Common Units, Distributed Amount

No definition available.

Name:	psx_CommonUnitsDistributedAmount
Namespace Prefix:	psx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Direct Ownership Interest, Percent

+ References

No definition available.

+ Details

Name:	psx_DirectOwnershipInterestPercent
Namespace Prefix:	psx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Equity Method Investment, Direct and Indirect Ownership Interests, Percent

+ References

No definition available.

+ Details

Name:	psx_EquityMethodInvestmentDirectAndIndirectOwnershipInterestsPercent
Namespace Prefix:	psx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Equity Method Investment, Indirect Economic, Percent

+ References

No definition available.

+ Details

Name:	psx_EquityMethodInvestmentIndirectEconomicPercent
Namespace Prefix:	psx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Indirect Economic Interest, Percent

+ References

No definition available.

+ Details

Name:	psx_IndirectEconomicInterestPercent
Namespace Prefix:	psx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Classes Of Membership Created

+ References

No definition available.

+ Details

Name:	psx_NumberOfClassesOfMembershipCreated
Namespace Prefix:	psx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Payment To Acquire Noncontrolling Interests Held By Public

+ References

No definition available.

+ Details

Name:	psx_PaymentToAcquireNoncontrollingInterestsHeldByPublic
Namespace Prefix:	psx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage Of Ownership

+ References

No definition available.

+ Details

Name:	psx_PercentageOfOwnership
Namespace Prefix:	psx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Preferred Units, Liquidation Preference, Value

+ References

No definition available.

+ Details

Name:	psx_PreferredUnitsLiquidationPreferenceValue
Namespace Prefix:	psx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Per share price of saleable stock paid or offered to be paid by acquirer in business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479299/805-40-55-10

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-42

+ Details

Name:	us-gaap_BusinessAcquisitionSharePrice
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of voting equity interests acquired in a business combination achieved in stages, including equity interests in the acquiree held by the acquirer immediately before the acquisition date and acquired at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 25
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479405/805-10-25-9

+ Details

Name:	us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeIncludingSubsequentAcquisitionPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=psx_MergerOfDCPMidstreamLLCAndGrayOakHoldingsLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=psx_AcquisitionOfDCPLPCommonUnitsHeldByPublicMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=psx_MergerWithDCPLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=psx_DCPMidstreamLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=psx_GrayOakHoldingsLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=psx_DCPMidstreamLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesCPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesBPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=psx_DCPMidstreamClassASegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=psx_DCPSandHillsAndDCPSouthernHillsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=psx_DCPMidstreamLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=psx_EnbridgeIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=psx_DCPMidstreamLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=psx_GrayOakHoldingsLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=psx_GrayOakPipelineLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	psx_ClassOfMembershipAxis=psx_ClassBMembershipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=psx_DCPMidstreamClassBSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=psx_DCPSandHillsAndSouthernHillsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

DCP Midstream, LLC and DCP Midstream, LP Mergers - Narrative (Details) $ / shares in Units, $ in Millions			12 Months Ended
	Jun. 15, 2023 USD ($) $ / shares	Aug. 17, 2022 class	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Oct. 16, 2023 USD ($)	Jun. 14, 2023	Aug. 16, 2022
Merger of DCP Midstream, LLC and Gray Oak Holdings LLC
Schedule of Equity Method Investments [Line Items]
Number of classes of membership created \| class		2
Acquisition Of DCP LP Common Units Held By Public
Schedule of Equity Method Investments [Line Items]
Cash consideration (in dollars per share) \| $ / shares	$ 41.75
Merger With DCP LP
Schedule of Equity Method Investments [Line Items]
Cash consideration paid	$ 3,796
DCP Midstream, LP \| Variable Interest Entity, Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Indirect economic interests		43.30%
Gray Oak Holdings LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership								65.00%
DCP Midstream, LP \| Variable Interest Entity, Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Common units, distribution			$ 130	$ 47	$ 125
DCP Midstream, LP \| Variable Interest Entity, Primary Beneficiary \| Series C Preferred Stock
Schedule of Equity Method Investments [Line Items]
Preferred units, liquidation preference						$ 110
DCP Midstream, LP \| Variable Interest Entity, Primary Beneficiary \| Series B Preferred Stock
Schedule of Equity Method Investments [Line Items]
Preferred units, liquidation preference	$ 161
DCP Midstream, LP \| Merger With DCP LP \| Variable Interest Entity, Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Economic interest percent after merger	86.80%						43.30%
DCP Midstream Class A Segment \| DCP Midstream, LP
Schedule of Equity Method Investments [Line Items]
Percentage of ownership		76.64%
DCP Sand Hills And DCP Southern Hills
Schedule of Equity Method Investments [Line Items]
Percentage of ownership		62.20%					62.20%
Direct and indirect economic interest		33.33%
DCP Sand Hills And DCP Southern Hills \| Merger With DCP LP
Schedule of Equity Method Investments [Line Items]
Economic interest percent after merger	91.20%
DCP Midstream, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)								50.00%
DCP Midstream, LLC \| Enbridge Inc
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)								50.00%
DCP Midstream, LP
Schedule of Equity Method Investments [Line Items]
Indirect economic interest								28.26%
Gray Oak Holdings LLC \| Enbridge Inc \| Gray Oak Holdings LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)								35.00%
Gray Oak Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Indirect economic interest								42.25%
Gray Oak Pipeline LLC \| Class B Membership
Schedule of Equity Method Investments [Line Items]
Indirect economic interest		6.50%
Gray Oak Pipeline LLC \| Gray Oak Holdings LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)								65.00%
Gray Oak Pipeline LLC \| Enbridge Inc
Schedule of Equity Method Investments [Line Items]
Indirect economic interest								22.75%
Gray Oak Pipeline LLC \| DCP Midstream Class B Segment
Schedule of Equity Method Investments [Line Items]
Percentage of ownership		10.00%
DCP Sand Hills and Southern Hills
Schedule of Equity Method Investments [Line Items]
Direct ownership interest								52.20%
DCP Sand Hills and Southern Hills \| DCP Midstream, LP \| Variable Interest Entity, Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Percentage of ownership		66.67%