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WLK Westlake Chemical

Cover Page

Cover Page - shares3 Months Ended
Mar. 31, 2021Apr. 28, 2021
Document Information [Line Items]
Document Type10-Q
Document Quarterly Reporttrue
Document Period End DateMar. 31,
2021
Document Transition Reportfalse
Entity File Number001-32260
Entity Registrant NameWestlake Chemical Corporation
Entity Incorporation, State or Country CodeDE
Entity Tax Identification Number76-0346924
Entity Address, Address Line One2801 Post Oak Boulevard
Entity Address, Address Line TwoSuite 600
Entity Address, City or TownHouston
Entity Address, State or ProvinceTX
Entity Address, Postal Zip Code77056
City Area Code713
Local Phone Number960-9111
Entity Current Reporting StatusYes
Entity Interactive Data CurrentYes
Entity Filer CategoryLarge Accelerated Filer
Entity Small Businessfalse
Entity Emerging Growth Companyfalse
Entity Shell Companyfalse
Entity Common Stock, Shares Outstanding128,132,613
Amendment Flagfalse
Document Fiscal Year Focus2021
Document Fiscal Period FocusQ1
Entity Central Index Key0001262823
Current Fiscal Year End Date--12-31
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) SecurityCommon Stock, $0.01 par value
Trading SymbolWLK
Security Exchange NameNYSE
1.625% Senior Notes Due 2029
Document Information [Line Items]
Title of 12(b) Security1.625% Senior Notes due 2029
Trading SymbolWLK29
Security Exchange NameNYSE

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Current assets
Cash and cash equivalents $ 1,393 $ 1,313
Accounts receivable, net1,327 1,214
Inventories955 918
Prepaid expenses and other current assets59 32
Total current assets3,734 3,477
Property, plant and equipment, net6,921 6,920
Operating lease right-of-use assets467 461
Goodwill1,082 1,083
Customer relationships, net419 444
Other intangible assets, net160 168
Equity method investments1,029 1,059
Other assets, net238 223
Total assets14,050 13,835
Current liabilities
Accounts payable603 536
Accrued and other liabilities723 821
Total current liabilities1,326 1,357
Long-term debt, net3,547 3,566
Deferred income taxes1,385 1,368
Pension and other post-retirement benefits378 391
Operating lease liabilities383 376
Other liabilities206 199
Total liabilities7,225 7,257
Commitments and contingencies (Note 13)
Stockholders' equity
Preferred stock, $0.01 par value, 50,000,000 shares authorized; no shares issued and outstanding0 0
Common stock, $0.01 par value, 300,000,000 shares authorized; 134,651,380 and 134,651,380 shares issued at March 31, 2021 and December 31, 2020, respectively1 1
Common stock, held in treasury, at cost; 6,520,062 and 6,821,174 shares at March 31, 2021 and December 31, 2020, respectively(379)(401)
Additional paid-in capital564 569
Retained earnings6,145 5,938
Accumulated other comprehensive loss(70)(64)
Total Westlake Chemical Corporation stockholders' equity6,261 6,043
Noncontrolling interests564 535
Total equity6,825 6,578
Total liabilities and equity $ 14,050 $ 13,835
Preferred stock, par value, in dollars per share $ 0.01 $ 0.01
Common stock, par value, in dollars per share $ 0.01 $ 0.01
Preferred stock, shares outstanding0 0
Preferred stock, shares authorized50,000,000 50,000,000
Common stock, shares authorized300,000,000 300,000,000
Common Stock [Member]
Stockholders' equity
Total equity $ 1 $ 1
Common Stock, Shares, Issued134,651,380 134,651,380
Common Stock, Held in Treasury [Member]
Stockholders' equity
Total equity $ (379) $ (401)
Treasury Stock, Shares6,520,062 6,821,174

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Income Statement [Abstract]
Net sales $ 2,357 $ 1,932
Cost of sales1,848 1,649
Gross profit509 283
Selling, general and administrative expenses136 120
Amortization of intangibles27 27
Income from operations346 136
Other income (expense)
Interest expense(33)(31)
Other income, net12 11
Income before income taxes325 116
Provision for (benefit from) income taxes72 (41)
Net income253 157
Net income attributable to noncontrolling interests11 12
Net income attributable to Westlake Chemical Corporation $ 242 $ 145
Earnings per common share attributable to Westlake Chemical Corporation:
Basic (in dollars per share) $ 1.88 $ 1.13
Diluted (in dollars per share) $ 1.87 $ 1.13
Weighted average common shares outstanding:
Basic (in shares)127,955,532 128,237,364
Diluted (in shares)128,483,373 128,442,972

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income $ 253 $ 157
Foreign Currency Translation Adjustment, by Component [Abstract]
Foreign currency translation3 (25)
Income tax provision on foreign currency translation(10)(7)
Other comprehensive loss, net of income taxes(7)(32)
Comprehensive income246 125
Comprehensive income attributable to noncontrolling interests, net of tax of $0 and $1 for the three months ended March 31, 2021 and 2020, respectively10 12
Comprehensive income attributable to Westlake Chemical Corporation $ 236 $ 113

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Stockholders' Equity Statement - USD ($) $ in MillionsTotalCommon Stock [Member]Common Stock, Held in Treasury [Member]Additional Paid-in Capital [Member]Retained Earnings [Member]Accumulated Other Comprehensive Income (Loss) [Member]Noncontrolling Interests [Member]
Beginning balances at Dec. 31, 2019 $ 6,403 $ 1 $ (377) $ 553 $ 5,757 $ (74) $ 543
Beginning balance, shares issued at Dec. 31, 2019134,651,380
Beginning balance, Treasury shares at Dec. 31, 20196,266,609
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Westlake Chemical Corporation145 145
Net income attributable to noncontrolling interests12 12
Net income157
Other comprehensive income(32)(32)0
Common stock repurchased, shares995,529
Common stock repurchased(54) $ (54)
Shares issued—stock- based compensation (in shares)(282,476)
Shares issued—stock-based compensation2 $ 18 (8)(8)
Stock-based compensation6 6
Dividends declared(34)(34)
Distributions to noncontrolling interests(10)(10)
Ending balances at Mar. 31, 20206,438 $ 1 $ (413)551 5,860 (106)545
Ending balance, shares issued at Mar. 31, 2020134,651,380
Ending balance, Treasury shares at Mar. 31, 20206,979,662
Beginning balances at Dec. 31, 20206,578 $ 1 $ (401)569 5,938 (64)535
Beginning balance, shares issued at Dec. 31, 2020134,651,380
Beginning balance, Treasury shares at Dec. 31, 20206,821,174
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Westlake Chemical Corporation242 242
Net income attributable to noncontrolling interests11 11
Net income253
Other comprehensive income(7)(6)(1)
Shares issued—stock- based compensation (in shares)(301,112)
Shares issued—stock-based compensation9 $ 22 (13)
Stock-based compensation8 8
Dividends declared(35)(35)
Distributions to noncontrolling interests(11)(11)
Noncontrolling Interest, Increase from Consolidating Previously Unconsolidated Subsidiary30
Ending balances at Mar. 31, 2021 $ 6,825 $ 1 $ (379) $ 564 $ 6,145 $ (70) $ 564
Ending balance, shares issued at Mar. 31, 2021134,651,380
Ending balance, Treasury shares at Mar. 31, 20216,520,062

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Cash flows from operating activities
Net income $ 253 $ 157
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization195 190
Stock-based compensation expense8 6
Loss from disposition and write-off of property, plant and equipment4 5
Deferred income taxes10 126
Other losses (gains), net3 (2)
Changes in operating assets and liabilities, net of effect of business acquisitions
Accounts receivable(120)(240)
Inventories(42)(8)
Prepaid expenses and other current assets(12)7
Accounts payable75 (2)
Accrued and other liabilities(84)(146)
Other, net(25)(32)
Net cash provided by operating activities265 61
Cash flows from investing activities
Additions to property, plant and equipment(141)(164)
Return of (additions to) investment from unconsolidated subsidiaries(7)39
Other, net13 (7)
Net cash used for investing activities(135)(132)
Cash flows from financing activities
Distributions to noncontrolling interests(11)(10)
Dividends paid(35)(34)
Proceeds from debt issuance4 0
Net proceeds from (repayment of) short-term notes payable0 (21)
Proceeds from drawdown of revolver0 1,000
Repurchase of common stock for treasury0 (54)
Other, net8 2
Net cash provided by (used for) financing activities(34)883
Effect of exchange rate changes on cash, cash equivalents and restricted cash(3)(3)
Net increase in cash, cash equivalents and restricted cash93 809
Cash, cash equivalents and restricted cash at beginning of period1,337 750
Cash, cash equivalents and restricted cash at end of period $ 1,430 $ 1,559

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) OC Parenthetical - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest $ 0 $ 1

Basis of Financial Statements (

Basis of Financial Statements (Notes)3 Months Ended
Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial StatementsBasis of Financial Statements The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of Westlake Chemical Corporation (the "Company") included in the annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), filed with the SEC on February 24, 2021. These consolidated financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Company for the fiscal year ended December 31, 2020. In the opinion of the Company's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Company's financial position as of March 31, 2021, its results of operations for the three months ended March 31, 2021 and 2020, and the changes in its cash position for the three months ended March 31, 2021 and 2020. Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2021 or any other interim period. The preparation of consolidated financial statements in conformity with U.S. GAAP 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. The coronavirus ("COVID-19") pandemic resulted in widespread adverse impacts on the global economy in 2020. As the COVID-19 pandemic and its impacts on the global economy continue, the Company may experience impacts on its business operations. However, the impact that COVID-19 will have on the financial condition, results of operations and cash flows of the Company cannot be estimated with certainty at this time as it will depend on future developments, including, among others, the timing and logistics with respect to the distribution of vaccines (in the United States, Europe and globally) and the efficacy of the available vaccines (including with respect to the more recent variants of COVID-19) and other treatments, the ultimate duration of the pandemic, geographic spread and severity of the virus, the consequences of governmental and other measures designed to prevent the spread of the virus, actions taken by customers, suppliers and other third parties, workforce availability, and the timing and extent to which normal economic and operating conditions resume. The Company holds a 50% interest in RS Cogen, LLC ("RS Cogen") with Entergy Power RS, LLC ("Entergy") holding the remaining interest. Effective January 2021, the Company consolidated RS Cogen into its consolidated financial statements and classified Entergy's 50% interest in RS Cogen as a component of noncontrolling interest on the consolidated balance sheet. Recent Accounting Pronouncements Reference Rate Reform (ASU No. 2020-04) In March 2020, the FASB issued an accounting standards update to provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform, if certain criteria are met. The amendments in this update are effective for all entities from January 1, 2020 through December 31, 2022, and the adoption is not expected to have a material impact on our consolidated financial statements. Certain exceptions provided under this guidance may be applicable to future reference rate reform related transitions. Recently Adopted Accounting Standards Income Taxes (ASU No. 2019-12) In December 2019, the Financial Accounting Standards Board ("FASB") issued an accounting standards update removing certain exceptions for investments, intraperiod allocations and interim calculations and adding guidance to reduce complexity in accounting for income taxes. The accounting standard became effective for reporting periods beginning after December 15, 2020. The Company adopted this accounting standard effective January 1, 2021, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows.

Financial Instruments (Notes)

Financial Instruments (Notes)3 Months Ended
Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Financial InstrumentsFinancial Instruments Restricted Cash and Cash Equivalents The Company had restricted cash and cash equivalents of $37 and $24 at March 31, 2021 and December 31, 2020, 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. In addition, the Company's restricted cash and cash equivalents include RS Cogen's cash that is restricted under its senior credit facility. Restricted cash and cash equivalents are reflected primarily in other assets, net in the consolidated balance sheets.

Accounts Receivable (Notes)

Accounts Receivable (Notes)3 Months Ended
Mar. 31, 2021
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts ReceivableAccounts Receivable Accounts receivable consist of the following: March 31, December 31, Trade customers $ 1,265 $ 1,086 Related parties 2 9 Allowance for credit losses (18) (17) 1,249 1,078 Federal and state taxes 43 92 Other 35 44 Accounts receivable, net $ 1,327 $ 1,214

Inventories (Notes)

Inventories (Notes)3 Months Ended
Mar. 31, 2021
Inventory Disclosure [Abstract]
InventoriesInventories Inventories consist of the following: March 31, December 31, Finished products $ 534 $ 524 Feedstock, additives, chemicals and other raw materials 255 227 Materials and supplies 166 167 Inventories $ 955 $ 918

Goodwill (Notes)

Goodwill (Notes)3 Months Ended
Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
GoodwillGoodwill The gross carrying amounts and changes in the carrying amount of goodwill for the three months ended March 31, 2021 were as follows: Vinyls Segment Olefins Segment Total Balances at December 31, 2020 $ 1,053 $ 30 $ 1,083 Effects of changes in foreign exchange rates (1) — (1) Balances at March 31, 2021 $ 1,052 $ 30 $ 1,082

Accounts Payable (Notes)

Accounts Payable (Notes)3 Months Ended
Mar. 31, 2021
Accounts Payable [Abstract]
Accounts and Notes PayableAccounts Payable Accounts payable consist of the following: March 31, December 31, Accounts payable—third parties $ 568 $ 529 Accounts payable to related parties 1 — Notes payable and current portion of long-term debt 34 7 Accounts payable $ 603 $ 536

Long-Term Debt (Notes)

Long-Term Debt (Notes)3 Months Ended
Mar. 31, 2021
Debt Disclosure [Abstract]
Long-Term DebtLong-Term Debt Long-term debt consists of the following: March 31, 2021 December 31, 2020 Principal Unamortized Net Principal Unamortized Net 3.60% senior notes due 2022 (the "3.60% 2022 Senior Notes") $ 250 $ — $ 250 $ 250 $ (1) $ 249 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750 (6) 744 750 (6) 744 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 — 11 11 — 11 1.625% senior notes due 2029 (the "1.625% 2029 Senior Notes") 821 (10) 811 859 (10) 849 3.375% senior notes due 2030 (the "3.375% 2030 Senior Notes") 300 (4) 296 300 (4) 296 3.50% senior notes due 2032 (the "3.50% 2032 GO Zone Refunding Senior Notes") 250 (1) 249 250 (1) 249 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700 (22) 678 700 (23) 677 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 (9) 491 500 (9) 491 8.73% RS Cogen debt due 2022 (the "8.73% 2022 RS Cogen Debt") 34 — 34 — — — Term loans due 2026 (the "2026 Term Loans") 4 — 4 — — — Total long-term debt 3,620 (52) 3,568 3,620 (54) 3,566 Less: Current portion of 8.73% 2022 RS Cogen Debt - Classified in Accounts Payable (21) — (21) — — — Long-term debt, net of current portion $ 3,599 $ (52) $ 3,547 $ 3,620 $ (54) $ 3,566 Credit Agreement The Company has a $1,000 revolving credit facility that is scheduled to mature on July 24, 2023 (the "Credit Agreement"). The Credit Agreement bears interest at either (a) LIBOR plus a spread ranging from 1.00% to 1.75% or (b) Alternate Base Rate plus a spread ranging from 0.00% to 0.75% in each case depending on the credit rating of the Company. At March 31, 2021, the Company had no borrowings outstanding under the Credit Agreement. As of March 31, 2021, the Company had no outstanding letters of credit and had $1,000 of borrowing availability under the Credit Agreement. The Credit Agreement contains certain affirmative and negative covenants, including a quarterly total leverage ratio financial maintenance covenant. As of March 31, 2021, 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 thereunder and payments of any outstanding amounts could be accelerated by the lenders. 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. 8.73% 2022 RS Cogen Debt In July 2000, RS Cogen, our 50%-owned joint venture, entered into a $75 aggregate principal amount senior credit facility institutional loan at an interest rate of 8.73%. All of the assets of RS Cogen are pledged as collateral under its senior credit facility. Borrowings under this senior credit facility are repayable quarterly by September 2022. The Company does not guarantee RS Cogen's debt commitments and RS Cogen is not a guarantor for any of the Company's other long-term debt obligations. 2026 Term Loans In March 2021, Taiwan Chlorine Industries, Ltd., our 60%-owned joint venture, entered into five-year loan agreements for a maximum total limit of approximately $23. The interest rate on these loans at March 31, 2021 was 0.2%. The unsecured loans include a government rate subsidy and have a 5-year maturity. As of March 31, 2021, the Company was in compliance with all of its long-term debt covenants. Unamortized debt issuance costs on long-term debt were $27 and $28 at March 31, 2021 and December 31, 2020, respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss) (Notes)3 Months Ended
Mar. 31, 2021
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) by component for the three months ended March 31, 2021 and 2020 were as follows: Pension and Other Post-Retirement Benefits Cumulative Total Balances at December 31, 2020 $ (24) $ (40) $ (64) Net other comprehensive loss attributable to Westlake Chemical Corporation — (6) (6) Balances at March 31, 2021 $ (24) $ (46) $ (70) Balances at December 31, 2019 $ 3 $ (77) $ (74) Net other comprehensive loss attributable to Westlake Chemical Corporation — (32) (32) Balances at March 31, 2020 $ 3 $ (109) $ (106)

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)3 Months Ended
Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value MeasurementsFair Value Measurements The Company reports certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). 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 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 majority of 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. The carrying and fair values of the Company's long-term debt are summarized in the table below. March 31, 2021 December 31, 2020 Carrying Fair Carrying Fair 3.60% 2022 Senior Notes $ 250 $ 257 $ 249 $ 259 3.60% 2026 Senior Notes 744 809 744 846 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 11 11 1.625% 2029 Senior Notes 811 855 849 897 3.375% 2030 Senior Notes 296 312 296 332 3.50% 2032 GO Zone Refunding Senior Notes 249 275 249 276 5.0% 2046 Senior Notes 678 827 677 905 4.375% 2047 Senior Notes 491 544 491 597 8.73% 2022 RS Cogen Debt 34 34 — — 2026 Term Loans 4 4 — —

Income Taxes (Notes)

Income Taxes (Notes)3 Months Ended
Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income TaxesIncome TaxesThe effective income tax rate was an expense of 22.2% for the three months ended March 31, 2021 as compared to a benefit of 35.3% for the three months ended March 31, 2020. The effective income tax rate for the three months ended March 31, 2021 was above the statutory rate of 21.0% primarily due to state and foreign taxes. The effective income tax rate for the three months ended March 31, 2020 was a benefit and below the statutory rate of 21.0% primarily due to the income tax rate benefit resulting from the carryback of federal net operating loss ("NOL") to taxable years that were taxed at the U.S. corporate tax rate of 35.0% as permitted under the Coronavirus Aid, Relief, and Economic Security Act, partially offset by the reduction in the Internal Revenue Code Section 199 domestic manufacturing deduction, as a result of the NOL carryback.

Earnings and Dividends per Shar

Earnings and Dividends per Share (Notes)3 Months Ended
Mar. 31, 2021
Earnings and Dividends Per Share [Abstract]
Earnings per ShareEarnings and Dividends per Share Earnings 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 each period. Diluted earnings per share include the effects of certain stock options and performance stock units. Three Months Ended March 31, 2021 2020 Net income attributable to Westlake Chemical Corporation $ 242 $ 145 Less: Net income attributable to participating securities (1) — Net income attributable to common shareholders $ 241 $ 145 The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Three Months Ended March 31, 2021 2020 Weighted average common shares—basic 127,955,532 128,237,364 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 527,841 205,608 Weighted average common shares—diluted 128,483,373 128,442,972 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 1.88 $ 1.13 Diluted $ 1.87 $ 1.13 Excluded from the computation of diluted earnings per share are options to purchase 575,727 and 1,099,638 shares of common stock for the three months ended March 31, 2021 and 2020, 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 three months ended March 31, 2021 and 2020 were as follows: Three Months Ended March 31, 2021 2020 Dividends per common share $ 0.2700 $ 0.2625

Supplemental Information (Notes

Supplemental Information (Notes)3 Months Ended
Mar. 31, 2021
Supplemental Cash Flow Information [Abstract]
Supplemental InformationSupplemental Information Equity Method Investments LACC, LLC The Company's investment in LACC, LLC ("LACC"), a related party, was $958 and $961 at March 31, 2021 and December 31, 2020, respectively. The Company made capital contributions to LACC of $7 during the three months ended March 31, 2021. Accrued and Other Liabilities Accrued and other liabilities were $723 and $821 at March 31, 2021 and December 31, 2020, respectively. Accrued rebates and operating lease liability, which are components of accrued and other liabilities, were $84 and $89 at March 31, 2021, respectively; and $128 and $89 at December 31, 2020, respectively. No other component of accrued and other liabilities was more than five percent of total current liabilities. Accrued liabilities with related parties were $37 and $61 at March 31, 2021 and December 31, 2020, respectively. Non-cash Investing Activity The change in capital expenditure accruals increasing additions to property, plant and equipment was $32 and $27 for t

Commitments and Contingencies (

Commitments and Contingencies (Notes)3 Months Ended
Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and ContingenciesCommitments 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. 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 Petroleum Corporation, Occidental Chemical Corporation d/b/a OxyChem, Shin-Etsu Chemical Co., Ltd., Shintech Incorporated, Formosa Plastics Corporation, 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 seek an unspecified amount of damages and injunctive relief. The defendants' joint motion to dismiss the direct purchaser lawsuits was denied and the cases have proceeded to discovery. Beginning in October 2020, similar class action proceedings were also filed in Canada before the Superior Court of Quebec 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. 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. Environmental. As of March 31, 2021 and December 31, 2020, the Company had reserves for environmental contingencies totaling approximately $56 and $53, 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. At this time, the Company is not able to estimate the impact, if any, that any subsequent arbitration or judicial proceeding could have on the Company's consolidated financial statements either in the current period or in later periods. Any cash expenditures that the Company might incur in the future with respect to the remediation of contamination at the Calvert City complex would likely be spread out over an extended period. As a result, the Company believes it is unlikely that any remediation costs allocable to it will be material in terms of expenditures made in any individual reporting period. 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 $65 to $130.

Segment Information (Notes)

Segment Information (Notes)3 Months Ended
Mar. 31, 2021
Segment Reporting [Abstract]
Segment InformationSegment Information The Company operates in two principal operating segments: Vinyls and Olefins. These segments are strategic business units that offer a variety of different products. The Company manages each segment separately as each business requires different technology and marketing strategies. Three Months Ended March 31, 2021 2020 Net external sales Vinyls PVC, caustic soda and other $ 1,408 $ 1,213 Building products 412 292 Total Vinyls 1,820 1,505 Olefins Polyethylene 414 310 Styrene, feedstock and other 123 117 Total Olefins 537 427 $ 2,357 $ 1,932 Intersegment sales Vinyls $ — $ — Olefins 150 68 $ 150 $ 68 Income (loss) from operations Vinyls $ 200 $ 73 Olefins 180 62 Corporate and other (34) 1 $ 346 $ 136 Depreciation and amortization Vinyls $ 157 $ 153 Olefins 36 35 Corporate and other 2 2 $ 195 $ 190 Other income, net Vinyls $ 10 $ 6 Olefins — 1 Corporate and other 2 4 $ 12 $ 11 Provision for (benefit from) income taxes Vinyls $ 42 $ (78) Olefins 41 41 Corporate and other (11) (4) $ 72 $ (41) Three Months Ended March 31, 2021 2020 Capital expenditures Vinyls $ 118 $ 136 Olefins 23 27 Corporate and other — 1 $ 141 $ 164 A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Three Months Ended March 31, 2021 2020 Income from operations $ 346 $ 136 Interest expense (33) (31) Other income, net 12 11 Income before income taxes $ 325 $ 116 March 31, December 31, Total assets Vinyls $ 10,791 $ 10,680 Olefins 1,987 1,923 Corporate and other 1,272 1,232 $ 14,050 $ 13,835

Westlake Chemical Partners LP (

Westlake Chemical Partners LP (Notes)3 Months Ended
Mar. 31, 2021
Partners' Capital [Abstract]
Westlake Chemical Partners LPWestlake Chemical Partners LP In 2014, the Company formed Westlake Chemical Partners LP ("WLK Partners") to operate, acquire and develop ethylene production facilities and related assets. Also in 2014, WLK Partners completed its initial public offering of 12,937,500 common units. At March 31, 2021, WLK Partners had a 22.8% limited partner interest in Westlake Chemical OpCo LP ("OpCo"), and the Company retained a 77.2% limited partner interest in OpCo and a significant interest in WLK Partners through the Company's ownership of WLK 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, WLK Partners and Westlake Partners GP, the general partner of WLK 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 WLK 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 were issued under this program as of March 31, 2021.

Basis of Financial Statements_2

Basis of Financial Statements (Policies)3 Months Ended
Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial StatementsThe accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of Westlake Chemical Corporation (the "Company") included in the annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), filed with the SEC on February 24, 2021. These consolidated financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Company for the fiscal year ended December 31, 2020. In the opinion of the Company's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Company's financial position as of March 31, 2021, its results of operations for the three months ended March 31, 2021 and 2020, and the changes in its cash position for the three months ended March 31, 2021 and 2020.
Recent Accounting PronouncementsRecent Accounting Pronouncements Reference Rate Reform (ASU No. 2020-04) In March 2020, the FASB issued an accounting standards update to provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform, if certain criteria are met. The amendments in this update are effective for all entities from January 1, 2020 through December 31, 2022, and the adoption is not expected to have a material impact on our consolidated financial statements. Certain exceptions provided under this guidance may be applicable to future reference rate reform related transitions. Recently Adopted Accounting Standards Income Taxes (ASU No. 2019-12) In December 2019, the Financial Accounting Standards Board ("FASB") issued an accounting standards update removing certain exceptions for investments, intraperiod allocations and interim calculations and adding guidance to reduce complexity in accounting for income taxes. The accounting standard became effective for reporting periods beginning after December 15, 2020. The Company adopted this accounting standard effective January 1, 2021, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows.

Accounts Receivable (Tables)

Accounts Receivable (Tables)3 Months Ended
Mar. 31, 2021
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Schedule Of Accounts ReceivableAccounts receivable consist of the following: March 31, December 31, Trade customers $ 1,265 $ 1,086 Related parties 2 9 Allowance for credit losses (18) (17) 1,249 1,078 Federal and state taxes 43 92 Other 35 44 Accounts receivable, net $ 1,327 $ 1,214

Inventories (Tables)

Inventories (Tables)3 Months Ended
Mar. 31, 2021
Inventory Disclosure [Abstract]
Schedule Of InventoryInventories consist of the following: March 31, December 31, Finished products $ 534 $ 524 Feedstock, additives, chemicals and other raw materials 255 227 Materials and supplies 166 167 Inventories $ 955 $ 918

Goodwill (Tables)

Goodwill (Tables)3 Months Ended
Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of GoodwillThe gross carrying amounts and changes in the carrying amount of goodwill for the three months ended March 31, 2021 were as follows: Vinyls Segment Olefins Segment Total Balances at December 31, 2020 $ 1,053 $ 30 $ 1,083 Effects of changes in foreign exchange rates (1) — (1) Balances at March 31, 2021 $ 1,052 $ 30 $ 1,082

Accounts Payable (Tables)

Accounts Payable (Tables)3 Months Ended
Mar. 31, 2021
Accounts Payable [Abstract]
Schedule of Accounts Payable and Accrued LiabilitiesAccounts payable consist of the following: March 31, December 31, Accounts payable—third parties $ 568 $ 529 Accounts payable to related parties 1 — Notes payable and current portion of long-term debt 34 7 Accounts payable $ 603 $ 536

Long-Term Debt (Tables)

Long-Term Debt (Tables)3 Months Ended
Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule Of Long-Term DebtLong-term debt consists of the following: March 31, 2021 December 31, 2020 Principal Unamortized Net Principal Unamortized Net 3.60% senior notes due 2022 (the "3.60% 2022 Senior Notes") $ 250 $ — $ 250 $ 250 $ (1) $ 249 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750 (6) 744 750 (6) 744 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 — 11 11 — 11 1.625% senior notes due 2029 (the "1.625% 2029 Senior Notes") 821 (10) 811 859 (10) 849 3.375% senior notes due 2030 (the "3.375% 2030 Senior Notes") 300 (4) 296 300 (4) 296 3.50% senior notes due 2032 (the "3.50% 2032 GO Zone Refunding Senior Notes") 250 (1) 249 250 (1) 249 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700 (22) 678 700 (23) 677 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 (9) 491 500 (9) 491 8.73% RS Cogen debt due 2022 (the "8.73% 2022 RS Cogen Debt") 34 — 34 — — — Term loans due 2026 (the "2026 Term Loans") 4 — 4 — — — Total long-term debt 3,620 (52) 3,568 3,620 (54) 3,566 Less: Current portion of 8.73% 2022 RS Cogen Debt - Classified in Accounts Payable (21) — (21) — — — Long-term debt, net of current portion $ 3,599 $ (52) $ 3,547 $ 3,620 $ (54) $ 3,566

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)3 Months Ended
Mar. 31, 2021
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)Changes in accumulated other comprehensive income (loss) by component for the three months ended March 31, 2021 and 2020 were as follows: Pension and Other Post-Retirement Benefits Cumulative Total Balances at December 31, 2020 $ (24) $ (40) $ (64) Net other comprehensive loss attributable to Westlake Chemical Corporation — (6) (6) Balances at March 31, 2021 $ (24) $ (46) $ (70) Balances at December 31, 2019 $ 3 $ (77) $ (74) Net other comprehensive loss attributable to Westlake Chemical Corporation — (32) (32) Balances at March 31, 2020 $ 3 $ (109) $ (106)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)3 Months Ended
Mar. 31, 2021
Fair Value Disclosures [Abstract]
Summary Of Carrying And Fair Values Of Long-Term DebtThe carrying and fair values of the Company's long-term debt are summarized in the table below. March 31, 2021 December 31, 2020 Carrying Fair Carrying Fair 3.60% 2022 Senior Notes $ 250 $ 257 $ 249 $ 259 3.60% 2026 Senior Notes 744 809 744 846 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 11 11 1.625% 2029 Senior Notes 811 855 849 897 3.375% 2030 Senior Notes 296 312 296 332 3.50% 2032 GO Zone Refunding Senior Notes 249 275 249 276 5.0% 2046 Senior Notes 678 827 677 905 4.375% 2047 Senior Notes 491 544 491 597 8.73% 2022 RS Cogen Debt 34 34 — — 2026 Term Loans 4 4 — —

Earnings and Dividends per Sh_2

Earnings and Dividends per Share (Tables)3 Months Ended
Mar. 31, 2021
Earnings and Dividends Per Share [Abstract]
Schedule Of Net Income Attributable To Common StockholdersDiluted earnings per share include the effects of certain stock options and performance stock units. Three Months Ended March 31, 2021 2020 Net income attributable to Westlake Chemical Corporation $ 242 $ 145 Less: Net income attributable to participating securities (1) — Net income attributable to common shareholders $ 241 $ 145
Reconciliation Of Denominator For Basic And Diluted Earnings Per ShareThe following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Three Months Ended March 31, 2021 2020 Weighted average common shares—basic 127,955,532 128,237,364 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 527,841 205,608 Weighted average common shares—diluted 128,483,373 128,442,972 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 1.88 $ 1.13 Diluted $ 1.87 $ 1.13
Dividends Per ShareDividends per Share Dividends per common share for the three months ended March 31, 2021 and 2020 were as follows: Three Months Ended March 31, 2021 2020 Dividends per common share $ 0.2700 $ 0.2625

Segment Information (Tables)

Segment Information (Tables)3 Months Ended
Mar. 31, 2021
Segment Reporting [Abstract]
Segment Reporting InformationThree Months Ended March 31, 2021 2020 Net external sales Vinyls PVC, caustic soda and other $ 1,408 $ 1,213 Building products 412 292 Total Vinyls 1,820 1,505 Olefins Polyethylene 414 310 Styrene, feedstock and other 123 117 Total Olefins 537 427 $ 2,357 $ 1,932 Intersegment sales Vinyls $ — $ — Olefins 150 68 $ 150 $ 68 Income (loss) from operations Vinyls $ 200 $ 73 Olefins 180 62 Corporate and other (34) 1 $ 346 $ 136 Depreciation and amortization Vinyls $ 157 $ 153 Olefins 36 35 Corporate and other 2 2 $ 195 $ 190 Other income, net Vinyls $ 10 $ 6 Olefins — 1 Corporate and other 2 4 $ 12 $ 11 Provision for (benefit from) income taxes Vinyls $ 42 $ (78) Olefins 41 41 Corporate and other (11) (4) $ 72 $ (41) Three Months Ended March 31, 2021 2020 Capital expenditures Vinyls $ 118 $ 136 Olefins 23 27 Corporate and other — 1 $ 141 $ 164
Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income TaxesA reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Three Months Ended March 31, 2021 2020 Income from operations $ 346 $ 136 Interest expense (33) (31) Other income, net 12 11 Income before income taxes $ 325 $ 116
Total AssetsMarch 31, December 31, Total assets Vinyls $ 10,791 $ 10,680 Olefins 1,987 1,923 Corporate and other 1,272 1,232 $ 14,050 $ 13,835

Basis of Financial Statements_3

Basis of Financial Statements (Details)Mar. 31, 2021
RS Cogen
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent50.00%
Entergy
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners50.00%

Financial Instruments (Narrativ

Financial Instruments (Narrative) (Details) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Restricted Cash and Cash Equivalents $ 37 $ 24

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Trade customers $ 1,265 $ 1,086
Related parties2 9
Allowance for credit losses(18)(17)
Accounts receivable from trade customers, net1,249 1,078
Federal and state taxes43 92
Other35 44
Accounts receivable, net $ 1,327 $ 1,214

Inventories (Details)

Inventories (Details) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Inventory Disclosure [Abstract]
Finished products $ 534 $ 524
Feedstock, additives, chemicals and other raw materials255 227
Materials and supplies166 167
Inventories $ 955 $ 918

Goodwill (Details)

Goodwill (Details) $ in Millions3 Months Ended
Mar. 31, 2021USD ($)
Goodwill [Roll Forward]
Beginning Balance $ 1,083
Effects of changes in foreign exchange rates(1)
Ending Balance1,082
Olefins [Member]
Goodwill [Roll Forward]
Beginning Balance30
Effects of changes in foreign exchange rates0
Ending Balance30
Vinyls
Goodwill [Roll Forward]
Beginning Balance1,053
Effects of changes in foreign exchange rates(1)
Ending Balance $ 1,052

Accounts Payable (Details)

Accounts Payable (Details) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Accounts Payable [Abstract]
Accounts payable—third parties $ 568 $ 529
Accounts payable to related parties1 0
Notes payable and current portion of long-term debt34 7
Accounts payable $ 603 $ 536

Long-Term Debt (Schedule of Lon

Long-Term Debt (Schedule of Long-term Debt) (Details) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Debt Instrument [Line Items]
Principal Amount $ 3,620 $ 3,620
Unamortized Premium (Discount) and Debt Issuance Costs(52)(54)
Net, Long-term Debt3,568 3,566
Long-term Debt, Current Maturities(21)0
Debt Instrument Unamortized Discount Premium and Debt Issuance Cost Net Excluding Current Maturities(52)(54)
Long term Debt Gross Excluding Current Maturities3,599 3,620
Long-term debt, net $ 3,547 3,566
Line of Credit | 8.73% Senior Notes Due 2022
Debt Instrument [Line Items]
Stated interest rate (percent)8.73%
Senior Notes | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Principal Amount $ 250 250
Unamortized Premium (Discount) and Debt Issuance Costs0 (1)
Net, Long-term Debt $ 250 249
Stated interest rate (percent)3.60%
Senior Notes | 3.6% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Principal Amount $ 750 750
Unamortized Premium (Discount) and Debt Issuance Costs(6)(6)
Net, Long-term Debt $ 744 744
Stated interest rate (percent)3.60%
Senior Notes | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Debt Instrument [Line Items]
Principal Amount $ 11 11
Unamortized Premium (Discount) and Debt Issuance Costs0 0
Net, Long-term Debt11 11
Senior Notes | 1.625% Senior Notes Due 2029
Debt Instrument [Line Items]
Principal Amount821 859
Unamortized Premium (Discount) and Debt Issuance Costs(10)(10)
Net, Long-term Debt $ 811 849
Stated interest rate (percent)1.625%
Senior Notes | 3.375% Senior Notes Due 2030
Debt Instrument [Line Items]
Principal Amount $ 300 300
Unamortized Premium (Discount) and Debt Issuance Costs(4)(4)
Net, Long-term Debt $ 296 296
Stated interest rate (percent)3.375%
Senior Notes | 3.50% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Principal Amount $ 250 250
Unamortized Premium (Discount) and Debt Issuance Costs(1)(1)
Net, Long-term Debt $ 249 249
Stated interest rate (percent)3.50%
Senior Notes | 5.0% Senior Notes Due 2046 [Member]
Debt Instrument [Line Items]
Principal Amount $ 700 700
Unamortized Premium (Discount) and Debt Issuance Costs(22)(23)
Net, Long-term Debt $ 678 677
Stated interest rate (percent)5.00%
Senior Notes | 4.375% Senior Notes Due 2047 [Member]
Debt Instrument [Line Items]
Principal Amount $ 500 500
Unamortized Premium (Discount) and Debt Issuance Costs(9)(9)
Net, Long-term Debt $ 491 491
Stated interest rate (percent)4.375%
Senior Notes | 8.73% Senior Notes Due 2022
Debt Instrument [Line Items]
Principal Amount $ 34 0
Unamortized Premium (Discount) and Debt Issuance Costs0 0
Net, Long-term Debt34 0
Debt Instrument Unamortized Discount Premium and debt issuance cost net Current Maturities0 0
Long Term Debt Gross Current Maturities $ (21)0
Stated interest rate (percent)8.73%
Senior Notes | Term Loan Due Twenty Twenty Six
Debt Instrument [Line Items]
Principal Amount $ 4 0
Unamortized Premium (Discount) and Debt Issuance Costs0 0
Net, Long-term Debt $ 4 $ 0
Stated interest rate (percent)0.20%

Long-Term Debt (Credit Agreemen

Long-Term Debt (Credit Agreement) (Details) - Credit Agreement [Member] - USD ($) $ in MillionsJul. 24, 2018Mar. 31, 2021
Line of Credit | Minimum [Member]
Debt Instrument [Line Items]
Line of credit permitted increase $ 25
Line of Credit | Maximum [Member]
Debt Instrument [Line Items]
Line of credit permitted increase500
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Remaining borrowing capacity $ 1,000
Revolving Credit Facility [Member] | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity1,000
Line of Credit Facility, Fair Value of Amount Outstanding0
Outstanding letters of credit $ 0
Letter of Credit [Member] | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity150
Swingline Loan [Member] | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity $ 50
Alternate Base Rate [Domain] | Revolving Credit Facility [Member] | Line of Credit | Minimum [Member]
Debt Instrument [Line Items]
Spread on variable rate0.00%
Alternate Base Rate [Domain] | Revolving Credit Facility [Member] | Line of Credit | Maximum [Member]
Debt Instrument [Line Items]
Spread on variable rate0.75%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Line of Credit | Minimum [Member]
Debt Instrument [Line Items]
Spread on variable rate1.00%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Line of Credit | Maximum [Member]
Debt Instrument [Line Items]
Spread on variable rate1.75%

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions1 Months Ended
Mar. 31, 2021Dec. 31, 2020Jul. 31, 2000
Debt Instrument [Line Items]
Unamortized debt issuance cost $ 27 $ 28
RS Cogen
Debt Instrument [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent50.00%
Senior Notes | 8.73% Senior Notes Due 2022
Debt Instrument [Line Items]
Stated interest rate (percent)8.73%
Senior Notes | Term Loan Due Twenty Twenty Six
Debt Instrument [Line Items]
Maximum borrowing capacity $ 23
Stated interest rate (percent)0.20%
Debt instrument term5 years
Senior Notes | Term Loan Due Twenty Twenty Six | Taiwan Chlorine Industries, Ltd.
Debt Instrument [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent60.00%
Line of Credit | 8.73% Senior Notes Due 2022
Debt Instrument [Line Items]
Maximum borrowing capacity $ 75
Stated interest rate (percent)8.73%
Line of Credit | 8.73% Senior Notes Due 2022 | RS Cogen
Debt Instrument [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent50.00%

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance $ 6,043
Ending balance6,261
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance(24) $ 3
Net other Comprehensive Loss, attributable to Westlake Chemical Corporation0 0
Ending balance(24)3
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance(40)(77)
Net other Comprehensive Loss, attributable to Westlake Chemical Corporation(6)(32)
Ending balance(46)(109)
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance(64)(74)
Net other Comprehensive Loss, attributable to Westlake Chemical Corporation(6)(32)
Ending balance $ (70) $ (106)

Fair Value Measurements (Summar

Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 3,568 $ 3,566
3.60% Senior Notes Due 2022 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 250 249
Stated interest rate (percent)3.60%
3.6% Senior Notes Due 2026 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 744 744
Stated interest rate (percent)3.60%
Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 11 11
1.625% Senior Notes Due 2029 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 811 849
Stated interest rate (percent)1.625%
3.375% Senior Notes Due 2030 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 296 296
Stated interest rate (percent)3.375%
3.50% Senior Notes Due 2032 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 249 249
Stated interest rate (percent)3.50%
5.0% Senior Notes Due 2046 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 678 677
Stated interest rate (percent)5.00%
4.375% Senior Notes Due 2047 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 491 491
Stated interest rate (percent)4.375%
8.73% Senior Notes Due 2022 | Line of Credit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)8.73%
8.73% Senior Notes Due 2022 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 34 0
Stated interest rate (percent)8.73%
Term Loan Due Twenty Twenty Six | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 4 0
Stated interest rate (percent)0.20%
Fair Value [Member] | 3.60% Senior Notes Due 2022 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value $ 257 259
Fair Value [Member] | 3.6% Senior Notes Due 2026 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value809 846
Fair Value [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value11 11
Fair Value [Member] | 1.625% Senior Notes Due 2029 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value855 897
Fair Value [Member] | 3.375% Senior Notes Due 2030 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value312 332
Fair Value [Member] | 3.50% Senior Notes Due 2032 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value275 276
Fair Value [Member] | 5.0% Senior Notes Due 2046 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value827 905
Fair Value [Member] | 4.375% Senior Notes Due 2047 [Member] | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value544 597
Fair Value [Member] | 8.73% Senior Notes Due 2022 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value34 0
Fair Value [Member] | Term Loan Due Twenty Twenty Six | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value $ 4 $ 0

Income Taxes (Details)

Income Taxes (Details)3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate22.20%(35.30%)
U.S. federal statutory income tax rate21.00%21.00%

Earnings and Dividends per Sh_3

Earnings and Dividends per Share (Schedule of Net Income Attributable to Common Stockholders) (Details) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Earnings and Dividends Per Share [Abstract]
Net income attributable to Westlake Chemical Corporation $ 242 $ 145
Net income attributable to participating securities(1)0
Net income attributable to common shareholders $ 241 $ 145

Earnings and Dividends per Sh_4

Earnings and Dividends per Share (Reconciliation of Denominator for Basic and Diluted Earnings Per Share) (Details) - $ / shares3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Earnings and Dividends Per Share [Abstract]
Weighted average common shares—basic127,955,532 128,237,364
Weighted Average Number Diluted Shares Outstanding Adjustment527,841 205,608
Weighted average common shares-diluted128,483,373 128,442,972
Earnings per share attributable to Westlake Chemical Corporation: Basic (in dollars per share) $ 1.88 $ 1.13
Earnings per share attributable to Westlake Chemical Corporation: Diluted (in dollars per share) $ 1.87 $ 1.13

Earnings and Dividends per Sh_5

Earnings and Dividends per Share (Additional Information) (Details) - shares3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Earnings and Dividends Per Share [Abstract]
Number of options excluded from computation of diluted earnings per share575,727 1,099,638

Earnings and Dividends per Sh_6

Earnings and Dividends per Share Dividends Per Share (Details) - $ / shares3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Earnings and Dividends Per Share [Abstract]
Dividends per common share (in usd per share) $ 0.2700 $ 0.2625

Supplemental Information (Equit

Supplemental Information (Equity Method Investments) (Details) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Interest in Subsidiaries and Affiliates $ 7
LACC, LLC
Schedule of Equity Method Investments [Line Items]
Investments in and Advances to Affiliates, at Fair Value $ 958 $ 961

Supplemental Information (Addit

Supplemental Information (Additional Information) (Details) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020Dec. 31, 2020
Accrued Liabilities and Other Liabilities [Abstract]
Accrued and other liabilities $ 723 $ 821
Accrued rebates84 128
Accrued and other liabilities89 89
Accrued liabilities with related parties37 $ 61
Noncash Investing and Financing Items [Abstract]
Accruals for Capital Expenditure $ (32) $ (27)

Commitments and Contingencies_2

Commitments and Contingencies (Additional Information) (Detail) - USD ($) $ in MillionsMay 22, 2019Jun. 18, 2018May 31, 2017Mar. 31, 2021Dec. 31, 2020
Environmental Loss Contingencies [Line Items]
Environmental Loss contingency accrual $ 56 $ 53
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties [Line Items]100.00%
Avient [Member]
Environmental Loss Contingencies [Line Items]
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties [Line Items]100.00%
Avient [Member] | Pending Litigation [Member]
Environmental Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value $ 11
Minimum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss $ 65
Maximum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss130
Environmental Protection Agency [Member] | Operation and Maintenance [Member]
Environmental Loss Contingencies [Line Items]
Environmental Remediation Expense $ 107
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Minimum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Anticipated Cost1
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Maximum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Anticipated Cost $ 3

Segment Information (Additional

Segment Information (Additional Information) (Detail)3 Months Ended
Mar. 31, 2021Segment
Segment Reporting [Abstract]
Number of segments2

Segment Information (Segment Re

Segment Information (Segment Reporting Information) (Details) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Segment Reporting Information [Line Items]
Net sales $ 2,357 $ 1,932
Income (loss) from operations346 136
Depreciation and amortization195 190
Other income, net12 11
Provision for (benefit from) income taxes72 (41)
Capital expenditures141 164
Operating Segments [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales537 427
Income (loss) from operations180 62
Depreciation and amortization36 35
Other income, net0 1
Provision for (benefit from) income taxes41 41
Capital expenditures23 27
Operating Segments [Member] | Vinyls
Segment Reporting Information [Line Items]
Net sales1,820 1,505
Income (loss) from operations200 73
Depreciation and amortization157 153
Other income, net10 6
Provision for (benefit from) income taxes42 (78)
Capital expenditures118 136
Operating Segments [Member] | Polyethylene [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales414 310
Operating Segments [Member] | Styrene, Feedstock And Other [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales123 117
Operating Segments [Member] | PVC, Caustic Soda And Other [Member] | Vinyls
Segment Reporting Information [Line Items]
Net sales1,408 1,213
Operating Segments [Member] | Building Products [Member] | Vinyls
Segment Reporting Information [Line Items]
Net sales412 292
Corporate and other [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations(34)1
Depreciation and amortization2 2
Other income, net2 4
Provision for (benefit from) income taxes(11)(4)
Capital expenditures0 1
Intersegment sales [Member]
Segment Reporting Information [Line Items]
Net sales150 68
Intersegment sales [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales150 68
Intersegment sales [Member] | Vinyls
Segment Reporting Information [Line Items]
Net sales $ 0 $ 0

Segment Information (Reconcilia

Segment Information (Reconciliation of Total Segment Income from Operations to Consolidated Income before Income Taxes) (Details) - USD ($) $ in Millions3 Months Ended
Mar. 31, 2021Mar. 31, 2020
Segment Reporting [Abstract]
Income from operations $ 346 $ 136
Interest expense(33)(31)
Other income (expense), net12 11
Income before income taxes $ 325 $ 116

Segment Information (Total Asse

Segment Information (Total Assets) (Details) - USD ($) $ in MillionsMar. 31, 2021Dec. 31, 2020
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets $ 14,050 $ 13,835
Operating Segments [Member] | Olefins [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets1,987 1,923
Operating Segments [Member] | Vinyls
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets10,791 10,680
Corporate and other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets $ 1,272 $ 1,232

Westlake Chemical Partners LP_2

Westlake Chemical Partners LP (Details) - USD ($) $ in MillionsOct. 04, 2018Mar. 31, 2021Jun. 30, 2015
Related Party Transaction [Line Items]
Partners' Capital Account, Units, Sold in Public Offering12,937,500
Partners' Units, Maximum Aggregate Offering Amount, ATM $ 50
Westlake Chemical OpCo LP [Member] | Subsidiary of Common Parent [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest22.80%
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest77.20%
Westlake Chemical Partners LP [Member] | Subsidiary of Common Parent [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest40.10%
Ownership interest (in units)14,122,230