Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482987/272-10-50-3

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- 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

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- Definition

The number of units sold in a public offering of each class of partners' capital account. Units represent shares of ownership of the general, limited, and preferred partners.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-5

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

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- Definition

Number of Common Carrier Pipelines

+ References

No definition available.

+ Details

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Namespace Prefix:	wlkp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Production Facilities

+ References

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+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

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Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
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Name:	srt_OwnershipAxis=wlkp_WestlakeChemicalOpCoLPMember
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Description of Business and Basis of Presentation (Details)	Mar. 29, 2019 shares	Aug. 04, 2014 shares	Jun. 30, 2026 numberOfCommonCarrierPipelines production_facility
Westlake Chemical OpCo LP
Limited Partners' Capital Account [Line Items]
Number of production facilities \| production_facility			3
Number of common carrier pipelines \| numberOfCommonCarrierPipelines			1
Westlake Chemical Partners LP \| Affiliated Entity \| Westlake Chemical OpCo LP
Limited Partners' Capital Account [Line Items]
Limited partner interest	22.80%
Westlake Chemical Partners LP \| Limited Liability Company \| Westlake Chemical OpCo GP LLC
Limited Partners' Capital Account [Line Items]
Limited partner interest		100.00%
Westlake Chemical Corporation \| Majority-Owned Subsidiary, Unconsolidated \| Westlake \| Westlake Chemical OpCo LP
Limited Partners' Capital Account [Line Items]
Limited partner interest	77.20%
Westlake Chemical OpCo LP \| Affiliated Entity
Limited Partners' Capital Account [Line Items]
Limited partner interest	22.80%
Westlake Chemical OpCo LP \| Majority-Owned Subsidiary, Unconsolidated \| Westlake
Limited Partners' Capital Account [Line Items]
Limited partner interest	77.20%
Limited Partner
Limited Partners' Capital Account [Line Items]
Number of units sold in public offering (in shares) \| shares	2,940,818	12,937,500