Westlake (WLK) 10-K 21 Feb 24 2023 FY Annual report Financial data

Cover

Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2023	Feb. 14, 2024	Jun. 30, 2023
Document Information [Line Items]
Document Type	10-K
Document Quarterly Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	001-32260
Entity Registrant Name	Westlake Corporation
Entity Incorporation, State or Country Code	DE
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
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Central Index Key	0001262823
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 3.9
Entity Common Stock, Shares Outstanding		128,216,207
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE: Certain information required by Part II and Part III of this Form 10-K is incorporated by reference from the registrant's definitive Proxy Statement to be filed pursuant to Regulation 14A with respect to the registrant's 2024 Annual Meeting of Stockholders to be held on May 9, 2024.
Document Financial Statement Error Correction [Flag]	false
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	WLK
Security Exchange Name	NYSE
1.625% Senior Notes Due 2029
Document Information [Line Items]
Title of 12(b) Security	1.625% Senior Notes due 2029
Trading Symbol	WLK29
Security Exchange Name	NYSE

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023
Auditor [Abstract]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Houston, Texas
Auditor Firm ID	238

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 3,304	$ 2,228
Accounts receivable, net	1,601	1,801
Inventories	1,622	1,866
Prepaid expenses and other current assets	82	78
Total current assets	6,609	5,973
Property, plant and equipment, net	8,519	8,477
Operating lease right-of-use assets	697	615
Goodwill	2,041	2,161
Customer relationships, net	910	993
Other intangible assets, net	493	572
Equity method investments	1,115	1,142
Other assets, net	651	617
Total assets	21,035	20,550
Current liabilities
Accounts payable	877	889
Accrued and other liabilities	1,614	1,409
Current portion of long-term debt, net	299	0
Total current liabilities	2,790	2,298
Long-term debt, net	4,607	4,879
Deferred income taxes	1,560	1,735
Pension and other post-retirement benefits	363	355
Operating lease liabilities	611	504
Other liabilities	340	314
Total liabilities	10,271	10,085
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.01 par value, 50,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.01 par value, 300,000,000 shares authorized; 134,651,380 and 134,651,380 shares issued at December 31, 2023 and 2022, respectively	1	1
Common stock, held in treasury, at cost; 6,439,289 and 7,278,651 shares at December 31, 2023 and 2022, respectively	(435)	(467)
Additional paid-in capital	630	601
Retained earnings	10,143	9,885
Accumulated other comprehensive loss	(98)	(89)
Total Westlake Corporation stockholders' equity	10,241	9,931
Noncontrolling interests	523	534
Total equity	10,764	10,465
Total liabilities and equity	$ 21,035	$ 20,550

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	300,000,000	300,000,000
Common Stock, Shares	134,651,380	134,651,380
Treasury Stock, Shares	6,439,289	7,278,651

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Net sales	$ 12,548	$ 15,794	$ 11,778
Cost of sales	10,329	11,721	8,283
Gross profit	2,219	4,073	3,495
Selling, general and administrative expenses	865	835	551
Impairment of goodwill and long-lived assets	475	0	0
Amortization of intangibles	122	155	123
Restructuring, transaction and integration-related costs	28	33	21
Income from operations	729	3,050	2,800
Other income (expense)
Interest expense	(165)	(177)	(176)
Other income, net	136	73	53
Income before income taxes	700	2,946	2,677
Provision for income taxes	178	649	607
Net income	522	2,297	2,070
Net income attributable to noncontrolling interests	43	50	55
Net income attributable to Westlake Corporation	$ 479	$ 2,247	$ 2,015
Earnings per common share attributable to Westlake Corporation:
Basic (in dollars per share)	$ 3.73	$ 17.46	$ 15.66
Diluted (in dollars per share)	$ 3.70	$ 17.34	$ 15.58
Weighted average common shares outstanding:
Basic (in shares)	127,806,317	127,970,445	128,002,911
Diluted (in shares)	128,598,441	128,845,562	128,697,982

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 522	$ 2,297	$ 2,070
Pension and other post-retirement benefits
Pension and other post-retirement benefits reserves adjustment	(40)	29	60
Income tax benefit (provision) on pension and other post-retirement benefits	(8)	3	(16)
Foreign currency translation adjustments
Foreign currency translation	32	(78)	2
Income tax benefit (provision) on foreign currency translation	7	(12)	(17)
Other comprehensive income (loss), net of income taxes	(9)	(58)	29
Comprehensive income	513	2,239	2,099
Comprehensive income attributable to noncontrolling interests, net of tax of $3, $3 and $2 for 2023, 2022 and 2021, respectively	43	45	56
Comprehensive income attributable to Westlake Corporation	$ 470	$ 2,194	$ 2,043

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Comprehensive income (loss), tax portion attributable to noncontrolling interest	$ 3	$ 3	$ 2

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Common Stock, Held in Treasury	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balances at Dec. 31, 2020	$ 6,578	$ 1	$ (401)	$ 569	$ 5,938	$ (64)	$ 535
Beginning balance, shares issued at Dec. 31, 2020		134,651,380
Beginning balance, Treasury Stock, Shares at Dec. 31, 2020			6,821,174
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,070				2,015		55
Other comprehensive income	29					28	1
Common stock repurchased, shares			355,800
Common stock repurchased	(30)		$ (30)
Shares issued—stock- based compensation, shares			(441,335)
Shares issued—stock-based compensation	13		$ 32	(19)
Stock-based compensation	31			31
Dividends declared	(145)				(145)
Distributions to noncontrolling interests	(48)						(48)
Noncontrolling interests	(30)						(30)
Ending balances at Dec. 31, 2021	8,528	$ 1	$ (399)	581	7,808	(36)	573
Ending balance, shares issued at Dec. 31, 2021		134,651,380
Ending balance, Treasury Stock, Shares at Dec. 31, 2021			6,735,639
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,297				2,247		50
Other comprehensive income	(58)					(53)	(5)
Common stock repurchased, shares			1,079,736
Common stock repurchased	(102)		$ (102)
Shares issued—stock- based compensation, shares			(536,724)
Shares issued—stock-based compensation	18		$ 34	(16)
Stock-based compensation	35			35
Dividends declared	(169)				(169)
Distributions to noncontrolling interests	(60)						(60)
Noncontrolling interests	(24)			1	(1)		(24)
Ending balances at Dec. 31, 2022	$ 10,465	$ 1	$ (467)	601	9,885	(89)	534
Ending balance, shares issued at Dec. 31, 2022	134,651,380	134,651,380
Ending balance, Treasury Stock, Shares at Dec. 31, 2022	7,278,651		7,278,651
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 522				479		43
Other comprehensive income	(9)					(9)
Common stock repurchased, shares			211,294
Common stock repurchased	(23)		$ (23)
Shares issued—stock- based compensation, shares			(1,050,656)
Shares issued—stock-based compensation	44		$ 55	(11)
Stock-based compensation	40			40
Dividends declared	(221)				(221)
Distributions to noncontrolling interests	(54)						(54)
Ending balances at Dec. 31, 2023	$ 10,764	$ 1	$ (435)	$ 630	$ 10,143	$ (98)	$ 523
Ending balance, shares issued at Dec. 31, 2023	134,651,380	134,651,380
Ending balance, Treasury Stock, Shares at Dec. 31, 2023	6,439,289		6,439,289

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net income	$ 522	$ 2,297	$ 2,070
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	1,097	1,056	840
Stock-based compensation expense	43	36	31
Loss from disposition and write-off of property, plant and equipment	45	46	28
Impairment of goodwill and long-lived assets	475	0	0
Deferred income taxes	(175)	(21)	23
Other (gains) losses, net	(3)	5	16
Changes in operating assets and liabilities, net of effect of business acquisitions
Accounts receivable	225	325	(528)
Inventories	250	(140)	(309)
Prepaid expenses and other current assets	(19)	5	(27)
Accounts payable	(26)	(153)	242
Accrued and other liabilities	170	137	239
Other, net	(268)	(198)	(231)
Net cash provided by operating activities	2,336	3,395	2,394
Cash flows from investing activities
Acquisition of businesses, net of cash acquired	0	(1,203)	(2,554)
Additions to investments in unconsolidated subsidiaries	(25)	(180)	(24)
Additions to property, plant and equipment	(1,034)	(1,108)	(658)
Other, net	22	12	23
Net cash used for investing activities	(1,037)	(2,479)	(3,213)
Cash flows from financing activities
Debt issuance costs	0	0	(18)
Distributions to noncontrolling interests	(54)	(60)	(48)
Dividends paid	(221)	(169)	(145)
Proceeds from debt issuance and drawdown of revolver, net	0	0	1,671
Proceeds from exercise of stock options	44	18	13
Repayment of revolver and senior notes	0	(250)	0
Repurchase of common stock for treasury	(23)	(101)	(30)
Other, net	9	(25)	(6)
Net cash provided by (used for) financing activities	(245)	(587)	1,437
Effect of exchange rate changes on cash, cash equivalents and restricted cash	19	(24)	(14)
Net increase in cash, cash equivalents and restricted cash	1,073	305	604
Cash, cash equivalents and restricted cash at beginning of the year	2,246	1,941	1,337
Cash, cash equivalents and restricted cash at end of the year	$ 3,319	$ 2,246	$ 1,941

Description of Business and Sig

Description of Business and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Significant Accounting Policies	Description of Business and Significant Accounting Policies Description of Business Westlake Corporation, formerly known as Westlake Chemical Corporation (the "Company") operates as an integrated global manufacturer and marketer of performance and essential materials and housing and infrastructure products. These products include some of the most widely used materials in the world, which are fundamental to many diverse consumer and industrial markets, including residential construction, flexible and rigid packaging, automotive products, healthcare products, water treatment, coatings as well as other durable and non-durable goods. The Company's customers range from large chemical processors and plastics fabricators to small construction contractors, municipalities and supply warehouses throughout North America, Europe and Asia. The industries in which the Company operates are subject to price fluctuations and volatile feedstock pricing typical of a commodity-based industry, the effects of which may not be immediately passed along to customers. Westlake Chemical Partners LP In 2014, the Company formed Westlake Chemical Partners LP ("Westlake Partners") to operate, acquire and develop ethylene production facilities and related assets. Westlake Partners' assets consist of a limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in OpCo. OpCo's assets include two ethylene production facilities at the Company's Lake Charles, Louisiana site, one ethylene production facility at the Company's Calvert City, Kentucky site and a 200-mile common carrier ethylene pipeline that runs from Mont Belvieu, Texas to the Company's Longview, Texas site. As of December 31, 2023, the Company held a 77.2% limited partner interest in OpCo and a controlling interest in Westlake Partners. The operations of Westlake Partners are consolidated in the Company's financial statements. Principles of Consolidation The consolidated financial statements include the accounts of the Company and subsidiaries in which the Company directly or indirectly owns more than a 50% voting interest and exercises control and, when applicable, entities for which the Company has a controlling financial interest or is the primary beneficiary. Investments in majority-owned companies where the Company does not exercise control and investments in nonconsolidated affiliates (20%-50% owned companies, joint ventures and partnerships) are accounted for using the equity method of accounting. Undistributed earnings from joint ventures included in retained earnings were immaterial as of December 31, 2023. All intercompany transactions and balances are eliminated in consolidation. Certain reclassifications have been made to the prior-year financial statements to conform to the current year presentation. Noncontrolling interests represent the direct equity interests held by investors in the Company's consolidated subsidiaries, Westlake Partners, Taiwan Chlorine Industries, Ltd. and Suzhou Huasu Plastics Co., Ltd. Effective January 2021, the Company consolidated RS Cogen, LLC ("RS Cogen") into its consolidated financial statements. Effective October 31, 2022, the Company acquired the remaining 50% interest in RS Cogen. Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with the accounting principles generally accepted in the United States. Cash and Cash Equivalents Cash equivalents consist of highly liquid investments that are readily convertible into cash and have a maturity of three months or less at the date of acquisition. Concentration of Credit Risk Financial instruments which potentially subject the Company to concentration of risk consist principally of trade receivables from customers engaged in manufacturing polyethylene products, polyvinyl chloride ("PVC") products, epoxy products, chlor-alkali and derivative products as well as housing and infrastructure products such as PVC compounds, PVC pipe and fittings, trim and mouldings, stone, windows, roofing and exterior products. The Company's large number of customers, the diversity of these customers' businesses and the markets they serve and customers geographic dispersion limits the concentrations of credit risk with respect to receivables. The Company performs periodic credit evaluations of the customers' financial condition and generally does not require collateral. The Company maintains allowances for potential losses. Allowance for Credit Losses The determination of the allowance for credit losses is based on estimation of the amount of accounts receivable that the Company believes are unlikely to be collected. Estimating this amount requires analysis of the financial strength of the Company's customers, the use of historical experience, the Company's accounts receivable aged trial balance, customer specific collectability analysis and an evaluation of economic conditions. The allowance for credit losses is reviewed quarterly. Past due balances over 90 days and high-risk accounts as determined by the analysis of financial strength of customers are reviewed individually for collectability. Inventories Inventories primarily include product, material and supplies. Inventories are stated at lower of cost or net realizable value. Cost is determined using the first-in, first-out ("FIFO") or average method. Property, Plant and Equipment Property, plant and equipment are carried at cost, net of accumulated depreciation. Cost includes expenditures for improvements and betterments that extend the useful lives of the assets and interest capitalized on significant capital projects. Capitalized interest was $8, $4 and $3 for the years ended December 31, 2023, 2022 and 2021, respectively. Repair and maintenance costs are charged to operations as incurred. Gains and losses on the disposition or retirement of fixed assets are reflected in the consolidated statement of operations when the assets are sold or retired. Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 40 Plant and equipment 10-25 Other 3-15 Impairment of Long-Lived Assets The Company reviews long-lived assets, including tangible assets and intangible assets with finite lives, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Long-lived assets assessed for impairment are grouped by asset group, the lowest level for which identifiable cash flows are largely independent of the cash flows of other groups of assets and liabilities. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net undiscounted cash flows expected to be generated by the asset group from its use and eventual disposition of that asset group. Assets are considered to be impaired if the carrying amount of an asset exceeds the future undiscounted cash flows. The impairment recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or estimated fair value less costs to sell. Intangible assets with finite lives are amortized over their estimated useful lives and evaluated with the associated long-lived asset group for impairment whenever impairment indicators exist. See Note 6 for more information on the Company's long-lived assets impairment tests. Impairment of Goodwill Goodwill is tested for impairment at least annually, or when events or changes in circumstances indicate the fair value of a reporting unit with goodwill has been reduced below its carrying amount. The Company performed its annual goodwill impairment tests for each of the reporting units within the Performance and Essential Materials and Housing and Infrastructure Products segments in the fourth quarter of 2023. The tests indicated impairment of the Westlake Epoxy reporting unit under the Performance and Essential Materials segment as the carrying amount of the reporting unit exceeded its fair value. See Note 8 for more information on the Company's annual goodwill impairment tests. Equity Method Investments The Company accounts for investments using the equity method of accounting if the Company has the ability to exercise significant influence over, but not control of, an investee. Significant influence generally exists if the Company has an ownership interest representing between 20% and 50% of the voting rights. Under the equity method of accounting, investments are stated initially at cost and are adjusted for subsequent additional investments and the proportionate share of profit or losses and distributions. The Company records its share of the profits or losses of the equity investments, net of income taxes, in the consolidated statements of income. The equity method investments are evaluated for impairment when events or changes in circumstances indicate, in management's judgment, that the carrying value of such investments may have experienced an other-than-temporary decline in value. When evidence of loss in value has occurred, management compares the estimated fair value of the investment to the carrying value of the investment to determine whether an impairment has occurred. If the estimated fair value is less than the carrying value and management considers the decline in value to be other-than-temporary, the excess of the carrying value over the estimated fair value is recognized in the consolidated financial statements as an impairment. Other Assets, net Other assets, net include turnaround costs, investments in unconsolidated subsidiaries, restricted cash, deferred charges and other long-term assets. The Company accounts for turnaround costs under the deferral method. Turnarounds are the scheduled and required shutdowns of specific operating units in order to perform planned major maintenance activities. The costs related to the significant overhaul and refurbishment activities include maintenance materials, parts and direct labor costs. The costs of the turnaround are deferred when incurred at the time of the turnaround and amortized (within depreciation and amortization) on a straight-line basis until the next planned turnaround, which typically range from three Business Combinations The Company records business combinations using the acquisition method of accounting. Under the acquisition method of accounting, identifiable assets acquired and liabilities assumed are recorded at their acquisition date fair values. The excess of the purchase price over the estimated fair value is recorded as goodwill. Changes in the estimated fair values of net assets recorded for acquisitions prior to the finalization of more detailed analysis, but not to exceed one year from the date of acquisition, will adjust the amount of the purchase price allocable to goodwill. Measurement period adjustments are reflected in the period in which they occur. Income Taxes The Company utilizes the balance sheet method of accounting for deferred income taxes. Under this method, deferred tax assets or liabilities are recorded based upon temporary differences between the tax basis of assets and liabilities and their carrying values for financial reporting purposes. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities during the period. Valuation allowances are recorded against deferred tax assets when it is considered more likely than not that the deferred tax assets will not be realized. Foreign Currency Translation Assets and liabilities of foreign subsidiaries are translated to U.S. dollars at the exchange rate as of the end of the year. Statement of operations items are translated at the average exchange rate for the year. The resulting translation adjustment is recorded as a separate component of stockholders' equity. Revenue Recognition Revenue is recognized when the Company transfers control of inventories to its customers. Amounts recognized as revenues reflect the consideration to which the Company expects to be entitled in exchange for those inventories. Provisions for discounts, rebates and returns are incorporated in the estimate of variable consideration and reflected as a reduction to revenue in the same period as the related sales. Control of inventories generally transfers upon shipment for domestic sales. The Company excludes taxes collected on behalf of customers from the estimated contract price. For export contracts, the point at which control passes to the customer varies depending on the terms specified in the customer contract. The Company generally invoices customers and recognizes revenue and accounts receivable upon transferring control of inventories. In limited circumstances, the Company transfers control of inventories shortly before it has an unconditional right to receive consideration, resulting in recognition of contract assets. The Company also receives advance payments from certain customers, resulting in recognition of contract liabilities. Contract assets and liabilities are generally settled within the period and are not material to the consolidated balance sheets. The Company expenses sales commissions when incurred. These costs are recorded within selling, general and administrative expenses. Aside from the amounts disclosed within Note 9, the Company does not disclose the value of unsatisfied performance obligations because its contracts with customers (1) have an original expected duration of one year or less or (2) have only variable consideration that is calculated based on market prices at specified dates and is allocated to wholly unsatisfied performance obligations. Revenue from Contracts with Customers ("ASC 606") requires disclosure of disaggregated revenue into categories that depict the nature of how the Company's revenue and cash flows are affected by economic factors. The Company discloses revenues by business and segment in Note 23. Leases The Company is obligated under various long-term and short-term operating leases for rail cars, buildings, land and other transportation and storage assets. The Company determines whether an arrangement is, or contains, a lease at contract inception. Some of the Company's arrangements contain both lease and non-lease components. For certain transportation equipment leases, the Company accounts for the lease and non-lease components as a single lease component. The Company records right-of-use assets and corresponding lease liabilities for operating leases with terms greater than one year. Operating lease right-of-use assets and liabilities are recorded at the present value of the fixed lease payments over the life of the lease. The majority of the Company's leases do not provide an implicit rate. Therefore, the Company uses its incremental borrowing rate at lease commencement to measure operating lease right-of-use assets and lease liabilities. Certain of the Company's leases provide for renewal and purchase options. Renewal and purchase options are evaluated at lease commencement and included in the lease term if they are reasonably certain to be exercised. Short-term leases are recognized in rental expense on a straight-line basis over the lease term and are not recorded in the consolidated balance sheets. The Company's finance leases are not material to the consolidated financial statements. Transportation and Freight Amounts billed to customers for freight and handling costs on outbound shipments are included in net sales in the consolidated statements of operations. Transportation and freight costs incurred by the Company on outbound shipments are included in cost of sales in the consolidated statements of operations. Price Risk Management The Company recognizes derivative instruments on the balance sheet at fair value, and changes in a derivative's fair value are currently recognized in earnings or comprehensive income, depending on the designation of the derivative. If the derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized in earnings. If the derivative is designated as a cash flow hedge, the effective portion of the change in the fair value of the derivative is recorded in comprehensive income and is recognized in the statement of operations when the hedged item affects earnings. Ineffective portions of changes in the fair value of cash flow hedges are recognized in earnings currently. The derivative instruments did not have a material impact on the Company's consolidated financial statements. Asset Retirement Obligations The Company has conditional asset retirement obligations for the removal and disposal of hazardous materials from certain of the Company's manufacturing facilities. The Company recognizes asset retirement obligations in the period in which the liability becomes probable and reasonably estimable. Recognized asset retirement obligations are initially recorded at fair value and capitalized as a component of the carrying value of the long-lived asset to which the obligation relates. The liability is accreted to its future value each period, and the capitalized cost is depreciated over the estimated useful life of the related asset. Upon settlement of the liability, a gain or loss is recorded. As of December 31, 2023, the Company had $3 and $37 of asset retirement obligations recorded as accrued and other liabilities and other liabilities, respectively. As of December 31, 2022, the Company had no asset retirement obligations recorded as accrued and other liabilities and had $31 of asset retirement obligations recorded as other liabilities. The Company also has conditional asset retirement obligations that have not been recognized because the fair values of the conditional legal obligations cannot be measured due to the indeterminate settlement date of the obligations. Settlements of the unrecognized conditional asset retirement obligations are not expected to have a material adverse effect on the Company's financial condition, results of operations or cash flows in any individual reporting period. Environmental Costs Environmental costs relating to current operations are expensed or capitalized, as appropriate, depending on whether such costs provide future economic benefits. Remediation liabilities are recognized when the costs are considered probable and can be reasonably estimated. Measurement of liabilities is based on currently enacted laws and regulations, existing technology and undiscounted site-specific costs. Environmental liabilities in connection with properties that are sold or closed are realized upon such sale or closure, to the extent they are probable and estimable and not previously reserved. Recognition of any joint and several liabilities is based upon the Company's best estimate of its final pro rata share of the liability. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. Warranty Costs The Company provides warranties for certain products, primarily under the housing and infrastructure segment, against defects in material and performance. The accrual for warranty claims is recorded at the time of sale based on historical warranty claims experience. Warranty liabilities are included in accrued liabilities and other liabilities in the consolidated balance sheets. The warranty liabilities activity for the years ended December 31, 2023 and 2022 is as follows: Year Ended December 31, 2023 2022 Beginning balance, January 1, $ 58 $ 55 Estimated fair value of warranty liability assumed in acquisition — 1 Warranty provisions 24 15 Warranty claims paid (13) (13) Ending balance, December 31, $ 69 $ 58 Recently Issued Accounting Pronouncements Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU No.2023-09) In December 2023, the Financial Accounting Standards Board ("FASB") issued accounting standards update No. 2023-09 to enhance the transparency and decision-usefulness of income tax disclosures and to provide information to better assess how an entity's operations and related tax risks and tax planning and operational opportunities affect its tax rate and prospects for future cash flows. For public business entities, the amendments in this update are effective for annual periods beginning after December 15, 2024. The Company is in the process of evaluating the impact of this standard on the disclosures in the Company's financial statements. Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07) In November 2023, the FASB issued accounting standards update No. 2023-07 to improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The update requires public entities to disclose, on an annual and interim basis, significant segment expenses that are regularly provided to the chief operating decision maker (CODM), the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources. The amendments in this update are effective for public entities in fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 and are to be applied retrospectively to all prior periods presented in the financial statements. Early adoption is permitted. The Company is in the process of evaluating the impact of this standard on the disclosures in the Company's financial statements. Business Combinations—Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement (ASU 2023-05) In August 2023, the FASB issued accounting standards update No. 2023-05 to address the accounting for contributions made to a joint venture, upon formation, in a joint venture's financial statements, and to (1) provide decision-useful information to investors and other allocators of capital (collectively, investors) in a joint venture's financial statements and (2) reduce diversity in practice. Under the ASU, upon formation, a joint venture should recognize and initially measure its assets and liabilities at fair value (with exceptions to fair value measurement that are consistent with guidance for business combinations). The amendments in this update become effective for all joint venture formations with a formation date on or after January 1, 2025. Additionally, a joint venture that was formed before January 1, 2025 may elect to apply the amendments retrospectively if it has sufficient information. Early adoption is permitted in any interim or annual period in which financial statements have not yet been issued (or made available for issuance), either prospectively or retrospectively. The Company does not expect that this accounting standard will have a material impact, upon adoption, on the Company's consolidated financial position, results of operations and cash flows. Leases (Topic 842): Common Control Arrangements (ASU 2023-01) In March 2023, the FASB issued accounting standards update No. 2023-01 to amend certain provisions of ASC 842 that apply to arrangements between related parties under common control. The update requires all companies to amortize leasehold improvements associated with common control leases over the asset's useful life to the common control group regardless of the lease term. The amendment in this update is effective for all entities in fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early application is permitted. The Company does not expect that this accounting standard will have a material impact, upon adoption, on the Company's consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Liabilities—Supplier Finance Programs (ASU No. 2022-04) In September 2022, the FASB issued accounting standards update No. 2022-04 to enhance transparency of supplier finance programs. Under the ASU, the buyer in a supplier finance program is required to disclose information about the key terms of the program, outstanding confirmed amounts as of the end of the period, a rollforward of the amount of obligations confirmed and the amount of obligations subsequently paid, and a description of where in the financial statements outstanding amounts are presented. The amendments in this update became effective for all entities for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, except for the disclosure of rollforward information, which is effective for fiscal years beginning after December 15, 2023. The Company adopted this accounting standard effective January 1, 2023, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. Business Combinations—Accounting for Contract Assets and Contract Liabilities from Contracts with Customers Update (ASU No.2021-08) In October 2021, the FASB issued an accounting standards update that requires acquiring entities to recognize and measure contract assets and contract liabilities in a business combination in accordance with the accounting guidance on Revenue from Contracts with Customers (ASC 606). The guidance in this update improves comparability for both the recognition and measurement of acquired revenue contracts with customers at the date of and after a business combination. The accounting standard became effective for reporting periods beginning after December 15, 2022. The Company adopted this accounting standard effective January 1, 2023, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. The standard will be applicable to future business combinations.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2023
Business Combinations [Abstract]
Acquisitions	Acquisitions Hexion Epoxy Business. On February 1, 2022, the Company completed its acquisition of Hexion's global epoxy business ("Westlake Epoxy") for total consideration of $1,207. The assets acquired and liabilities assumed and the results of operations of the Westlake Epoxy business are included in the Performance and Essential Materials segment. The purchase accounting adjustments for the year ended December 31, 2023 resulted in a $4 increase in goodwill. The intangible assets that have been acquired are being amortized over periods of 11 to 19 years, except for certain intangible assets that were subject to impairment in the fourth quarter of 2023 as discussed in Note 6. The information below represents the purchase price allocation: Cash $ 42 Accounts receivable 299 Inventories 346 Prepaid expenses and other current assets 22 Property, plant and equipment 664 Operating lease right-of-use assets 59 Intangible assets 145 Other assets 104 Total assets acquired 1,681 Accounts payable 189 Accrued and other liabilities 88 Deferred income taxes 96 Pensions and other post-retirement benefits 163 Operating lease liabilities 48 Other liabilities 19 Total liabilities assumed 603 Total identifiable net assets acquired 1,078 Noncontrolling interest (2) Goodwill 131 Total Westlake Corporation purchase consideration $ 1,207 Boral Target Companies in North America . On October 1, 2021, the Company completed its acquisition of Boral Limited's North American building products businesses in roofing, siding, trim and shutters, decorative stone and windows (the "Boral Target Companies") for total consideration of $2,140. The assets acquired and liabilities assumed and the results of operations of the Boral Target Companies are included in the Housing and Infrastructure Products segment. LASCO Fittings, Inc . On August 19, 2021, the Company completed its acquisition of LASCO Fittings, Inc., a Delaware corporation ("LASCO"), a manufacturer of injected-molded polyvinyl chloride ("PVC") fittings that serve the plumbing, pool and spa, industrial, irrigation and retail markets in the United States, for total consideration of $277. The assets acquired and liabilities assumed and the results of operations of LASCO are included in the Housing and Infrastructure Products segment. Dimex LLC.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Financial Instruments	Financial Instruments Cash Equivalents The Company had $360 of held-to-maturity securities with original maturities of three months or less, primarily consisting of corporate debt securities, classified as cash equivalents at December 31, 2023. There were no held-to-maturity securities at December 31, 2022. The Company's investments in held-to-maturity securities were held at amortized cost, which approximates fair value. Restricted Cash and Cash Equivalents The Company had restricted cash and cash equivalents of $15 and $18 at December 31, 2023 and 2022, respectively. The Company's restricted cash and cash equivalents are primarily related to balances that are restricted for payment of distributions to certain of the Company's current and former employees and are reflected primarily in other assets, net in the consolidated balance sheets.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Accounts Receivable	Accounts Receivable Accounts receivable consist of the following at December 31: 2023 2022 Trade customers $ 1,413 $ 1,676 Related parties 7 3 Allowance for credit losses (27) (28) 1,393 1,651 Federal and state taxes 65 69 Other 143 81 Accounts receivable, net $ 1,601 $ 1,801

Inventories

Inventories	12 Months Ended
	Dec. 31, 2023
Inventory, Net [Abstract]
Inventories	Inventories Inventories consist of the following at December 31: 2023 2022 Finished products $ 989 $ 1,157 Feedstock, additives, chemicals and other raw materials 401 496 Materials and supplies 232 213 Inventories $ 1,622 $ 1,866

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment, Net [Abstract]
Property, Plant And Equipment	Property, Plant and Equipment Property, plant and equipment consist of the following at December 31: 2023 2022 Land $ 304 $ 299 Buildings and improvements 951 895 Plant and equipment 10,771 10,408 Other 803 711 12,829 12,313 Less: Accumulated depreciation 5,240 4,655 7,589 7,658 Construction in progress 930 819 Property, plant and equipment, net $ 8,519 $ 8,477 Depreciation expense on property, plant and equipment of $763, $762 and $604 is included primarily in cost of sales in the consolidated statements of operations for the years ended December 31, 2023, 2022 and 2021, respectively. Westlake Epoxy During the fourth quarter of 2023, the Westlake Epoxy business's sales volumes and prices, specifically base epoxy resins in Europe, continued to deteriorate. These lower sales volumes and prices were primarily driven by record exports out of Asia into Europe and North America. In addition, Westlake Epoxy operations in Europe have experienced sustained high energy and power costs. These factors negatively impacted Westlake Epoxy financial results during 2023. The Company identified these developments, along with management's outlook for the Westlake Epoxy business over the foreseeable future, as impairment indicators during the fourth quarter of 2023. Based on this triggering event, the Company performed a quantitative impairment analysis of Westlake Epoxy's long-lived assets along with the annual goodwill impairment assessment during the fourth quarter of 2023. Long-Lived Assets Impairment The Company evaluated Westlake Epoxy's long-lived asset groups for impairment during the fourth quarter of 2023 in line with the identification of the triggering event discussed above. Recoverability tests were performed for each of Westlake Epoxy's asset groups to compare the carrying amounts to the net undiscounted cash flow projections of the respective asset groups. The undiscounted cash flow projections were based on historical results, estimates made by management of future market conditions, current and future strategic and operational plans and future financial performance projected through the remaining useful life of the primary asset in the asset group. Based on the recoverability tests, the Company determined that the carrying amount of the primary assets of the Westlake Epoxy Netherlands asset group is not recoverable. We determined all other Epoxy asset groups to be recoverable. The fair value of the asset group was calculated using a discounted cash flow methodology and a non-cash impairment charge of $347, related to the Company's base epoxy resin business in the Netherlands, was recognized within the Performance and Essential Materials segment to reduce the carrying amount of the asset group to its fair value. The long-lived assets impairment within the Westlake Epoxy Netherlands asset group consists of non-cash charges of $256 in property, plant and equipment, $32 in operating lease right-of-use assets, $6 in customer relationships, $43 in other intangible assets, and $10 in other assets. The long-lived assets impairment charge is reported in impairment of goodwill and long-lived assets

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	Leases Lease-related asset and liability balances consist of the following at December 31: 2023 2022 Operating Leases Right-of-use assets $ 697 $ 615 Accrued and other liabilities $ 124 $ 116 Operating lease liabilities 611 504 Total operating lease liabilities $ 735 $ 620 Weighted Average Remaining Term (in years) 9 9 Weighted Average Lease Discount Rate 3.8 % 2.9 % The Company's operating lease cost is comprised of payments related to operating leases recorded in the consolidated balance sheet and short-term rental payments for leases that are not recorded in the consolidated balance sheet. Variable operating lease cost was not material to the consolidated statements of operations for the years ended December 31, 2023, 2022, and 2021. The components of operating lease expense were as follows: Year Ended December 31, 2023 2022 2021 Operating lease cost (1) $ 142 $ 139 $ 117 Short-term lease cost 121 101 85 Total operating lease cost $ 263 $ 240 $ 202 _____________________________ (1) Includes fixed lease payments for operating leases recorded in the consolidated balance sheet. Maturities of lease liabilities were as follows at December 31, 2023: Operating Leases 2024 $ 142 2025 122 2026 108 2027 95 2028 81 Thereafter 362 Total lease payments 910 Less: imputed interest (175) Present value of lease liabilities $ 735 Related Party Leases The Company leases certain assets under operating leases with related parties. Right-of-use assets and the associated operating lease liabilities for related party operating leases were approximately $26 and $29 as of December 31, 2023 and December 31, 2022, respectively. The Company recognized operating lease cost for fixed lease payments to related parties of $5 and $6 for the years ended December 31, 2023 and 2022, respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill The following table summarizes gross carrying amounts and changes in the carrying amount of goodwill for the years ended December 31, 2023 and 2022. Performance and Essential Materials Segment Housing and Infrastructure Products Segment Total Balance at December 31, 2021 $ 902 $ 1,122 $ 2,024 Goodwill acquired during the year 119 5 124 Measurement period adjustment 8 16 24 Effects of changes in foreign exchange rates (9) (2) (11) Balance at December 31, 2022 1,020 1,141 2,161 Measurement period adjustment 4 1 5 Impairment of goodwill (128) — (128) Effects of changes in foreign exchange rates 1 2 3 Balance at December 31, 2023 $ 897 $ 1,144 $ 2,041 Goodwill Impairment The Company performed a quantitative assessment for the purposes of its annual goodwill impairment analysis for each of the reporting units within the Performance and Essential Materials and the Housing and Infrastructure Products segments during the fourth quarter of 2023. The fair values of the reporting units were determined using both a discounted cash flow methodology and a market value methodology. The discounted cash flow projections were based on a long-term forecast to reflect the cyclicality of the business. The forecast is based on historical results, estimates by management of future market conditions, current and future strategic and operational plans and future financial performance. Significant assumptions used in the discounted cash flow projection included projected sales volumes based on production capacities, future sales prices, feedstock, energy and power costs and capital expenditures to maintain safe and reliable plant operations. The future cash flows were discounted to present value using a discount rate ranging from 10.0% to 12.0%. The significant assumptions used in determining the fair value of the reporting unit using the market value methodology include the determination of appropriate market comparables and the estimated multiples of net income before interest expense, income taxes, depreciation and amortization (EBITDA) a willing buyer is likely to pay. Based on the quantitative tests performed during the fourth quarter of 2023, the Company determined that the fair value of the Westlake Epoxy reporting unit did not exceed its carrying amount, and as such, a goodwill impairment charge of $128 was recognized within the Performance and Essential Materials segment. The goodwill impairment charge is reported in impairment of goodwill and long-lived assets on the consolidated statements of operations. For all other reporting units, the Company determined that the fair value of each of the reporting units were substantially in excess of carrying value. Intangible Assets Intangible assets consist of the following at December 31: 2023 2022 Weighted Cost Accumulated Net Cost Accumulated Net Customer relationships $ 1,586 $ (676) $ 910 $ 1,589 $ (596) $ 993 15 Other intangible assets: Licenses and intellectual property 264 (136) 128 306 (124) 182 15 Trade name 385 (104) 281 411 (86) 325 18 Other 112 (28) 84 84 (19) 65 17 Total other intangible assets $ 761 $ (268) $ 493 $ 801 $ (229) $ 572 Scheduled amortization of intangible assets for the next five years is as follows: $142, $113, $105, $103 and $103 in 2024, 2025, 2026, 2027 and 2028, respectively.

Equity Method Investments

Equity Method Investments	12 Months Ended
	Dec. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments LACC, LLC Joint Venture In 2015, Eagle US 2 LLC ("Eagle"), a wholly-owned subsidiary of the Company, and Lotte Chemical USA Corporation, a subsidiary of Lotte Chemical Corporation ("Lotte"), formed a joint venture, LACC, LLC ("LACC"), to design, build and operate an ethylene facility with 2.2 billion pounds per year of ethylene production capacity. Pursuant to a contribution and subscription agreement between Eagle and LACC, Eagle contributed $225 to LACC to fund construction costs of the ethylene plant, representing approximately 12% of the membership interests in LACC. On November 12, 2019, the Company, through Eagle, completed the acquisition of an additional 34.8% of the membership interests in LACC from Lotte for approximately $817. On March 15, 2022, the Company acquired an additional 3.2% of the membership interests in LACC from Lotte for $89. As of December 31, 2023, the Company owned an aggregate 50% membership interest in LACC. As of December 31, 2023, the Company's investment exceeded the underlying equity in net assets by approximately $200 which was assigned to goodwill and not amortized. The ethylene plant was built adjacent to the Company's chlor-alkali facility in Lake Charles. During the third quarter of 2019, the ethylene plant began commercial operations. The Company accounts for its investment in LACC under the equity method of accounting. The LACC joint venture is a cost-sharing arrangement between the members of LACC. The members of LACC receive their proportionate shares of ethylene offtake each month and fund cash operating costs, excluding depreciation and amortization. As a result, LACC recognizes net losses equal to depreciation and amortization each period. The Company's equity in losses from LACC, which is equal to its share of depreciation and amortization expenses, is recognized in cost of sales in the consolidated statements of operations. The Company's investment in LACC is classified as an equity method investment in the consolidated balance sheets. The Company's capital contributions to fund its share of capital expenditures are classified within investing activities in the consolidated statements of cash flows. The Company's ethylene offtake from LACC was approximately 935 million and 766 million pounds during the years ended December 31, 2023 and 2022, respectively. Changes in the Company's investment in LACC for the years ended December 31, 2023 and 2022 were as follows: Investment in LACC Balance at December 31, 2021 $ 943 Cash contributions 87 Additional interest purchased 89 Depreciation and amortization (44) Balance at December 31, 2022 1,075 Cash contributions 21 Depreciation and amortization (49) Balance at December 31, 2023 $ 1,047 Services Provided to LACC and Lotte The Company provides certain utilities and other services to LACC and Lotte. Pursuant to a construction and reimbursement agreement, LACC and Lotte agreed to reimburse the Company for construction costs over a 6.5-year period beginning in 2020. In addition to the reimbursements for construction costs, the Company charges LACC and Lotte certain fixed fees under an operating, maintenance and logistics agreement. The Company accounts for the reimbursement of construction costs and the fixed fees as components of the total transaction price and recognizes it ratably in net sales over approximately 25 years. The remaining performance obligations at December 31, 2023, representing these fixed components of the transaction price, totaled $52 and $72 from LACC and Lotte, respectively. The associated contract liabilities recorded from LACC and Lotte totaled $23 and $29 as of December 31, 2023, respectively, and $19 and $24 as of December 31, 2022, respectively. In addition to the reimbursements for construction costs and other fixed fees, the Company charges LACC and Lotte certain variable fees. Other Equity Method Investments In addition to LACC, the Company has other equity method investments amounting to $68 and $67 as of December 31, 2023 and 2022, respectively. See Note 20 for more detailed information.

Accounts Payable

Accounts Payable	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accounts Payable	Accounts Payable Accounts payable consist of the following at December 31: 2023 2022 Accounts payable—third parties $ 849 $ 870 Accounts payable to related parties 15 16 Notes payable 13 3 Accounts payable $ 877 $ 889

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consist of the following at December 31: December 31, December 31, 0.875% senior notes due 2024 (the "0.875% 2024 Senior Notes") $ 300 $ 300 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750 750 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 1.625% €700 million senior notes due 2029 (the "1.625% 2029 Senior Notes") 773 750 3.375% senior notes due 2030 (the "3.375% 2030 Senior Notes") 300 300 3.50% senior notes due 2032 (the "3.50% 2032 tax-exempt GO Zone Refunding Senior Notes") 250 250 2.875% senior notes due 2041 (the "2.875% 2041 Senior Notes") 350 350 5.00% senior notes due 2046 (the "5.00% 2046 Senior Notes") 700 700 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 500 3.125% senior notes due 2051 (the "3.125% 2051 Senior Notes") 600 600 3.375% senior notes due 2061 (the "3.375% 2061 Senior Notes") 450 450 Term loans due 2026 13 15 Long-term debt, principal amount 4,997 4,976 Less: Unamortized discount and debt issuance costs 91 97 Long-term debt, carrying value 4,906 4,879 Less current portion: 0.875% senior notes due 2024 299 — Long-term debt, carrying value, net of current portion $ 4,607 $ 4,879 Credit Agreement On June 9, 2022, the Company entered into a new $1,500 revolving credit facility that is scheduled to mature on June 9, 2027 (the "Credit Agreement") and, in connection therewith, terminated the Company's then existing revolving credit agreement. The Credit Agreement bears interest at either (a) Adjusted Term SOFR (as defined in the Credit Agreement) plus a margin ranging from 1.00% to 1.625% per annum or (b) Alternate Base Rate (as defined in the Credit Agreement) plus a margin ranging from 0.00% to 0.625% per annum, in each case depending on the credit rating of the Company. The Credit Agreement contains certain affirmative and negative covenants, including a quarterly total leverage ratio financial maintenance covenant. As of December 31, 2023, the Company was in compliance with the total leverage ratio financial maintenance covenant. The Credit Agreement also contains certain events of default and, if and for so long as certain events of default have occurred and are continuing, any overdue amounts outstanding under the Credit Agreement will accrue interest at an increased rate, the lenders can terminate their commitments to lend thereunder and payments of any outstanding amounts thereunder could be accelerated by the lenders. None of the Company's subsidiaries are required to guarantee the obligations of the Company under the Credit Agreement. The Credit Agreement includes a $150 sub-limit for letters of credit, and any outstanding letters of credit will be deducted from availability under the facility. The Credit Agreement also provides for a discretionary $50 commitment for swingline loans to be provided on a same-day basis. The Company may also increase the size of the facility, in increments of at least $25, up to a maximum of $500, subject to certain conditions and if certain lenders agree to commit to such an increase. As of December 31, 2023, the Company had no borrowings and no letters of credit outstanding, and had borrowing availability of $1,500, under the Credit Agreement. 0.875% Senior Notes due 2024 In August 2021, the Company completed the registered public offering of $300 aggregate principal amount of the 0.875% 2024 Senior Notes. The Company may optionally redeem the 0.875% 2024 Senior Notes at any time and from time to time on or after August 15, 2022 for 100% of the principal amount plus accrued and unpaid interest. 3.60% Senior Notes due 2026 and 5.00% Senior Notes due 2046 In August 2016, the Company issued $750 aggregate principal amount of the 3.60% 2026 Senior Notes and $700 aggregate principal amount of the 5.00% 2046 Senior Notes. In March 2017, the Company commenced registered exchange offers to exchange the 3.60% 2026 Senior Notes and the 5.00% 2046 Senior Notes for new notes that are identical in all material respects to the 3.60% 2026 Senior Notes and the 5.00% 2046 Senior Notes, except that the offer and issuance of the new Securities and Exchange Commission-registered notes have been registered under the Securities Act of 1933, as amended (the "Securities Act"). The exchange offers expired on April 24, 2017, and approximately 99.97% of the 3.60% 2026 Senior Notes and 100% of the 5.00% 2046 Senior Notes were exchanged. The 3.60% 2026 Senior Notes that were not exchanged in the 3.60% 2026 Senior Notes exchange offer have not been registered under the Securities Act or any state securities laws and may not be offered or sold in the U.S. absent registration or an applicable exemption from registration requirements or a transaction not subject to the registration requirements of the Securities Act or any state securities law. Revenue Bonds In December 1997, the Company entered into a loan agreement with a public trust established for public purposes for the benefit of the Parish of Calcasieu, Louisiana. The public trust issued $11 principal amount of tax-exempt waste disposal revenue bonds in order to finance the Company's construction of waste disposal facilities for an ethylene plant. The waste disposal revenue bonds expire in December 2027 and are subject to redemption and mandatory tender for purchase prior to maturity under certain conditions. The interest rate on the waste disposal revenue bonds at December 31, 2023 and 2022 was 4.30% and 3.88%, respectively. 1.625% Senior Notes due 2029 On July 17, 2019, the Company completed the registered public offering of €700 million aggregate principal amount of the 1.625% 2029 Senior Notes. The Company received approximately $779 of net proceeds from the offering. The 1.625% 2029 Senior Notes will accrue interest from July 17, 2019 at a rate of 1.625% per annum, payable annually in arrears on July 17 of each year, beginning July 17, 2020. The Company may optionally redeem the 1.625% 2029 Senior Notes in accordance with the terms of the 1.625% 2029 Senior Notes. The Company designated this euro-denominated debt as a non-derivative net investment hedge of a portion of the Company's net investments in euro functional-currency denominated subsidiaries to offset foreign currency fluctuations. 3.375% Senior Notes due 2030 On June 12, 2020, the Company completed the registered public offering of $300 aggregate principal amount of the 3.375% 2030 Senior Notes. There is no sinking fund and no scheduled amortization of the 3.375% 2030 Senior Notes prior to maturity. The 3.375% 2030 Senior Notes accrue interest from June 12, 2020 at a rate of 3.375% per annum, payable semi-annually in arrears on June 15 and December 15 of each year, beginning December 15, 2020. The Company may optionally redeem the 3.375% 2030 Senior Notes in accordance with the terms of the 3.375% 2030 Senior Notes. 3.50% 2032 GO Zone Refunding Bonds In November 2017, the Louisiana Local Government Environmental Facility and Development Authority (the "Authority") completed the remarketing of $250 aggregate principal amount of 3.50% tax-exempt revenue refunding bonds due November 1, 2032 (the "3.50% 2032 GO Zone Bonds"), the net proceeds of which were used to redeem $250 aggregate principal amount of the Authority's 6 ¾% tax-exempt revenue bonds due November 1, 2032 issued by the Authority under the GO Zone Act in December 2007. In connection with the remarketing of the 3.50% 2032 GO Zone Bonds, the Company issued $250 aggregate principal amount of the 3.50% 2032 GO Zone Refunding Senior Notes. The 3.50% 2032 GO Zone Bonds are subject to optional redemption by the Authority upon the direction of the Company at any time on or after November 1, 2027, for 100% of the principal amount plus accrued interest. 2.875% Senior Notes due 2041 In August 2021, the Company completed the registered public offering of $350 aggregate principal amount of the 2.875% 2041 Senior Notes. The Company may optionally redeem the 2.875% 2041 Senior Notes at any time and from time to time prior to February 15, 2041 (six months prior to the maturity date) for a redemption price equal to the greater of (i) 100% of the principal amount plus accrued and unpaid interest and (ii) the sum of the present values of the remaining scheduled payments on the 2.875% 2041 Senior Notes being redeemed that would be due if the 2.875% 2041 Senior Notes matured on February 15, 2041, discounted to the redemption date on a semi-annual basis, plus 20 basis points, and plus accrued and unpaid interest. In addition, the Company may optionally redeem the 2.875% 2041 Senior Notes at any time on or after February 15, 2041 for 100% of the principal amount plus accrued and unpaid interest. 4.375% Senior Notes due 2047 In November 2017, the Company completed the registered public offering of $500 aggregate principal amount of the 4.375% 2047 Senior Notes. The 4.375% 2047 Senior Notes are unsecured and mature on November 15, 2047. There is no sinking fund and no scheduled amortization of the 4.375% 2047 Senior Notes prior to maturity. The Company may optionally redeem the 4.375% 2047 Senior Notes in accordance with the terms of the 4.375% 2047 Senior Notes. 3.125% Senior Notes due 2051 In August 2021, the Company completed the registered public offering of $600 aggregate principal amount of the 3.125% 2051 Senior Notes. The Company may optionally redeem the 3.125% 2051 Senior Notes at any time and from time to time prior to February 15, 2051 (six months prior to the maturity date) for a redemption price equal to the greater of (i) 100% of the principal amount plus accrued and unpaid interest and (ii) the sum of the present values of the remaining scheduled payments on the 3.125% 2051 Senior Notes being redeemed that would be due if the 3.125% 2051 Senior Notes matured on February 15, 2051, discounted to the redemption date on a semi-annual basis, plus 25 basis points, and plus accrued and unpaid interest. In addition, the Company may optionally redeem the 3.125% 2051 Senior Notes at any time on or after February 15, 2051 for 100% of the principal amount plus accrued and unpaid interest. 3.375% Senior Notes due 2061 In August 2021, the Company completed the registered public offering of $450 aggregate principal amount of the 3.375% 2061 Senior Notes. The Company may optionally redeem the 3.375% 2061 Senior Notes at any time and from time to time prior to February 15, 2061 (six months prior to the maturity date) for a redemption price equal to the greater of (i) 100% of the principal amount plus accrued and unpaid interest and (ii) the sum of the present values of the remaining scheduled payments on the 3.375% 2061 Senior Notes being redeemed that would be due if the 3.375% 2061 Senior Notes matured on February 15, 2061, discounted to the redemption date on a semi-annual basis, plus 25 basis points, and plus accrued and unpaid interest. In addition, the Company may optionally redeem the 3.375% 2061 Senior Notes at any time on or after February 15, 2061 for 100% of the principal amount plus accrued and unpaid interest. The holders of the 0.875% 2024 Senior Notes, the 3.60% 2026 Senior Notes, the 1.625% 2029 Senior Notes, the 3.375% 2030 Senior Notes, the 3.50% 2032 GO Zone Refunding Senior Notes, the 2.875% 2041 Senior Notes, the 5.00% 2046 Senior Notes, the 4.375% 2047 Senior Notes, the 3.125% 2051 Senior Notes and the 3.375% 2061 Senior Notes may require the Company to repurchase the notes at a price equal to 101% of their principal amount, plus accrued and unpaid interest to, but not including, the date of repurchase, upon the occurrence of both a "change of control" and, within 60 days of such change of control, a "below investment grade rating event" (as such terms are defined in the respective indentures governing these notes). The indenture governing the 0.875% 2024 Senior Notes, the 3.60% 2026 Senior Notes, the 1.625% 2029 Senior Notes, the 3.375% 2030 Senior Notes, the 3.50% 2032 GO Zone Refunding Senior Notes, the 2.875% 2041 Senior Notes, the 5.00% 2046 Senior Notes, the 4.375% 2047 Senior Notes, the 3.125% 2051 Senior Notes, and the 3.375% 2061 Senior Notes (together, the "Notes") contains customary events of default and covenants that, among other things and subject to certain exceptions, restrict the Company and certain of the Company's subsidiaries' ability to (1) incur certain secured indebtedness, (2) engage in certain sale and leaseback transactions and (3) consolidate, merge or transfer all or substantially all of its assets. The Notes are unsecured and none of the Company's subsidiaries have guaranteed any series of the Notes. 2026 Term Loans In March 2021, Taiwan Chlorine Industries, Ltd., the Company's 60%-owned joint venture, entered into five-year loan agreements for a maximum total limit of approximately $22. The interest rate on these loans at December 31, 2023 was 0.95%. The unsecured loans include a government rate subsidy and have a 5-year maturity. The balance outstanding under these loans was approximately $13 at December 31, 2023. As of December 31, 2023, the Company was in compliance with all of its long-term debt covenants. The weighted average interest rate on all long-term debt was 3.2% at December 31, 2023 and 2022. Unamortized debt issuance costs on long-term debt were $36 and $40 at December 31, 2023 and 2022, respectively.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity The Company's Board of Directors has declared regular quarterly dividends to holders of its common stock aggregating $221, $169 and $145 for the years ended December 31, 2023, 2022 and 2021, respectively. Common Stock Each share of common stock entitles the holder to one vote on all matters on which holders are permitted to vote, including the election of directors. There are no cumulative voting rights. Accordingly, holders of a majority of the total votes entitled to vote in an election of directors will be able to elect all of the directors standing for election. Subject to preferences that may be applicable to any outstanding preferred stock, the holders of the common stock will share equally on a per share basis any dividends when, as and if declared by the Board of Directors out of funds legally available for that purpose. If the Company is liquidated, dissolved or wound up, the holders of the Company's common stock will be entitled to a ratable share of any distribution to stockholders, after satisfaction of all the Company's liabilities and of the prior rights of any outstanding class of the Company's preferred stock. The Company's common stock has no preemptive or conversion rights or other subscription rights. There are no redemption or sinking fund provisions applicable to the Company's common stock. Preferred Stock The Company's charter authorizes the issuance of shares of preferred stock. The Company's Board of Directors has the authority, without shareholder approval, to issue preferred shares from time to time in one or more series, and to fix the number of shares and terms of each such series. The Board may determine the designations and other terms of each series including dividend rates, whether dividends will be cumulative or non-cumulative, redemption rights, liquidation rights, sinking fund provisions, conversion or exchange rights and voting rights. Stock Repurchase Program In November 2014, the Company's Board of Directors approved a $250 share repurchase program (the "2014 Program"). In November 2015, the Company's Board of Directors approved the expansion of the 2014 Program by an additional $150. In August 2018, the Company's Board of Directors approved the expansion of the 2014 Program by an additional $150. In August 2022, the Company's Board of Directors approved the further expansion of the existing 2014 Program by an additional $500. The number of shares repurchased by the Company under the 2014 Program was 211,294, 1,079,736 and 355,800 for the years ended December 31, 2023, 2022 and 2021, respectively. As of December 31, 2023, the Company had repurchased a total of 8,722,550 shares of its common stock for an aggregate purchase price of approximately $574. Any shares repurchased under the 2014 Program are held by the Company as treasury stock and may be used for general corporate purposes, including for the 2013 Omnibus Incentive Plan. In 2014, the Company began delivering treasury shares to employees and non-employee directors for options exercised, for the settlement of restricted stock units and for the settlement of performance stock units. The cost of treasury shares delivered is determined using the specific identification method.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) by component were as follows: Pension and Other Post-Retirement Benefits Liability, Net of Tax Cumulative Foreign Currency Total Balances at December 31, 2021 $ 20 $ (56) $ (36) Net other comprehensive income (loss) attributable to Westlake Corporation 32 (85) (53) Balances at December 31, 2022 52 (141) (89) Net other comprehensive income (loss) attributable to Westlake Corporation (48) 39 (9) Balances at December 31, 2023 $ 4 $ (102) $ (98)

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
Employee Benefits	Employee Benefits Defined Contribution Plans U.S. Plans The Company has a defined contribution savings plan covering the eligible U.S. regular full-time and part-time employees, whereby eligible employees may elect to contribute up to 100% of their annual eligible compensation, subject to an annual plan limit in line with the annual elective contribution limit as determined by the Internal Revenue Service. The Company matches its employee's contribution up to a certain percentage of such employee's compensation, per the terms of the plan. The Company may, at its discretion and per the terms of the plan, make an additional non-matching contribution in an amount as the Board of Directors may determine. For the years ended December 31, 2023, 2022 and 2021, the Company recorded approximately $36, $33 and $24, respectively, to expense for these contributions. Further, within the plan, the Company also makes an annual retirement contribution to substantially all employees of certain subsidiaries. The Company's contributions to the plan are determined as a percentage of employees' pay. For the years ended December 31, 2023, 2022 and 2021, the Company charged approximately $48, $46 and $35, respectively, to expense for these contributions. Non-U.S. Plans The Company has defined contribution plans in several countries covering eligible employees of the Company. The Company's contributions to the plans are based on applicable laws in each country and eligibility of employees of certain subsidiaries for the annual retirement contribution. Contributions to the Company's non-U.S. defined contribution plans are made by both the employee and the Company. For the years ended December 31, 2023, 2022 and 2021, the Company charged approximately $13, $3 and $4, respectively, to expense for its contributions to these plans. For the years ended December 31, 2023, 2022 and 2021, the Company charged an additional $3, $2 and $1, respectively, to expense related to the annual retirement contributions to these plans. Defined Benefit Plans U.S. Plans The Company has noncontributory defined benefit pension plans that cover certain eligible salaried and wage employees of certain subsidiaries. However, eligibility for the Company's plans has been frozen. Benefits for salaried employees under these plans are based primarily on years of service and employees' pay near retirement. Benefits for wage employees are based upon years of service and a fixed amount as periodically adjusted. The Company recognizes the years of service prior to the Company's acquisition of the subsidiary's facilities for purposes of determining vesting, eligibility and benefit levels for certain employees of the subsidiary and for determining vesting and eligibility for certain other employees of the subsidiary. The measurement date for these plans is December 31. Non-U.S. Plans The Company has defined benefit pension plans covering current and former employees associated with the Company's operations. In conjunction with the Westlake Epoxy acquisition on February 1, 2022, as disclosed in Note 2, the Company assumed certain defined benefit pension plans that are incorporated in the information disclosed. Several non-U.S. pension plans are unfunded and have no plan assets. These pension plans are closed to new participants. Benefits for employees for these plans are based primarily on employees' pay near retirement. The measurement date for the non-U.S. plans is December 31. Details of the changes in benefit obligations, plan assets and funded status of the Company's pension plans are as follows: 2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 518 $ 530 $ 673 $ 152 Benefit obligation assumed with acquisition — — — 612 Service cost 1 4 1 3 Interest cost 24 19 14 7 Actuarial loss (gain) (7) 82 (121) (188) Benefits paid (42) (21) (49) (17) Settlements — (3) — (1) Foreign exchange effects — 18 — (38) Benefit obligation, end of year $ 494 $ 629 $ 518 $ 530 Change in plan assets Fair value of plan assets, beginning of year $ 415 $ 370 $ 562 $ 21 Plan assets assumed with acquisition — — — 538 Actual return 55 19 (97) (145) Employer contribution 2 15 2 1 Benefits paid (42) (21) (49) (17) Administrative expenses paid (3) — (3) — Settlements — (3) — (1) Foreign exchange effects — 11 — (27) Fair value of plan assets, end of year $ 427 $ 391 $ 415 $ 370 Funded status, end of year $ (67) $ (238) $ (103) $ (160) The actuarial loss (gain) in the benefit obligation for the periods presented is primarily driven by discount rate assumption changes. 2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Noncurrent assets $ — $ 36 $ — $ 63 Current liabilities (2) (11) (2) (9) Noncurrent liabilities (65) (263) (101) (214) Net amount recognized $ (67) $ (238) $ (103) $ (160) 2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income (loss) Net loss (gain) $ (66) $ 67 $ (30) $ (10) Prior service credit (1) (4) (2) (4) Total before tax (1) $ (67) $ 63 $ (32) $ (14) ______________________________ (1) After-tax totals for pension benefits were a loss of $4 and a gain of $45 for 2023 and 2022, respectively, and are reflected in stockholders' equity as accumulated other comprehensive income (loss). In the U.S., the Pension Protection Act of 2006 (the "Pension Protection Act") established a relationship between a qualified pension plan's funded status and the actual benefits that can be provided. Restrictions on plan benefits and additional funding and notice requirements are imposed when a plan's funded status is less than certain threshold levels. For the 2023 plan year, the funded status for the Company's U.S. pension plans are above 80% and, as such, are exempt from the Pension Protection Act's benefit restrictions. Pension plans with an accumulated benefit obligation in excess of plan assets at December 31 are as follows: 2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Information for pension plans with an accumulated benefit obligation in excess of plan assets Projected benefit obligation $ (494) $ (273) $ (518) $ (223) Accumulated benefit obligation (494) (271) (518) (221) Fair value of plan assets 427 — 415 — The following table provides the components of net periodic benefit costs, other changes in plan assets and benefit obligation recognized in other comprehensive income. Year Ended December 31, 2023 2022 2021 U.S. Non-U.S. U.S. Non-U.S. U.S. Non-U.S. Components of net periodic benefit cost Service cost $ 1 $ 4 $ 1 $ 3 $ 3 $ 2 Administrative expenses 3 — 3 — 3 — Interest cost 24 19 14 7 11 1 Expected return on plan assets (26) (12) (38) (12) (38) (1) Net amortization (1) (2) — 1 — 3 Net periodic benefit cost (gain) $ 1 $ 9 $ (20) $ (1) $ (21) $ 5 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net loss (gain) emerging $ (36) $ 74 $ 13 $ (31) $ (49) $ (9) Prior service credit — — — — (2) — Amortization of prior service credit 1 — — — — — Amortization of net gain (loss) — 2 — (1) — (2) Foreign exchange effects — 1 — (1) — — Total recognized in OCI $ (35) $ 77 $ 13 $ (33) $ (51) $ (11) Total net periodic benefit cost and OCI $ (34) $ 86 $ (7) $ (34) $ (72) $ (6) The estimated prior service credit and net gain (loss) for the defined benefit plans to be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost during 2024 are expected to be $1 and $0, respectively. The weighted-average assumptions used to determine pension plan obligations and net periodic benefit costs for the plans are as follows: 2023 2022 2021 U.S. Non-U.S. U.S. Non-U.S. U.S. Non-U.S. Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 5.0 % 3.2 % 4.9 % 3.7 % 2.6 % 1.4 % Rate of compensation increase — % 3.1 % — % 2.9 % — % 2.6 % Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 4.9 % 3.7 % 2.5 % 1.2 % 2.1 % 0.8 % Discount rate for service cost 5.0 % 3.8 % 2.8 % 1.4 % 2.4 % 0.8 % Discount rate for interest cost 4.8 % 3.7 % 2.1 % 1.2 % 1.5 % 0.8 % Expected return on plan assets 6.5 % 3.3 % 7.0 % 2.6 % 7.0 % 4.0 % Rate of compensation increase — % 2.9 % — % 2.8 % — % 2.6 % The discount rates for the Company's U.S. and non-U.S. plans are determined using a benchmark pension discount curve and applying spot rates from the curve to each year of expected benefit payments to determine the appropriate discount rate for the Company. The assumed long-term return on plan assets is estimated by considering factors such as the plan's overall investment strategy, current economic conditions and historical averages. The Company's U.S. pension plan investments are held in the Westlake Defined Benefit Plan. The Company's overall investment strategy for these pension plan assets is to achieve a balance between moderate income generation and capital appreciation. The investment strategy includes a mix of approximately 60% of investments for long-term growth, and 40% for near-term benefit payments and liability hedging, with a diversification of asset types. These pension funds' investment policies target asset allocations of approximately 60% equity securities and 40% fixed income securities in order to pursue a balance between moderate income generation, capital appreciation and a reduction in funded status volatility. The Company's non-U.S. pension plan investments are primarily held in three pension plans in the Netherlands (collectively, the "Netherlands Plan"). Per the terms of the Netherlands Plan asset management agreement between the Company and the asset manager, the Netherlands Plan's current portfolio is strategically weighted towards fixed income securities. The Netherlands Plan's investment policy targets asset allocations of approximately 20% equity securities and 80% fixed income securities. The Netherlands Plan's investment strategy allows for re-allocations of either of the equity or the fixed income securities from 0% up to 100%. Equity securities primarily include investments in large-cap and small-cap companies located in the U.S. and international developed and emerging markets stocks. Fixed income securities are comprised of investment and non-investment grade bonds, including U.S. Treasuries and U.S. and non-U.S. corporate bonds of companies from diversified industries. These bonds also include longer duration securities to reduce funding volatility and reduce the asset/liability mismatch in terms of interest rate sensitivity. Fixed income funds also include international government bonds and mortgage funds. The U.S. pension fund investment policy allows a discretionary range in various asset classes within the asset allocation model of up to 10%. The Company does not believe that there are significant concentrations of risk in the pension plan assets due to its strategy of asset diversification. At December 31, 2023, plan assets did not include direct ownership of the Company's common stock. Under the accounting guidance for fair value measurements, inputs used to measure fair value are classified in one of three levels: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data. The investments in the collective trust and mutual funds are valued using a market approach based on the net asset value of units held. The fair values of the Company's plan assets at December 31, by asset category, are as follows: 2023 U.S. Plans Non-U.S. Plans Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ — $ 3 $ — $ — $ 3 Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 47 92 — 139 — 1 — 1 Small-cap funds (2) — 8 — 8 — — — — International funds (3) 70 23 — 93 — 74 — 74 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 39 138 — 177 — 303 — 303 Short-term investment funds — 10 — 10 — — — — Group insurance contract — — — — — — 10 10 $ 156 $ 271 $ — $ 427 $ 3 $ 378 $ 10 $ 391 2022 U.S. Plans Non-U.S. Plans Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ — $ 7 $ — $ — $ 7 Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 42 90 — 132 — 1 — 1 Small-cap funds (2) — 10 — 10 — — — — International funds (3) 72 24 — 96 — 73 — 73 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 37 128 — 165 — 280 — 280 Short-term investment funds — 12 — 12 — — — — Group insurance contract — — — — — — 9 9 $ 151 $ 264 $ — $ 415 $ 7 $ 354 $ 9 $ 370 ______________________________ (1) Substantially all of the assets of these funds are invested in large-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (2) Substantially all of the assets of these funds are invested in small-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (3) Substantially all of the assets of the U.S. Plans' funds are invested in international companies in developed markets (excluding the U.S.), and the remainder of the assets of these funds is invested in cash reserves. The assets of the non-U.S. Plans' funds are primarily invested in diversified global equities, real estate and private equities. (4) The assets of the U.S. Plans' funds represent investment grade bonds of U.S. issuers, including U.S. Treasury notes. The assets of the non-U.S. Plans represent fixed income funds that are primarily invested in international government bonds and mortgage funds. The Company's funding policy for its U.S. plans is consistent with the minimum funding requirements of federal law and regulations. Based on preliminary estimates, the Company expects to make contributions of approximately $0 and $5 for the U.S. and Non-U.S. pension plans, respectively, in 2024. Multi-employer Plans Non-U.S. Plans The Company participates in two multi-employer plans, Pensionskasse der Mitarbeiter der Hoechst-Gruppe VVaG and Pensionskasse der Wacker-Chemie GmbH VVaG, which provide benefits to certain of the Company's employees in Germany. These multi-employer plans are closed to new participants. The plans provide fixed, monthly retirement payments on the basis of the credits earned by the participating employees. To the extent that the plans are underfunded, future contributions to the plans may increase and may be used to fund retirement benefits for employees related to other employers. The benefit obligations are covered up to a certain salary threshold by contributions made by the Company and employees to the plans. Contributions to the Company's multi-employer plans are expensed as incurred. Other Post-retirement Benefits In the U.S., the Company provides post-retirement healthcare and life insurance benefits for certain employees and their dependents who meet minimum age and service requirements. The Company has the right to modify or terminate some of these benefits. The Company has a post-retirement plan in Canada which is unfunded and provides medical and life insurance benefits for certain employees and their dependents. The Company also has an unfunded post-retirement benefit plan in the Netherlands. The amounts recognized in the consolidated balance sheets related to other post-retirement benefits plans were as follows: 2023 2022 U.S. Plans Non-U.S. U.S. Plans Non-U.S. Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (8) $ (1) $ (8) $ (1) Noncurrent liabilities (33) (2) (38) (2) Net amount recognized $ (41) $ (3) $ (46) $ (3) Estimated Future Benefit Payments The following benefit payments are expected to be paid: Pension Other Post- Estimated future benefit payments: Year 1 $ 68 $ 8 Year 2 67 6 Year 3 67 4 Year 4 66 3 Year 5 65 3 Years 6 to 10 329 15

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Compensation	Stock-Based Compensation Under the Westlake Corporation 2013 Omnibus Incentive Plan (as amended and restated in 2023, the "2013 Plan"), all employees and non-employee directors of the Company, as well as certain individuals who have agreed to become the Company's employees, are eligible for awards. Shares of common stock may be issued as authorized in the 2013 Plan. At the discretion of the administrator of the 2013 Plan, employees and non-employee directors may be granted awards in the form of stock options, stock appreciation rights, stock awards, restricted stock units or cash awards (any of which may be a performance award). Outstanding stock option awards have a 10-year term and vest (1) ratably on an annual basis over a three-year period or (2) at the end of a five-year period. Outstanding restricted stock units and performance stock units vest either (1) ratably on an annual basis over a one three Option activity and changes during the year ended December 31, 2023 were as follows: Options Weighted Weighted Aggregate Outstanding at December 31, 2022 1,531,070 $ 77.76 Granted 197,251 122.65 Exercised (615,296) 73.31 Cancelled (39,136) 110.25 Outstanding at December 31, 2023 1,073,889 $ 87.37 6.1 $ 56 Exercisable at December 31, 2023 683,794 $ 74.23 4.8 $ 45 For options outstanding at December 31, 2023, the options had the following range of exercise prices: Range of Prices Options Weighted $44.42 - $61.87 169,789 2.6 $65.81 - $68.09 218,529 5.1 $79.83 - $86.54 262,357 6.3 $107.75 - $108.12 243,933 7.0 $122.65 - $122.65 179,281 9.1 The aggregate intrinsic value in the table above represents the total pretax intrinsic value (the difference between the Company's closing stock price on the last trading day of the year and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2023. This amount changes based on the fair market value of the Company's common stock. For the years ended December 31, 2023, 2022 and 2021, the total intrinsic value of options exercised was $34, $13 and $9, respectively. As of December 31, 2023, $8 of total unrecognized compensation cost related to stock options is expected to be recognized over a weighted-average period of 1.8 years. Income tax benefits of $4, $2 and $2 were realized from the exercise of stock options during the years ended December 31, 2023, 2022 and 2021, respectively. The Company used the Black-Scholes option pricing model to value its options. The table below presents the weighted average value and assumptions used in determining each option's fair value. Volatility was calculated using historical trends of the Company's common stock price. Stock Option Grants Year Ended December 31, 2023 2022 2021 Weighted average fair value $ 44.91 $ 34.20 $ 25.18 Risk-free interest rate 4.0 % 1.8 % 0.6 % Expected life in years 5 5 5 Expected volatility 39.1 % 36.9 % 36.9 % Expected dividend yield 1.1 % 1.1 % 1.2 % Non-vested restricted stock units as of December 31, 2023 and changes during the year ended December 31, 2023 were as follows: Number of Weighted Non-vested at December 31, 2022 690,414 $ 85.77 Granted 247,131 120.77 Vested (228,113) 69.45 Forfeited (67,804) 97.87 Non-vested at December 31, 2023 641,628 $ 103.77 As of December 31, 2023, there was $31 of unrecognized stock-based compensation expense related to non-vested restricted stock units. This cost is expected to be recognized over a weighted-average period of 2.0 years. The total fair value of restricted stock units that vested during the years ended December 31, 2023, 2022 and 2021 was $28, $18 and $18, respectively. Performance stock unit payout is based on the greater of the average annual economic-value added results for the Company (equal to net operating profit after tax less a capital charge based upon the weighted average cost of capital) and relative total shareholder return as compared to a peer group of companies. The units have payouts that range from zero to 200 percent of the target award. Non-vested performance stock units as of December 31, 2023 and changes during the year ended December 31, 2023 were as follows: Number of Weighted Non-vested at December 31, 2022 250,369 $ 106.13 Granted 72,627 167.76 Vested (106,705) 74.99 Forfeited (19,370) 142.29 Non-vested at December 31, 2023 196,921 $ 142.18 As of December 31, 2023, there was $13 of unrecognized stock-based compensation expense related to non-vested performance stock units. This cost is expected to be recognized over a weighted-average period of 1.8 years. The total fair value of performance stock units that vested during the years ended December 31, 2023, 2022 and 2021 was $13, $8 and $0, respectively. The Company used a Monte Carlo simulation model to value the performance stock units on the grant date. The table below presents the assumptions used in determining grant date fair value. Volatility was calculated using historical trends of the Company's common stock price. Performance Stock Units Year Ended December 31, 2023 2022 2021 Risk-free interest rate 4.4 % 1.7 % 0.2 % Expected life in years 2.87 2.87 2.87 Expected volatility of Westlake Corporation common stock 40.8 % 49.3 % 49.4 % Expected volatility of peer companies 26.6% - 53.2% 30.8% - 67.2% 30.7% - 65.6% Average correlation coefficient of peer companies 0.61 0.66 0.65 Grant date fair value $ 167.76 $ 147.98 $ 109.94 Westlake Chemical Partners LP Awards The Company's wholly-owned subsidiary and the general partner of Westlake Partners, Westlake Chemical Partners GP LLC ("Westlake Partners GP"), maintains a unit-based compensation plan for directors and employees of Westlake Partners GP and Westlake Partners. The Westlake Partners 2014 Long-term Incentive Plan ("Westlake Partners 2014 Plan") permits various types of equity awards including but not limited to grants of phantom units and restricted units. Awards granted under the Westlake Partners 2014 Plan may be settled with Westlake Partners units or in cash or a combination thereof. Compensation expense for these awards was not material to the Company's consolidated financial statements for the years ended December 31, 2023, 2022 and 2021.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company has financial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and long-term debt, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Company's long-term debt at December 31, 2023 and 2022 are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy. 2023 2022 Carrying Fair Carrying Fair Long-term Debt $ 4,906 $ 4,236 $ 4,879 $ 3,940

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income before income taxes are as follows: Year Ended December 31, 2023 2022 2021 Domestic $ 923 $ 2,523 $ 2,298 Foreign (223) 423 379 $ 700 $ 2,946 $ 2,677 The Company's provision for (benefit from) income taxes consist of the following: Year Ended December 31, 2023 2022 2021 Current Federal $ 229 $ 473 $ 434 State 26 74 57 Foreign 98 123 93 Total current 353 670 584 Deferred Federal (82) (1) 19 State (31) (14) 13 Foreign (62) (6) (9) Total deferred (175) (21) 23 Total provision for (benefit from) income taxes $ 178 $ 649 $ 607 A reconciliation of taxes computed at the statutory rate to the Company's income tax expense is as follows: Year Ended December 31, 2023 2022 2021 Provision for federal income tax, at statutory rate $ 148 $ 619 $ 563 State income tax provision, net of federal income tax effect 7 59 56 Foreign income tax rate differential (15) 30 22 Noncontrolling interests (7) (8) (11) Change in valuation allowance 76 — (29) U.S. federal research and development credits (54) (27) (1) Uncertain Income Tax Positions 14 6 2 Goodwill impairment 26 — — Other, net (17) (30) 5 Total income tax expense (benefit) $ 178 $ 649 $ 607 The tax effects of the principal temporary differences between financial reporting and income tax reporting at December 31 are as follows: 2023 2022 Net operating loss carryforward $ 166 $ 103 Credit carryforward 20 19 Operating lease liabilities 177 149 Accruals 139 96 Pension 88 99 Inventories 34 34 Research and experimental expenditures 124 94 Other 36 18 Deferred taxes assets—total 784 612 Property, plant and equipment (1,257) (1,301) Intangibles (240) (272) Operating lease right-of-use asset (168) (149) Turnaround costs (61) (49) Consolidated partnerships (213) (234) Equity method investments (228) (237) Other (47) (42) Deferred tax liabilities—total (2,214) (2,284) Valuation allowance (118) (47) Total net deferred tax liabilities $ (1,548) $ (1,719) Balance sheet classifications Noncurrent deferred tax asset $ 12 $ 16 Noncurrent deferred tax liability (1,560) (1,735) Total net deferred tax liabilities $ (1,548) $ (1,719) At December 31, 2023, the Company had federal, foreign and state net operating loss carryforwards ("NOLs") of approximately $15, $432 and $952, respectively. The federal NOL and certain foreign and state NOLs do not expire, while certain other foreign and state NOLs expire in varying amounts between 2024 and 2043. The federal NOL and certain state NOLs are subject to limitations on an annual basis. At December 31, 2023, the Company had various federal and state credit carryforwards of $2 and $18, respectively, which either do not expire or expire in varying amounts between 2028 and 2033. Management believes the Company will realize the benefit of a portion of the net operating loss and credit carryforwards before they expire, but to the extent that the full benefit may not be realized, a valuation allowance has been recorded. The valuation allowance increased by $71 primarily due to the impairment of long-lived assets of Westlake Epoxy's base resin business in the Netherlands, which generated deferred tax assets including net operating loss carryforwards that are not expected to be realized. The Company has recognized a liability for uncertain income tax positions of $38 as of December 31, 2023. The Company does not believe it is likely that any material amounts will be paid in 2024. The ultimate resolution and timing of payment for remaining matters continues to be uncertain. The Company files income tax returns in the U.S. federal jurisdiction, various states and foreign jurisdictions. The Company is no longer subject to examinations by tax authorities before the year 2014. On October 8, 2021, the Organization for Economic Co-operation and Development (the "OECD")/G20 Inclusive Framework on Base Erosion and Profit Shifting released a statement indicating that its members had agreed to a Two – Pillar Solution to Address the Tax Challenges Arising from the Digitalisation of the Economy. Pillar One aims to reallocate a taxpayer's residual profits to the market jurisdictions with which the taxpayer has a nexus. Pillar Two aims to establish a minimum global tax rate of 15%, assessed through a top-up tax imposed on a country-by-country basis. Pillar One targets multinational companies with global annual revenue exceeding €20 billion and profit-to-revenue ratio of more than 10%. Based on the current threshold requirements, the Company does not expect to be subject to Pillar One. On December 20, 2021, the OECD released the Pillar Two model rules providing a framework for implementing a 15% minimum tax, also referred to as the Global Anti-Base Erosion ("GloBE") rules, on earnings of multinational companies with consolidated annual revenue exceeding €750 million.

Earnings and Dividends per Shar

Earnings and Dividends per Share	12 Months Ended
	Dec. 31, 2023
Earnings and Dividends Per Share [Abstract]
Earnings and Dividends per Share	Earnings and Dividends per Share The Company has unvested restricted stock units outstanding that are considered participating securities and, therefore, computes basic and diluted earnings per share under the two-class method. Basic earnings per share for the periods are based upon the weighted average number of shares of common stock outstanding during the periods. Diluted earnings per share include the effects of certain stock options and performance stock units. Year Ended December 31, 2023 2022 2021 Net income attributable to Westlake Corporation $ 479 $ 2,247 $ 2,015 Less: Net income attributable to participating securities 3 12 10 Net income attributable to common shareholders $ 476 $ 2,235 $ 2,005 The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Year Ended December 31, 2023 2022 2021 Weighted average common shares—basic 127,806,317 127,970,445 128,002,911 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 792,124 875,117 695,071 Weighted average common shares—diluted 128,598,441 128,845,562 128,697,982 Earnings per common share attributable to Westlake Corporation: Basic $ 3.73 $ 17.46 $ 15.66 Diluted $ 3.70 $ 17.34 $ 15.58 Excluded from the computation of diluted earnings per share for the years ended December 31, 2023, 2022 and 2021 are options to purchase 263,131, 315,864 and 461,618 shares of common stock, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive. Dividends per Share Dividends per common share for the years ended December 31, 2023, 2022 and 2021 were as follows: Year Ended December 31, 2023 2022 2021 Dividends per common share $ 1.7140 $ 1.3090 $ 1.1350

Supplemental Information

Supplemental Information	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Information	Supplemental Information Other Assets, Net Other assets, net were $651 and $617 at December 31, 2023 and 2022, respectively. Deferred turnaround costs, net of accumulated amortization, included in other assets, net were $391 and $359 at December 31, 2023 and 2022, respectively. Accrued and Other Liabilities Accrued and other liabilities were $1,614 and $1,409 at December 31, 2023 and 2022, respectively. Accrued rebates and accrued litigation reserves, which are components of accrued and other liabilities, were $217 and $297 at December 31, 2023 and $227 and $90 at December 31, 2022, respectively. No other component of accrued and other liabilities was more than five percent of total current liabilities. Accrued liabilities with related parties were $41 and $44 at December 31, 2023 and 2022, respectively. Non-cash Investing Activity Capital expenditure related liabilities, included in accounts payable and accrued and other liabilities, were $184, $171, and $156 at December 31, 2023, 2022, and 2021, respectively. Restructuring, Transaction and Integration-related Costs For the years ended December 31, 2023, 2022 and 2021, the restructuring, transaction and integration-related costs of $28, $33 and $21, respectively. The costs in 2023 are restructuring and integration costs primarily related to plant closures resulting from the Company's manufacturing footprint optimization efforts. The 2022 and 2021 expenses primarily consist of integration-related consulting fees, restructuring expenses and costs associated with the Company's acquisitions in previous years. Other Income, Net For the year ended December 31, 2023, other income, net Operating Lease Supplemental Cash Flow Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2023 2022 2021 Operating cash flows from operating leases (1) $ 139 $ 134 $ 114 Right-of-use assets obtained in exchange for operating lease obligations 240 187 215 ______________________________ (1) Includes cash paid for amounts included in the measurement of operating lease liabilities recorded in the consolidated balance sheets. Cash Flow Information Year Ended December 31, 2023 2022 2021 Cash paid for: Interest paid, net of interest capitalized $ 159 $ 172 $ 130 Income taxes paid 421 570 466

Related Party and Affiliate Tra

Related Party and Affiliate Transactions	12 Months Ended
	Dec. 31, 2023
Related Party Transactions [Abstract]
Related Party And Affiliate Transactions	Related Party and Affiliate Transactions The Company and Lotte have a joint venture, LACC, to operate an ethylene facility with 2.2 billion pounds per year of ethylene production capacity. See Note 9 for details of the Company's transactions with LACC. The Company leases office space for management and administrative services from an affiliate of the Company's principal stockholder. For each of the years ended December 31, 2023, 2022 and 2021, the Company incurred lease payments of approximately $3. Cypress Interstate Pipeline L.L.C., a natural gas liquids pipeline joint venture in which the Company owns a 50% equity interest, transports natural gas liquid feedstocks to the Company's Lake Charles complex through its pipeline. The Company accounts for its investments in Cypress Interstate Pipeline L.L.C. under the equity method of accounting. The investment in Cypress Interstate Pipeline L.L.C. at December 31, 2023 and 2022 was $8 and $7, respectively. For the years ended December 31, 2023, 2022 and 2021, the Company incurred pipeline lease service fees of approximately $20, $16 and $14, respectively, payable to this joint venture for usage of the pipeline. The amounts due to this joint venture were $1 at December 31, 2023 and 2022. The Company owns an approximately 20% equity interest in both YNCORIS GmbH & Co. KG (formerly known as InfraServ Knapsack GmbH & Co. KG) and InfraServ Gendorf GmbH & Co. KG (collectively "Infraserv"). The Company accounts for its investments in Infraserv under the equity method of accounting. The Company has service agreements with these entities, including contracts to provide electricity, technical and leasing services to certain of the Company's production facilities in Germany. The investment in Infraserv was $53 and $53 at December 31, 2023 and 2022, respectively. For the years ended December 31, 2023, 2022 and 2021, the Company incurred charges aggregating approximately $176, $188 and $174, respectively, for these services. The amounts accrued for these related parties were approximately 34 and $37 at December 31, 2023 and 2022, respectively. In conjunction with the Westlake Epoxy acquisition, the Company acquired 49.99% equity interest in Westlake UV Coatings (Shanghai) Co., Ltd. (formerly known as Hexion UV Coatings Co., LTD). The investment in Westlake UV Coatings (Shanghai) Co., Ltd. was $7 at December 31, 2023. The Company accounts for its investments in Westlake UV Coatings (Shanghai) Co., Ltd. under the equity method of accounting. Dividends received from equity method investments were $18, $16 and $15 for the years ended December 31, 2023, 2022 and 2021, respectively. One of the Company's directors serves as Chairman and Chief Executive Officer of American Air Liquide, Inc. and Executive Vice President of the Air Liquide Group ("Air Liquide"). The Company purchased oxygen, nitrogen and utilities and leased cylinders from various affiliates of American Air Liquide, Inc. aggregating approximately $43, $43 and $39 for the years ended December 31, 2023, 2022 and 2021, respectively. The Company also sold certain utilities to Air Liquide aggregating approximately $14, $11 and $8 during the years ended December 31, 2023, 2022 and 2021, respectively. The amounts payable to Air Liquide were $4 and $4 at December 31, 2023 and 2022, respectively, and the amounts receivable from Air Liquide were $1 and $2 at December 31, 2023 and 2022, respectively.

Westlake Chemical Partners LP

Westlake Chemical Partners LP	12 Months Ended
	Dec. 31, 2023
Partners' Capital [Abstract]
Westlake Chemical Partners LP	Westlake Chemical Partners LP In 2014, the Company formed Westlake Partners to operate, acquire and develop ethylene production facilities and related assets. Also in 2014, Westlake Partners completed its initial public offering of 12,937,500 common units. Most recently, on March 29, 2019, Westlake Partners purchased an additional 4.5% newly issued limited partner interests in OpCo and completed a private placement of 2,940,818 common units. TTWF LP, the Company's principal stockholder and a related party, acquired 1,401,869 units out of the 2,940,818 common units issued in the private placement. At December 31, 2023, Westlake Partners had a 22.8% limited partner interest in OpCo, and the Company retained a 77.2% limited partner interest in OpCo and a significant interest in Westlake Partners through the Company's ownership of Westlake Partners' general partner, 40.1% of the limited partner interests (consisting of 14,122,230 common units) and incentive distribution rights. On October 4, 2018, Westlake Partners and Westlake Partners GP, the general partner of Westlake Partners, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell Westlake Partners' common units, from time to time, up to an aggregate offering amount of $50. This Equity Distribution Agreement was amended on February 28, 2020 to reference a new shelf registration for utilization under this agreement. No common units had been issued under this program as of December 31, 2023.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies The Company is involved in a number of legal and regulatory matters, principally environmental in nature, that are incidental to the normal conduct of its business, including lawsuits, investigations and claims. The outcome of these matters are inherently unpredictable. The Company believes that, in the aggregate, the outcome of all known legal and regulatory matters will not have a material adverse effect on its consolidated financial statements; however, under certain circumstances, if required to recognize costs in a specific period, when combined with other factors, outcomes with respect to such matters may be material to the Company's consolidated statements of operations in such period. The Company's assessment of the potential impact of environmental matters, in particular, is subject to uncertainty due to the complex, ongoing and evolving process of investigation and remediation of such environmental matters, and the potential for technological and regulatory developments. In addition, the impact of evolving claims and programs, such as natural resource damage claims, industrial site reuse initiatives and state remediation programs creates further uncertainty of the ultimate resolution of these matters. The Company anticipates that the resolution of many legal and regulatory matters, and in particular environmental matters, will occur over an extended period of time. Caustic Soda Antitrust . The Company and other caustic soda producers were named as defendants in multiple purported class action civil lawsuits filed since March 2019 in the U.S. District Court for the Western District of New York. The lawsuits allege the defendants conspired to fix, raise, maintain and stabilize the price of caustic soda, restrict domestic (U.S.) supply of caustic soda and allocate caustic soda customers. The other defendants named in the lawsuits are Olin Corporation, K.A. Steel Chemicals (a wholly-owned subsidiary of Olin), Occidental Chemical Corporation d/b/a OxyChem, Shintech Incorporated and Formosa Plastics Corporation, U.S.A. Each of the lawsuits is filed on behalf of the respective named plaintiff or plaintiffs and a putative class comprised of either direct purchasers or indirect purchasers of caustic soda in the U.S. The plaintiffs in the putative class for such direct purchasers seek $861 in single damages from the defendants, in addition to treble damages and attorney's fees. The plaintiffs in the putative class for such indirect purchasers seek approximately $500 in single damages from the defendants, in addition to treble damages (if permitted under applicable state law) and injunctive relief. The defendants' joint motion to dismiss the direct purchaser lawsuits was denied. The defendants' joint motion to dismiss the indirect purchaser lawsuits was granted in part and denied in part. Both groups of cases have proceeded to discovery. On October 16, 2023, the Company entered into a settlement agreement whereby the Company agreed, subject to the terms and conditions of the settlement agreement, to pay $19 to the direct purchaser plaintiffs and in which the Company admits to no violations of law and will be released from liability and dismissed from the direct purchaser lawsuits with prejudice upon receipt of final court approval of the settlement. Preliminary court approval of the settlement, which remains subject to certification of the class, has been requested and is pending. If the court grants such preliminary approval, notice of the settlement will be disseminated to the settlement class, and the settlement class members will, for a limited time period, have an opportunity to opt-out of or object to the settlement. The Company reserved $19 in connection with the litigation in the third quarter of 2023. Beginning in October 2020, similar class action proceedings were also filed in Canada before the Superior Court of Qu é bec as well as before the Federal Court. These proceedings seek the certification or authorization of a class action on behalf of all residents of Canada who purchased caustic soda (including, in one of the cases, those who merely purchased products containing caustic soda) from October 1, 2015 through the present or such date deemed appropriate by the court. On December 10, 2021, the Superior Court of Québec stayed its proceedings until after a final certification decision is released in the Federal Court proceedings. At this time, the Company is not able to estimate the impact, if any, that these lawsuits could have on the Company's consolidated financial statements either in the current period or in future periods. Ethylene Antitrust. The Company and other ethylene consumers were named as defendants in a civil lawsuit filed by Shell Chemical Europe B.V. ("SCE") in March 2023 in the District Court of Amsterdam, the Netherlands, following the European Commission Decision AT.40410 – Ethylene from July 14, 2020. SCE is a producer of ethylene in the European market and the lawsuit alleges the defendants conspired to lower the purchase price for ethylene and ethylene derivatives by manipulating the monthly contract price. SCE initially sought declaratory relief. In October 2023, SCE amended its claim and is now seeking a judgment establishing that the Company and the co-defendants are jointly and severally liable for alleged damages in the amount of approximately €1,026 million with interest compounding daily from January 1, 2020 and continuing until payment in full, as provided by Dutch law, resulting from artificially lowered prices for ethylene and ethylene derivatives during the specified period. SCE is also seeking reimbursement of costs related to the proceeding plus statutory interest. The Company and other ethylene consumers were also named as defendants in a civil lawsuit filed by Stichting Ethylene Claims ("Stichting") in November 2023 in the District Court of Amsterdam, the Netherlands, following the same European Commission decision. Stichting is a foundation under Dutch Law that claims to represent various parties asserting injury by the same alleged conduct of defendants, seeking a declaratory judgment establishing that the Company and other defendants are jointly and severally liable for an unspecified amount of damages. At this time, the Company is not able to estimate the impact, if any, that the SCE lawsuit and/or the Stichting lawsuit could have on the Company's consolidated financial statements either in the current period or in future periods. Triad Hunter. In April 2018, Triad Hunter, LLC ("Triad Hunter") filed suit against the Company and certain of its subsidiaries in the Court of Common Pleas in Monroe County, Ohio seeking injunctive relief and alleging negligence and trespass at the Natrium Plant with respect to Triad Hunter's well drilling activities in Ohio. On October 27, 2022, the jury returned a verdict finding that the Company had committed trespass and was negligent in conducting salt mining operations at the Natrium Plant. Upon receipt of the jury verdict, the Company reserved approximately $70 for the damages awarded to Triad Hunter. The court subsequently denied Triad Hunter's request to enjoin further solution mining from one of the brine fields at the Natrium Plant. On September 12, 2023, final judgment was entered in the amount of $70 with interest accruing at the rate of 5% from the date the judgment was rendered, as provided by law. The Company appealed the verdict and sought a stay of execution pending appeal on October 30, 2023. Petro 2 Flash Fire and EDC Storage Tank Explosion. Petro 2 Flash Fire and EDC Storage Tank Explosion. In September 2021, shortly after the turnaround on Westlake Chemical OpCo LP's Petro 2 ethylene facility commenced, there was a flash fire at the quench tower of the Petro 2 facility. In January 2022, an ethylene dichloride storage tank exploded at one of the Company's Lake Charles, Louisiana complexes. Certain employees and contractors working on the sites at the time of the events were injured during these events and multiple lawsuits were filed against us. Final settlements totaling approximately $382 in the aggregate were reached with all of the plaintiffs to fully resolve the lawsuits, but payment by the Company and the insurance carriers has not yet been completed. Certain of the Company's excess insurers have taken the coverage position that there has been insufficient exhaustion of the retention levels beneath their respective attachment points to obligate them to cover these events. The practical effect of this coverage position is that approximately $150 of the $382 total final settlement amount is currently not being covered by the insurers and, as such, approximately $150 has been included in cost of sales in the fourth quarter of 2023. The Company disagrees with the insurers' coverage position, and is pursuing recovery of the approximately $150 and any other amount the Company may be entitled to. The Company has reserved for the full final settlement amount and recorded an insurance receivable for $43 and a legal accrual of $183 as of December 31, 2023. Environmental Contingencies. As of December 31, 2023 and 2022, the Company had reserves for environmental contingencies totaling approximately $58 and $55, respectively, most of which was classified as noncurrent liabilities. The Company's assessment of the potential impact of these environmental contingencies is subject to considerable uncertainty due to the complex, ongoing and evolving process of investigation and remediation, if necessary, of such environmental contingencies, and the potential for technological and regulatory developments. Calvert City Proceedings. For several years, the Environmental Protection Agency (the "EPA") has been conducting remedial investigation and feasibility studies at the Company's Calvert City, Kentucky facility pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 ("CERCLA"). As the current owner of the Calvert City facility, the Company was named by the EPA as a potentially responsible party ("PRP") along with Goodrich Corporation ("Goodrich") and its successor-in-interest, Avient Corporation (formerly known as PolyOne Corporation, "Avient"). On November 30, 2017, the EPA published a draft Proposed Plan, incorporating by reference an August 2015 draft Remedial Investigation ("RI") report, an October 2017 draft Feasibility Study ("FS") report and a Technical Impracticability Waiver document dated December 19, 2017. On June 18, 2018, the EPA published an amendment to its Proposed Plan. The amended Proposed Plan describes a final remedy for the onshore portion of the site comprised of a containment wall, targeted treatment and supplemental hydraulic containment. The amended Proposed Plan also describes an interim approach to address the contamination under the river that would include recovery of any mobile contaminants by an extraction well along with further study of the extent of the contamination and potential treatment options. The EPA's estimated cost of implementation is $107, with an estimated $1 to $3 in annual operation and maintenance ("O&M") costs. In September 2018, the EPA published the Record of Decision ("ROD") for the site, formally selecting the preferred final and interim remedies outlined in the amended Proposed Plan. In October 2018, the EPA issued Special Notice letters to the PRPs for the remedial design phase of work under the ROD. In April 2019, the PRPs and the EPA entered into an administrative settlement agreement and order on consent for remedial design. In October 2019, the PRPs received special notice letters for the remedial action phase of work at the site. The Company, jointly with the other PRPs, submitted a good faith offer response in December 2019. On September 17, 2020, the EPA and the Department of Justice filed a proposed consent decree for the remedial action with the U.S. District Court for the Western District of Kentucky. On November 16, 2020, the Department of Justice filed a motion to approve and enter the consent decree. On January 28, 2021, the Court granted the unopposed motion to enter the consent decree, which became effective the same day. The Company's allocation of liability for remedial and O&M costs at the Calvert City site, if any, is governed by a series of agreements between the Company, Goodrich and Avient. These agreements and the associated litigation are described below. In connection with the 1990 and 1997 acquisitions of the Goodrich chemical manufacturing complex in Calvert City, Goodrich agreed to indemnify the Company for any liabilities related to preexisting contamination at the complex. For its part, the Company agreed to indemnify Goodrich for post-closing contamination caused by the Company's operations. The soil and groundwater at the complex, which does not include the Company's nearby PVC facility, had been extensively contaminated by Goodrich's operations. In 1993, Goodrich spun off the predecessor of Avient, and that predecessor assumed Goodrich's indemnification obligations relating to preexisting contamination. In 2003, litigation arose among the Company, Goodrich and Avient with respect to the allocation of the cost of remediating contamination at the site. The parties settled this litigation in December 2007 and the case was dismissed. In the settlement, the parties agreed that, among other things: (1) Avient would pay 100% of the costs (with specified exceptions), net of recoveries or credits from third parties, incurred with respect to environmental issues at the Calvert City site from August 1, 2007 forward; and (2) either the Company or Avient might, from time to time in the future (but not more than once every five years), institute an arbitration proceeding to adjust that percentage. In May 2017, Avient filed a demand for arbitration. In this proceeding, Avient sought to readjust the percentage allocation of future costs and to recover approximately $11 from the Company in reimbursement of previously paid remediation costs. The Company's cross demand for arbitration seeking unreimbursed remediation costs incurred during the relevant period was dismissed from the proceedings when Avient paid such costs in full at the beginning of the arbitration hearing. On July 10, 2018, Avient sued the Company in the U.S. District Court for the Western District of Kentucky and sought to invalidate the arbitration provisions in the parties' 2007 settlement agreement and enjoin the arbitration it had initiated in 2017. On July 30, 2018, the district court refused to enjoin the arbitration and, on January 15, 2019, the court granted the Company's motion to dismiss Avient's suit. On February 13, 2019, Avient appealed those decisions to the U.S. Court of Appeals for the Sixth Circuit. The court of appeals issued an opinion and final order on September 6, 2019, affirming the district court. The arbitration hearing began in August 2018 and concluded in December 2018. On May 22, 2019, the arbitration panel issued its final award. It determined that Avient was responsible for 100% of the allocable costs at issue in the proceeding and that Avient would remain responsible for 100% of the costs to operate the existing groundwater remedy at the Calvert City site. In August 2019, Avient filed a motion to vacate before the U.S. District Court for the Western District of Kentucky, seeking to invalidate the final award under the Federal Arbitration Act. On February 11, 2020, the U.S. District Court for the Western District of Kentucky denied Avient's motion to vacate and affirmed the arbitration final award. Avient did not file a notice of appeal before the March 10, 2020 deadline to contest the court's decision. Accordingly, the final award was affirmed, and the arbitration proceeding is fully and finally resolved. In March 2022, the Company filed a demand for arbitration seeking reimbursement for certain allocable costs incurred during the applicable period since May 2017, and which Avient has failed to pay or disputed as not subject to indemnity under the 1990 and 1997 agreements. In April 2022, Avient filed a complaint in the federal district court for the Western District of Kentucky disputing the enforceability of the 2007 settlement agreement and seeking to enjoin arbitration. Avient claims that the allocable costs at issue are up to $22, for which Avient claims the Company is totally liable. On September 30, 2023, the court issued an order denying without prejudice the parties' cross motions for summary judgment and set a 30-day deadline for the parties to refile and provide additional briefing on specific aspects of the arguments before the court. The parties each refiled and provided additional briefing by the deadline and the motions are pending before the court. The Company disputes these claims and at this time, the Company believes it is unlikely that any remediation costs allocable to it would result in material expenditures in any individual reporting period. Sulphur Brine Dome. Westlake owns and operates salt solution-mining caverns at the Sulphur Brine Dome in Sulphur, Louisiana. The Louisiana Department of Natural Resources issued Compliance Order No. IMD 2022-027 and several supplements to that order, the latest in October 2023, in response to pressure anomaly events in two of the Company's brine caverns. The brine caverns were not active, operating wells but under ongoing, post-operational monitoring requirements. The compliance order and supplements thereto have required us to undertake various activities related to response planning, monitoring, investigation and mitigation of potential impacts in the event of future cavern pressure anomalies or failures. Since December 2022 continuous brine injection has maintained cavern pressure while the Company continues to pursue active monitoring, studies, groundwater monitoring, modeling and other activities under the compliance order and supplements. In September 2023, the Office of Conservation issued an emergency declaration as a conservative step and to ensure that the full suite of powers and resources are available to the government in its response and management of the evolving circumstances at the Sulphur Dome. The capital costs and expenditures required to comply with the compliance order and supplements have been and will continue to be incurred. In response to the most recent supplement to the compliance order, the Company reserved approximately $13 in connection with groundwater monitoring wells and monitoring required by the supplement. At this time, the Company is unable to estimate the impact, if any, that other ongoing expenditures or future injunctive relief ordered by the government could have on the Company's consolidated financial statements either in the current period or in future periods. Environmental Remediation: Reasonably Possible Matters. The Company's assessment of the potential impact of environmental contingencies is subject to considerable uncertainty due to the complex, ongoing and evolving process of investigation and remediation, if necessary, of such environmental contingencies, and the potential for technological and regulatory developments. As such, in addition to the amounts currently reserved, the Company may be subject to reasonably possible loss contingencies related to environmental matters in the range of $98 to $165. Other Commitments

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2023
Segment Reporting [Abstract]
Segment and Geographic Information	Segment and Geographic Information Segment Information The Company has two principal operating segments, Performance and Essential Materials and Housing and Infrastructure Products. These segments are strategic business units that offer a variety of different materials and products. The Company manages each segment separately as each business requires different technology and marketing strategies. The Company's Performance and Essential Materials segment manufactures and markets polyethylene, styrene monomer, ethylene co-products, PVC, VCM, ethylene dichloride ("EDC"), chlor-alkali (chlorine and caustic soda), chlorinated derivative products and epoxy resins. The Company's ethylene production is used in the Company's polyethylene, styrene and VCM operations. In addition, the Company sells ethylene and ethylene co-products, primarily propylene, crude butadiene, pyrolysis gasoline and hydrogen, to external customers. The Company's primary North American manufacturing facilities are located in its Calvert City, Kentucky; Lake Charles, Plaquemine and Geismar, Louisiana; Longview and Deer Park, Texas; Lakeland, Florida and Argo, Illinois sites. The Company's primary European facilities are located in Germany and the Netherlands. The Company produces ethylene and polyethylene at its facilities in Lake Charles, Louisiana; Calvert City, Kentucky and Longview, Texas. The Company produces chlorine, caustic soda, VCM, EDC, PVC, hydrogen and chlorinated derivative materials at its facilities in Lake Charles, Plaquemine and Geismar, Louisiana; Calvert City, Kentucky; Natrium, West Virginia; Longview, Washington; Beauharnois, Quebec; Aberdeen, Mississippi and in Germany. Epoxy resins primarily comprise of Epoxy Specialty Resins and Base Epoxy Resins and Intermediaries. Epoxy Specialty Resins are produced at manufacturing facilities in Duisburg and Esslingen in Germany; Argo and Lakeland in the United States; one plant in Spain and one plant in South Korea. Base Epoxy Resins and Intermediaries are produced at Company's facilities plants in Pernis, the Netherlands and Deer Park, United States. In addition, the Company also has other manufacturing facilities and product development facilities in North America, Europe and Asia. No single customer accounted for more than 10% of sales in the Performance and Essential Materials segment for the years ended December 31, 2023, 2022 or 2021. The Housing and Infrastructure Products segment manufactures and markets products including residential siding, trim and mouldings, stone, roofing, windows, outdoor living products, PVC pipe and fittings and PVC compounds. As of December 31, 2023, the Company owned or leased 70 manufacturing facilities in North America, Europe and Asia. The Company's North American PVC facilities within the Performance and Essential Materials segment supply most of the PVC required for the building products and pipes and fittings plants. The raw materials for stone, roofing and accessories, windows, shutters and specialty tool products are externally purchased. PVC required for the PVC compounds plants is either internally sourced from Company's North American or Asian facilities or externally purchased at market prices based on the location of the plants. No single customer accounted for more than 10% of sales in the Housing and Infrastructure Products segment for the years ended December 31, 2023, 2022 or 2021. The accounting policies of the individual segments are the same as those described in Note 1. Year Ended December 31, 2023 2022 2021 Net external sales Performance and Essential Materials Performance Materials $ 4,656 $ 6,964 $ 5,997 Essential Materials 3,680 4,044 2,673 Total Performance and Essential Materials 8,336 11,008 8,670 Housing and Infrastructure Products Housing Products 3,494 3,864 2,334 Infrastructure Products 718 922 774 Total Housing and Infrastructure Products 4,212 4,786 3,108 $ 12,548 $ 15,794 $ 11,778 Intersegment sales Performance and Essential Materials $ 408 $ 908 $ 798 Housing and Infrastructure Products — — — $ 408 $ 908 $ 798 Income (loss) from operations Performance and Essential Materials $ 59 $ 2,416 $ 2,549 Housing and Infrastructure Products 710 675 356 Corporate and other (40) (41) (105) $ 729 $ 3,050 $ 2,800 Depreciation and amortization Performance and Essential Materials $ 881 $ 784 $ 665 Housing and Infrastructure Products 207 263 168 Corporate and other 9 9 7 $ 1,097 $ 1,056 $ 840 Other income, net Performance and Essential Materials $ 25 $ 37 $ 33 Housing and Infrastructure Products 32 17 10 Corporate and other 79 19 10 $ 136 $ 73 $ 53 Provision for (benefit from) income taxes Performance and Essential Materials $ (63) $ 435 $ 542 Housing and Infrastructure Products 194 185 80 Corporate and other 47 29 (15) $ 178 $ 649 $ 607 Capital expenditures Performance and Essential Materials $ 857 $ 913 $ 567 Housing and Infrastructure Products 164 187 88 Corporate and other 13 8 3 $ 1,034 $ 1,108 $ 658 A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Year Ended December 31, 2023 2022 2021 Income from operations for reportable segments $ 729 $ 3,050 $ 2,800 Interest expense (165) (177) (176) Other income, net 136 73 53 Income before income taxes $ 700 $ 2,946 $ 2,677 December 31, 2023 December 31, 2022 Total assets Performance and Essential Materials $ 13,538 $ 13,978 Housing and Infrastructure Products 4,888 5,022 Corporate and other 2,609 1,550 $ 21,035 $ 20,550 Geographic Information Year Ended December 31, 2023 2022 2021 Net sales to external customers (1) United States $ 8,955 $ 10,899 $ 8,157 Foreign Canada 808 1,051 980 Germany 602 875 628 China 220 262 216 Mexico 217 228 149 Brazil 215 353 141 France 138 172 100 Italy 135 200 181 Other 1,258 1,754 1,226 $ 12,548 $ 15,794 $ 11,778 December 31, 2023 December 31, 2022 Property, plant and equipment, net United States $ 7,395 $ 7,155 Foreign Germany 790 749 Other 334 573 $ 8,519 $ 8,477 ______________________________ (1) Net sales are attributed to countries based on location of customer.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss) Attributable to Parent	$ 479	$ 2,247	$ 2,015

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Description of Business and S_2

Description of Business and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business
Westlake Chemical Partners LP	Westlake Chemical Partners LP In 2014, the Company formed Westlake Chemical Partners LP ("Westlake Partners") to operate, acquire and develop ethylene production facilities and related assets. Westlake Partners' assets consist of a limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in OpCo. OpCo's assets include two ethylene production facilities at the Company's Lake Charles, Louisiana site, one ethylene production facility at the Company's Calvert City, Kentucky site and a 200-mile common carrier ethylene pipeline that runs from Mont Belvieu, Texas to the Company's Longview, Texas site. As of December 31, 2023, the Company held a 77.2% limited partner interest in OpCo and a controlling interest in Westlake Partners. The operations of Westlake Partners are consolidated in the Company's financial statements.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and subsidiaries in which the Company directly or indirectly owns more than a 50% voting interest and exercises control and, when applicable, entities for which the Company has a controlling financial interest or is the primary beneficiary. Investments in majority-owned companies where the Company does not exercise control and investments in nonconsolidated affiliates (20%-50% owned companies, joint ventures and partnerships) are accounted for using the equity method of accounting. Undistributed earnings from joint ventures included in retained earnings were immaterial as of December 31, 2023. All intercompany transactions and balances are eliminated in consolidation. Certain reclassifications have been made to the prior-year financial statements to conform to the current year presentation. Noncontrolling interests represent the direct equity interests held by investors in the Company's consolidated subsidiaries, Westlake Partners, Taiwan Chlorine Industries, Ltd. and Suzhou Huasu Plastics Co., Ltd. Effective January 2021, the Company consolidated RS Cogen, LLC ("RS Cogen") into its consolidated financial statements. Effective October 31, 2022, the Company acquired the remaining 50% interest in RS Cogen.
Basis of Accounting, Policy	Basis of Presentation
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents consist of highly liquid investments that are readily convertible into cash and have a maturity of three months or less at the date of acquisition.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments which potentially subject the Company to concentration of risk consist principally of trade receivables from customers engaged in manufacturing polyethylene products, polyvinyl chloride ("PVC") products, epoxy products, chlor-alkali and derivative products as well as housing and infrastructure products such as PVC compounds, PVC pipe and fittings, trim and mouldings, stone, windows, roofing and exterior products. The Company's large number of customers, the diversity of these customers' businesses and the markets they serve and customers geographic dispersion limits the concentrations of credit risk with respect to receivables. The Company performs periodic credit evaluations of the customers' financial condition and generally does not require collateral. The Company maintains allowances for potential losses.
Allowance for Doubtful Accounts	Allowance for Credit Losses
Inventories	Inventories
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are carried at cost, net of accumulated depreciation. Cost includes expenditures for improvements and betterments that extend the useful lives of the assets and interest capitalized on significant capital projects. Capitalized interest was $8, $4 and $3 for the years ended December 31, 2023, 2022 and 2021, respectively. Repair and maintenance costs are charged to operations as incurred. Gains and losses on the disposition or retirement of fixed assets are reflected in the consolidated statement of operations when the assets are sold or retired. Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 40 Plant and equipment 10-25 Other 3-15
Impairment of Long-Lived Assets and Impairment of Goodwill and Intangible Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets, including tangible assets and intangible assets with finite lives, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Long-lived assets assessed for impairment are grouped by asset group, the lowest level for which identifiable cash flows are largely independent of the cash flows of other groups of assets and liabilities. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net undiscounted cash flows expected to be generated by the asset group from its use and eventual disposition of that asset group. Assets are considered to be impaired if the carrying amount of an asset exceeds the future undiscounted cash flows. The impairment recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or estimated fair value less costs to sell. Intangible assets with finite lives are amortized over their estimated useful lives and evaluated with the associated long-lived asset group for impairment whenever impairment indicators exist. See Note 6 for more information on the Company's long-lived assets impairment tests. Impairment of Goodwill Goodwill is tested for impairment at least annually, or when events or changes in circumstances indicate the fair value of a reporting unit with goodwill has been reduced below its carrying amount. The Company performed its annual goodwill impairment tests for each of the reporting units within the Performance and Essential Materials and Housing and Infrastructure Products segments in the fourth quarter of 2023. The tests indicated impairment of the Westlake Epoxy reporting unit under the Performance and Essential Materials segment as the carrying amount of the reporting unit exceeded its fair value. See Note 8 for more information on the Company's annual goodwill impairment tests.
Equity Method Investments	Equity Method Investments The Company accounts for investments using the equity method of accounting if the Company has the ability to exercise significant influence over, but not control of, an investee. Significant influence generally exists if the Company has an ownership interest representing between 20% and 50% of the voting rights. Under the equity method of accounting, investments are stated initially at cost and are adjusted for subsequent additional investments and the proportionate share of profit or losses and distributions. The Company records its share of the profits or losses of the equity investments, net of income taxes, in the consolidated statements of income. The equity method investments are evaluated for impairment when events or changes in circumstances indicate, in management's judgment, that the carrying value of such investments may have experienced an other-than-temporary decline in value. When evidence of loss in value has occurred, management compares the estimated fair value of the investment to the carrying value of the investment to determine whether an impairment has occurred. If the estimated fair value is less than the carrying value and management considers the decline in value to be other-than-temporary, the excess of the carrying value over the estimated fair value is recognized in the consolidated financial statements as an impairment.
Other Assets, Net	Other Assets, net Other assets, net include turnaround costs, investments in unconsolidated subsidiaries, restricted cash, deferred charges and other long-term assets. The Company accounts for turnaround costs under the deferral method. Turnarounds are the scheduled and required shutdowns of specific operating units in order to perform planned major maintenance activities. The costs related to the significant overhaul and refurbishment activities include maintenance materials, parts and direct labor costs. The costs of the turnaround are deferred when incurred at the time of the turnaround and amortized (within depreciation and amortization) on a straight-line basis until the next planned turnaround, which typically range from three
Business Combinations	Business Combinations The Company records business combinations using the acquisition method of accounting. Under the acquisition method of accounting, identifiable assets acquired and liabilities assumed are recorded at their acquisition date fair values. The excess of the purchase price over the estimated fair value is recorded as goodwill. Changes in the estimated fair values of net assets recorded for acquisitions prior to the finalization of more detailed analysis, but not to exceed one year from the date of acquisition, will adjust the amount of the purchase price allocable to goodwill. Measurement period adjustments are reflected in the period in which they occur.
Income Taxes	Income Taxes The Company utilizes the balance sheet method of accounting for deferred income taxes. Under this method, deferred tax assets or liabilities are recorded based upon temporary differences between the tax basis of assets and liabilities and their carrying values for financial reporting purposes. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities during the period. Valuation allowances are recorded against deferred tax assets when it is considered more likely than not that the deferred tax assets will not be realized.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of foreign subsidiaries are translated to U.S. dollars at the exchange rate as of the end of the year. Statement of operations items are translated at the average exchange rate for the year. The resulting translation adjustment is recorded as a separate component of stockholders' equity.
Revenue Recognition	Revenue Recognition Revenue is recognized when the Company transfers control of inventories to its customers. Amounts recognized as revenues reflect the consideration to which the Company expects to be entitled in exchange for those inventories. Provisions for discounts, rebates and returns are incorporated in the estimate of variable consideration and reflected as a reduction to revenue in the same period as the related sales. Control of inventories generally transfers upon shipment for domestic sales. The Company excludes taxes collected on behalf of customers from the estimated contract price. For export contracts, the point at which control passes to the customer varies depending on the terms specified in the customer contract. The Company generally invoices customers and recognizes revenue and accounts receivable upon transferring control of inventories. In limited circumstances, the Company transfers control of inventories shortly before it has an unconditional right to receive consideration, resulting in recognition of contract assets. The Company also receives advance payments from certain customers, resulting in recognition of contract liabilities. Contract assets and liabilities are generally settled within the period and are not material to the consolidated balance sheets. The Company expenses sales commissions when incurred. These costs are recorded within selling, general and administrative expenses. Aside from the amounts disclosed within Note 9, the Company does not disclose the value of unsatisfied performance obligations because its contracts with customers (1) have an original expected duration of one year or less or (2) have only variable consideration that is calculated based on market prices at specified dates and is allocated to wholly unsatisfied performance obligations.
Leases	Leases The Company is obligated under various long-term and short-term operating leases for rail cars, buildings, land and other transportation and storage assets. The Company determines whether an arrangement is, or contains, a lease at contract inception. Some of the Company's arrangements contain both lease and non-lease components. For certain transportation equipment leases, the Company accounts for the lease and non-lease components as a single lease component. The Company records right-of-use assets and corresponding lease liabilities for operating leases with terms greater than one year. Operating lease right-of-use assets and liabilities are recorded at the present value of the fixed lease payments over the life of the lease. The majority of the Company's leases do not provide an implicit rate. Therefore, the Company uses its incremental borrowing rate at lease commencement to measure operating lease right-of-use assets and lease liabilities. Certain of the Company's leases provide for renewal and purchase options. Renewal and purchase options are evaluated at lease commencement and included in the lease term if they are reasonably certain to be exercised. Short-term leases are recognized in rental expense on a straight-line basis over the lease term and are not recorded in the consolidated balance sheets. The Company's finance leases are not material to the consolidated financial statements.
Transportation and Freight	Transportation and Freight Amounts billed to customers for freight and handling costs on outbound shipments are included in net sales in the consolidated statements of operations. Transportation and freight costs incurred by the Company on outbound shipments are included in cost of sales in the consolidated statements of operations.
Price Risk Management	Price Risk Management The Company recognizes derivative instruments on the balance sheet at fair value, and changes in a derivative's fair value are currently recognized in earnings or comprehensive income, depending on the designation of the derivative. If the derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized in earnings. If the derivative is designated as a cash flow hedge, the effective portion of the change in the fair value of the derivative is recorded in comprehensive income and is recognized in the statement of operations when the hedged item affects earnings. Ineffective portions of changes in the fair value of cash flow hedges are recognized in earnings currently. The derivative instruments did not have a material impact on the Company's consolidated financial statements.
Asset Retirement Obligations	Asset Retirement Obligations The Company has conditional asset retirement obligations for the removal and disposal of hazardous materials from certain of the Company's manufacturing facilities. The Company recognizes asset retirement obligations in the period in which the liability becomes probable and reasonably estimable. Recognized asset retirement obligations are initially recorded at fair value and capitalized as a component of the carrying value of the long-lived asset to which the obligation relates. The liability is accreted to its future value each period, and the capitalized cost is depreciated over the estimated useful life of the related asset. Upon settlement of the liability, a gain or loss is recorded. As of December 31, 2023, the Company had $3 and $37 of asset retirement obligations recorded as accrued and other liabilities and other liabilities, respectively. As of December 31, 2022, the Company had no asset retirement obligations recorded as accrued and other liabilities and had $31 of asset retirement obligations recorded as other liabilities.
Environmental Costs	Environmental Costs Environmental costs relating to current operations are expensed or capitalized, as appropriate, depending on whether such costs provide future economic benefits. Remediation liabilities are recognized when the costs are considered probable and can be reasonably estimated. Measurement of liabilities is based on currently enacted laws and regulations, existing technology and undiscounted site-specific costs. Environmental liabilities in connection with properties that are sold or closed are realized upon such sale or closure, to the extent they are probable and estimable and not previously reserved. Recognition of any joint and several liabilities is based upon the Company's best estimate of its final pro rata share of the liability.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.
Warranty Costs	Warranty Costs The Company provides warranties for certain products, primarily under the housing and infrastructure segment, against defects in material and performance. The accrual for warranty claims is recorded at the time of sale based on historical warranty claims experience. Warranty liabilities are included in accrued liabilities and other liabilities in the consolidated balance sheets.
Recent Accounting Pronouncements	Recently Issued Accounting Pronouncements Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU No.2023-09) In December 2023, the Financial Accounting Standards Board ("FASB") issued accounting standards update No. 2023-09 to enhance the transparency and decision-usefulness of income tax disclosures and to provide information to better assess how an entity's operations and related tax risks and tax planning and operational opportunities affect its tax rate and prospects for future cash flows. For public business entities, the amendments in this update are effective for annual periods beginning after December 15, 2024. The Company is in the process of evaluating the impact of this standard on the disclosures in the Company's financial statements. Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07) In November 2023, the FASB issued accounting standards update No. 2023-07 to improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The update requires public entities to disclose, on an annual and interim basis, significant segment expenses that are regularly provided to the chief operating decision maker (CODM), the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources. The amendments in this update are effective for public entities in fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 and are to be applied retrospectively to all prior periods presented in the financial statements. Early adoption is permitted. The Company is in the process of evaluating the impact of this standard on the disclosures in the Company's financial statements. Business Combinations—Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement (ASU 2023-05) In August 2023, the FASB issued accounting standards update No. 2023-05 to address the accounting for contributions made to a joint venture, upon formation, in a joint venture's financial statements, and to (1) provide decision-useful information to investors and other allocators of capital (collectively, investors) in a joint venture's financial statements and (2) reduce diversity in practice. Under the ASU, upon formation, a joint venture should recognize and initially measure its assets and liabilities at fair value (with exceptions to fair value measurement that are consistent with guidance for business combinations). The amendments in this update become effective for all joint venture formations with a formation date on or after January 1, 2025. Additionally, a joint venture that was formed before January 1, 2025 may elect to apply the amendments retrospectively if it has sufficient information. Early adoption is permitted in any interim or annual period in which financial statements have not yet been issued (or made available for issuance), either prospectively or retrospectively. The Company does not expect that this accounting standard will have a material impact, upon adoption, on the Company's consolidated financial position, results of operations and cash flows. Leases (Topic 842): Common Control Arrangements (ASU 2023-01) In March 2023, the FASB issued accounting standards update No. 2023-01 to amend certain provisions of ASC 842 that apply to arrangements between related parties under common control. The update requires all companies to amortize leasehold improvements associated with common control leases over the asset's useful life to the common control group regardless of the lease term. The amendment in this update is effective for all entities in fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early application is permitted. The Company does not expect that this accounting standard will have a material impact, upon adoption, on the Company's consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Liabilities—Supplier Finance Programs (ASU No. 2022-04) In September 2022, the FASB issued accounting standards update No. 2022-04 to enhance transparency of supplier finance programs. Under the ASU, the buyer in a supplier finance program is required to disclose information about the key terms of the program, outstanding confirmed amounts as of the end of the period, a rollforward of the amount of obligations confirmed and the amount of obligations subsequently paid, and a description of where in the financial statements outstanding amounts are presented. The amendments in this update became effective for all entities for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, except for the disclosure of rollforward information, which is effective for fiscal years beginning after December 15, 2023. The Company adopted this accounting standard effective January 1, 2023, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. Business Combinations—Accounting for Contract Assets and Contract Liabilities from Contracts with Customers Update (ASU No.2021-08) In October 2021, the FASB issued an accounting standards update that requires acquiring entities to recognize and measure contract assets and contract liabilities in a business combination in accordance with the accounting guidance on Revenue from Contracts with Customers (ASC 606). The guidance in this update improves comparability for both the recognition and measurement of acquired revenue contracts with customers at the date of and after a business combination. The accounting standard became effective for reporting periods beginning after December 15, 2022. The Company adopted this accounting standard effective January 1, 2023, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. The standard will be applicable to future business combinations.

Description of Business and S_3

Description of Business and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Estimated Useful Lives of Assets	Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 40 Plant and equipment 10-25 Other 3-15
Schedule of Warranty Liabilities	The warranty liabilities activity for the years ended December 31, 2023 and 2022 is as follows: Year Ended December 31, 2023 2022 Beginning balance, January 1, $ 58 $ 55 Estimated fair value of warranty liability assumed in acquisition — 1 Warranty provisions 24 15 Warranty claims paid (13) (13) Ending balance, December 31, $ 69 $ 58

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2023
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The information below represents the purchase price allocation: Cash $ 42 Accounts receivable 299 Inventories 346 Prepaid expenses and other current assets 22 Property, plant and equipment 664 Operating lease right-of-use assets 59 Intangible assets 145 Other assets 104 Total assets acquired 1,681 Accounts payable 189 Accrued and other liabilities 88 Deferred income taxes 96 Pensions and other post-retirement benefits 163 Operating lease liabilities 48 Other liabilities 19 Total liabilities assumed 603 Total identifiable net assets acquired 1,078 Noncontrolling interest (2) Goodwill 131 Total Westlake Corporation purchase consideration $ 1,207

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Schedule Of Accounts Receivable	Accounts receivable consist of the following at December 31: 2023 2022 Trade customers $ 1,413 $ 1,676 Related parties 7 3 Allowance for credit losses (27) (28) 1,393 1,651 Federal and state taxes 65 69 Other 143 81 Accounts receivable, net $ 1,601 $ 1,801

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2023
Inventory, Net [Abstract]
Schedule Of Inventory	Inventories consist of the following at December 31: 2023 2022 Finished products $ 989 $ 1,157 Feedstock, additives, chemicals and other raw materials 401 496 Materials and supplies 232 213 Inventories $ 1,622 $ 1,866

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment, Net [Abstract]
Schedule Of Property, Plant And Equipment	Property, plant and equipment consist of the following at December 31: 2023 2022 Land $ 304 $ 299 Buildings and improvements 951 895 Plant and equipment 10,771 10,408 Other 803 711 12,829 12,313 Less: Accumulated depreciation 5,240 4,655 7,589 7,658 Construction in progress 930 819 Property, plant and equipment, net $ 8,519 $ 8,477

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Lease related asset and liability	Lease-related asset and liability balances consist of the following at December 31: 2023 2022 Operating Leases Right-of-use assets $ 697 $ 615 Accrued and other liabilities $ 124 $ 116 Operating lease liabilities 611 504 Total operating lease liabilities $ 735 $ 620 Weighted Average Remaining Term (in years) 9 9 Weighted Average Lease Discount Rate 3.8 % 2.9 %
Lease, Cost	The components of operating lease expense were as follows: Year Ended December 31, 2023 2022 2021 Operating lease cost (1) $ 142 $ 139 $ 117 Short-term lease cost 121 101 85 Total operating lease cost $ 263 $ 240 $ 202 _____________________________ (1) Includes fixed lease payments for operating leases recorded in the consolidated balance sheet.
Lessee, Operating Lease, Liability, Maturity	Maturities of lease liabilities were as follows at December 31, 2023: Operating Leases 2024 $ 142 2025 122 2026 108 2027 95 2028 81 Thereafter 362 Total lease payments 910 Less: imputed interest (175) Present value of lease liabilities $ 735

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Intangible assets consist of the following at December 31: 2023 2022 Weighted Cost Accumulated Net Cost Accumulated Net Customer relationships $ 1,586 $ (676) $ 910 $ 1,589 $ (596) $ 993 15 Other intangible assets: Licenses and intellectual property 264 (136) 128 306 (124) 182 15 Trade name 385 (104) 281 411 (86) 325 18 Other 112 (28) 84 84 (19) 65 17 Total other intangible assets $ 761 $ (268) $ 493 $ 801 $ (229) $ 572
Schedule of Goodwill	The following table summarizes gross carrying amounts and changes in the carrying amount of goodwill for the years ended December 31, 2023 and 2022. Performance and Essential Materials Segment Housing and Infrastructure Products Segment Total Balance at December 31, 2021 $ 902 $ 1,122 $ 2,024 Goodwill acquired during the year 119 5 124 Measurement period adjustment 8 16 24 Effects of changes in foreign exchange rates (9) (2) (11) Balance at December 31, 2022 1,020 1,141 2,161 Measurement period adjustment 4 1 5 Impairment of goodwill (128) — (128) Effects of changes in foreign exchange rates 1 2 3 Balance at December 31, 2023 $ 897 $ 1,144 $ 2,041

Equity Method Investments (Tabl

Equity Method Investments (Tables)	12 Months Ended
	Dec. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Changes in the Company's investment in LACC for the years ended December 31, 2023 and 2022 were as follows: Investment in LACC Balance at December 31, 2021 $ 943 Cash contributions 87 Additional interest purchased 89 Depreciation and amortization (44) Balance at December 31, 2022 1,075 Cash contributions 21 Depreciation and amortization (49) Balance at December 31, 2023 $ 1,047

Accounts Payable (Tables)

Accounts Payable (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Schedule of Accounts Payable	Accounts payable consist of the following at December 31: 2023 2022 Accounts payable—third parties $ 849 $ 870 Accounts payable to related parties 15 16 Notes payable 13 3 Accounts payable $ 877 $ 889

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule Of Long-Term Debt	Long-term debt consist of the following at December 31: December 31, December 31, 0.875% senior notes due 2024 (the "0.875% 2024 Senior Notes") $ 300 $ 300 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750 750 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 1.625% €700 million senior notes due 2029 (the "1.625% 2029 Senior Notes") 773 750 3.375% senior notes due 2030 (the "3.375% 2030 Senior Notes") 300 300 3.50% senior notes due 2032 (the "3.50% 2032 tax-exempt GO Zone Refunding Senior Notes") 250 250 2.875% senior notes due 2041 (the "2.875% 2041 Senior Notes") 350 350 5.00% senior notes due 2046 (the "5.00% 2046 Senior Notes") 700 700 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 500 3.125% senior notes due 2051 (the "3.125% 2051 Senior Notes") 600 600 3.375% senior notes due 2061 (the "3.375% 2061 Senior Notes") 450 450 Term loans due 2026 13 15 Long-term debt, principal amount 4,997 4,976 Less: Unamortized discount and debt issuance costs 91 97 Long-term debt, carrying value 4,906 4,879 Less current portion: 0.875% senior notes due 2024 299 — Long-term debt, carrying value, net of current portion $ 4,607 $ 4,879

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive income (loss) by component were as follows: Pension and Other Post-Retirement Benefits Liability, Net of Tax Cumulative Foreign Currency Total Balances at December 31, 2021 $ 20 $ (56) $ (36) Net other comprehensive income (loss) attributable to Westlake Corporation 32 (85) (53) Balances at December 31, 2022 52 (141) (89) Net other comprehensive income (loss) attributable to Westlake Corporation (48) 39 (9) Balances at December 31, 2023 $ 4 $ (102) $ (98)

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2023
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule Of Estimated Future Benefit Payments	The following benefit payments are expected to be paid: Pension Other Post- Estimated future benefit payments: Year 1 $ 68 $ 8 Year 2 67 6 Year 3 67 4 Year 4 66 3 Year 5 65 3 Years 6 to 10 329 15
Defined Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan	Details of the changes in benefit obligations, plan assets and funded status of the Company's pension plans are as follows: 2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 518 $ 530 $ 673 $ 152 Benefit obligation assumed with acquisition — — — 612 Service cost 1 4 1 3 Interest cost 24 19 14 7 Actuarial loss (gain) (7) 82 (121) (188) Benefits paid (42) (21) (49) (17) Settlements — (3) — (1) Foreign exchange effects — 18 — (38) Benefit obligation, end of year $ 494 $ 629 $ 518 $ 530 Change in plan assets Fair value of plan assets, beginning of year $ 415 $ 370 $ 562 $ 21 Plan assets assumed with acquisition — — — 538 Actual return 55 19 (97) (145) Employer contribution 2 15 2 1 Benefits paid (42) (21) (49) (17) Administrative expenses paid (3) — (3) — Settlements — (3) — (1) Foreign exchange effects — 11 — (27) Fair value of plan assets, end of year $ 427 $ 391 $ 415 $ 370 Funded status, end of year $ (67) $ (238) $ (103) $ (160)
Schedule of Amounts Recognized in Balance Sheet	2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Noncurrent assets $ — $ 36 $ — $ 63 Current liabilities (2) (11) (2) (9) Noncurrent liabilities (65) (263) (101) (214) Net amount recognized $ (67) $ (238) $ (103) $ (160)
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income (loss) Net loss (gain) $ (66) $ 67 $ (30) $ (10) Prior service credit (1) (4) (2) (4) Total before tax (1) $ (67) $ 63 $ (32) $ (14) ______________________________ (1) After-tax totals for pension benefits were a loss of $4 and a gain of $45 for 2023 and 2022, respectively, and are reflected in stockholders' equity as accumulated other comprehensive income (loss).
Schedule Of Accumulated Benefit Obligations In Excess Of Plan Assets	Pension plans with an accumulated benefit obligation in excess of plan assets at December 31 are as follows: 2023 2022 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Information for pension plans with an accumulated benefit obligation in excess of plan assets Projected benefit obligation $ (494) $ (273) $ (518) $ (223) Accumulated benefit obligation (494) (271) (518) (221) Fair value of plan assets 427 — 415 —
Schedule Of Net Benefit Costs And Amounts Recognized In Other Comprehensive Income	The following table provides the components of net periodic benefit costs, other changes in plan assets and benefit obligation recognized in other comprehensive income. Year Ended December 31, 2023 2022 2021 U.S. Non-U.S. U.S. Non-U.S. U.S. Non-U.S. Components of net periodic benefit cost Service cost $ 1 $ 4 $ 1 $ 3 $ 3 $ 2 Administrative expenses 3 — 3 — 3 — Interest cost 24 19 14 7 11 1 Expected return on plan assets (26) (12) (38) (12) (38) (1) Net amortization (1) (2) — 1 — 3 Net periodic benefit cost (gain) $ 1 $ 9 $ (20) $ (1) $ (21) $ 5 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net loss (gain) emerging $ (36) $ 74 $ 13 $ (31) $ (49) $ (9) Prior service credit — — — — (2) — Amortization of prior service credit 1 — — — — — Amortization of net gain (loss) — 2 — (1) — (2) Foreign exchange effects — 1 — (1) — — Total recognized in OCI $ (35) $ 77 $ 13 $ (33) $ (51) $ (11) Total net periodic benefit cost and OCI $ (34) $ 86 $ (7) $ (34) $ (72) $ (6)
Schedule Of Weighted Average Assumptions Used	The weighted-average assumptions used to determine pension plan obligations and net periodic benefit costs for the plans are as follows: 2023 2022 2021 U.S. Non-U.S. U.S. Non-U.S. U.S. Non-U.S. Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 5.0 % 3.2 % 4.9 % 3.7 % 2.6 % 1.4 % Rate of compensation increase — % 3.1 % — % 2.9 % — % 2.6 % Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 4.9 % 3.7 % 2.5 % 1.2 % 2.1 % 0.8 % Discount rate for service cost 5.0 % 3.8 % 2.8 % 1.4 % 2.4 % 0.8 % Discount rate for interest cost 4.8 % 3.7 % 2.1 % 1.2 % 1.5 % 0.8 % Expected return on plan assets 6.5 % 3.3 % 7.0 % 2.6 % 7.0 % 4.0 % Rate of compensation increase — % 2.9 % — % 2.8 % — % 2.6 %
Schedule Of Fair Value Of Pension Plan Assets	The investments in the collective trust and mutual funds are valued using a market approach based on the net asset value of units held. The fair values of the Company's plan assets at December 31, by asset category, are as follows: 2023 U.S. Plans Non-U.S. Plans Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ — $ 3 $ — $ — $ 3 Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 47 92 — 139 — 1 — 1 Small-cap funds (2) — 8 — 8 — — — — International funds (3) 70 23 — 93 — 74 — 74 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 39 138 — 177 — 303 — 303 Short-term investment funds — 10 — 10 — — — — Group insurance contract — — — — — — 10 10 $ 156 $ 271 $ — $ 427 $ 3 $ 378 $ 10 $ 391 2022 U.S. Plans Non-U.S. Plans Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ — $ 7 $ — $ — $ 7 Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 42 90 — 132 — 1 — 1 Small-cap funds (2) — 10 — 10 — — — — International funds (3) 72 24 — 96 — 73 — 73 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 37 128 — 165 — 280 — 280 Short-term investment funds — 12 — 12 — — — — Group insurance contract — — — — — — 9 9 $ 151 $ 264 $ — $ 415 $ 7 $ 354 $ 9 $ 370 ______________________________ (1) Substantially all of the assets of these funds are invested in large-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (2) Substantially all of the assets of these funds are invested in small-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (3) Substantially all of the assets of the U.S. Plans' funds are invested in international companies in developed markets (excluding the U.S.), and the remainder of the assets of these funds is invested in cash reserves. The assets of the non-U.S. Plans' funds are primarily invested in diversified global equities, real estate and private equities. (4) The assets of the U.S. Plans' funds represent investment grade bonds of U.S. issuers, including U.S. Treasury notes. The assets of the non-U.S. Plans represent fixed income funds that are primarily invested in international government bonds and mortgage funds.
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan	The amounts recognized in the consolidated balance sheets related to other post-retirement benefits plans were as follows: 2023 2022 U.S. Plans Non-U.S. U.S. Plans Non-U.S. Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (8) $ (1) $ (8) $ (1) Noncurrent liabilities (33) (2) (38) (2) Net amount recognized $ (41) $ (3) $ (46) $ (3)

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Schedule Of Option Activity And Changes	Option activity and changes during the year ended December 31, 2023 were as follows: Options Weighted Weighted Aggregate Outstanding at December 31, 2022 1,531,070 $ 77.76 Granted 197,251 122.65 Exercised (615,296) 73.31 Cancelled (39,136) 110.25 Outstanding at December 31, 2023 1,073,889 $ 87.37 6.1 $ 56 Exercisable at December 31, 2023 683,794 $ 74.23 4.8 $ 45
Schedule Of Range Of Exercise Prices For Outstanding Options	For options outstanding at December 31, 2023, the options had the following range of exercise prices: Range of Prices Options Weighted $44.42 - $61.87 169,789 2.6 $65.81 - $68.09 218,529 5.1 $79.83 - $86.54 262,357 6.3 $107.75 - $108.12 243,933 7.0 $122.65 - $122.65 179,281 9.1
Schedule Of Weighted Average Value And Assumptions For Fair Value Of Options	The Company used the Black-Scholes option pricing model to value its options. The table below presents the weighted average value and assumptions used in determining each option's fair value. Volatility was calculated using historical trends of the Company's common stock price. Stock Option Grants Year Ended December 31, 2023 2022 2021 Weighted average fair value $ 44.91 $ 34.20 $ 25.18 Risk-free interest rate 4.0 % 1.8 % 0.6 % Expected life in years 5 5 5 Expected volatility 39.1 % 36.9 % 36.9 % Expected dividend yield 1.1 % 1.1 % 1.2 %
Schedule Of Non-Vested Restricted Stock Award Activity And Changes	Non-vested restricted stock units as of December 31, 2023 and changes during the year ended December 31, 2023 were as follows: Number of Weighted Non-vested at December 31, 2022 690,414 $ 85.77 Granted 247,131 120.77 Vested (228,113) 69.45 Forfeited (67,804) 97.87 Non-vested at December 31, 2023 641,628 $ 103.77
Share-based Payment Arrangement, Performance Shares, Activity	Non-vested performance stock units as of December 31, 2023 and changes during the year ended December 31, 2023 were as follows: Number of Weighted Non-vested at December 31, 2022 250,369 $ 106.13 Granted 72,627 167.76 Vested (106,705) 74.99 Forfeited (19,370) 142.29 Non-vested at December 31, 2023 196,921 $ 142.18
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions	The table below presents the assumptions used in determining grant date fair value. Volatility was calculated using historical trends of the Company's common stock price. Performance Stock Units Year Ended December 31, 2023 2022 2021 Risk-free interest rate 4.4 % 1.7 % 0.2 % Expected life in years 2.87 2.87 2.87 Expected volatility of Westlake Corporation common stock 40.8 % 49.3 % 49.4 % Expected volatility of peer companies 26.6% - 53.2% 30.8% - 67.2% 30.7% - 65.6% Average correlation coefficient of peer companies 0.61 0.66 0.65 Grant date fair value $ 167.76 $ 147.98 $ 109.94

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule Of Carrying And Fair Values Of Long-Term Debt	The carrying and fair values of the Company's long-term debt at December 31, 2023 and 2022 are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy. 2023 2022 Carrying Fair Carrying Fair Long-term Debt $ 4,906 $ 4,236 $ 4,879 $ 3,940

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Components of Income (Loss) Before Income Taxes	The components of income before income taxes are as follows: Year Ended December 31, 2023 2022 2021 Domestic $ 923 $ 2,523 $ 2,298 Foreign (223) 423 379 $ 700 $ 2,946 $ 2,677
Schedule of The Provision For (Benefit From) Income Taxes	The Company's provision for (benefit from) income taxes consist of the following: Year Ended December 31, 2023 2022 2021 Current Federal $ 229 $ 473 $ 434 State 26 74 57 Foreign 98 123 93 Total current 353 670 584 Deferred Federal (82) (1) 19 State (31) (14) 13 Foreign (62) (6) (9) Total deferred (175) (21) 23 Total provision for (benefit from) income taxes $ 178 $ 649 $ 607
Reconciliation of Taxes Computed at the Statutory Rate to Income Tax Expense	A reconciliation of taxes computed at the statutory rate to the Company's income tax expense is as follows: Year Ended December 31, 2023 2022 2021 Provision for federal income tax, at statutory rate $ 148 $ 619 $ 563 State income tax provision, net of federal income tax effect 7 59 56 Foreign income tax rate differential (15) 30 22 Noncontrolling interests (7) (8) (11) Change in valuation allowance 76 — (29) U.S. federal research and development credits (54) (27) (1) Uncertain Income Tax Positions 14 6 2 Goodwill impairment 26 — — Other, net (17) (30) 5 Total income tax expense (benefit) $ 178 $ 649 $ 607
Schedule of Deferred Tax Assets And Liabilities	The tax effects of the principal temporary differences between financial reporting and income tax reporting at December 31 are as follows: 2023 2022 Net operating loss carryforward $ 166 $ 103 Credit carryforward 20 19 Operating lease liabilities 177 149 Accruals 139 96 Pension 88 99 Inventories 34 34 Research and experimental expenditures 124 94 Other 36 18 Deferred taxes assets—total 784 612 Property, plant and equipment (1,257) (1,301) Intangibles (240) (272) Operating lease right-of-use asset (168) (149) Turnaround costs (61) (49) Consolidated partnerships (213) (234) Equity method investments (228) (237) Other (47) (42) Deferred tax liabilities—total (2,214) (2,284) Valuation allowance (118) (47) Total net deferred tax liabilities $ (1,548) $ (1,719) Balance sheet classifications Noncurrent deferred tax asset $ 12 $ 16 Noncurrent deferred tax liability (1,560) (1,735) Total net deferred tax liabilities $ (1,548) $ (1,719)

Earnings and Dividends per Sh_2

Earnings and Dividends per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings and Dividends Per Share [Abstract]
Schedule Of Net Income Attributable To Common Stockholders	Diluted earnings per share include the effects of certain stock options and performance stock units. Year Ended December 31, 2023 2022 2021 Net income attributable to Westlake Corporation $ 479 $ 2,247 $ 2,015 Less: Net income attributable to participating securities 3 12 10 Net income attributable to common shareholders $ 476 $ 2,235 $ 2,005
Reconciliation Of Denominator For Basic And Diluted Earnings (Loss) Per Share	The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Year Ended December 31, 2023 2022 2021 Weighted average common shares—basic 127,806,317 127,970,445 128,002,911 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 792,124 875,117 695,071 Weighted average common shares—diluted 128,598,441 128,845,562 128,697,982 Earnings per common share attributable to Westlake Corporation: Basic $ 3.73 $ 17.46 $ 15.66 Diluted $ 3.70 $ 17.34 $ 15.58
Dividends Per Share	Dividends per Share Dividends per common share for the years ended December 31, 2023, 2022 and 2021 were as follows: Year Ended December 31, 2023 2022 2021 Dividends per common share $ 1.7140 $ 1.3090 $ 1.1350

Supplemental Information (Table

Supplemental Information (Tables)	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Cash Flow Information	Operating Lease Supplemental Cash Flow Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2023 2022 2021 Operating cash flows from operating leases (1) $ 139 $ 134 $ 114 Right-of-use assets obtained in exchange for operating lease obligations 240 187 215 ______________________________ (1) Includes cash paid for amounts included in the measurement of operating lease liabilities recorded in the consolidated balance sheets. Cash Flow Information Year Ended December 31, 2023 2022 2021 Cash paid for: Interest paid, net of interest capitalized $ 159 $ 172 $ 130 Income taxes paid 421 570 466

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2023
Segment Reporting [Abstract]
Segment Reporting Information	Year Ended December 31, 2023 2022 2021 Net external sales Performance and Essential Materials Performance Materials $ 4,656 $ 6,964 $ 5,997 Essential Materials 3,680 4,044 2,673 Total Performance and Essential Materials 8,336 11,008 8,670 Housing and Infrastructure Products Housing Products 3,494 3,864 2,334 Infrastructure Products 718 922 774 Total Housing and Infrastructure Products 4,212 4,786 3,108 $ 12,548 $ 15,794 $ 11,778 Intersegment sales Performance and Essential Materials $ 408 $ 908 $ 798 Housing and Infrastructure Products — — — $ 408 $ 908 $ 798 Income (loss) from operations Performance and Essential Materials $ 59 $ 2,416 $ 2,549 Housing and Infrastructure Products 710 675 356 Corporate and other (40) (41) (105) $ 729 $ 3,050 $ 2,800 Depreciation and amortization Performance and Essential Materials $ 881 $ 784 $ 665 Housing and Infrastructure Products 207 263 168 Corporate and other 9 9 7 $ 1,097 $ 1,056 $ 840 Other income, net Performance and Essential Materials $ 25 $ 37 $ 33 Housing and Infrastructure Products 32 17 10 Corporate and other 79 19 10 $ 136 $ 73 $ 53 Provision for (benefit from) income taxes Performance and Essential Materials $ (63) $ 435 $ 542 Housing and Infrastructure Products 194 185 80 Corporate and other 47 29 (15) $ 178 $ 649 $ 607 Capital expenditures Performance and Essential Materials $ 857 $ 913 $ 567 Housing and Infrastructure Products 164 187 88 Corporate and other 13 8 3 $ 1,034 $ 1,108 $ 658
Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes	A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Year Ended December 31, 2023 2022 2021 Income from operations for reportable segments $ 729 $ 3,050 $ 2,800 Interest expense (165) (177) (176) Other income, net 136 73 53 Income before income taxes $ 700 $ 2,946 $ 2,677
Total Assets	December 31, 2023 December 31, 2022 Total assets Performance and Essential Materials $ 13,538 $ 13,978 Housing and Infrastructure Products 4,888 5,022 Corporate and other 2,609 1,550 $ 21,035 $ 20,550
Geographic Information For Sales To External Customers And Long-Lived Assets	Geographic Information Year Ended December 31, 2023 2022 2021 Net sales to external customers (1) United States $ 8,955 $ 10,899 $ 8,157 Foreign Canada 808 1,051 980 Germany 602 875 628 China 220 262 216 Mexico 217 228 149 Brazil 215 353 141 France 138 172 100 Italy 135 200 181 Other 1,258 1,754 1,226 $ 12,548 $ 15,794 $ 11,778 December 31, 2023 December 31, 2022 Property, plant and equipment, net United States $ 7,395 $ 7,155 Foreign Germany 790 749 Other 334 573 $ 8,519 $ 8,477 ______________________________ (1) Net sales are attributed to countries based on location of customer.

Description of Business and S_4

Description of Business and Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) plant	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Oct. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Capitalized interest	$ 8	$ 4	$ 3
Asset Retirement Obligation, Current	3	0
Asset Retirement Obligations, Noncurrent	$ 37	$ 31
Minimum
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Deferred Cost, Amortization Period	3 years
Maximum
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Deferred Cost, Amortization Period	6 years
RS Cogen
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Ownership interest acquired				50%
Westlake Chemical OpCo LP | Limited Partner | IPO | Subsidiary of Common Parent
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Limited partner interest (percent)	77.20%
Westlake Chemical OpCo LP | Subsidiaries [Member] | Louisiana
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of production facilities | plant	2
Westlake Chemical OpCo LP | Subsidiaries [Member] | Kentucky
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of production facilities | plant	1

Description of Business and S_5

Description of Business and Significant Accounting Policies (Schedule Of Estimated Useful Lives Of Assets) (Details)	Dec. 31, 2023
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	40 years
Minimum | Plant and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	10 years
Minimum | Other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	3 years
Maximum | Plant and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	25 years
Maximum | Other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	15 years

Description of Business and S_6

Description of Business and Significant Accounting Policies (Warranty Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance, January 1,	$ 58	$ 55
Estimated fair value of warranty liability assumed in acquisition	0	1
Warranty provisions	24	15
Warranty claims paid	(13)	(13)
Ending balance, December 31,	$ 69	$ 58

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) - USD ($) $ in Millions			12 Months Ended
	Feb. 01, 2022	Oct. 01, 2021	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Measurement period adjustment			$ 5	$ 24
Housing and Infrastructure Products Segment
Business Acquisition [Line Items]
Measurement period adjustment			1	16
Performance and Essential Materials Segment
Business Acquisition [Line Items]
Measurement period adjustment				$ 8
Hexion
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 1,207
Hexion | Minimum
Business Acquisition [Line Items]
Intangible assets useful life	11 years
Hexion | Maximum
Business Acquisition [Line Items]
Intangible assets useful life	19 years
Hexion | Performance and Essential Materials Segment
Business Acquisition [Line Items]
Measurement period adjustment			$ 4
Boral Target Companies
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 2,140

Acquisitions (Business Acquisit

Acquisitions (Business Acquisition) (Details) - USD ($) $ in Millions		12 Months Ended
	Feb. 01, 2022	Dec. 31, 2022
Business Acquisition [Line Items]
Goodwill, Acquired During Period		$ 124
Hexion
Business Acquisition [Line Items]
Cash	$ 42
Accounts receivable	299
Inventories	346
Prepaid expenses and other current assets	22
Property, plant and equipment	664
Operating lease right-of-use assets	59
Intangible assets	145
Other assets	104
Total assets acquired	1,681
Accounts payable	189
Accrued and other liabilities	88
Deferred income taxes	96
Pensions and other post-retirement benefits	163
Operating lease liabilities	48
Other liabilities	19
Total liabilities assumed	603
Total identifiable net assets acquired	1,078
Noncontrolling interest	(2)
Goodwill, Acquired During Period	131
Business Combination, Consideration Transferred	$ 1,207

Acquisitions (LASCO) (Details)

Acquisitions (LASCO) (Details) $ in Millions	Aug. 19, 2021 USD ($)
LASCO Fittings, Inc.
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 277

Acquisitions (Dimex) (Details)

Acquisitions (Dimex) (Details) $ in Millions	Sep. 10, 2021 USD ($)
Dimex LLC
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 172

Financial Instruments (Cash Equ

Financial Instruments (Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Held-to-maturity securities	$ 360	$ 0
Restricted cash and cash equivalents	$ 15	$ 18

Accounts Receivable (Schedule O

Accounts Receivable (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ (27)	$ (28)
Accounts Receivable from trade customers, net	1,393	1,651
Federal and state taxes	65	69
Other	143	81
Accounts receivable, net	1,601	1,801
Nonrelated Party
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade customers	1,413	1,676
Related Party
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade customers	$ 7	$ 3

Inventories (Schedule Of Invent

Inventories (Schedule Of Inventory) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Inventory, Net [Abstract]
Finished products	$ 989	$ 1,157
Feedstock, additives, chemicals and other raw materials	401	496
Materials and supplies	232	213
Inventories	$ 1,622	$ 1,866

Property, Plant And Equipment_2

Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment, Net [Abstract]
Land	$ 304	$ 299
Buildings and improvements	951	895
Plant and equipment	10,771	10,408
Other	803	711
Property, Plant and Equipment, Gross	12,829	12,313
Less: Accumulated depreciation	5,240	4,655
Property, plant and equipment, net, before construction in progress	7,589	7,658
Construction in progress	930	819
Property, plant and equipment, net	$ 8,519	$ 8,477

Property, Plant And Equipment_3

Property, Plant And Equipment (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Depreciation expense on property, plant and equipment		$ 763	$ 762	$ 604
Impairment of goodwill and long-lived assets		$ 475	$ 0	$ 0
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]	Impairment of goodwill and long-lived assets
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]	Impairment of goodwill and long-lived assets
Performance and Essential Materials Segment
Property, Plant and Equipment [Line Items]
Impairment of goodwill and long-lived assets	$ 347
Property, plant and equipment impairment	256
Operating lease right-of-use assets impairment	32
Other asset impairment	10
Customer relationships | Performance and Essential Materials Segment
Property, Plant and Equipment [Line Items]
Intangible asset impairment	6
Other | Performance and Essential Materials Segment
Property, Plant and Equipment [Line Items]
Intangible asset impairment	$ 43

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use assets	$ 697	$ 615
Accrued and other liabilities	124	116
Operating lease liabilities	611	504
Total operating lease liabilities	$ 735	$ 620
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued and other liabilities	Accrued and other liabilities
Weighted Average Remaining Term (in years)	9 years	9 years
Weighted Average Lease Discount Rate	3.80%	2.90%
Lease, Cost [Abstract]
Operating lease cost	$ 142	$ 139	$ 117
Short-term lease cost	121	101	85
Total operating lease cost	263	240	$ 202
Operating Leased Assets [Line Items]
2024	142
2025	122
2026	108
2027	95
2028	81
Thereafter	362
Total lease payments	910
Less: imputed interest	(175)
Affiliates
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use assets	26	29
Fixed Lease Payments | Affiliates
Lease, Cost [Abstract]
Operating lease cost	$ 5	$ 6

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Millions		12 Months Ended
	Feb. 01, 2022	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Roll Forward]
Balance at beginning of year		$ 2,161	$ 2,024
Goodwill acquired during the year			124
Measurement period adjustment		5	24
Impairment of goodwill		(128)
Effects of changes in foreign exchange rates		3	(11)
Balance at end of year		2,041	2,161
Hexion
Goodwill [Roll Forward]
Goodwill acquired during the year	$ 131
Performance and Essential Materials Segment
Goodwill [Roll Forward]
Balance at beginning of year		1,020	902
Goodwill acquired during the year			119
Measurement period adjustment			8
Impairment of goodwill		(128)
Effects of changes in foreign exchange rates		1	(9)
Balance at end of year		897	1,020
Performance and Essential Materials Segment | Hexion
Goodwill [Roll Forward]
Measurement period adjustment		4
Housing and Infrastructure Products Segment
Goodwill [Roll Forward]
Balance at beginning of year		1,141	1,122
Goodwill acquired during the year			5
Measurement period adjustment		1	16
Impairment of goodwill		0
Effects of changes in foreign exchange rates		2	(2)
Balance at end of year		$ 1,144	$ 1,141

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Schedule of Finite-Lived Intangible Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Acquired Finite-Lived Intangible Assets [Line Items]
Net	$ 910	$ 993
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Customer relationships	1,586	1,589
Accumulated Amortization	$ (676)	(596)
Weighted Average Life	15 years
Licenses and intellectual property
Acquired Finite-Lived Intangible Assets [Line Items]
Licenses and intellectual property, Gross	$ 264	306
Accumulated Amortization	(136)	(124)
Net	$ 128	182
Weighted Average Life	15 years
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Trade name, Gross	$ 385	411
Accumulated Amortization	(104)	(86)
Net	$ 281	325
Weighted Average Life	18 years
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Other, Gross	$ 112	84
Accumulated Amortization	(28)	(19)
Net	$ 84	65
Weighted Average Life	17 years
Total other intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (268)	(229)
Net	493	572
Finite-Lived Intangible Assets, Gross	$ 761	$ 801

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Goodwill [Line Items]
Impairment of goodwill	$ (128)
Performance and Essential Materials Segment
Goodwill [Line Items]
Impairment of goodwill	$ (128)
Measurement Input, Discount Rate | Valuation Technique, Discounted Cash Flow | Minimum
Goodwill [Line Items]
Alternative Investment, Measurement Input	0.100
Measurement Input, Discount Rate | Valuation Technique, Discounted Cash Flow | Maximum
Goodwill [Line Items]
Alternative Investment, Measurement Input	0.120

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets (Amortization) (Details) $ in Millions	Dec. 31, 2023 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2024	$ 142
2025	113
2026	105
2027	103
2028	$ 103

Equity Method Investments (Narr

Equity Method Investments (Narrative) (Details) lb in Millions, $ in Millions		12 Months Ended
	Jun. 17, 2015 lb	Dec. 31, 2023 USD ($) lb	Dec. 31, 2022 USD ($) lb	Mar. 15, 2022 USD ($)	Nov. 12, 2019 USD ($)	Oct. 28, 2019
Schedule of Equity Method Investments [Line Items]
Investments in joint ventures		$ 225
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity		200
Equity method investments		$ 1,115	$ 1,142
LACC, LLC
Schedule of Equity Method Investments [Line Items]
Reimbursement agreement term		6 years 6 months
Revenue, Remaining Performance Obligation, Amount		$ 52
Contract with Customer, Liability		$ 23	19
LACC, LLC | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Schedule of Equity Method Investments [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period		25 years
Lotte Chemical Corporation
Schedule of Equity Method Investments [Line Items]
Revenue, Remaining Performance Obligation, Amount		$ 72
Contract with Customer, Liability		$ 29	24
LACC, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)		50%		3.20%	34.80%	12%
Additional interest purchased			$ 89	$ 89	$ 817
Investments in and Advances to Affiliates, Proportionate Share Of Production, Mass | lb		935	766
other equity method investments
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 68	$ 67
Affiliates
Schedule of Equity Method Investments [Line Items]
Plant capacity (in lbs) | lb	2,200

Equity Method Investments (Chan

Equity Method Investments (Changes in Investment) (Details) - LACC, LLC - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Mar. 15, 2022	Nov. 12, 2019
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Balance at beginning of period	$ 1,075	$ 943
Cash contributions	21	87
Additional interest purchased		89	$ 89	$ 817
Depreciation and amortization	(49)	(44)
Balance at end of period	$ 1,047	$ 1,075

Accounts Payable (Details)

Accounts Payable (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Notes payable	$ 13	$ 3
Accounts payable	877	889
Nonrelated Party
Related Party Transaction [Line Items]
Accounts payable—third parties	849	870
Related Party
Related Party Transaction [Line Items]
Accounts payable—third parties	$ 15	$ 16

Long-Term Debt (Schedule Of Lon

Long-Term Debt (Schedule Of Long-Term Debt) (Details) € in Millions, $ in Millions	Dec. 31, 2023 USD ($)	Dec. 31, 2023 Rate	Dec. 31, 2023 EUR (€)	Dec. 31, 2023	Dec. 31, 2022 USD ($)	Nov. 30, 2017 USD ($)	Aug. 10, 2016 USD ($)
Debt Instrument [Line Items]
Long-term debt, principal amount	$ 4,997				$ 4,976
Unamortized discount and debt issuance costs	91				97
Long-term debt, carrying value	4,906				4,879
Current portion	299				0
Long-term debt, net	4,607				4,879
Senior Notes | 0.875% Senior Notes Due 2024
Debt Instrument [Line Items]
Stated interest rate (percent)		0.875%		0.875%
Long-term debt, principal amount	300				300
Current portion	299				0
Senior Notes | 3.60% Senior Notes Due 2026
Debt Instrument [Line Items]
Stated interest rate (percent)		3.60%		3.60%
Long-term debt, principal amount	750				750		$ 750
Senior Notes | Loan related to tax-exempt waste disposal revenue bonds due 2027
Debt Instrument [Line Items]
Long-term debt, principal amount	11				11
Senior Notes | 1.625% Senior Notes Due 2029
Debt Instrument [Line Items]
Stated interest rate (percent)		1.625%		1.625%
Long-term debt, principal amount	773		€ 700		750
Senior Notes | 3.375% Senior Notes Due 2030
Debt Instrument [Line Items]
Stated interest rate (percent) | Rate		3.375%
Long-term debt, principal amount	300				300
Senior Notes | 3.50% Senior Notes Due 2032
Debt Instrument [Line Items]
Stated interest rate (percent)		3.50%		3.50%
Long-term debt, principal amount	250				250
Senior Notes | 2.875% Senior Notes Due 2041
Debt Instrument [Line Items]
Stated interest rate (percent)		2.875%		2.875%
Long-term debt, principal amount	350				350
Senior Notes | 5.00% Senior Notes Due 2026
Debt Instrument [Line Items]
Stated interest rate (percent)		5%		5%
Long-term debt, principal amount	700				700		$ 700
Senior Notes | 4.375% Senior Notes Due 2047
Debt Instrument [Line Items]
Stated interest rate (percent)		4.375%		4.375%
Long-term debt, principal amount	500				500	$ 500
Senior Notes | 3.125% Senior Notes Due 2051
Debt Instrument [Line Items]
Stated interest rate (percent)		3.125%		3.125%
Long-term debt, principal amount	600				600
Senior Notes | 3.375% Senior Notes Due 2061
Debt Instrument [Line Items]
Stated interest rate (percent)		3.375%		3.375%
Long-term debt, principal amount	450				450
Senior Notes | Term Loan Due 2026
Debt Instrument [Line Items]
Stated interest rate (percent)				0.95%
Long-term debt, principal amount	$ 13				$ 15

Long-Term Debt (New Credit Agre

Long-Term Debt (New Credit Agreement) (Details) - New Credit Agreement - Senior Secured Revolving Credit Facility $ in Millions	Jun. 09, 2022 USD ($)
Minimum
Credit Agreement [Line Items]
Line Of Credit Facility Permitted Increase	$ 25
Maximum
Credit Agreement [Line Items]
Line Of Credit Facility Permitted Increase	500
Revolving Credit Facility
Credit Agreement [Line Items]
Maximum borrowing capacity	$ 1,500
Revolving Credit Facility | Minimum | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1%
Revolving Credit Facility | Minimum | Alternate Base Rate
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0%
Revolving Credit Facility | Maximum | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.625%
Revolving Credit Facility | Maximum | Alternate Base Rate
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.625%
Letter of Credit
Credit Agreement [Line Items]
Maximum borrowing capacity	$ 150
Swingline Loan
Credit Agreement [Line Items]
Maximum borrowing capacity	$ 50

Long-Term Debt (0.875% Senior N

Long-Term Debt (0.875% Senior Notes due 2024) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 4,997		$ 4,976
0.875% Senior Notes Due 2024 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 300		$ 300
Stated interest rate (percent)	0.875%		0.875%
Redemption price percentage	100%

Long-Term Debt (Senior Notes Du

Long-Term Debt (Senior Notes Due 2026 and 2046) (Details) - USD ($) $ in Millions	Apr. 24, 2017	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Aug. 10, 2016
Debt Instrument [Line Items]
Principal Amount			$ 4,997		$ 4,976
3.60% Senior Notes Due 2026 | Senior Notes
Debt Instrument [Line Items]
Principal Amount			750		750	$ 750
Exchange Offer Percentage	99.97%
Stated interest rate (percent)		3.60%		3.60%
5.00% Senior Notes Due 2026 | Senior Notes
Debt Instrument [Line Items]
Principal Amount			$ 700		$ 700	$ 700
Exchange Offer Percentage	100%
Stated interest rate (percent)		5%		5%

Long-Term Debt (Revenue Bonds)

Long-Term Debt (Revenue Bonds) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt, principal amount	$ 4,997	$ 4,976
Loan related to tax-exempt waste disposal revenue bonds due 2027 | Senior Notes
Debt Instrument [Line Items]
Long-term debt, principal amount	$ 11	$ 11
Effective interest rate	4.30%	3.88%

Long-Term Debt (1.625% Senior N

Long-Term Debt (1.625% Senior Notes due 2029) (Details) € in Millions, $ in Millions	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jul. 17, 2019 USD ($)	Jul. 17, 2019 EUR (€)
Debt Instrument [Line Items]
Long-term Debt	$ 4,906	$ 4,879
Senior Notes | 1.625% Senior Notes Due 2029
Debt Instrument [Line Items]
Debt Instrument, Face Amount | €				€ 700
Long-term Debt			$ 779

Long-Term Debt (3.375 Senior No

Long-Term Debt (3.375 Senior Notes due 2030) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Credit Agreement [Line Items]
Long-term debt, principal amount	$ 4,997	$ 4,976
3.375 Senior Notes Due 2030 | Senior Notes
Credit Agreement [Line Items]
Stated interest rate (percent)	3.375%

Long-Term Debt (3.50% 2032 GO Z

Long-Term Debt (3.50% 2032 GO Zone Refunding Bonds) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Nov. 30, 2017
Debt Instrument [Line Items]
Long-term debt, principal amount		$ 4,997		$ 4,976
Senior Notes | Go Zone 3.50% Bonds Due 2032
Debt Instrument [Line Items]
Amount of bonds remarketed					$ 250
Senior Notes | 3.50% Senior Notes Due 2032
Debt Instrument [Line Items]
Stated interest rate (percent)	3.50%		3.50%
Debt Instrument, Face Amount		250
Long-term debt, principal amount		$ 250		$ 250
Redemption price percentage	100%

Long-Term Debt (2.875% Senior N

Long-Term Debt (2.875% Senior Notes Due 2041) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 4,997		$ 4,976
2.875% Senior Notes Due 2041 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 350		$ 350
Stated interest rate (percent)	2.875%		2.875%
Redemption price percentage	100%
Basis spread on redemption price percentage	0.20%

Long-Term Debt (4.375% Senior N

Long-Term Debt (4.375% Senior Notes due 2047) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Nov. 30, 2017
Debt Instrument [Line Items]
Long-term debt, principal amount		$ 4,997		$ 4,976
Senior Notes | 4.375% Senior Notes Due 2047
Debt Instrument [Line Items]
Long-term debt, principal amount		$ 500		$ 500	$ 500
Stated interest rate (percent)	4.375%		4.375%

Long-Term Debt (3.125% Senior N

Long-Term Debt (3.125% Senior Notes due 2051) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 4,997		$ 4,976
3.125% Senior Notes Due 2051 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 600		$ 600
Stated interest rate (percent)	3.125%		3.125%
Redemption price percentage	100%
Basis spread on redemption price percentage	0.25%

Long-Term Debt (3.375% Senior N

Long-Term Debt (3.375% Senior Notes Due 2061) (Details) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023 Rate	Dec. 31, 2023 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2023	Dec. 31, 2022 USD ($)	Nov. 30, 2017 USD ($)	Aug. 10, 2016 USD ($)
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 4,997			$ 4,976
Senior Notes
Credit Agreement [Line Items]
Redemption price percentage upon change of control	101%
3.375% Senior Notes Due 2061 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		450			450
Stated interest rate (percent)	3.375%			3.375%
Redemption price percentage	100%
Basis spread on redemption price percentage	0.25%
0.875% Senior Notes Due 2024 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		300			300
Stated interest rate (percent)	0.875%			0.875%
Redemption price percentage	100%
3.60% Senior Notes Due 2026 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		750			750		$ 750
Stated interest rate (percent)	3.60%			3.60%
1.625% Senior Notes Due 2029 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		773	€ 700		750
Stated interest rate (percent)	1.625%			1.625%
3.375 Senior Notes Due 2030 | Senior Notes
Credit Agreement [Line Items]
Stated interest rate (percent)				3.375%
3.50% Senior Notes Due 2032 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		250			250
Stated interest rate (percent)	3.50%			3.50%
Redemption price percentage	100%
2.875% Senior Notes Due 2041 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		350			350
Stated interest rate (percent)	2.875%			2.875%
Redemption price percentage	100%
Basis spread on redemption price percentage	0.20%
5.00% Senior Notes Due 2026 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		700			700		$ 700
Stated interest rate (percent)	5%			5%
4.375% Senior Notes Due 2047 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		500			500	$ 500
Stated interest rate (percent)	4.375%			4.375%
3.125% Senior Notes Due 2051 | Senior Notes
Credit Agreement [Line Items]
Long-term debt, principal amount		$ 600			$ 600
Stated interest rate (percent)	3.125%			3.125%
Redemption price percentage	100%
Basis spread on redemption price percentage	0.25%

Long-Term Debt (2026 Term Loans

Long-Term Debt (2026 Term Loans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt, principal amount	$ 4,997	$ 4,976
Weighted average interest rate	3.20%
Unamortized debt issuance costs	$ 36	40
Long-term debt, maturity, year one	300
Long-term debt, maturity, year three	763
Long-term debt, maturity, year four	$ 11
Term Loan Due 2026 | Senior Notes
Debt Instrument [Line Items]
Loan term	5 years
Maximum borrowing capacity	$ 22
Stated interest rate (percent)	0.95%
Long-term debt, principal amount	$ 13	$ 15
Taiwan Chlorine Industries, Ltd. | Term Loan Due 2026 | Senior Notes
Debt Instrument [Line Items]
Ownership percentage by parent	60%

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Aug. 31, 2022	Aug. 31, 2018	Nov. 20, 2015	Nov. 30, 2014
Class of Stock [Line Items]
Dividends, Common Stock, Cash	$ 221	$ 169	$ 145
Common Stock, Voting Rights, Number of Votes Per Share	one
Stock repurchase program, authorized amount				$ 500	$ 150	$ 150	$ 250
Stock Repurchase Program, Shares Repurchased, Gross	8,722,550
Treasury Stock Purchase Price, Repurchase Program	$ 574
Treasury Stock
Class of Stock [Line Items]
Stock repurchased 2014 program, shares repurchase	211,294	1,079,736	355,800
Ordinary Dividend
Class of Stock [Line Items]
Dividends, Common Stock, Cash	$ 221	$ 169	$ 145

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at start of period	$ (89)	$ (36)
Balance at end of period	(98)	(89)
Pension and Other Post-Retirement Benefits Liability, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at start of period	52	20
Net other comprehensive income (loss) attributable to Westlake Corporation	(48)	32
Balance at end of period	4	52
Cumulative Foreign Currency Exchange, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at start of period	(141)	(56)
Net other comprehensive income (loss) attributable to Westlake Corporation	39	(85)
Balance at end of period	(102)	(141)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Net other comprehensive income (loss) attributable to Westlake Corporation	$ (9)	$ (53)

Employee Benefits (Narrative De

Employee Benefits (Narrative Defined Contribution Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
United States
Defined Contribution Plan [Line Items]
Maximum employee contribution as a percentage of annual compensation	100%
Employer contributions to plans	$ 36	$ 33	$ 24
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	0
United States | Defined Contribution Retirement Plan
Defined Contribution Plan [Line Items]
Employer Contributions to Plan	48	46	35
Foreign Plan
Defined Contribution Plan [Line Items]
Employer contributions to plans	3	2	1
Employer Contributions to Plan	13	$ 3	$ 4
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 5

Employee Benefits (Schedule Of

Employee Benefits (Schedule Of Change In Benefit Obligation and Change In Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
United States
Change in plan assets
Fair value of plan assets, beginning of year	$ 415
Fair value of plan assets, end of year	427	$ 415
Foreign Plan
Change in plan assets
Fair value of plan assets, beginning of year	370
Fair value of plan assets, end of year	391	370
Pension Plan | United States
Change in benefit obligation
Benefit obligation, beginning of year	518	673
Benefit obligation assumed with acquisition	0	0
Service cost	1	1	$ 3
Interest cost	24	14	11
Actuarial loss (gain)	(7)	(121)
Benefits paid	(42)	(49)
Settlements	0	0
Foreign exchange effects	0	0
Benefit obligation, end of year	494	518	673
Change in plan assets
Fair value of plan assets, beginning of year	415	562
Plan assets assumed with acquisition	0	0
Actual return	55	(97)
Employer contribution	2	2
Benefits paid	(42)	(49)
Administrative expenses paid	(3)	(3)
Settlements	0	0
Foreign exchange effects	0	0
Fair value of plan assets, end of year	427	415	562
Funded status, end of year	(67)	(103)
Pension Plan | Foreign Plan
Change in benefit obligation
Benefit obligation, beginning of year	530	152
Benefit obligation assumed with acquisition	0	612
Service cost	4	3	2
Interest cost	19	7	1
Actuarial loss (gain)	82	(188)
Benefits paid	(21)	(17)
Settlements	(3)	(1)
Foreign exchange effects	18	(38)
Benefit obligation, end of year	629	530	152
Change in plan assets
Fair value of plan assets, beginning of year	370	21
Plan assets assumed with acquisition	0	538
Actual return	19	(145)
Employer contribution	15	1
Benefits paid	(21)	(17)
Administrative expenses paid	0	0
Settlements	(3)	(1)
Foreign exchange effects	11	(27)
Fair value of plan assets, end of year	391	370	$ 21
Funded status, end of year	$ (238)	$ (160)

Employee Benefits (Schedule O_2

Employee Benefits (Schedule Of Amounts Recognized In The Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	$ (363)	$ (355)
Pension Plan | United States
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Current liabilities	(2)	(2)
Noncurrent liabilities	(65)	(101)
Net amount recognized	(67)	(103)
Pension Plan | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	36	63
Current liabilities	(11)	(9)
Noncurrent liabilities	(263)	(214)
Net amount recognized	(238)	(160)
Other Postretirement Benefits Plan | United States
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(8)	(8)
Noncurrent liabilities	(33)	(38)
Net amount recognized	(41)	(46)
Other Postretirement Benefits Plan | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(1)	(1)
Noncurrent liabilities	(2)	(2)
Net amount recognized	$ (3)	$ (3)

Employee Benefits (Schedule O_3

Employee Benefits (Schedule Of Amounts Recognized In Accumulated Other Comprehensive Income (Loss)) (Details) - Pension Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income (loss), benefits, net of tax	$ (4)	$ 45
United States
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	(66)	(30)
Prior service credit	(1)	(2)
Total before tax	(67)	(32)
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	67	(10)
Prior service credit	(4)	(4)
Total before tax	$ 63	$ (14)

Employee Benefits (Narrative _2

Employee Benefits (Narrative Defined Benefit Plan) (Details) - USD ($) $ in Millions	11 Months Ended	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Expected net loss, Next Fiscal Year		$ 1
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year		$ 0
United States
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Long-Term		60%
Defined Benefit Plan, Target Allocation Percentage of Assets, Short-Term		40%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Discretionary Range		10%
Minimum | United States
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funded Status, Percentage		80%
Minimum | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Discretionary Range	0%
Maximum | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Discretionary Range	100%
Equity Securities | United States
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		60%
Equity Securities | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		20%
Fixed Income | United States
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		40%
Fixed Income | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		80%

Employee Benefits (Schedule O_4

Employee Benefits (Schedule Of Accumulated Benefit Obligations In Excess Of Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funding Status [Extensible Enumeration]	Underfunded Plan	Underfunded Plan
United States
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ (494)	$ (518)
Accumulated benefit obligation	(494)	(518)
Fair value of plan assets	427	415
United States | Underfunded Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	427	415
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	(273)	(223)
Accumulated benefit obligation	(271)	(221)
Fair value of plan assets	391	370
Foreign Plan | Underfunded Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

Employee Benefits (Schedule O_5

Employee Benefits (Schedule Of Net Benefit Costs, Other Changes in Plan Assets and Benefit Obligation Recognized In Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Expected net loss, Next Fiscal Year	$ 1
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year	0
United States | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	$ 1	$ 3
Administrative expenses	3	3	3
Interest cost	24	14	11
Expected return on plan assets	(26)	(38)	(38)
Net amortization	(1)	0	0
Net periodic benefit cost (gain)	1	(20)	(21)
Net loss (gain) emerging	(36)	13	(49)
Prior service credit	0	0	(2)
Amortization of prior service credit	1	0	0
Amortization of net gain (loss)	0	0	0
Foreign exchange effects	0	0	0
Total recognized in OCI	(35)	13	(51)
Total net periodic benefit cost and OCI	(34)	(7)	(72)
Foreign Plan | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	3	2
Administrative expenses	0	0	0
Interest cost	19	7	1
Expected return on plan assets	(12)	(12)	(1)
Net amortization	(2)	1	3
Net periodic benefit cost (gain)	9	(1)	5
Net loss (gain) emerging	74	(31)	(9)
Prior service credit	0	0	0
Amortization of prior service credit	0	0	0
Amortization of net gain (loss)	2	(1)	(2)
Foreign exchange effects	1	(1)	0
Total recognized in OCI	77	(33)	(11)
Total net periodic benefit cost and OCI	$ 86	$ (34)	$ (6)

Employee Benefits (Schedule O_6

Employee Benefits (Schedule Of Weighted Average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
United States
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5%	4.90%	2.60%
Rate of compensation increase	0%	0%	0%
Discount rate for benefit obligations	4.90%	2.50%	2.10%
Discount rate for service cost	5%	2.80%	2.40%
Discount rate for interest cost	4.80%	2.10%	1.50%
Expected return on plan assets	6.50%	7%	7%
Rate of compensation increase	0%	0%	0%
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.20%	3.70%	1.40%
Rate of compensation increase	3.10%	2.90%	2.60%
Discount rate for benefit obligations	3.70%	1.20%	0.80%
Discount rate for service cost	3.80%	1.40%	0.80%
Discount rate for interest cost	3.70%	1.20%	0.80%
Expected return on plan assets	3.30%	2.60%	4%
Rate of compensation increase	2.90%	2.80%	2.60%

Employee Benefits (Schedule O_7

Employee Benefits (Schedule Of Fair Value Of Pension Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
United States
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 427	$ 415
United States | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	156	151
United States | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	271	264
United States | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	391	370
Foreign Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	7
Foreign Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	378	354
Foreign Plan | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	9
Pension Plan | United States
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	427	415	$ 562
Pension Plan | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	391	370	$ 21
Cash and Cash Equivalents | United States
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents | United States | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents | United States | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents | United States | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	7
Cash and Cash Equivalents | Foreign Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	7
Cash and Cash Equivalents | Foreign Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents | Foreign Plan | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large-Cap Mutual Funds | United States | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	139	132
Large-Cap Mutual Funds | United States | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	47	42
Large-Cap Mutual Funds | United States | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	92	90
Large-Cap Mutual Funds | United States | Fair Value, Inputs, Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large-Cap Mutual Funds | Foreign Plan | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	1
Large-Cap Mutual Funds | Foreign Plan | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large-Cap Mutual Funds | Foreign Plan | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	1
Large-Cap Mutual Funds | Foreign Plan | Fair Value, Inputs, Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds | United States | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	10
Small-Cap Mutual Funds | United States | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds | United States | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	10
Small-Cap Mutual Funds | United States | Fair Value, Inputs, Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds | Foreign Plan | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds | Foreign Plan | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds | Foreign Plan | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds | Foreign Plan | Fair Value, Inputs, Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International Mutual Funds | United States | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	93	96
International Mutual Funds | United States | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	70	72
International Mutual Funds | United States | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23	24
International Mutual Funds | United States | Fair Value, Inputs, Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International Mutual Funds | Foreign Plan | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	74	73
International Mutual Funds | Foreign Plan | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International Mutual Funds | Foreign Plan | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	74	73
International Mutual Funds | Foreign Plan | Fair Value, Inputs, Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Bond Mutual Funds | United States | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	177	165
Bond Mutual Funds | United States | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39	37
Bond Mutual Funds | United States | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	138	128
Bond Mutual Funds | United States | Fair Value, Inputs, Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Bond Mutual Funds | Foreign Plan | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	303	280
Bond Mutual Funds | Foreign Plan | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Bond Mutual Funds | Foreign Plan | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	303	280
Bond Mutual Funds | Foreign Plan | Fair Value, Inputs, Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds | United States | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	12
Short Term Investment Funds | United States | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds | United States | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	12
Short Term Investment Funds | United States | Fair Value, Inputs, Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds | Foreign Plan | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds | Foreign Plan | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds | Foreign Plan | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds | Foreign Plan | Fair Value, Inputs, Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Group Insurance Policy | United States | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Group Insurance Policy | United States | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Group Insurance Policy | United States | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Group Insurance Policy | United States | Fair Value, Inputs, Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Group Insurance Policy | Foreign Plan | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	9
Group Insurance Policy | Foreign Plan | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Group Insurance Policy | Foreign Plan | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Group Insurance Policy | Foreign Plan | Fair Value, Inputs, Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 10	$ 9

Employee Benefits (Multiemploye

Employee Benefits (Multiemployer Plans) (Details)	12 Months Ended
	Dec. 31, 2023 plan
Multiemployer Plans [Line Items]
Number of multiemployer plans	2

Employee Benefits (Schedule O_8

Employee Benefits (Schedule Of Estimated Future Benefit Payments) (Details) $ in Millions	Dec. 31, 2023 USD ($)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Year 1	$ 68
Year 2	67
Year 3	67
Year 4	66
Year 5	65
Years 6 to 10	329
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Year 1	8
Year 2	6
Year 3	4
Year 4	3
Year 5	3
Years 6 to 10	$ 15

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense on restricted stock	$ 40	$ 35	$ 31
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	34	13	9
Share-based Payment Arrangement, Exercise of Option, Tax Benefit	$ 4	2	2
Ratably On Annual Basis | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	1 year
Ratably On Annual Basis | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	5 years
Cliff Vest | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	3 years
Cliff Vest | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	6 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awards, term (in years)	10 years
Unrecognized compensation expense	$ 8
Unrecognized compensation expense, weighted-average period of recognition (in years)	1 year 9 months 18 days
Stock Options | Ratably On Annual Basis
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	3 years
Stock Options | Cliff Vest
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	5 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 31
Unrecognized compensation expense, weighted-average period of recognition (in years)	2 years
Total fair value of shares of restricted stock that vested	$ 28	18	18
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 13
Unrecognized compensation expense, weighted-average period of recognition (in years)	1 year 9 months 18 days
Total fair value of shares of restricted stock that vested	$ 13	$ 8	$ 0

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule Of Option Activity And Changes) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
Options
Options, Outstanding, beginning balance | shares	1,531,070
Options, Granted | shares	197,251
Options, Exercised | shares	(615,296)
Options, Cancelled | shares	(39,136)
Options, Outstanding, ending balance | shares	1,073,889
Options, Exercisable, ending balance | shares	683,794
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding, beginning balance (in dollars per share) | $ / shares	$ 77.76
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	122.65
Weighted Average Exercise Price, Exercised (in dollars per share) | $ / shares	73.31
Weighted Average Exercise Price, Cancelled (in dollars per share) | $ / shares	110.25
Weighted Average Exercise Price, Outstanding, ending balance (in dollars per share) | $ / shares	87.37
Weighted Average Exercise Price, Exercisable, ending balance (in dollars per share) | $ / shares	$ 74.23
Weighted Average Remaining Term (Years) [Abstract]
Weighted Average Remaining Term (Years), Outstanding	6 years 1 month 6 days
Weighted Average Remaining Term (Years), Exercisable	4 years 9 months 18 days
Aggregate Intrinsic Value [Abstract]
Aggregate Intrinsic Value, Outstanding | $	$ 56
Aggregate Intrinsic Value, Exercisable | $	$ 45

Stock-Based Compensation (Sch_2

Stock-Based Compensation (Schedule Of Range Of Exercise Prices For Outstanding Options) (Details)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
$44.42 - $61.87
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 44.42
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 61.87
Options Outstanding | shares	169,789
Weighted Average Remaining Contractual Life (Years)	2 years 7 months 6 days
$65.81 - $68.09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 65.81
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 68.09
Options Outstanding | shares	218,529
Weighted Average Remaining Contractual Life (Years)	5 years 1 month 6 days
$79.83 - $86.54
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 79.83
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 86.54
Options Outstanding | shares	262,357
Weighted Average Remaining Contractual Life (Years)	6 years 3 months 18 days
$107.75 - $108.12
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 107.75
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 108.12
Options Outstanding | shares	243,933
Weighted Average Remaining Contractual Life (Years)	7 years
$122.65 - $122.65
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 122.65
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 122.65
Options Outstanding | shares	179,281
Weighted Average Remaining Contractual Life (Years)	9 years 1 month 6 days

Stock-Based Compensation (Sch_3

Stock-Based Compensation (Schedule Of Weighted Average Value And Assumptions For Fair Value Of Options) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 44.91	$ 34.20	$ 25.18
Risk-free interest rate	4%	1.80%	0.60%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	5 years	5 years	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	39.10%	36.90%	36.90%
Expected dividend yield	1.10%	1.10%	1.20%

Stock-Based Compensation (Sch_4

Stock-Based Compensation (Schedule Of Non-Vested Restricted Stock Units and Performance Stock Units) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restricted Stock Units (RSUs)
Number of Shares
Number of Shares, Non-vested, beginning balance	690,414
Number of Shares, Granted	247,131
Number of Shares, Vested	(228,113)
Number of Shares, Forfeited	(67,804)
Number of Shares, Non-vested, ending balance	641,628	690,414
Weighted Average Grant Date Fair Value
Weighted Average Fair Value, Non-vested, beginning balance (in dollars per share)	$ 85.77
Weighted Average Fair Value, Granted (in dollars per share)	120.77
Weighted Average Fair Value, Vested (in dollars per share)	69.45
Weighted Average Fair Value, Forfeited (in dollars per share)	97.87
Weighted Average Fair Value, Non-vested, ending balance (in dollars per share)	$ 103.77	$ 85.77
Performance Stock Units
Number of Shares
Number of Shares, Non-vested, beginning balance	250,369
Number of Shares, Granted	72,627
Number of Shares, Vested	(106,705)
Number of Shares, Forfeited	(19,370)
Number of Shares, Non-vested, ending balance	196,921	250,369
Weighted Average Grant Date Fair Value
Weighted Average Fair Value, Non-vested, beginning balance (in dollars per share)	$ 106.13
Weighted Average Fair Value, Granted (in dollars per share)	167.76	$ 147.98	$ 109.94
Weighted Average Fair Value, Vested (in dollars per share)	74.99
Weighted Average Fair Value, Forfeited (in dollars per share)	142.29
Weighted Average Fair Value, Non-vested, ending balance (in dollars per share)	$ 142.18	$ 106.13

Stock-Based Compensation (Perfo

Stock-Based Compensation (Performance Stock Units Assumptions) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	4%	1.80%	0.60%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	5 years	5 years	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	39.10%	36.90%	36.90%
Performance Stock Units
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	4.40%	1.70%	0.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	2 years 10 months 13 days	2 years 10 months 13 days	2 years 10 months 13 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	40.80%	49.30%	49.40%
Share Base Compensation Average Correlation Coefficient of Peer Companies	0.61	0.66	0.65
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 167.76	$ 147.98	$ 109.94
Minimum | Performance Stock Units
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share Based Compensation Arrangements Expected Volatility Rate of Peer Companies	26.60%	30.80%	30.70%
Maximum | Performance Stock Units
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share Based Compensation Arrangements Expected Volatility Rate of Peer Companies	53.20%	67.20%	65.60%

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Carrying And Fair Values Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Carrying Value	$ 4,906	$ 4,879
Fair Value	$ 4,236	$ 3,940

Income Taxes (Components Of Inc

Income Taxes (Components Of Income (Loss) Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Domestic	$ 923	$ 2,523	$ 2,298
Foreign	(223)	423	379
Income before income taxes	$ 700	$ 2,946	$ 2,677

Income Taxes (Schedule Of The P

Income Taxes (Schedule Of The Provision For (Benefit From) Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current
Federal	$ 229	$ 473	$ 434
State	26	74	57
Foreign	98	123	93
Total Current	353	670	584
Deferred
Federal	(82)	(1)	19
State	(31)	(14)	13
Foreign	(62)	(6)	(9)
Total Deferred	(175)	(21)	23
Provision for (benefit from) income taxes	$ 178	$ 649	$ 607

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Taxes Computed At The Statutory Rate To Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Provision for federal income tax, at statutory rate	$ 148	$ 619	$ 563
State income tax provision, net of federal income tax effect	7	59	56
Foreign income tax rate differential	(15)	30	22
Noncontrolling interests	(7)	(8)	(11)
Change in valuation allowance	76	0	(29)
U.S. federal research and development credits	(54)	(27)	(1)
Goodwill impairment	26	0	0
Other, net	(17)	(30)	5
Provision for (benefit from) income taxes	$ 178	$ 649	$ 607

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ 166	$ 103
Credit carryforward	20	19
Operating lease liabilities	177	149
Accruals	139	96
Pension	88	99
Inventories	34	34
Research and experimental expenditures	124	94
Other	36	18
Deferred taxes assets—total	784	612
Property, plant and equipment	(1,257)	(1,301)
Intangibles	(240)	(272)
Operating lease right-of-use asset	(168)	(149)
Turnaround costs	(61)	(49)
Consolidated partnerships	(213)	(234)
Equity method investments	(228)	(237)
Other	(47)	(42)
Deferred tax liabilities—total	(2,214)	(2,284)
Valuation allowance	(118)	(47)
Total net deferred tax liabilities	(1,548)	(1,719)
Noncurrent deferred tax asset	12	16
Noncurrent deferred tax liability	$ (1,560)	$ (1,735)

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Change in valuation allowance	$ 71
Unrecognized Tax Benefits	38
Federal
Operating Loss Carryforwards	15
Tax Credit Carryforward, Amount	2
Foreign Tax Authority
Operating Loss Carryforwards	432
State and Local Jurisdiction
Operating Loss Carryforwards	952
Tax Credit Carryforward, Amount	$ 18

Earnings and Dividends per Sh_3

Earnings and Dividends per Share (Schedule Of Net Income Attributable To Common Stockholders) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings and Dividends Per Share [Abstract]
Net income attributable to Westlake Corporation	$ 479	$ 2,247	$ 2,015
Net income attributable to participating securities	3	12	10
Net income attributable to common shareholders	$ 476	$ 2,235	$ 2,005

Earnings and Dividends per Sh_4

Earnings and Dividends per Share (Reconciliation Of Denominator For Basic And Diluted Earnings (Loss) Per Share) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings and Dividends Per Share [Abstract]
Weighted average common shares—basic	127,806,317	127,970,445	128,002,911
Assumed exercise of options and vesting of performance stock units	792,124	875,117	695,071
Weighted average common shares—diluted	128,598,441	128,845,562	128,697,982
Basic (in dollars per share)	$ 3.73	$ 17.46	$ 15.66
Diluted (in dollars per share)	$ 3.70	$ 17.34	$ 15.58

Earnings and Dividends per Sh_5

Earnings and Dividends per Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings and Dividends Per Share [Abstract]
Number of options excluded from computation of diluted earnings per share	263,131	315,864	461,618

Earnings and Dividends per Sh_6

Earnings and Dividends per Share (Dividends Per Share) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings and Dividends Per Share [Abstract]
Dividends Per Common Share (in usd per share)	$ 1.7140	$ 1.3090	$ 1.1350

Supplemental Information (Detai

Supplemental Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accrued Liabilities
Other assets, net	$ 651	$ 617
Deferred turnaround costs	391	359
Accrued and other liabilities	1,614	1,409
Accrued rebates	217	227
Estimated Litigation Liability	297	90
Non-Cash Investing Activity [Abstract]
Capital Expenditures Incurred but Not yet Paid	184	171	$ 156
Restructuring and Related Activities [Abstract]
Restructuring, transaction and integration-related costs	$ 28	33	21
Other Income and Expenses [Abstract]
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other income, net
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other income, net
Interest income	$ 104	24	7
Insurance recoveries	28
Income from pension and post-retirement plans		26	23
Income from unconsolidated subsidiaries	19	15	13
Supplemental Cash Flow Information [Abstract]
Operating Lease, Payments	139	134	114
Right-of-use assets obtained in exchange for operating lease obligations	240	187	215
Interest paid, net of interest capitalized	159	172	130
Income taxes paid	421	570	$ 466
Related Party
Accrued Liabilities
Other Liabilities, Current	$ 41	$ 44

Related Party and Affiliate T_2

Related Party and Affiliate Transactions (Details) $ in Millions, lb in Billions		12 Months Ended
	Jun. 17, 2015 lb	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Feb. 01, 2022 USD ($)
Related Party Transaction [Line Items]
Investments in joint ventures		$ 225
Accounts payable		877	$ 889
Dividends received from equity method investments		18	16	$ 15
Net sales		12,548	15,794	11,778
Accounts receivable, net		1,601	1,801
Affiliates
Related Party Transaction [Line Items]
Plant capacity (in lbs) | lb	2.2
Incurred and paid lease payments		3	3	3
Affiliates | YNCORIS GmbH & Co. KG
Related Party Transaction [Line Items]
Investments in joint ventures		$ 53	53
Affiliates | YNCORIS GmbH & Co. KG | YNCORIS GmbH & Co. KG
Related Party Transaction [Line Items]
Ownership interest (in percent)		20%
Affiliates | YNCORIS GmbH & Co. KG | Electricity And Technical Services
Related Party Transaction [Line Items]
Purchases from related parties		$ 176	188	174
Accounts payable		34	37
Affiliates | Westlake UV Coatings (Shanghai) Co., Ltd.
Related Party Transaction [Line Items]
Investments in joint ventures					$ 7
Affiliates | Westlake UV Coatings (Shanghai) Co., Ltd. | Westlake UV Coatings (Shanghai) Co., Ltd.
Related Party Transaction [Line Items]
Ownership interest (in percent)					49.99%
Corporate Joint Venture | Pipeline Fees For Transport Of Natural Gas Liquid Feedstocks | Cypress Interstate Pipeline L.L.C
Related Party Transaction [Line Items]
Purchases from related parties		20	16	14
Accounts payable		1	1
Corporate Joint Venture | Cypress Interstate Pipeline L.L.C
Related Party Transaction [Line Items]
Investments in joint ventures		$ 8	7
Corporate Joint Venture | Cypress Interstate Pipeline L.L.C | Cypress Interstate Pipeline L.L.C
Related Party Transaction [Line Items]
Ownership interest (in percent)		50%
American Air Liquide Holdings, Inc. | American Air Liquide Holdings
Related Party Transaction [Line Items]
Accounts payable		$ 4	4
Purchases and lease expense to related parties		43	43	39
Net sales		14	11	$ 8
Accounts receivable, net		$ 1	$ 2

Westlake Chemical Partners LP (

Westlake Chemical Partners LP (Details) - USD ($) $ in Millions				12 Months Ended
	Mar. 29, 2019	Oct. 04, 2018	Aug. 04, 2014	Dec. 31, 2023
Related Party Transaction [Line Items]
Partners' Capital Account, Units, Sold in Public Offering			12,937,500
Partners' Capital Account, Units, Sold in Private Placement	2,940,818
Partners' Units, Maximum Aggregate Offering Amount, ATM		$ 50
Limited Partner | Westlake Chemical OpCo LP
Related Party Transaction [Line Items]
Limited Partnership Ownership Percentage Increase	4.50%
Principal Owner | TTWF LP
Related Party Transaction [Line Items]
Partners' Capital Account, Units, Acquisitions	1,401,869
Subsidiary of Common Parent | Limited Partner | Westlake Chemical Partners LP
Related Party Transaction [Line Items]
Partners' Capital Account, Units				14,122,230
Subsidiary of Common Parent | IPO | Limited Partner | Westlake Chemical OpCo LP
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest				22.80%
Limited partner interest (percent)				77.20%
Subsidiary of Common Parent | IPO | Limited Partner | Westlake Chemical Partners LP
Related Party Transaction [Line Items]
Limited partner interest (percent)				40.10%

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions

1 Months Ended

3 Months Ended

12 Months Ended

Oct. 16, 2023

Sep. 12, 2023

May 22, 2019

Jun. 18, 2018

Oct. 31, 2023

Sep. 30, 2023

Apr. 30, 2022

Mar. 31, 2019

May 31, 2017

Dec. 31, 2023

Dec. 31, 2023

Dec. 31, 2022

Environmental Loss Contingencies [Line Items]

Loss contingency accrual

$ 58

$ 58

$ 55

Avient

Environmental Loss Contingencies [Line Items]

Site Contingency, Percentage of Cost Potentially of Other Responsible Parties

100%

Pending Litigation | Avient

Environmental Loss Contingencies [Line Items]

Damages sought

$ 22

$ 11

Site Contingency, Percentage of Cost Potentially of Other Responsible Parties

100%

Minimum

Environmental Loss Contingencies [Line Items]

Environmental Exit Costs, Reasonably Possible Additional Loss

$ 98

Maximum

Environmental Loss Contingencies [Line Items]

Environmental Exit Costs, Reasonably Possible Additional Loss

165

Cost of Implementation | Environmental Protection Agency

Environmental Loss Contingencies [Line Items]

Environmental Exit Costs, Anticipated Cost

$ 107

Operation and Maintenance | Environmental Protection Agency | Minimum

Environmental Loss Contingencies [Line Items]

Environmental Exit Costs, Anticipated Cost

1

Operation and Maintenance | Environmental Protection Agency | Maximum

Environmental Loss Contingencies [Line Items]

Environmental Exit Costs, Anticipated Cost

$ 3

Groundwater Monitoring

Environmental Loss Contingencies [Line Items]

Environmental Exit Costs, Anticipated Cost

$ 13

Caustic Soda Antitrust Proceedings | Direct Purchasers | Settled Litigation

Environmental Loss Contingencies [Line Items]

Damages sought

$ 861

Litigation settlement, amount awarded to other party

$ 19

Caustic Soda Antitrust Proceedings | Indirect Purchasers | Settled Litigation

Environmental Loss Contingencies [Line Items]

Damages sought

$ 500

Ethylene Antitrust Litigation Proceedings | Pending Litigation

Environmental Loss Contingencies [Line Items]

Damages sought

$ 1,026

Triad Hunter Proceedings | Settled Litigation

Environmental Loss Contingencies [Line Items]

Litigation settlement, amount awarded to other party

$ 70

Petro 2 Flash Fire And EDC Storage Tank Explosion

Environmental Loss Contingencies [Line Items]

Litigation settlement, amount awarded to other party

150

Loss Contingency, Damages Awarded, Value

382

Loss contingency, receivable

43

43

Loss contingency accrual

$ 183

183

Petro 2 Flash Fire And EDC Storage Tank Explosion | Insurance Claims

Environmental Loss Contingencies [Line Items]

Damages sought

$ 150

Commitments and Contingencies_2

Commitments and Contingencies (Minimum Purchase Obligations) (Details) $ in Millions	Dec. 31, 2023 USD ($)
Unconditional purchase obligations
Unrecorded Unconditional Purchase Obligation	$ 6,345
2024	983
2025	1,016
2026	936
2027	825
2028	628
Thereafter	$ 1,957

Segment and Geographic Inform_3

Segment and Geographic Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2023 plant customer Segment	Dec. 31, 2022 customer	Dec. 31, 2021 customer
Segment Reporting Information [Line Items]
Number of Operating Segments | Segment	2
Number of Building Product Facilities | plant	70
Performance and Essential Materials Segment
Segment Reporting Information [Line Items]
Number of major customers	0	0	0
Housing and Infrastructure Products Segment
Segment Reporting Information [Line Items]
Number of major customers	0	0	0

Segment and Geographic Inform_4

Segment and Geographic Information (Segment Reporting Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net sales	$ 12,548	$ 15,794	$ 11,778
Income (loss) from operations	729	3,050	2,800
Depreciation and amortization	1,097	1,056	840
Other income, net	136	73	53
Provision for (benefit from) income taxes	178	649	607
Capital expenditures	1,034	1,108	658
Operating Segments
Segment Reporting Information [Line Items]
Net sales	12,548	15,794	11,778
Operating Segments | Performance and Essential Materials Segment
Segment Reporting Information [Line Items]
Net sales	8,336	11,008	8,670
Income (loss) from operations	59	2,416	2,549
Depreciation and amortization	881	784	665
Other income, net	25	37	33
Provision for (benefit from) income taxes	(63)	435	542
Capital expenditures	857	913	567
Operating Segments | Performance and Essential Materials Segment | Performance Materials
Segment Reporting Information [Line Items]
Net sales	4,656	6,964	5,997
Operating Segments | Performance and Essential Materials Segment | Essential Materials
Segment Reporting Information [Line Items]
Net sales	3,680	4,044	2,673
Operating Segments | Housing and Infrastructure Products Segment
Segment Reporting Information [Line Items]
Net sales	4,212	4,786	3,108
Income (loss) from operations	710	675	356
Depreciation and amortization	207	263	168
Other income, net	32	17	10
Provision for (benefit from) income taxes	194	185	80
Capital expenditures	164	187	88
Operating Segments | Housing and Infrastructure Products Segment | Housing Products
Segment Reporting Information [Line Items]
Net sales	3,494	3,864	2,334
Operating Segments | Housing and Infrastructure Products Segment | Infrastructure Products
Segment Reporting Information [Line Items]
Net sales	718	922	774
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales	408	908	798
Intersegment Eliminations | Performance and Essential Materials Segment
Segment Reporting Information [Line Items]
Net sales	408	908	798
Intersegment Eliminations | Housing and Infrastructure Products Segment
Segment Reporting Information [Line Items]
Net sales	0	0	0
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Income (loss) from operations	(40)	(41)	(105)
Depreciation and amortization	9	9	7
Other income, net	79	19	10
Provision for (benefit from) income taxes	47	29	(15)
Capital expenditures	$ 13	$ 8	$ 3

Segment and Geographic Inform_5

Segment and Geographic Information (Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting [Abstract]
Income from operations for reportable segments	$ 729	$ 3,050	$ 2,800
Interest expense	(165)	(177)	(176)
Other income, net	136	73	53
Income before income taxes	$ 700	$ 2,946	$ 2,677

Segment and Geographic Inform_6

Segment and Geographic Information (Total Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total assets	$ 21,035	$ 20,550
Operating Segments | Performance and Essential Materials Segment
Segment Reporting Information [Line Items]
Total assets	13,538	13,978
Operating Segments | Housing and Infrastructure Products Segment
Segment Reporting Information [Line Items]
Total assets	4,888	5,022
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total assets	$ 2,609	$ 1,550

Segment and Geographic Inform_7

Segment and Geographic Information (Geographic Information for Sales to External Customers and Long-lived Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 12,548	$ 15,794	$ 11,778
Long-lived assets	8,519	8,477
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	8,955	10,899	8,157
Long-lived assets	7,395	7,155
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	808	1,051	980
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	602	875	628
Long-lived assets	790	749
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	220	262	216
Mexico
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	217	228	149
Brazil
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	215	353	141
France
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	138	172	100
Italy
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	135	200	181
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	1,258	1,754	$ 1,226
Long-lived assets	$ 334	$ 573