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

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
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Data Type:	num:percentItemType
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Period Type:	instant

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Percent

No definition available.

Name:	wlk_ConsolidationLessthanWhollyOwnedSubsidiaryParentOwnershipInterestPercent
Namespace Prefix:	wlk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Debt amount in excess of guaranteed by subsidiaries.

No definition available.

Name:	wlk_DebtAmountInExcessOfGuaranteedBySubsidiaries
Namespace Prefix:	wlk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Debt Instrument, Maturity

No definition available.