Pacific [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	390	384	584
Interest income	9	7	6
Other International [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	33	121	8
Interest income	0	0	0
Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Consolidated capital expenditures and investments	53	40	61
Interest income	22	88	149
Interest and debt expense	$ 884	$ 806	$ 778

Segment reporting information capital expenditures and investments.

No definition available.

Name:	cop_SegmentReportingInformationCapitalExpendituresAndInvestments
Namespace Prefix:	cop_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Interest and debt related expenses associated with nonoperating financing activities of the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

+ Details

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

- Definition

Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(b))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

+ Details

Name:	us-gaap_InvestmentIncomeInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cop_AlaskaSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cop_LowerFortyEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cop_CanadaOperatingSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cop_EuropeMiddleEastAndNorthAfricaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cop_AsiaPacificOperatingSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cop_OtherInternationalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: