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WLK Westlake Chemical

Cover Page

Cover Page - shares6 Months Ended
Jun. 30, 2020Jul. 30, 2020
Document Information [Line Items]
Document Type10-Q
Document Quarterly Reporttrue
Document Period End DateJun. 30,
2020
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 Outstanding127,688,310
Amendment Flagfalse
Document Fiscal Year Focus2020
Document Fiscal Period FocusQ2
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 MillionsJun. 30, 2020Dec. 31, 2019
Current assets
Cash and cash equivalents $ 1,109 $ 728
Accounts receivable, net1,160 1,036
Inventories845 936
Prepaid expenses and other current assets51 42
Total current assets3,165 2,742
Property, plant and equipment, net6,887 6,912
Operating lease right-of-use assets462 443
Goodwill1,070 1,074
Customer relationships, net479 523
Other intangible assets, net174 187
Equity method investments1,052 1,112
Other assets, net266 268
Total assets13,555 13,261
Current liabilities
Accounts payable444 473
Accrued and other liabilities665 768
Total current liabilities1,109 1,241
Long-term debt, net3,745 3,445
Deferred income taxes1,354 1,255
Pension and other post-retirement benefits350 360
Operating lease liabilities372 355
Other liabilities188 202
Total liabilities7,118 6,858
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 June 30, 2020 and December 31, 2019, respectively1 1
Common stock, held in treasury, at cost; 6,963,331 and 6,266,609 shares at June 30, 2020 and December 31, 2019, respectively(411)(377)
Additional paid-in capital558 553
Retained earnings5,840 5,757
Accumulated other comprehensive loss(87)(74)
Total Westlake Chemical Corporation stockholders' equity5,901 5,860
Noncontrolling interests536 543
Total equity6,437 6,403
Total liabilities and equity $ 13,555 $ 13,261

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / sharesJun. 30, 2020Dec. 31, 2019
Preferred stock, par value, in dollars per share $ 0.01 $ 0.01
Preferred stock, shares authorized50,000,000 50,000,000
Preferred stock, shares issued0 0
Preferred stock, shares outstanding0 0
Common stock, par value, in dollars per share $ 0.01 $ 0.01
Common stock, shares authorized300,000,000 300,000,000
Common Stock [Member]
Common Stock, Shares, Issued134,651,380 134,651,380
Common Stock, Held in Treasury [Member]
Treasury Stock, Shares6,963,331 6,266,609

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Income Statement [Abstract]
Net sales $ 1,709 $ 2,144 $ 3,641 $ 4,169
Cost of sales1,540 1,804 3,189 3,530
Gross profit169 340 452 639
Selling, general and administrative expenses104 117 224 233
Amortization of intangibles27 27 54 54
Restructuring, transaction and integration-related costs2 2 2 24
Income from operations36 194 172 328
Other income (expense)
Interest expense(40)(28)(71)(58)
Other income, net9 2 20 11
Income before income taxes5 168 121 281
Provision for (benefit from) income taxes(19)39 (60)70
Net income24 129 181 211
Net income attributable to noncontrolling interests9 10 21 20
Net income attributable to Westlake Chemical Corporation $ 15 $ 119 $ 160 $ 191
Earnings per common share attributable to Westlake Chemical Corporation:
Basic (in dollars per share) $ 0.11 $ 0.92 $ 1.24 $ 1.48
Diluted (in dollars per share) $ 0.11 $ 0.92 $ 1.24 $ 1.47
Weighted average common shares outstanding:
Basic (in shares)127,680,478 128,485,182 127,958,921 128,506,712
Diluted (in shares)127,823,629 128,850,335 128,133,300 128,881,952

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income $ 24 $ 129 $ 181 $ 211
Foreign Currency Translation Adjustment, by Component [Abstract]
Foreign currency translation15 15 (10)13
Income tax provision on foreign currency translation5 (2)(2)(2)
Other comprehensive income (loss), net of income taxes20 13 (12)11
Comprehensive income44 142 169 222
Comprehensive income attributable to noncontrolling interests, net of tax of $0 and $0 for the three months ended June 30, 2020 and 2019; and net of tax of $1 and $1 for the six months ended June 30, 2020 and 2019, respectively10 9 22 19
Comprehensive income attributable to Westlake Chemical Corporation $ 34 $ 133 $ 147 $ 203

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) OCI Parenthetical - USD ($) $ in Millions3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
OCI Parenthetical [Abstract]
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest $ 0 $ 0 $ 1 $ 1

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, 2018 $ 6,076 $ 1 $ (382) $ 556 $ 5,477 $ (62) $ 486
Beginning balance, shares issued at Dec. 31, 2018134,651,380
Beginning balance, Treasury shares at Dec. 31, 20186,183,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Westlake Chemical Corporation72
Net income attributable to noncontrolling interests10
Net income82
Other comprehensive income(2)(2)0
Shares issued—stock- based compensation (in shares)(124,052)
Shares issued—stock-based compensation0 $ 11 (8)(3)
Stock-based compensation7 7
Dividends declared(33)(33)
Distributions to noncontrolling interests(8)(8)
Issuance of Westlake Chemical Partners LP common units63 (2)65
Ending balances at Mar. 31, 20196,185 $ 1 $ (371)553 5,513 (64)553
Ending balance, shares issued at Mar. 31, 2019134,651,380
Ending balance, Treasury shares at Mar. 31, 20196,059,073
Beginning balances at Dec. 31, 20186,076 $ 1 $ (382)556 5,477 (62)486
Beginning balance, shares issued at Dec. 31, 2018134,651,380
Beginning balance, Treasury shares at Dec. 31, 20186,183,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Westlake Chemical Corporation191
Net income attributable to noncontrolling interests20
Net income211
Other comprehensive income11
Ending balances at Jun. 30, 20196,259 $ 1 $ (390)558 5,600 (50)540
Ending balance, shares issued at Jun. 30, 2019134,651,380
Ending balance, Treasury shares at Jun. 30, 20196,382,640
Beginning balances at Mar. 31, 20196,185 $ 1 $ (371)553 5,513 (64)553
Beginning balance, shares issued at Mar. 31, 2019134,651,380
Beginning balance, Treasury shares at Mar. 31, 20196,059,073
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Westlake Chemical Corporation119 119
Net income attributable to noncontrolling interests10 10
Net income129
Other comprehensive income13 14 (1)
Common stock repurchased, shares342,740
Common stock repurchased(20) $ (20)
Shares issued—stock- based compensation (in shares)(19,173)
Shares issued—stock-based compensation0 $ 1 (1)0
Stock-based compensation6 6
Dividends declared(32)(32)
Distributions to noncontrolling interests(22)(22)
Ending balances at Jun. 30, 20196,259 $ 1 $ (390)558 5,600 (50)540
Ending balance, shares issued at Jun. 30, 2019134,651,380
Ending balance, Treasury shares at Jun. 30, 20196,382,640
Beginning balances at Dec. 31, 20196,403 $ 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
Net income attributable to noncontrolling interests12
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, 20196,403 $ 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 Corporation160
Net income attributable to noncontrolling interests21
Net income181
Other comprehensive income(12)
Ending balances at Jun. 30, 20206,437 $ 1 $ (411)558 5,840 (87)536
Ending balance, shares issued at Jun. 30, 2020134,651,380
Ending balance, Treasury shares at Jun. 30, 20206,963,331
Beginning balances at Mar. 31, 20206,438 $ 1 $ (413)551 5,860 (106)545
Beginning balance, shares issued at Mar. 31, 2020134,651,380
Beginning balance, Treasury shares at Mar. 31, 20206,979,662
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Westlake Chemical Corporation15 15
Net income attributable to noncontrolling interests9 9
Net income24
Other comprehensive income20 19 1
Shares issued—stock- based compensation (in shares)(16,331)
Shares issued—stock-based compensation0 $ 2 (1)(1)
Stock-based compensation8 8
Dividends declared(34)(34)
Distributions to noncontrolling interests(19)(19)
Ending balances at Jun. 30, 2020 $ 6,437 $ 1 $ (411) $ 558 $ 5,840 $ (87) $ 536
Ending balance, shares issued at Jun. 30, 2020134,651,380
Ending balance, Treasury shares at Jun. 30, 20206,963,331

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions6 Months Ended
Jun. 30, 2020Jun. 30, 2019
Cash flows from operating activities
Net income $ 181 $ 211
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization381 347
Stock-based compensation expense14 13
Loss from disposition and write-off of property, plant and equipment9 27
Deferred income taxes96 15
Other losses, net3 16
Changes in operating assets and liabilities, net of effect of business acquisitions
Accounts receivable(128)(119)
Inventories87 125
Prepaid expenses and other current assets(16)(8)
Accounts payable8 (40)
Accrued and other liabilities(75)(62)
Other, net(51)(58)
Net cash provided by operating activities509 467
Cash flows from investing activities
Acquisition of businesses, net of cash acquired0 (314)
Additions to property, plant and equipment(291)(411)
Additions to investments in unconsolidated subsidiaries0 (42)
Return of investment from an equity investee39 0
Other, net(8)4
Net cash used for investing activities(260)(763)
Cash flows from financing activities
Dividends paid(68)(65)
Distributions to noncontrolling interests(29)(30)
Net proceeds from issuance of Westlake Chemical Partners LP common units0 63
Net proceeds from debt issuance and drawdown of revolver1,299 0
Proceeds from (repayment of) short-term notes payable(14)4
Repayment of revolver(1,000)0
Repurchase of common stock for treasury(54)(20)
Other(3)0
Net cash provided by (used for) financing activities131 (48)
Effect of exchange rate changes on cash, cash equivalents and restricted cash0 0
Net increase (decrease) in cash, cash equivalents and restricted cash380 (344)
Cash, cash equivalents and restricted cash at beginning of period750 775
Cash, cash equivalents and restricted cash at end of period $ 1,130 $ 431

Basis of Financial Statements (

Basis of Financial Statements (Notes)6 Months Ended
Jun. 30, 2020
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, 2019 (the " 2019 Form 10-K"), filed with the SEC on February 19, 2020 . 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, 2019 with the exception of those accounting standards adopted in 2020 as discussed in Note 1. 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 June 30, 2020 , its results of operations for the three and six months ended June 30, 2020 and 2019 , and the changes in its cash position for the six months ended June 30, 2020 and 2019 . 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, 2020 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. Events surrounding the ongoing coronavirus ("COVID-19") pandemic resulted in widespread adverse impacts on the global economy. The Company experienced significant disruptions in the second quarter of 2020 as the pandemic and its impact on the global economy spread through most of its markets. The Company expected lower demand for certain of its products, which led the Company to proactively temporarily idle production at several of its smaller non-integrated plants and reduce operating rates at others in the beginning of the second quarter of 2020. Since the middle of the second quarter of 2020, a general ease in government restrictions in many jurisdictions across the world has resulted in a gradual increase in demand for the Company's products. As a result, all of the Company's idled plants have now recommenced production. Additionally, plant operating rates have generally improved over the course of the second quarter of 2020. As the pandemic and its impacts on the global economy continue, the Company expects to experience further near-term impacts on its business operations. However, the effect 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 ultimate duration, geographic spread and severity of the virus, the actions to contain the virus, the consequences of governmental and other measures designed to prevent the spread of the virus, the development of effective treatments, actions taken by customers, suppliers and other third parties, workforce availability, and the timing and extent to which normal economic and operating conditions resume. Recent Accounting Pronouncements 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 will be effective for reporting periods beginning after December 15, 2020. Early adoption of this guidance is permitted. The Company is in the process of evaluating the impact that the new accounting guidance will have on the Company's consolidated financial position, results of operations and cash flows. 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 as of March 12, 2020 through December 31, 2022. The Company is in the process of evaluating the impact that the new accounting guidance will have on the Company's consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Credit Losses (ASU No. 2016-13) In June 2016, the FASB issued an accounting standards update providing new guidance for the accounting for credit losses on loans and other financial instruments. The new guidance introduces an approach based on expected losses to estimate credit losses on trade receivables, debt securities and certain types of financial instruments. The standard also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. In November 2019, the FASB issued an additional authoritative guidance related to credit losses. The accounting standard became effective for reporting periods beginning after December 15, 2019. The Company adopted this accounting standard effective January 1, 2020 and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. Intangibles - Goodwill and Other (ASU No. 2017-04) In January 2017, the FASB issued an accounting standards update to simplify the subsequent measurement of goodwill. The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The accounting standard became effective for reporting periods beginning after December 15, 2019. The Company adopted this accounting standard effective January 1, 2020 and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. Fair Value Measurement (ASU No. 2018-13) In August 2018, the FASB issued an accounting standards update to modify the disclosure requirements on fair value measurements. An entity is permitted to early adopt any removed or modified disclosures and delay adoption of the additional disclosures until the effective date. Most amendments should be applied retrospectively, but certain amendments will be applied prospectively. The accounting standard became effective for reporting periods beginning after December 15, 2019. The Company adopted this accounting standard effective January 1, 2020 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)6 Months Ended
Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Financial InstrumentsFinancial Instruments Cash Equivalents The Company had $0 and $240 of held-to-maturity securities with original maturities of three months or less, primarily consisting of corporate debt securities, classified as cash equivalents at June 30, 2020 and December 31, 2019 , respectively. 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 $21 and $22 at June 30, 2020 and December 31, 2019 , respectively. The Company's restricted cash and cash equivalents are 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 (Notes)

Accounts Receivable (Notes)6 Months Ended
Jun. 30, 2020
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts ReceivableAccounts Receivable Accounts receivable consist of the following: June 30, December 31, Trade customers $ 926 $ 948 Related parties 5 12 Allowance for credit losses (15 ) (22 ) 916 938 Federal and state taxes 211 59 Other 33 39 Accounts receivable, net $ 1,160 $ 1,036

Inventories (Notes)

Inventories (Notes)6 Months Ended
Jun. 30, 2020
Inventory Disclosure [Abstract]
InventoriesInventories Inventories consist of the following: June 30, December 31, Finished products $ 469 $ 568 Feedstock, additives, chemicals and other raw materials 212 210 Materials and supplies 164 158 Inventories $ 845 $ 936

Goodwill (Notes)

Goodwill (Notes)6 Months Ended
Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
GoodwillGoodwill The gross carrying amounts and changes in the carrying amount of goodwill for the six months ended June 30, 2020 were as follows: Olefins Segment Vinyls Segment Total Balances at December 31, 2019 $ 30 $ 1,044 $ 1,074 Effects of changes in foreign exchange rates — (4 ) (4 ) Balances at June 30, 2020 $ 30 $ 1,040 $ 1,070 The Company performed its annual impairment assessment for the Vinyls reporting units during the second quarter of 2020 and did not identify any impairment. The fair value of the Vinyls reporting units was calculated using both a discounted cash flow methodology and a market value methodology. The discounted cash flow projections were based on a long-term forecast. The forecast was based on prices and spreads projected by third party industry publications, historical results and estimates by management, including its strategic and operational plans. Significant assumptions used in the discounted cash flow projection included projected sales volumes based on production capacities. The future cash flows were discounted to present value using a discount rate. Significant assumptions used in determining the fair value of the reporting unit using the market value methodology included the determination of 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. The Company performs its annual impairment assessment for the Olefins reporting unit in the fourth quarter or when events or circumstances indicate a reporting unit's carrying value may not be recoverable. There were no events or circumstances indicating that the fair value of the Olefins reporting unit had been reduced below its carrying value during the second quarter of 2020. During the six months ended June 30, 2020 , the Company evaluated various events resulting from the COVID-19 pandemic. Based on the evaluation, the Company does not believe that these events indicate that the fair values of the Company's reporting units have more likely than not fallen below their carrying values as of June 30, 2020 . As events and changes in circumstances evolve after June 30, 2020 , such events will be considered in the Company's estimates for future periods.

Accounts Payable (Notes)

Accounts Payable (Notes)6 Months Ended
Jun. 30, 2020
Accounts Payable [Abstract]
Accounts and Notes PayableAccounts Payable Accounts payable consist of the following: June 30, December 31, Accounts payable—third parties $ 427 $ 435 Accounts payable to related parties 14 12 Notes payable 3 26 Accounts payable $ 444 $ 473

Long-Term Debt (Notes)

Long-Term Debt (Notes)6 Months Ended
Jun. 30, 2020
Debt Disclosure [Abstract]
Long-Term DebtLong-Term Debt Long-term debt consists of the following: June 30, 2020 December 31, 2019 Principal Unamortized Discount Net Principal Unamortized Net 3.60% senior notes due 2022 (the "3.60% 2022 Senior Notes") $ 250 $ (1 ) $ 249 $ 250 $ (1 ) $ 249 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750 (7 ) 743 750 (8 ) 742 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") 786 (10 ) 776 785 (11 ) 774 6 ½% senior notes due 2029 (the "6 ½% 2029 GO Zone Senior Notes") (1) 100 — 100 100 (1 ) 99 3.375% senior notes due 2030 (the "3.375% 2030 Senior Notes") 300 (4 ) 296 — — — 3.50% senior notes due 2032 (the "3.50% 2032 GO Zone Refunding Senior Notes") 250 (1 ) 249 250 (1 ) 249 6 ½% senior notes due 2035 (the "6 ½% 2035 GO Zone Senior Notes") 89 (1 ) 88 89 (1 ) 88 6 ½% senior notes due 2035 (the "6 ½% 2035 IKE Zone Senior Notes") 65 — 65 65 — 65 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700 (23 ) 677 700 (23 ) 677 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 (9 ) 491 500 (9 ) 491 Total Long-term debt $ 3,801 $ (56 ) $ 3,745 $ 3,500 $ (55 ) $ 3,445 _____________ (1) See the discussion below regarding the purchase of the 2029 GO Zone Bonds in lieu of optional redemption on August 1, 2020. Credit Agreement The Company has a $1,000 revolving credit facility that is scheduled to mature on July 24, 2023 (the "Credit Agreement"). On March 20, 2020, out of an abundance of caution, the Company borrowed $1,000 under 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. On June 4, 2020, the Company fully repaid the $1,000 of borrowings under the Credit Agreement and, as a result, had no borrowings outstanding under its revolving credit facility as of June 30, 2020 . As of June 30, 2020 , 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 June 30, 2020 , 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. 3.375% Senior Notes due 2030 On June 12, 2020 , the Company completed the registered public offering of $300 aggregate principal amount of its 3.375% Senior Notes due June 15, 2030 (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 indenture and supplemental indenture governing the 3.375% 2030 Senior Notes contain customary events of default and covenants that restrict the Company and certain of its subsidiaries' ability to (1) incur certain secured indebtedness, (2) engage in certain sale-leaseback transactions and (3) consolidate, merge or transfer all or substantially all of its assets. The Company may optionally redeem the 3.375% 2030 Senior Notes in accordance with the terms of the 3.375% 2030 Senior Notes. 6 ½% Senior Notes due 2029 During June 2020, the Company directed the Louisiana Local Government Environmental Facilities and Community Development Authority (the "Authority") to optionally redeem in full $100 aggregate principal amount of the Authority's outstanding Revenue Bonds (Westlake Chemical Corporation Projects) Series 2009A due August 1, 2029 (the "2029 GO Zone Bonds") on August 1, 2020 at a redemption price equal to 100% of the principal amount of the 2029 GO Zone Bonds plus accrued and unpaid interest to the redemption date. The 2029 GO Zone Bonds were offered by the Authority in July 2010 under the Gulf Opportunity Zone Act of 2005 for the benefit of the Company and bore interest at a rate of 6.50% per annum. In connection with the offering of the 2029 GO Zone Bonds in July 2010, the Company issued $100 aggregate principal amount of its 6 ½% senior notes due 2029 (the "6 ½% 2029 GO Zone Senior Notes") to evidence and secure the Company's obligations under the Amended and Restated Loan Agreement relating to the 2029 GO Zone Bonds. On August 1, 2020, the Company purchased the 2029 GO Zone Bonds in lieu of optional redemption. In connection with the purchase of the 2029 GO Zone Bonds by the Company in lieu of optional redemption, the Authority is required to cause the 2029 GO Zone Bonds trustee to surrender the 6 ½% 2029 GO Zone Senior Notes to the Senior Notes trustee for cancellation. A portion of the net proceeds from the issuance of the 3.375% 2030 Senior Notes was used to fund the purchase in lieu of optional redemption of the 2029 GO Zone Bonds. As of June 30, 2020 , the Company was in compliance with all of its long-term debt covenants. Unamortized debt issuance costs on long-term debt were $31 and $30 at June 30, 2020 and December 31, 2019 , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss) (Notes)6 Months Ended
Jun. 30, 2020
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) by component for the six months ended June 30, 2020 and 2019 were as follows: Pension and Other Post-Retirement Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Total Balances at December 31, 2019 $ 3 $ (77 ) $ (74 ) Other comprehensive loss before reclassifications — (13 ) (13 ) Net other comprehensive loss attributable to Westlake Chemical Corporation — (13 ) (13 ) Balances at June 30, 2020 $ 3 $ (90 ) $ (87 ) Balances at December 31, 2018 $ 27 $ (89 ) $ (62 ) Other comprehensive income before reclassifications — 12 12 Net other comprehensive income attributable to Westlake Chemical Corporation — 12 12 Balances at June 30, 2019 $ 27 $ (77 ) $ (50 )

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)6 Months Ended
Jun. 30, 2020
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 Company's long-term debt instruments, except for the revolving credit facility, 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. June 30, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value 3.60% 2022 Senior Notes $ 249 $ 258 $ 249 $ 255 3.60% 2026 Senior Notes 743 796 742 777 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 11 11 1.625% 2029 Senior Notes 776 755 774 785 6 ½% 2029 GO Zone Senior Notes 100 100 99 103 3.375% 2030 Senior Notes 296 306 — — 3.50% 2032 GO Zone Refunding Senior Notes 249 249 249 267 6 ½% 2035 GO Zone Senior Notes 88 90 88 92 6 ½% 2035 IKE Zone Senior Notes 65 66 65 68 5.0% 2046 Senior Notes 677 745 677 761 4.375% 2047 Senior Notes 491 500 491 505

Income Taxes (Notes)

Income Taxes (Notes)6 Months Ended
Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income TaxesIncome Taxes The effective income tax rate was a benefit of 380.0% for the three months ended June 30, 2020 as compared to an expense of 23.2% for the three months ended June 30, 2019 . The effective income tax rate for the three months ended June 30, 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 additional 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 (the "CARES Act"), partially offset by the reduction in the Internal Revenue Code Section 199 ("Section 199") domestic manufacturing deduction, as a result of the NOL carryback, the depletion deduction, the foreign earnings rate differential and the state income tax benefit. The effective income tax rate for the three months ended June 30, 2019 was above the statutory rate of 21.0% primarily due to state taxes. The effective income tax rate was a benefit of 49.6% for the six months ended June 30, 2020 as compared to an expense of 24.9% for the six months ended June 30, 2019 . The effective income tax rate for the six months ended June 30, 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 NOL to taxable years that were taxed at the U.S. corporate tax rate of 35.0% as permitted under the CARES Act, partially offset by the reduction in the Section 199 domestic manufacturing deduction as a result of the NOL carryback, the depletion deduction, the foreign earnings rate differential and the state income tax benefit. The effective income tax rate for the six months ended June 30, 2019 was above the statutory rate of 21.0% primarily due to state taxes and the tax effect related to charges associated with the write-off of certain assets. On March 27, 2020, the CARES Act was enacted and signed into law. The CARES Act, among other things, permits any federal NOL generated in 2018, 2019 and 2020 to be carried back to each of the five tax years preceding the tax year of the federal NOL to fully offset taxable income to generate a refund of previously paid income taxes. However, any such federal NOL not carried back can be carried forward to fully offset taxable income, but only for the taxable years beginning before January 1, 2021, after which, the federal NOL deduction limitation not to exceed 80.0% of taxable income under the U.S. Tax Cuts and Jobs Act (the "Tax Act") will be reinstated. Federal NOLs generated in 2018, 2019 and 2020 measured at the current U.S. corporate tax rate of 21.0% that are carried back to taxable years prior to the Tax Act to fully offset taxable income taxed at the U.S. corporate tax rate of 35.0% result in an income tax rate benefit. At the end of 2019, the Company generated a federal NOL primarily due to bonus tax depreciation from the Company's investment in LACC, LLC ("LACC"), which is accounted for as an equity method investment. This federal NOL was increased to account for the disallowed interest deduction which originated in 2019 that is no longer disallowed due to the increase in the business interest expense deduction limitation from 30.0% to 50.0% of adjusted taxable income for tax years 2019 and 2020 as permitted under the CARES Act. For the three and six months ended June 30, 2020 , the carryback of the federal NOL resulted in a net tax benefit of $6 and $68

Earnings and Dividends per Shar

Earnings and Dividends per Share (Notes)6 Months Ended
Jun. 30, 2020
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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Net income attributable to Westlake Chemical Corporation $ 15 $ 119 $ 160 $ 191 Less: Net income attributable to participating securities (1 ) (1 ) (1 ) (1 ) Net income attributable to common shareholders $ 14 $ 118 $ 159 $ 190 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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Weighted average common shares—basic 127,680,478 128,485,182 127,958,921 128,506,712 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 143,151 365,153 174,379 375,240 Weighted average common shares—diluted 127,823,629 128,850,335 128,133,300 128,881,952 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 0.11 $ 0.92 $ 1.24 $ 1.48 Diluted $ 0.11 $ 0.92 $ 1.24 $ 1.47 Excluded from the computation of diluted earnings per share are options to purchase 1,303,372 and 562,342 shares of common stock for the three months ended June 30, 2020 and 2019 , respectively; and 1,201,505 and 442,076 shares of common stock for the six months ended June 30, 2020 and 2019 , 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 and six months ended June 30, 2020 and 2019 were as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Dividends per common share $ 0.2625 $ 0.2500 $ 0.5250 $ 0.5000

Supplemental Information (Notes

Supplemental Information (Notes)6 Months Ended
Jun. 30, 2020
Supplemental Cash Flow Information [Abstract]
Supplemental InformationSupplemental Information Equity Method Investments The Company's investment in LACC, a related party, was $981 and $1,038 at June 30, 2020 and December 31, 2019 , respectively. During the six months ended June 30, 2020 , the Company received $39 from LACC representing return of investment. Accrued and Other Liabilities Accrued and other liabilities were $665 and $768 at June 30, 2020 and December 31, 2019 , respectively. Accrued rebates and operating lease liability, which are components of accrued and other liabilities, were $87 and $94 at June 30, 2020 , respectively; and $115 and $93 at December 31, 2019 , respectively. No other component of accrued and other liabilities was more than five percent of total current liabilities. Accrued liabilities with related parties were $33 and $41 at June 30, 2020 and December 31, 2019 , respectively. Non-cash Investing Activity The non-cash investing activities related to accruals for capital expenditures were $29 and $9 , for t he six months ended June 30, 2020

Commitments and Contingencies (

Commitments and Contingencies (Notes)6 Months Ended
Jun. 30, 2020
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, so those cases will proceed with discovery. 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 June 30, 2020 and December 31, 2019 , the Company had reserves for environmental contingencies totaling approximately $46 and $47 , 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, PolyOne Corporation ("PolyOne"). 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 new 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. The PRPs signed a consent decree for remedial action in March 2020, which is subject to approval by the EPA and the Department of Justice before it is filed with the court. 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 PolyOne. These agreements and 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 PolyOne, and that predecessor assumed Goodrich's indemnification obligations relating to preexisting contamination. In 2003, litigation arose among the Company, Goodrich and PolyOne 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) PolyOne 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 PolyOne 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, PolyOne filed a demand for arbitration. In this proceeding, PolyOne 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 PolyOne paid such costs in full at the beginning of the arbitration hearing. On July 10, 2018, PolyOne 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 PolyOne's suit. On February 13, 2019, PolyOne 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 PolyOne was responsible for 100% of the allocable costs at issue in the proceeding and that PolyOne would remain responsible for 100% of the costs to operate the existing groundwater remedy at the Calvert City site. In August 2019, PolyOne 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 PolyOne's motion to vacate and affirmed the arbitration final award. PolyOne 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 $70 to $130 .

Segment Information (Notes)

Segment Information (Notes)6 Months Ended
Jun. 30, 2020
Segment Reporting [Abstract]
Segment InformationSegment Information The Company operates in two principal operating segments: Olefins and Vinyls. 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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Net external sales Olefins Polyethylene $ 302 $ 345 $ 612 $ 682 Styrene, feedstock and other 59 132 176 254 Total Olefins 361 477 788 936 Vinyls PVC, caustic soda and other 1,004 1,319 2,217 2,626 Building products 344 348 636 607 Total Vinyls 1,348 1,667 2,853 3,233 $ 1,709 $ 2,144 $ 3,641 $ 4,169 Intersegment sales Olefins $ 36 $ 74 $ 104 $ 166 Vinyls 1 1 1 1 $ 37 $ 75 $ 105 $ 167 Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Income (loss) from operations Olefins $ 25 $ 82 $ 87 $ 119 Vinyls 20 129 93 230 Corporate and other (9 ) (17 ) (8 ) (21 ) $ 36 $ 194 $ 172 $ 328 Depreciation and amortization Olefins $ 35 $ 36 $ 70 $ 71 Vinyls 154 138 307 272 Corporate and other 2 2 4 4 $ 191 $ 176 $ 381 $ 347 Other income (loss), net Olefins $ — $ 1 $ 1 $ 3 Vinyls 8 2 14 6 Corporate and other 1 (1 ) 5 2 $ 9 $ 2 $ 20 $ 11 Provision for (benefit from) income taxes Olefins $ (4 ) $ 18 $ 37 $ 27 Vinyls (18 ) 22 (96 ) 45 Corporate and other 3 (1 ) (1 ) (2 ) $ (19 ) $ 39 $ (60 ) $ 70 Capital expenditures Olefins $ 17 $ 37 $ 44 $ 62 Vinyls 108 169 244 346 Corporate and other 2 2 3 3 $ 127 $ 208 $ 291 $ 411 A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Income from operations $ 36 $ 194 $ 172 $ 328 Interest expense (40 ) (28 ) (71 ) (58 ) Other income, net 9 2 20 11 Income before income taxes $ 5 $ 168 $ 121 $ 281 June 30, December 31, Total assets Olefins $ 1,916 $ 1,991 Vinyls 10,384 10,597 Corporate and other 1,255 673 $ 13,555 $ 13,261

Westlake Chemical Partners LP (

Westlake Chemical Partners LP (Notes)6 Months Ended
Jun. 30, 2020
Partners' Capital [Abstract]
Westlake Chemical Partners LPWestlake Chemical Partners LP In 2014, the Company formed Westlake Chemical Partners LP ("WLKP") to operate, acquire and develop ethylene production facilities and related assets. Also in 2014, WLKP completed its initial public offering of 12,937,500 common units. At June 30, 2020 , WLKP 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 WLKP through the Company's ownership of WLKP's general partner, 40.1% of the limited partner interests (consisting of 14,122,230 common units) and incentive distribution rights. On October 4, 2018, WLKP and Westlake Partners GP, the general partner of WLKP, 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 WLKP's 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 June 30, 2020 .

Basis of Financial Statements_2

Basis of Financial Statements (Policies)6 Months Ended
Jun. 30, 2020
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, 2019 (the " 2019 Form 10-K"), filed with the SEC on February 19, 2020 . 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, 2019 with the exception of those accounting standards adopted in 2020 as discussed in Note 1. 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 June 30, 2020 , its results of operations for the three and six months ended June 30, 2020 and 2019 , and the changes in its cash position for the six months ended June 30, 2020 and 2019 . 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, 2020 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.
Recent Accounting PronouncementsRecent Accounting Pronouncements 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 will be effective for reporting periods beginning after December 15, 2020. Early adoption of this guidance is permitted. The Company is in the process of evaluating the impact that the new accounting guidance will have on the Company's consolidated financial position, results of operations and cash flows. 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 as of March 12, 2020 through December 31, 2022. The Company is in the process of evaluating the impact that the new accounting guidance will have on the Company's consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Credit Losses (ASU No. 2016-13) In June 2016, the FASB issued an accounting standards update providing new guidance for the accounting for credit losses on loans and other financial instruments. The new guidance introduces an approach based on expected losses to estimate credit losses on trade receivables, debt securities and certain types of financial instruments. The standard also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. In November 2019, the FASB issued an additional authoritative guidance related to credit losses. The accounting standard became effective for reporting periods beginning after December 15, 2019. The Company adopted this accounting standard effective January 1, 2020 and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. Intangibles - Goodwill and Other (ASU No. 2017-04) In January 2017, the FASB issued an accounting standards update to simplify the subsequent measurement of goodwill. The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The accounting standard became effective for reporting periods beginning after December 15, 2019. The Company adopted this accounting standard effective January 1, 2020 and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. Fair Value Measurement (ASU No. 2018-13) In August 2018, the FASB issued an accounting standards update to modify the disclosure requirements on fair value measurements. An entity is permitted to early adopt any removed or modified disclosures and delay adoption of the additional disclosures until the effective date. Most amendments should be applied retrospectively, but certain amendments will be applied prospectively. The accounting standard became effective for reporting periods beginning after December 15, 2019. The Company adopted this accounting standard effective January 1, 2020 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)6 Months Ended
Jun. 30, 2020
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Schedule Of Accounts ReceivableAccounts receivable consist of the following: June 30, December 31, Trade customers $ 926 $ 948 Related parties 5 12 Allowance for credit losses (15 ) (22 ) 916 938 Federal and state taxes 211 59 Other 33 39 Accounts receivable, net $ 1,160 $ 1,036

Inventories (Tables)

Inventories (Tables)6 Months Ended
Jun. 30, 2020
Inventory Disclosure [Abstract]
Schedule Of InventoryInventories consist of the following: June 30, December 31, Finished products $ 469 $ 568 Feedstock, additives, chemicals and other raw materials 212 210 Materials and supplies 164 158 Inventories $ 845 $ 936

Goodwill (Tables)

Goodwill (Tables)6 Months Ended
Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of GoodwillThe gross carrying amounts and changes in the carrying amount of goodwill for the six months ended June 30, 2020 were as follows: Olefins Segment Vinyls Segment Total Balances at December 31, 2019 $ 30 $ 1,044 $ 1,074 Effects of changes in foreign exchange rates — (4 ) (4 ) Balances at June 30, 2020 $ 30 $ 1,040 $ 1,070

Accounts Payable (Tables)

Accounts Payable (Tables)6 Months Ended
Jun. 30, 2020
Accounts Payable [Abstract]
Schedule of Accounts Payable and Accrued LiabilitiesAccounts payable consist of the following: June 30, December 31, Accounts payable—third parties $ 427 $ 435 Accounts payable to related parties 14 12 Notes payable 3 26 Accounts payable $ 444 $ 473

Long-Term Debt (Tables)

Long-Term Debt (Tables)6 Months Ended
Jun. 30, 2020
Debt Disclosure [Abstract]
Schedule Of Long-Term DebtLong-term debt consists of the following: June 30, 2020 December 31, 2019 Principal Unamortized Discount Net Principal Unamortized Net 3.60% senior notes due 2022 (the "3.60% 2022 Senior Notes") $ 250 $ (1 ) $ 249 $ 250 $ (1 ) $ 249 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750 (7 ) 743 750 (8 ) 742 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") 786 (10 ) 776 785 (11 ) 774 6 ½% senior notes due 2029 (the "6 ½% 2029 GO Zone Senior Notes") (1) 100 — 100 100 (1 ) 99 3.375% senior notes due 2030 (the "3.375% 2030 Senior Notes") 300 (4 ) 296 — — — 3.50% senior notes due 2032 (the "3.50% 2032 GO Zone Refunding Senior Notes") 250 (1 ) 249 250 (1 ) 249 6 ½% senior notes due 2035 (the "6 ½% 2035 GO Zone Senior Notes") 89 (1 ) 88 89 (1 ) 88 6 ½% senior notes due 2035 (the "6 ½% 2035 IKE Zone Senior Notes") 65 — 65 65 — 65 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700 (23 ) 677 700 (23 ) 677 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 (9 ) 491 500 (9 ) 491 Total Long-term debt $ 3,801 $ (56 ) $ 3,745 $ 3,500 $ (55 ) $ 3,445 _____________ (1) See the discussion below regarding the purchase of the 2029 GO Zone Bonds in lieu of optional redemption on August 1, 2020.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)6 Months Ended
Jun. 30, 2020
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)Changes in accumulated other comprehensive income (loss) by component for the six months ended June 30, 2020 and 2019 were as follows: Pension and Other Post-Retirement Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Total Balances at December 31, 2019 $ 3 $ (77 ) $ (74 ) Other comprehensive loss before reclassifications — (13 ) (13 ) Net other comprehensive loss attributable to Westlake Chemical Corporation — (13 ) (13 ) Balances at June 30, 2020 $ 3 $ (90 ) $ (87 ) Balances at December 31, 2018 $ 27 $ (89 ) $ (62 ) Other comprehensive income before reclassifications — 12 12 Net other comprehensive income attributable to Westlake Chemical Corporation — 12 12 Balances at June 30, 2019 $ 27 $ (77 ) $ (50 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)6 Months Ended
Jun. 30, 2020
Fair Value Disclosures [Abstract]
Summary Of Carrying And Fair Values Of Long-Term DebtThe Company's long-term debt instruments, except for the revolving credit facility, 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. June 30, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value 3.60% 2022 Senior Notes $ 249 $ 258 $ 249 $ 255 3.60% 2026 Senior Notes 743 796 742 777 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 11 11 1.625% 2029 Senior Notes 776 755 774 785 6 ½% 2029 GO Zone Senior Notes 100 100 99 103 3.375% 2030 Senior Notes 296 306 — — 3.50% 2032 GO Zone Refunding Senior Notes 249 249 249 267 6 ½% 2035 GO Zone Senior Notes 88 90 88 92 6 ½% 2035 IKE Zone Senior Notes 65 66 65 68 5.0% 2046 Senior Notes 677 745 677 761 4.375% 2047 Senior Notes 491 500 491 505

Earnings and Dividends per Sh_2

Earnings and Dividends per Share (Tables)6 Months Ended
Jun. 30, 2020
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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Net income attributable to Westlake Chemical Corporation $ 15 $ 119 $ 160 $ 191 Less: Net income attributable to participating securities (1 ) (1 ) (1 ) (1 ) Net income attributable to common shareholders $ 14 $ 118 $ 159 $ 190
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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Weighted average common shares—basic 127,680,478 128,485,182 127,958,921 128,506,712 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 143,151 365,153 174,379 375,240 Weighted average common shares—diluted 127,823,629 128,850,335 128,133,300 128,881,952 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 0.11 $ 0.92 $ 1.24 $ 1.48 Diluted $ 0.11 $ 0.92 $ 1.24 $ 1.47
Dividends Per ShareDividends per Share Dividends per common share for the three and six months ended June 30, 2020 and 2019 were as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Dividends per common share $ 0.2625 $ 0.2500 $ 0.5250 $ 0.5000

Segment Information (Tables)

Segment Information (Tables)6 Months Ended
Jun. 30, 2020
Segment Reporting [Abstract]
Segment Reporting Information Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Net external sales Olefins Polyethylene $ 302 $ 345 $ 612 $ 682 Styrene, feedstock and other 59 132 176 254 Total Olefins 361 477 788 936 Vinyls PVC, caustic soda and other 1,004 1,319 2,217 2,626 Building products 344 348 636 607 Total Vinyls 1,348 1,667 2,853 3,233 $ 1,709 $ 2,144 $ 3,641 $ 4,169 Intersegment sales Olefins $ 36 $ 74 $ 104 $ 166 Vinyls 1 1 1 1 $ 37 $ 75 $ 105 $ 167 Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Income (loss) from operations Olefins $ 25 $ 82 $ 87 $ 119 Vinyls 20 129 93 230 Corporate and other (9 ) (17 ) (8 ) (21 ) $ 36 $ 194 $ 172 $ 328 Depreciation and amortization Olefins $ 35 $ 36 $ 70 $ 71 Vinyls 154 138 307 272 Corporate and other 2 2 4 4 $ 191 $ 176 $ 381 $ 347 Other income (loss), net Olefins $ — $ 1 $ 1 $ 3 Vinyls 8 2 14 6 Corporate and other 1 (1 ) 5 2 $ 9 $ 2 $ 20 $ 11 Provision for (benefit from) income taxes Olefins $ (4 ) $ 18 $ 37 $ 27 Vinyls (18 ) 22 (96 ) 45 Corporate and other 3 (1 ) (1 ) (2 ) $ (19 ) $ 39 $ (60 ) $ 70 Capital expenditures Olefins $ 17 $ 37 $ 44 $ 62 Vinyls 108 169 244 346 Corporate and other 2 2 3 3 $ 127 $ 208 $ 291 $ 411
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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Income from operations $ 36 $ 194 $ 172 $ 328 Interest expense (40 ) (28 ) (71 ) (58 ) Other income, net 9 2 20 11 Income before income taxes $ 5 $ 168 $ 121 $ 281
Total Assets June 30, December 31, Total assets Olefins $ 1,916 $ 1,991 Vinyls 10,384 10,597 Corporate and other 1,255 673 $ 13,555 $ 13,261

Financial Instruments (Narrativ

Financial Instruments (Narrative) (Details) - USD ($) $ in MillionsJun. 30, 2020Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Held-to-maturity $ 0 $ 240
Restricted Cash and Cash Equivalents $ 21 $ 22

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in MillionsJun. 30, 2020Dec. 31, 2019
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Trade customers $ 926 $ 948
Related parties5 12
Allowance for credit losses(15)(22)
Accounts receivable from trade customers, net916 938
Federal and state taxes211 59
Other33 39
Accounts receivable, net $ 1,160 $ 1,036

Inventories (Details)

Inventories (Details) - USD ($) $ in MillionsJun. 30, 2020Dec. 31, 2019
Inventory Disclosure [Abstract]
Finished products $ 469 $ 568
Feedstock, additives, chemicals and other raw materials212 210
Materials and supplies164 158
Inventories $ 845 $ 936

Goodwill (Details)

Goodwill (Details) $ in Millions6 Months Ended
Jun. 30, 2020USD ($)
Goodwill [Roll Forward]
Beginning Balance $ 1,074
Effects of changes in foreign exchange rates(4)
Ending Balance1,070
Olefins [Member]
Goodwill [Roll Forward]
Beginning Balance30
Effects of changes in foreign exchange rates0
Ending Balance30
Vinyls [Member]
Goodwill [Roll Forward]
Beginning Balance1,044
Effects of changes in foreign exchange rates(4)
Ending Balance $ 1,040

Accounts Payable (Details)

Accounts Payable (Details) - USD ($) $ in MillionsJun. 30, 2020Dec. 31, 2019
Accounts Payable [Abstract]
Accounts payable—third parties $ 427 $ 435
Accounts payable to related parties14 12
Notes payable3 26
Accounts payable $ 444 $ 473

Long-Term Debt (Schedule of Lon

Long-Term Debt (Schedule of Long-term Debt) (Details) - USD ($) $ in Millions6 Months Ended
Jun. 30, 2020Jun. 12, 2020Dec. 31, 2019Jul. 31, 2010
Debt Instrument [Line Items]
Principal Amount $ 3,801 $ 3,500
Unamortized Premium (Discount) and Debt Issuance Costs(56)(55)
Net, Long-term Debt $ 3,745 3,445
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2022
Stated interest rate (percent)3.60%
Principal Amount $ 250 250
Unamortized Premium (Discount) and Debt Issuance Costs(1)(1)
Net, Long-term Debt $ 249 249
Senior Notes [Member] | 3.6% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2026
Stated interest rate (percent)3.60%
Principal Amount $ 750 750
Unamortized Premium (Discount) and Debt Issuance Costs(7)(8)
Net, Long-term Debt $ 743 742
Senior Notes [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2027
Principal Amount $ 11 11
Unamortized Premium (Discount) and Debt Issuance Costs0 0
Net, Long-term Debt $ 11 11
Senior Notes [Member] | 1.625% Senior Notes Due 2029
Debt Instrument [Line Items]
Debt Instrument Maturity2029
Stated interest rate (percent)1.625%
Principal Amount $ 786 785
Unamortized Premium (Discount) and Debt Issuance Costs(10)(11)
Net, Long-term Debt $ 776 774
Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2029
Stated interest rate (percent)6.50%
Principal Amount $ 100 100 $ 100
Unamortized Premium (Discount) and Debt Issuance Costs0 (1)
Net, Long-term Debt $ 100 99
Senior Notes [Member] | 3.375% Senior Notes Due 2030 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2030
Stated interest rate (percent)3.375%
Principal Amount $ 300 $ 300 0
Unamortized Premium (Discount) and Debt Issuance Costs(4)0
Net, Long-term Debt $ 296 0
Senior Notes [Member] | 3.50% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2032
Stated interest rate (percent)3.50%
Principal Amount $ 250 250
Unamortized Premium (Discount) and Debt Issuance Costs(1)(1)
Net, Long-term Debt $ 249 249
Senior Notes [Member] | 2035 GO Zone 6 1/2% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2035
Stated interest rate (percent)6.50%
Principal Amount $ 89 89
Unamortized Premium (Discount) and Debt Issuance Costs(1)(1)
Net, Long-term Debt $ 88 88
Senior Notes [Member] | 2035 IKE Zone 6 1/2% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2035
Stated interest rate (percent)6.50%
Principal Amount $ 65 65
Unamortized Premium (Discount) and Debt Issuance Costs0 0
Net, Long-term Debt $ 65 65
Senior Notes [Member] | 5.0% Senior Notes Due 2046 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2046
Stated interest rate (percent)5.00%
Principal Amount $ 700 700
Unamortized Premium (Discount) and Debt Issuance Costs(23)(23)
Net, Long-term Debt $ 677 677
Senior Notes [Member] | 4.375% Senior Notes Due 2047 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity2047
Stated interest rate (percent)4.375%
Principal Amount $ 500 500
Unamortized Premium (Discount) and Debt Issuance Costs(9)(9)
Net, Long-term Debt $ 491 $ 491

Long-Term Debt (Credit Agreemen

Long-Term Debt (Credit Agreement) (Details) - USD ($) $ in MillionsJun. 04, 2020Mar. 20, 2020Jul. 24, 2018Jun. 30, 2020Jun. 30, 2019
Debt Instrument [Line Items]
Repayments of Lines of Credit $ 1,000 $ 0
Credit Agreement [Member] | Line of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of credit permitted increase $ 25
Credit Agreement [Member] | Line of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Line of credit permitted increase500
Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Remaining borrowing capacity1,000
Credit Agreement [Member] | Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity1,000
Proceeds from Lines of Credit $ 1,000
Repayments of Lines of Credit $ 1,000
Line of Credit Facility, Fair Value of Amount Outstanding0
Outstanding letters of credit $ 0
Credit Agreement [Member] | Letter of Credit [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity150
Credit Agreement [Member] | Swingline Loan [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity $ 50
Credit Agreement [Member] | Alternate Base Rate [Domain] | Revolving Credit Facility [Member] | Line of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Spread on variable rate0.00%
Credit Agreement [Member] | Alternate Base Rate [Domain] | Revolving Credit Facility [Member] | Line of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Spread on variable rate0.75%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Spread on variable rate1.00%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Spread on variable rate1.75%

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) $ in MillionsAug. 01, 2020Jun. 30, 2020Jun. 12, 2020Dec. 31, 2019Jul. 31, 2010
Debt Instrument [Line Items]
Principal Amount $ 3,801 $ 3,500
Unamortized Debt Issuance Cost31 30
Senior Notes [Member] | 3.375% Senior Notes Due 2030 [Member]
Debt Instrument [Line Items]
Principal Amount300 $ 300 0
Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Principal Amount $ 100 $ 100 $ 100
Subsequent Event [Member] | Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed100.00%
Extinguishment of Debt, Amount $ 100

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions6 Months Ended
Jun. 30, 2020Jun. 30, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance $ 5,860
Ending balance5,901
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance3 $ 27
Other comprehensive income before reclassifications0 0
Net other comprehensive income attributable to Westlake Chemical Corporation0 0
Ending balance3 27
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance(77)(89)
Other comprehensive income before reclassifications(13)12
Net other comprehensive income attributable to Westlake Chemical Corporation(13)12
Ending balance(90)(77)
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance(74)(62)
Other comprehensive income before reclassifications(13)12
Net other comprehensive income attributable to Westlake Chemical Corporation(13)12
Ending balance $ (87) $ (50)

Fair Value Measurements (Summar

Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($) $ in Millions6 Months Ended
Jun. 30, 2020Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 3,745 $ 3,445
3.60% Senior Notes Due 2022 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 249 249
Debt Instrument Maturity2022
Stated interest rate (percent)3.60%
3.6% Senior Notes Due 2026 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 743 742
Debt Instrument Maturity2026
Stated interest rate (percent)3.60%
Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 11 11
Debt Instrument Maturity2027
1.625% Senior Notes Due 2029 | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 776 774
Debt Instrument Maturity2029
Stated interest rate (percent)1.625%
6 1/2% GO Zone Senior Notes Due 2029 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 100 99
Debt Instrument Maturity2029
Stated interest rate (percent)6.50%
3.375% Senior Notes Due 2030 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 296 0
Debt Instrument Maturity2030
Stated interest rate (percent)3.375%
3.50% Senior Notes Due 2032 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 249 249
Debt Instrument Maturity2032
Stated interest rate (percent)3.50%
2035 GO Zone 6 1/2% Notes [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 88 88
Debt Instrument Maturity2035
Stated interest rate (percent)6.50%
2035 IKE Zone 6 1/2% Notes [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 65 65
Debt Instrument Maturity2035
Stated interest rate (percent)6.50%
5.0% Senior Notes Due 2046 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 677 677
Debt Instrument Maturity2046
Stated interest rate (percent)5.00%
4.375% Senior Notes Due 2047 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt $ 491 491
Debt Instrument Maturity2047
Stated interest rate (percent)4.375%
Fair Value [Member] | 3.60% Senior Notes Due 2022 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value $ 258 255
Fair Value [Member] | 3.6% Senior Notes Due 2026 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value796 777
Fair Value [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value11 11
Fair Value [Member] | 1.625% Senior Notes Due 2029 | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value755 785
Fair Value [Member] | 6 1/2% GO Zone Senior Notes Due 2029 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value100 103
Fair Value [Member] | 3.375% Senior Notes Due 2030 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value306 0
Fair Value [Member] | 3.50% Senior Notes Due 2032 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value249 267
Fair Value [Member] | 2035 GO Zone 6 1/2% Notes [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value90 92
Fair Value [Member] | 2035 IKE Zone 6 1/2% Notes [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value66 68
Fair Value [Member] | 5.0% Senior Notes Due 2046 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value745 761
Fair Value [Member] | 4.375% Senior Notes Due 2047 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value $ 500 $ 505

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Income Tax Disclosure [Abstract]
Effective income tax rate(380.00%)23.20%(49.60%)24.90%
U.S. federal statutory income tax rate21.00%21.00%21.00%21.00%
CARES Act benefit $ 6 $ 68

Earnings and Dividends per Sh_3

Earnings and Dividends per Share (Schedule of Net Income Attributable to Common Stockholders) (Details) - USD ($) $ in Millions3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Earnings and Dividends Per Share [Abstract]
Net income attributable to Westlake Chemical Corporation $ 15 $ 119 $ 160 $ 191
Net income attributable to participating securities(1)(1)(1)(1)
Net income attributable to common shareholders $ 14 $ 118 $ 159 $ 190

Earnings and Dividends per Sh_4

Earnings and Dividends per Share (Reconciliation of Denominator for Basic and Diluted Earnings Per Share) (Details) - $ / shares3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Earnings and Dividends Per Share [Abstract]
Weighted average common shares—basic127,680,478 128,485,182 127,958,921 128,506,712
Weighted Average Number Diluted Shares Outstanding Adjustment143,151 365,153 174,379 375,240
Weighted average common shares-diluted127,823,629 128,850,335 128,133,300 128,881,952
Earnings per share attributable to Westlake Chemical Corporation: Basic (in dollars per share) $ 0.11 $ 0.92 $ 1.24 $ 1.48
Earnings per share attributable to Westlake Chemical Corporation: Diluted (in dollars per share) $ 0.11 $ 0.92 $ 1.24 $ 1.47

Earnings and Dividends per Sh_5

Earnings and Dividends per Share (Additional Information) (Details) - shares3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Earnings and Dividends Per Share [Abstract]
Number of options excluded from computation of diluted earnings per share1,303,372 562,342 1,201,505 442,076

Earnings and Dividends per Sh_6

Earnings and Dividends per Share Dividends Per Share (Details) - $ / shares3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Earnings and Dividends Per Share [Abstract]
Dividends per common share (in usd per share) $ 0.2625 $ 0.2500 $ 0.5250 $ 0.5000

Supplemental Information (Equit

Supplemental Information (Equity Method Investments) (Details) - USD ($) $ in Millions6 Months Ended
Jun. 30, 2020Jun. 30, 2019Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Return of investment from an equity investee $ 39 $ 0
LACC, LLC
Schedule of Equity Method Investments [Line Items]
Investments in and Advances to Affiliates, at Fair Value981 $ 1,038
Return of investment from an equity investee $ 39

Supplemental Information (Addit

Supplemental Information (Additional Information) (Details) - USD ($) $ in Millions6 Months Ended
Jun. 30, 2020Jun. 30, 2019Dec. 31, 2019
Accrued Liabilities and Other Liabilities [Abstract]
Accrued and other liabilities $ 665 $ 768
Accrued rebates87 115
Accrued and other liabilities94 93
Accrued liabilities with related parties33 $ 41
Noncash Investing and Financing Items [Abstract]
Accruals for Capital Expenditure $ (29) $ (9)

Commitments and Contingencies_2

Commitments and Contingencies (Additional Information) (Detail) - USD ($) $ in MillionsMay 22, 2019Jun. 18, 2018May 31, 2017Jun. 30, 2020Dec. 31, 2019
Environmental Loss Contingencies [Line Items]
Environmental Loss contingency accrual $ 46 $ 47
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties [Line Items]100.00%
PolyOne [Member]
Environmental Loss Contingencies [Line Items]
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties [Line Items]100.00%
PolyOne [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 $ 70
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)6 Months Ended
Jun. 30, 2020Segment
Segment Reporting [Abstract]
Number of segments2

Segment Information (Segment Re

Segment Information (Segment Reporting Information) (Details) - USD ($) $ in Millions3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Segment Reporting Information [Line Items]
Net sales $ 1,709 $ 2,144 $ 3,641 $ 4,169
Income (loss) from operations36 194 172 328
Depreciation and amortization191 176 381 347
Other income, net9 2 20 11
Provision for (benefit from) income taxes(19)39 (60)70
Capital expenditures127 208 291 411
Operating Segments [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales361 477 788 936
Income (loss) from operations25 82 87 119
Depreciation and amortization35 36 70 71
Other income, net0 1 1 3
Provision for (benefit from) income taxes(4)18 37 27
Capital expenditures17 37 44 62
Operating Segments [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net sales1,348 1,667 2,853 3,233
Income (loss) from operations20 129 93 230
Depreciation and amortization154 138 307 272
Other income, net8 2 14 6
Provision for (benefit from) income taxes(18)22 (96)45
Capital expenditures108 169 244 346
Operating Segments [Member] | Polyethylene [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales302 345 612 682
Operating Segments [Member] | Styrene, Feedstock And Other [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales59 132 176 254
Operating Segments [Member] | PVC, Caustic Soda And Other [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net sales1,004 1,319 2,217 2,626
Operating Segments [Member] | Building Products [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net sales344 348 636 607
Corporate and other [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations(9)(17)(8)(21)
Depreciation and amortization2 2 4 4
Other income, net1 (1)5 2
Provision for (benefit from) income taxes3 (1)(1)(2)
Capital expenditures2 2 3 3
Intersegment sales [Member]
Segment Reporting Information [Line Items]
Net sales37 75 105 167
Intersegment sales [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales36 74 104 166
Intersegment sales [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net sales $ 1 $ 1 $ 1 $ 1

Segment Information (Reconcilia

Segment Information (Reconciliation of Total Segment Income from Operations to Consolidated Income before Income Taxes) (Details) - USD ($) $ in Millions3 Months Ended6 Months Ended
Jun. 30, 2020Jun. 30, 2019Jun. 30, 2020Jun. 30, 2019
Segment Reporting [Abstract]
Income from operations $ 36 $ 194 $ 172 $ 328
Interest expense(40)(28)(71)(58)
Other income (expense), net9 2 20 11
Income before income taxes $ 5 $ 168 $ 121 $ 281

Segment Information (Total Asse

Segment Information (Total Assets) (Details) - USD ($) $ in MillionsJun. 30, 2020Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets $ 13,555 $ 13,261
Operating Segments [Member] | Olefins [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets1,916 1,991
Operating Segments [Member] | Vinyls [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets10,384 10,597
Corporate and other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets $ 1,255 $ 673

Westlake Chemical Partners LP_2

Westlake Chemical Partners LP (Details) - USD ($) $ in MillionsOct. 04, 2018Jun. 30, 2020Dec. 31, 2014
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