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

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

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

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.

No definition available.

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

- References

No definition available.

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

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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

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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Name:	us-gaap_PartnersCapitalAccountUnitsSoldInPublicOffering
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Cash outflow related to the acquisition or continued holding of limited partnership interests held for investment purposes.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

Name:	us-gaap_PaymentsToAcquireLimitedPartnershipInterests
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Ethylene Production, Optional

No definition available.

Name:	wlkp_EthyleneProductionOptional
Namespace Prefix:	wlkp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Lessee Leasing Arrangement, Operating Leases, Number

No definition available.

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

Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Additional Ownership Interest

No definition available.

Name:	wlkp_LimitedLiabilityCompanyLLCorLimitedPartnershipLPMembersorLimitedPartnersAdditionalOwnershipInterest
Namespace Prefix:	wlkp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Long-term Purchase Commitment, Exchange Fee, Fixed Margin

No definition available.

Name:	wlkp_LongtermPurchaseCommitmentExchangeFeeFixedMargin
Namespace Prefix:	wlkp_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Long-term Purchase Commitment, Maximum Volume Required

No definition available.

Name:	wlkp_LongtermPurchaseCommitmentMaximumVolumeRequired
Namespace Prefix:	wlkp_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

Long-term Purchase Commitment, Minimum Percentage Required

No definition available.

Name:	wlkp_LongtermPurchaseCommitmentMinimumPercentageRequired
Namespace Prefix:	wlkp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Long-term Purchase Commitment, Option To Purchase Excess Production, Percentage

No definition available.

Name:	wlkp_LongtermPurchaseCommitmentOptionToPurchaseExcessProductionPercentage
Namespace Prefix:	wlkp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Long-term Purchase Commitment, Renewal Term

No definition available.

Name:	wlkp_LongtermPurchaseCommitmentRenewalTerm
Namespace Prefix:	wlkp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Long-term Purchase Commitment, Terms of Fee, Number Of Years Used To Calculate Average Expenses

No definition available.

Name:	wlkp_LongtermPurchaseCommitmentTermsofFeeNumberOfYearsUsedToCalculateAverageExpenses
Namespace Prefix:	wlkp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Purchase Commitment, Purchase Agreement, Mass

No definition available.

Name:	wlkp_PurchaseCommitmentPurchaseAgreementMass
Namespace Prefix:	wlkp_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

Receivables under Investment Management Agreements with Related Parties, Current

No definition available.

Name:	wlkp_ReceivablesunderInvestmentManagementAgreementswithRelatedPartiesCurrent
Namespace Prefix:	wlkp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Related Party Transaction, Counterparty Default, Period Of Default, Allowing Termination Of Agreement

No definition available.

Name:	wlkp_RelatedPartyTransactionCounterpartyDefaultPeriodOfDefaultAllowingTerminationOfAgreement
Namespace Prefix:	wlkp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Related Party Transaction, Term Of Agreement

No definition available.

Name:	wlkp_RelatedPartyTransactionTermOfAgreement
Namespace Prefix:	wlkp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Term of Investment Management Agreement with Related Party, Maximum

No definition available.

Name:	wlkp_TermofInvestmentManagementAgreementwithRelatedPartyMaximum
Namespace Prefix:	wlkp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=us-gaap_LimitedPartnerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=wlkp_WestlakeChemicalOpCoLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=wlkp_EthyleneSalesAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_InvesteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_MajorityOwnedSubsidiaryUnconsolidatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=wlkp_ServicesAndSecondmentAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=wlkp_SiteLeaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=wlkp_EthyleneSalesAgreementDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=wlkp_FeedstockSupplyAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: