v3.25.4

Cover Page Cover Page	Feb. 24, 2026
Document Information [Line Items]
Document Type	8-K
Document Period End Date	Feb. 24, 2026
Entity Registrant Name	Westlake Corporation
Entity Incorporation, State or Country Code	DE
Entity File Number	001-32260
Entity Tax Identification Number	76-0346924
Entity Address, Address Line One	2801 Post Oak Boulevard,
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056
City Area Code	713
Local Phone Number	960-9111
Entity Emerging Growth Company	false
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Amendment Flag	false
Entity Central Index Key	0001262823
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	WLK
Security Exchange Name	NYSE
One Point Six Two Five Percentage Senior Notes Due Twenty Twenty Nine [Member] [Domain]
Document Information [Line Items]
Title of 12(b) Security	1.625% Senior Notes due 2029
Trading Symbol	WLK29
Security Exchange Name	NYSE

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For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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Address Line 1 such as Attn, Building Name, Street Name

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Name of the City or Town

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Name of the state or province.

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A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Local phone number for entity.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Trading symbol of an instrument as listed on an exchange.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

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WESTLAKE CORP 8-K