Westlake (WLK) 10-K 19 Feb 20 2019 FY Annual report Financial data

Cover

Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 12, 2020	Jun. 28, 2019
Document Information [Line Items]
Document Type	10-K
Document Quarterly Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-32260
Entity Registrant Name	Westlake Chemical Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	76-0346924
Entity Address, Address Line One	2801 Post Oak Boulevard
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056
City Area Code	713
Local Phone Number	960-9111
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0001262823
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 2.5
Entity Common Stock, Shares Outstanding		128,392,753
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	WLK
Security Exchange Name	NYSE
1.625% Senior Notes Due 2029
Document Information [Line Items]
Title of 12(b) Security	1.625% Senior Notes due 2029
Trading Symbol	WLK29
Security Exchange Name	NYSE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 728	$ 753
Accounts receivable, net	1,036	1,037
Inventories	936	1,014
Prepaid expenses and other current assets	42	38
Total current assets	2,742	2,842
Property, plant and equipment, net	6,912	6,595
Operating lease right-of-use assets	443	0
Goodwill	1,074	1,002
Other intangible assets, net	187	134
Equity Method Investments	1,112	253
Other assets, net	268	251
Total assets	13,261	11,602
Current liabilities
Accounts payable	473	507
Accrued and other liabilities	768	676
Total current liabilities	1,241	1,183
Long-term debt, net	3,445	2,668
Deferred income taxes	1,255	1,159
Pension and other post-retirement benefits	360	337
Operating lease liabilities	355	0
Other liabilities	202	179
Total liabilities	6,858	5,526
Stockholders' equity
Preferred stock, $0.01 par value, 50,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.01 par value, 300,000,000 shares authorized; 134,651,380 and 134,651,380 shares issued at December 31, 2019 and 2018, respectively	1	1
Common stock, held in treasury, at cost; 6,266,609 and 6,183,125 shares at December 31, 2019 and 2018, respectively	(377)	(382)
Additional paid-in capital	553	556
Retained earnings	5,757	5,477
Accumulated other comprehensive loss	(74)	(62)
Total Westlake Chemical Corporation stockholders' equity	5,860	5,590
Noncontrolling interests	543	486
Total equity	6,403	6,076
Total liabilities and equity	13,261	11,602
Customer Relationships [Member]
Current assets
Customer relationships, net	$ 523	$ 525

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	300,000,000	300,000,000
Common Stock, Shares	134,651,380	134,651,380
Common stock, held in treasury	6,266,609	6,183,125

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 8,118	$ 8,635	$ 8,041
Cost of sales	6,858	6,648	6,280
Gross profit	1,260	1,987	1,761
Selling, general and administrative expenses	458	445	399
Amortization of intangibles	109	101	108
Restructuring, transaction and integration-related costs	37	33	29
Income from operations	656	1,408	1,225
Other income (expense)
Interest expense	(124)	(126)	(159)
Other income, net	38	52	15
Income before income taxes	570	1,334	1,081
Provision for (benefit from) income taxes	108	300	(258)
Net income	462	1,034	1,339
Net income attributable to noncontrolling interests	41	38	35
Net income attributable to Westlake Chemical Corporation	$ 421	$ 996	$ 1,304
Earnings per common share attributable to Westlake Chemical Corporation:
Basic (in dollars per share)	$ 3.26	$ 7.66	$ 10.05
Diluted (in dollars per share)	$ 3.25	$ 7.62	$ 10
Weighted average common shares outstanding
Basic (in shares)	128,395,184	129,401,823	129,087,043
Diluted (in shares)	128,757,293	129,985,753	129,540,013

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 462	$ 1,034	$ 1,339
Pension and other post-retirement benefits
Pension and other post-retirement benefits reserves adjustment	(32)	(33)	19
Amortization of benefits liability	0	0	2
Income tax benefit (provision) on pension and other post-retirement benefits	8	8	(7)
Foreign Currency Translation Adjustment
Foreign currency translation	17	(59)	124
Income tax provision on foreign currency translation	(4)	0	(5)
Other comprehensive income (loss), net of income taxes	(11)	(84)	133
Comprehensive income	451	950	1,472
Comprehensive income attributable to noncontrolling interests, net of tax of $2, $4 and $1 for 2019, 2018 and 2017, respectively	42	36	40
Comprehensive income attributable to Westlake Chemical Corporation	$ 409	$ 914	$ 1,432

Consolidated Statements Of Co_2

Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Comprehensive income (loss), tax portion attributable to noncontrolling interest	$ 2	$ 4	$ 1

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	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, 2016	$ 3,892	$ 1	$ (319)	$ 551	$ 3,412	$ (121)	$ 368
Beginning balance, shares issued at Dec. 31, 2016		134,651,380
Beginning balance, Treasury Stock, Shares at Dec. 31, 2016			5,726,377
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Westlake Chemical Corporation	1,304				1,304
Net income attributable to noncontrolling interests	35						35
Net income	1,339
Other comprehensive income	133					128	5
Common stock repurchased, shares			0
Shares issued—stock- based compensation, shares		0	(493,502)
Shares issued—stock-based compensation	11	$ 0	$ 17	(6)
Stock-based compensation (in shares)			0
Stock-based compensation	14		$ 0	14
Dividends declared	(103)				(103)
Distributions to noncontrolling interests	(28)						(28)
Issuance of Westlake Chemical Partners LP common units	111			(4)			115
Ending balances at Dec. 31, 2017	5,369	$ 1	$ (302)	555	4,613	7	495
Ending balance, shares issued at Dec. 31, 2017		134,651,380
Ending balance, Treasury Stock, Shares at Dec. 31, 2017			5,232,875
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification of certain tax effects to retained earnings	0				(13)	13
Net income attributable to Westlake Chemical Corporation	996				996
Net income attributable to noncontrolling interests	38						38
Net income	1,034
Other comprehensive income	(84)					(82)	(2)
Common stock repurchased, shares			1,368,881
Common stock repurchased	(106)		$ (106)				0
Shares issued—stock- based compensation, shares		0	(418,631)
Shares issued—stock-based compensation	9	$ 0	$ 26	(17)
Stock-based compensation (in shares)			0
Stock-based compensation	18		$ 0	18
Dividends declared	(120)				(120)
Distributions to noncontrolling interests	(45)						(45)
Ending balances at Dec. 31, 2018	$ 6,076	$ 1	$ (382)	556	5,477	(62)	486
Ending balance, shares issued at Dec. 31, 2018	134,651,380	134,651,380
Ending balance, Treasury Stock, Shares at Dec. 31, 2018	6,183,125		6,183,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change	$ 1				1
Net income attributable to Westlake Chemical Corporation	421				421
Net income attributable to noncontrolling interests	41						41
Net income	462
Other comprehensive income	(11)					(12)	1
Common stock repurchased, shares			517,712
Common stock repurchased	(30)		$ (30)				0
Shares issued—stock- based compensation, shares		0	(434,228)
Shares issued—stock-based compensation	$ 1	$ 0	$ 35	(25)	(9)
Stock-based compensation (in shares)	(18,635)		0
Stock-based compensation	$ 24		$ 0	24
Dividends declared	(132)				(132)
Distributions to noncontrolling interests	(50)						(50)
Issuance of Westlake Chemical Partners LP common units	63			(2)			65
Ending balances at Dec. 31, 2019	$ 6,403	$ 1	$ (377)	$ 553	$ 5,757	$ (74)	$ 543
Ending balance, shares issued at Dec. 31, 2019	134,651,380	134,651,380
Ending balance, Treasury Stock, Shares at Dec. 31, 2019	6,266,609		6,266,609

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income	$ 462	$ 1,034	$ 1,339
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	713	641	601
Stock-based compensation expense	25	22	23
Loss from disposition and write-off of property, plant and equipment	49	44	22
Deferred income taxes	54	62	(534)
Other losses (gains), net	1	(20)	(3)
Changes in operating assets and liabilities, net of effect of business acquisitions
Accounts receivable	59	(58)	(40)
Inventories	112	(123)	(32)
Prepaid expenses and other current assets	(1)	(1)	26
Accounts payable	(89)	(100)	86
Accrued and other liabilities	(13)	(8)	115
Other, net	(71)	(84)	(75)
Net cash provided by operating activities	1,301	1,409	1,528
Cash flows from investing activities
Acquisition of businesses, net of cash acquired	(314)	0	(13)
Additions to property, plant and equipment	(787)	(702)	(577)
Additions to investments in unconsolidated subsidiaries	(862)	(68)	(66)
Other, net	9	16	4
Net cash used for investing activities	(1,954)	(754)	(652)
Cash flows from financing activities
Dividends paid	(132)	(120)	(103)
Distributions to noncontrolling interests	(50)	(45)	(28)
Proceeds from Issuance of Debt	784	0	0
Proceeds from notes payable	20	14	978
Net proceeds from issuance of Westlake Chemical Partners LP common units	63	0	111
Repayment of term loan	0	0	(150)
Repayment of revolver	0	0	(550)
Redemption and repayment of notes payable	(18)	(1,179)	(257)
Repurchase of common stock for treasury	(30)	(106)	0
Other	(7)	9	5
Net cash provided by (used for) financing activities	630	(1,427)	6
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(2)	(7)	26
Net increase (decrease) in cash, cash equivalents and restricted cash	(25)	(779)	908
Cash, cash equivalents and restricted cash at beginning of the year	775	1,554	646
Cash, cash equivalents and restricted cash at end of the year	$ 750	$ 775	$ 1,554

Description of Business and Sig

Description of Business and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description Of Business And Significant Accounting Policies	Description of Business and Significant Accounting Policies Description of Business Westlake Chemical Corporation (the "Company") operates as an integrated global manufacturer and marketer of basic chemicals, vinyls, polymers and building products. These products include some of the most widely used chemicals in the world, which are fundamental to many diverse consumer and industrial markets, including flexible and rigid packaging, automotive products, coatings, residential and commercial construction as well as other durable and non-durable goods. The Company's customers range from large chemical processors and plastics fabricators to small construction contractors, municipalities and supply warehouses primarily throughout North America and Europe. The petrochemical industry is subject to price fluctuations and volatile feedstock pricing typical of a commodity-based industry, the effects of which may not be immediately passed along to customers. Westlake Chemical Partners LP In 2014, the Company formed Westlake Chemical Partners LP ("Westlake Partners") to operate, acquire and develop ethylene production facilities and related assets. Westlake Partners' assets consist of a limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in OpCo. OpCo's assets include two ethylene production facilities at the Company's Lake Charles, Louisiana site, one ethylene production facility at the Company's Calvert City, Kentucky site and a 200 -mile common carrier ethylene pipeline that runs from Mont Belvieu, Texas to the Company's Longview, Texas site. As of December 31, 2019 , the Company held a 77.2% limited partner interest in OpCo and a controlling interest in Westlake Partners. The operations of Westlake Partners are consolidated in the Company's financial statements. Principles of Consolidation The consolidated financial statements include the accounts of the Company and subsidiaries in which the Company directly or indirectly owns more than a 50% voting interest and exercises control and, when applicable, entities for which the Company has a controlling financial interest or is the primary beneficiary. Investments in majority-owned companies where the Company does not exercise control and investments in nonconsolidated affiliates (20%-50% owned companies, joint ventures and partnerships) are accounted for using the equity method of accounting. Undistributed earnings from joint ventures included in retained earnings were immaterial as of December 31, 2019 . All intercompany transactions and balances are eliminated in consolidation. Certain reclassifications have been made to the prior-year financial statements to conform to the current-year presentation. Noncontrolling interests represent the direct equity interests held by investors in the Company's consolidated subsidiaries, Westlake Partners, Taiwan Chlorine Industries, Ltd. and Suzhou Huasu Plastics Co., Ltd. Cash and Cash Equivalents Cash equivalents consist of highly liquid investments that are readily convertible into cash and have a maturity of three months or less at the date of acquisition. Concentration of Credit Risk Financial instruments which potentially subject the Company to concentration of risk consist principally of trade receivables from customers engaged in manufacturing polyethylene products, polyvinyl chloride ("PVC") products and PVC pipe products. The Company performs periodic credit evaluations of the customers' financial condition and generally does not require collateral. The Company maintains allowances for potential losses. Allowance for Doubtful Accounts The determination of the allowance for doubtful accounts is based on estimation of the amount of accounts receivable that the Company believes are unlikely to be collected. Estimating this amount requires analysis of the financial strength of the Company's customers, the use of historical experience, the Company's accounts receivable aged trial balance, and specific collectibility analysis. The allowance for doubtful accounts is reviewed quarterly. Past due balances over 90 days and high risk accounts as determined by the analysis of financial strength of customers are reviewed individually for collectibility. Inventories Inventories primarily include product, material and supplies. Inventories are stated at lower of cost or net realizable value. Cost is determined using the first-in, first-out ("FIFO") or average method. Property, Plant and Equipment Property, plant and equipment are carried at cost, net of accumulated depreciation. Cost includes expenditures for improvements and betterments that extend the useful lives of the assets and interest capitalized on significant capital projects. Capitalized interest was $9 , $7 and $4 for the years ended December 31, 2019 , 2018 and 2017 , respectively. Repair and maintenance costs are charged to operations as incurred. Gains and losses on the disposition or retirement of fixed assets are reflected in the consolidated statement of operations when the assets are sold or retired. Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 40 Plant and equipment 10-25 Other 3-15 Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Long-lived assets assessed for impairment are grouped at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net undiscounted cash flows expected to be generated by the asset. Assets are considered to be impaired if the carrying amount of an asset exceeds the future undiscounted cash flows. The impairment recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or estimated fair value less costs to sell. Impairment of Goodwill and Intangible Assets Goodwill is tested for impairment at least annually, or when events or changes in circumstances indicate the fair value of a reporting unit with goodwill has been reduced below its carrying value. The Company performed its annual impairment tests for the Olefins and Vinyls segments' goodwill in October 2019 and April 2019 , respectively, and the impairment tests indicated that the recorded goodwill was not impaired. There has been no impairment of the Olefins or Vinyls segments' goodwill since the goodwill was initially recorded. Other intangible assets with finite lives are amortized over their estimated useful lives and reviewed for impairment in accordance with the provisions of the accounting guidance. See Note 8 for more information on the Company's annual goodwill impairment tests. Equity Method Investments The Company accounts for investments using the equity method of accounting if the Company has the ability to exercise significant influence over, but not control of, an investee. Significant influence generally exists if the Company has an ownership interest representing between 20% and 50% of the voting rights. Under the equity method of accounting, investments are stated initially at cost and are adjusted for subsequent additional investments and the proportionate share of profit or losses and distributions. The Company records its share of the profits or losses of the equity investments, net of income taxes, in the consolidated statements of income. The equity method investments are evaluated for impairment when events or changes in circumstances indicate, in management's judgment, that the carrying value of such investments may have experienced an other-than-temporary decline in value. When evidence of loss in value has occurred, management compares the estimated fair value of investment to the carrying value of investment to determine whether an impairment has occurred. If the estimated fair value is less than the carrying value and management considers the decline in value to be other-than-temporary, the excess of the carrying value over the estimated fair value is recognized in the consolidated financial statements as an impairment. Other Assets, net Other assets, net include turnaround costs, investments in unconsolidated subsidiaries, restricted cash, deferred charges and other long-term assets. The Company accounts for turnaround costs under the deferral method. Turnarounds are the scheduled and required shutdowns of specific operating units in order to perform planned major maintenance activities. The costs related to the significant overhaul and refurbishment activities include maintenance materials, parts and direct labor costs. The costs of the turnaround are deferred when incurred at the time of the turnaround and amortized (within depreciation and amortization) on a straight-line basis until the next planned turnaround, which ranges from three to six years . Deferred turnaround costs are presented as a component of other assets, net. The cash outflows related to these costs are included in operating activities in the consolidated statement of cash flows. Business Combinations The Company records business combinations using the acquisition method of accounting. Under the acquisition method of accounting, identifiable assets acquired and liabilities assumed are recorded at their acquisition date fair values. The excess of the purchase price over the estimated fair value is recorded as goodwill. Changes in the estimated fair values of net assets recorded for acquisitions prior to the finalization of more detailed analysis, but not to exceed one year from the date of acquisition, will adjust the amount of the purchase price allocable to goodwill. Measurement period adjustments are reflected in the period in which they occur. Income Taxes The Company utilizes the liability method of accounting for deferred income taxes. Under the liability method, deferred tax assets or liabilities are recorded based upon temporary differences between the tax basis of assets and liabilities and their carrying values for financial reporting purposes. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities during the period. Valuation allowances are recorded against deferred tax assets when it is considered more likely than not that the deferred tax assets will not be realized. On December 22, 2017, the United States ("U.S.") Tax Cuts and Jobs Act (the "Tax Act") was signed into law. The Tax Act, among other changes, reduced the U.S. corporate income tax rate from 35% to 21%, effective January 1, 2018, and also required a one-time deemed repatriation of foreign earnings at specified rates. The Company provisionally recognized a $591 income tax benefit in the 2017 consolidated financial statements that was primarily comprised of the revaluation of deferred tax assets and liabilities partially offset by a one-time U.S. tax on the mandatory deemed repatriation of the Company's post-1986 foreign earnings. The Company did not record any material measurement period adjustment in 2018. The Company's accounting for the income tax effects of the Tax Act was completed in 2018. In February 2018, the FASB issued an accounting standards update, Income Statement — Reporting Comprehensive Income, to (1) allow reclassification from accumulated other comprehensive income (loss) to retained earnings for stranded tax effects resulting from the Tax Act; and (2) require certain disclosures about stranded tax effects. Certain tax effects become stranded in accumulated other comprehensive income (loss) when deferred tax balances originally recorded at the historical income tax rate are adjusted in income from operations based on the lower, newly-enacted income tax rate. The Company adopted the accounting standard effective October 1, 2018 and reclassified $13 of stranded tax effects relating to its pension benefits liability and cumulative effect of foreign exchange from accumulated other comprehensive income (loss) to retained earnings. As a result of the Tax Act, the Financial Accounting Standards Board ("FASB") concluded that Global Intangible Low-Taxed Income Tax ("GILTI tax") can be recognized in the financial statements, no later than December 22, 2018, per an accounting policy choice, by: (1) recording a period cost (permanent item) or (2) providing deferred income taxes stemming from certain basis differences that are expected to result in GILTI tax. The Company elected to record GILTI tax as a period cost. The GILTI tax recognized in 2019 and 2018 were not material to the consolidated financial statements. Foreign Currency Translation Assets and liabilities of foreign subsidiaries are translated to U.S. dollars at the exchange rate as of the end of the year. Statement of operations items are translated at the average exchange rate for the year. The resulting translation adjustment is recorded as a separate component of stockholders' equity. Revenue Recognition Revenue is recognized when the Company transfers control of inventories to its customers. Amounts recognized as revenues reflect the consideration to which the Company expects to be entitled in exchange for those inventories. Provisions for discounts, rebates and returns are incorporated in the estimate of variable consideration and reflected as reduction to revenue in the same period as the related sales. Control of inventories generally transfers upon shipment for domestic sales. The Company excludes taxes collected on behalf of customers from the estimated contract price. For export contracts, the point at which control passes to the customer varies depending on the terms specified in the customer contract. The Company generally invoices customers and recognizes revenue and accounts receivable upon transferring control of inventories. In limited circumstances, the Company transfers control of inventories shortly before it has an unconditional right to receive consideration, resulting in recognition of contract assets. The Company also receives advance payments from certain customers, resulting in recognition of contract liabilities. Contract assets and liabilities are generally settled within the period and are not material to the consolidated balance sheets. The Company expenses sales commissions when incurred. These costs are recorded within selling, general and administrative expenses. Aside from the amounts disclosed within Note 9, the Company does not disclose the value of unsatisfied performance obligations because its contracts with customers (1) have an original expected duration of one year or less or (2) have only variable consideration that is calculated based on market prices at specified dates and is allocated to wholly unsatisfied performance obligations. The Company adopted ASU No. 2014-09, Revenue from Contracts with Customers ("ASC 606"), effective January 1, 2018. The Company applied the modified retrospective transition method to all contracts that were not completed as of the adoption date. Periods prior to January 1, 2018 were not adjusted and are reported under the accounting standards that were in place during those periods. The cumulative effects of changes to the Company's consolidated January 1, 2018 balance sheet for the adoption of this accounting standard were immaterial. The impact of ASC 606 adoption on the financial statements for the year ended December 31, 2018 as compared with the guidance that was in effect prior to January 1, 2018 was immaterial. ASC 606 requires disclosure of disaggregated revenue into categories that depict the nature of how the Company's revenue and cash flows are affected by economic factors. The Company discloses revenues by product and segment in Note 23. Prior to the adoption of ASC 606, the revenue was recognized when persuasive evidence of an arrangement existed, products were delivered to the customer, the sales price was fixed or determinable and collectability was reasonably assured. For domestic contracts, title and risk of loss had passed to the customer upon delivery under executed customer purchase orders or contracts. For export contracts, the title and risk of loss had passed to customers at the time specified by each contract. Transportation and Freight Amounts billed to customers for freight and handling costs on outbound shipments are included in net sales in the consolidated statements of operations. Transportation and freight costs incurred by the Company on outbound shipments are included in cost of sales in the consolidated statements of operations. Price Risk Management The Company recognizes derivative instruments on the balance sheet at fair value, and changes in a derivative's fair value are currently recognized in earnings or comprehensive income, depending on the designation of the derivative. If the derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized in earnings. If the derivative is designated as a cash flow hedge, the effective portion of the change in the fair value of the derivative is recorded in comprehensive income and is recognized in the statement of operations when the hedged item affects earnings. Ineffective portions of changes in the fair value of cash flow hedges are recognized in earnings currently. The derivative instruments did not have a material impact on the Company's consolidated financial statements. Asset Retirement Obligations The Company has conditional asset retirement obligations for the removal and disposal of hazardous materials from certain of the Company's manufacturing facilities. The Company recognizes asset retirement obligations in the period in which the liability becomes probable and reasonably estimable. Recognized asset retirement obligations are initially recorded at fair value and capitalized as a component of the carrying value of the long-lived asset to which the obligation relates. The liability is accreted to its future value each period, and the capitalized cost is depreciated over the estimated useful life of the related asset. Upon settlement of the liability, a gain or loss is recorded. As of December 31, 2019 , the Company had $7 and $20 of asset retirement obligations recorded as accrued liabilities and other liabilities, respectively. As of December 31, 2018 , the Company had $8 and $20 of asset retirement obligations recorded as accrued liabilities and other liabilities, respectively. The Company also has conditional asset retirement obligations that have not been recognized because the fair values of the conditional legal obligations cannot be measured due to the indeterminate settlement date of the obligations. Settlements of the unrecognized conditional asset retirement obligations are not expected to have a material adverse effect on the Company's financial condition, results of operations or cash flows in any individual reporting period. Environmental Costs Environmental costs relating to current operations are expensed or capitalized, as appropriate, depending on whether such costs provide future economic benefits. Remediation liabilities are recognized when the costs are considered probable and can be reasonably estimated. Measurement of liabilities is based on currently enacted laws and regulations, existing technology and undiscounted site-specific costs. Environmental liabilities in connection with properties that are sold or closed are realized upon such sale or closure, to the extent they are probable and estimable and not previously reserved. Recognition of any joint and several liabilities is based upon the Company's best estimate of its final pro rata share of the liability. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. Recent Accounting Pronouncements Credit Losses (ASU No. 2016-13) In June 2016, the Financial Accounting Standards Board ("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 additional authoritative guidance related to credit losses. The accounting standard is effective for reporting periods beginning after December 15, 2019 and is not expected to 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 will be effective for reporting periods beginning after December 15, 2019 and is not expected to 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. The amendments are effective for periods beginning after December 15, 2019. 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 Company is in the process of assessing the impact of the standard on the Company's fair value disclosures. However, the standard is not expected to have an impact on the Company's consolidated financial position, results of operations and cash flows. Income Taxes (ASU No. 2019-12) In December 2019, the 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 its consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Leases (ASU No. 2016-02) In February 2016, the FASB issued an accounting standards update on lease accounting that supersedes the previously issued lease guidance. The new standard requires lessees to recognize assets and liabilities for all long-term operating leases. An asset is recognized for the right to use an underlying leased asset and a liability is recognized for the obligation to make payments over the lease term. The standard also requires expanded lease disclosures. The standard requires a modified retrospective adoption approach and allows for the election of certain transition expedients. The Company adopted the standard on January 1, 2019 using the optional transition method, which allows entities to recognize a cumulative adjustment to the opening balance sheet in the period of adoption. The Company elected the package of optional transition expedients and was not required to reassess (1) whether any existing contracts are or contain leases, (2) classification of existing leases as operating or capital or (3) whether initial direct costs for existing leases qualify for capitalization under the new accounting standard. The Company did not elect the use of hindsight to determine the lease term when considering lease renewal or termination options. Additionally, the Company elected to continue accounting for existing land easements under its accounting policies that were in effect prior to adoption of the new lease standard. The following amounts were recorded as a result of adopting the new lease standard on January 1, 2019: Operating Lease Assets and Liabilities Balance Sheet Location Amounts Recorded in the Consolidated Balance Sheet January 1, 2019 Right-of-use assets Operating lease right-of-use assets $ 421 Current lease liabilities Accrued and other liabilities (94 ) Non-current lease liabilities Operating lease liabilities (331 ) Deferred rent Other liabilities 4

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Acquisitions	Acquisition NAKAN TM On January 2, 2019, the Company acquired all of the outstanding equity interests in the parent entity of the NAKAN TM global compounding solutions business. NAKAN's products are used in a wide-variety of applications, including in the automotive, building and construction, and medical industries. The closing purchase price of $249 was paid with available cash on hand. The acquisition is being accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed and the results of operations of NAKAN are included in the Vinyls segment. NAKAN's net sales and earnings since the acquisition date were not material to the Company's consolidated statement of operations for the year ended December 31, 2019 . The acquisition-related costs recognized in the consolidated statement of operations for the year ended December 31, 2019 were not material. The pro forma impact of this acquisition has not been presented as it is not material to the Company's consolidated statements of operations for the years ended December 31, 2019 and 2018. The following table summarizes the fair value of identified assets acquired and liabilities assumed at the date of acquisition. The allocation of consideration transferred is based on management's estimates, judgments and assumptions. When determining the fair values of assets acquired and liabilities assumed, management made significant estimates, judgments and assumptions. Management estimated that consideration paid exceeded the fair value of the net assets acquired. Therefore, goodwill of $40 was recorded. The goodwill recognized is primarily attributable to the expected value to be achieved from the acquisition. The information below represents the purchase price allocation: Cash $ 10 Accounts receivable 53 Inventories 40 Prepaid expenses and other current assets 7 Property, plant and equipment 75 Operating lease right-of-use assets 3 Intangible assets: Customer relationships (weighted average lives of 17 years) 65 Technology (weighted average lives of 14 years) 40 Trade name (life of 15 years) 25 Other assets 12 Total assets acquired 330 Accounts payable 57 Accrued and other liabilities 18 Deferred income taxes 31 Pension and other post-retirement benefits 4 Operating lease liabilities 3 Other long-term liabilities 8 Total liabilities assumed 121 Total identifiable net assets acquired 209 Goodwill 40 Total purchase consideration $ 249

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Financial Instruments	Financial Instruments Cash Equivalents The Company had $240 and $10 of held-to-maturity securities with original maturities of three months or less, primarily consisting of corporate debt securities, classified as cash equivalents at December 31, 2019 and 2018 , 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 $22 and $22 at December 31, 2019 and 2018

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Accounts Receivable	Accounts Receivable Accounts receivable consist of the following at December 31: 2019 2018 Trade customers $ 948 $ 969 Related parties 12 6 Allowance for doubtful accounts (22 ) (23 ) 938 952 Federal and state taxes 59 57 Other 39 28 Accounts receivable, net $ 1,036 $ 1,037

Inventories

Inventories	12 Months Ended
	Dec. 31, 2019
Inventory, Net [Abstract]
Inventories	Inventories Inventories consist of the following at December 31: 2019 2018 Finished products $ 568 $ 657 Feedstock, additives, chemicals and other raw materials 210 203 Materials and supplies 158 154 Inventories $ 936 $ 1,014

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment, Net [Abstract]
Property, Plant And Equipment	Property, Plant and Equipment Property, plant and equipment consist of the following at December 31: 2019 2018 Land $ 198 $ 193 Buildings and improvements 608 544 Plant and equipment 8,227 7,568 Other 496 437 9,529 8,742 Less: Accumulated depreciation (3,168 ) (2,720 ) 6,361 6,022 Construction in progress 551 573 Property, plant and equipment, net $ 6,912 $ 6,595 Depreciation expense on property, plant and equipment of $519 , $478 and $449 is included primarily in cost of sales in the consolidated statements of operations for the years ended December 31, 2019 , 2018 and 2017 , respectively.

Leases (Notes)

Leases (Notes)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases The Company is obligated under various long-term and short-term operating leases for rail cars, buildings, land and other transportation and storage assets. The Company determines whether an arrangement is, or contains, a lease at contract inception. Some of the Company's arrangements contain both lease and non-lease components. For certain transportation equipment leases, the Company accounts for the lease and non-lease components as a single lease component. The Company records right-of-use assets and corresponding lease liabilities for operating leases with terms greater than one year. Operating lease right-of-use assets and liabilities are recorded at the present value of the fixed lease payments over the life of the lease. The majority of the Company's leases do not provide an implicit rate. Therefore, the Company uses its incremental borrowing rate at lease commencement to measure operating lease right-of-use assets and lease liabilities. Certain of the Company's leases provide for renewal and purchase options. Renewal and purchase options are evaluated at lease commencement and included in the lease term if they are reasonably certain to be exercised. Short-term leases are recognized in rental expense on a straight-line basis over the lease term and are not recorded in the consolidated balance sheets. The Company's finance leases are not material to the consolidated financial statements. Lease-related asset and liability balances were as follows: December 31, Operating Leases Right-of-use assets $ 443 Accrued and other liabilities $ 93 Operating lease liabilities 355 Total operating lease liabilities $ 448 Weighted Average Remaining Term (in years) 8 Weighted Average Lease Discount Rate 3.5 % The Company's operating lease cost is comprised of payments related to operating leases recorded in the consolidated balance sheet and short-term rental payments for leases that are not recorded in the consolidated balance sheet. Variable operating lease cost was not material to the consolidated statement of operations for the years ended December 31, 2019 and 2018 . The components of operating lease expense were as follows: December 31, Operating lease cost (1) $ 113 Short-term lease cost 58 Total operating lease cost $ 171 _____________________________ (1) Includes fixed lease payments for operating leases recorded in the consolidated balance sheet. Maturities of lease liabilities were as follows at December 31, 2019 : Operating Leases 2020 $ 106 2021 83 2022 69 2023 55 2024 43 Thereafter 189 Total lease payments 545 Less: imputed interest (97 ) Present value of lease liabilities $ 448 Future lease commitments for operating lease obligations were as follows at December 31, 2018 : Operating Leases 2019 $ 94 2020 89 2021 70 2022 56 2023 42 Thereafter 152 Total lease payments $ 503 Related Party Leases The Company leases certain assets under operating leases with related parties. As of December 31, 2019, right-of-use assets and the associated operating lease liabilities for related party operating leases were approximately $50 . The Company recognized operating lease cost for fixed lease payments to related parties of $18 for the year ended December 31, 2019.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	8. Goodwill and Other Intangible Assets Goodwill The gross carrying amounts and changes in the carrying amount of goodwill for the years ended December 31, 2019 and 2018 are as follows: Olefins Segment Vinyls Segment Total Balance at December 31, 2017 $ 30 $ 982 $ 1,012 Effects of changes in foreign exchange rates — (10 ) (10 ) Balance at December 31, 2018 30 972 1,002 Goodwill acquired during the year — 67 67 Effects of changes in foreign exchange rates — 5 5 Balance at December 31, 2019 $ 30 $ 1,044 $ 1,074 Olefins Segment Goodwill The Company performed its annual impairment analysis for the Olefins segment, the reporting unit assessed, during the fourth quarter of 2019. The fair value of the Olefins segment reporting unit assessed during the October 2019 impairment analysis was determined using both a discounted cash flow methodology and a market value methodology. Based upon this assessment, the Company determined that the fair value of the Olefins segment reporting unit was greater than the carrying value. The discounted cash flow projections were based on a nine-year forecast, from 2020 to 2028, to reflect the cyclicality of the Company's Olefins business. The forecast was based on prices and spreads projected by IHS Markit ("IHS"), a chemical industry organization offering market and business advisory services for the chemical market, historical results and estimates by management, including its strategic and operational plans. Other 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 of 9.5% . The significant assumptions used in determining the fair values of the reporting units using the market value methodology included the determination of appropriate market comparables and the estimated multiples of EBITDA a willing buyer was likely to pay. Vinyls Segment Goodwill The Company performed its annual impairment analysis for the Vinyls reporting units during the second quarter of 2019. The fair values of the North America and other reporting units assessed during the April 2019 impairment analysis were determined using both a discounted cash flow methodology and a market value methodology. Based upon this assessment, the Company determined that the fair values of the Vinyls reporting units were greater than their carrying value. The discounted cash flow projections were based on a nine-year forecast, from 2020 to 2028 to reflect the cyclicality of the housing and construction markets as the Company's Vinyls businesses are significantly influenced by those markets. The forecast was based on prices and spreads projected by IHS, historical results and estimates by management, including its strategic and operational plans. Other 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 ranging from 9% to 12.5% . The significant assumptions used in determining the fair values of the reporting units using the market value methodology include the determination of appropriate market comparables and the estimated multiples of EBITDA a willing buyer is likely to pay. Intangible Assets Intangible assets consisted of the following at December 31: 2019 2018 Weighted Average Life Cost Accumulated Amortization Net Cost Accumulated Amortization Net Customer relationships $ 832 $ (309 ) $ 523 $ 745 $ (220 ) $ 525 11 Other intangible assets: Licenses and intellectual property 172 (79 ) 93 122 (65 ) 57 13 Trademarks 120 (37 ) 83 90 (26 ) 64 13 Other 35 (24 ) 11 35 (22 ) 13 10 Total other intangible assets $ 327 $ (140 ) $ 187 $ 247 $ (113 ) $ 134 Scheduled amortization of intangible assets for the next five years is as follows: $120 , $117 , $104 , $57 and $51 in 2020 , 2021 , 2022 , 2023 and 2024 , respectively.

Equity Method Investements (Not

Equity Method Investements (Notes)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	9. Equity Method Investments LACC, LLC Joint Venture In 2015, Eagle US 2 LLC ("Eagle"), a wholly-owned subsidiary of the Company, and Lotte Chemical USA Corporation, a subsidiary of Lotte Chemical Corporation ("Lotte"), formed a joint venture, LACC, LLC ("LACC"), to design, build and operate an ethylene facility with 2.2 billion pounds per year of ethylene production capacity. Pursuant to a contribution and subscription agreement between Eagle and LACC, Eagle contributed $225 to LACC to fund construction costs of the ethylene plant, representing approximately 12% of the membership interests in LACC. On November 12, 2019, we, through Eagle, completed the acquisition of an additional 34.8% of the membership interests in LACC from Lotte for approximately $817 . As of December 31, 2019 , the Company's investment exceeded the underlying equity in net assets by approximately $166 which was assigned to goodwill and not amortized. The ethylene plant was built adjacent to the Company's chlor-alkali facility in Lake Charles. During the third quarter of 2019, the ethylene plant began commercial operations. The Company accounts for its investment in LACC under the equity method of accounting. The LACC joint venture is a cost-sharing arrangement between the members of LACC. The members of LACC receive their proportionate shares of ethylene offtake each month and fund cash operating costs, excluding depreciation and amortization. As a result, LACC recognizes net losses equal to depreciation and amortization each period. The Company's equity in losses from LACC, which is equal to its share of depreciation and amortization expenses, is recognized in cost of sales in the consolidated statements of operations. The Company's investment in LACC is recorded as a component of equity method investments in the consolidated balance sheets. The Company's capital contributions to fund its share of capital expenditures are classified within investing activities in the consolidated statements of cash flows. The Company's ethylene offtake from LACC was approximately 215 million pounds during the year ended December 31, 2019 . Changes in the Company's investment in LACC for the year ended December 31, 2019 were as follows: Investment in LACC Balance at December 31, 2018 $ 183 Cash contributions 45 Additional interest purchased 817 Depreciation and amortization (7 ) Balance at December 31, 2019 $ 1,038 Services Provided to LACC and Lotte The Company provides certain utilities and other services to LACC and Lotte. Pursuant to a construction and reimbursement agreement, LACC and Lotte agreed to reimburse the Company for construction costs over a 6.5 -year period beginning in 2020. In addition to the reimbursements for construction costs, the Company charges LACC and Lotte certain fixed fees under an operating, maintenance and logistics agreement. The Company accounts for the reimbursement of construction costs and the fixed fees as components of the total transaction price and recognizes it ratably in net sales over approximately 25 years. The remaining performance obligations at December 31, 2019 , representing these fixed components of the transaction price, totaled $59 and $81 from LACC and Lotte, respectively. As of December 31, 2019 , the associated contract liabilities recorded totaled $5 and $7 from LACC and Lotte, respectively. There were no such contract liabilities recorded as of December 31, 2018 . In addition to the reimbursements for construction costs and other fixed fees, the Company charges LACC and Lotte certain variable fees. Other Equity Method Investments In addition to LACC, the Company has other equity method investments amounting to $74 and $70 as of December 31, 2019 and 2018 , respectively. See Note 20 for more detailed information.

Accounts and Notes Payable (Not

Accounts and Notes Payable (Notes)	12 Months Ended
	Dec. 31, 2019
Accounts and Notes Payable [Abstract]
Accounts Payable and Accrued Liabilities Disclosure [Text Block]	Accounts Payable Accounts payable consist of the following: December 31, December 31, Accounts payable—third parties $ 435 $ 504 Accounts payable to related parties 12 2 Notes payable 26 1 Accounts payable $ 473 $ 507

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consisted of the following at December 31: December 31, 2019 December 31, 2018 Principal Amount Unamortized Discount and Debt Issuance Costs Net Long-Term Debt Principal Amount Unamortized Discount and Debt Issuance Costs Net Long-Term Debt 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 (8 ) 742 750 (9 ) 741 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 — 11 11 — 11 6 ½% senior notes due 2029 (the "6 ½% 2029 GO Zone Senior Notes") 100 (1 ) 99 100 (1 ) 99 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 (24 ) 676 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 (9 ) 491 500 (9 ) 491 3.50% senior notes due 2032 (the "3.50% 2032 GO Zone Refunding Senior Notes") 250 (1 ) 249 250 (2 ) 248 1.625% senior notes due 2029 (the "1.625% 2029 Senior Notes") 785 (11 ) 774 — — — Long-term debt $ 3,500 $ (55 ) $ 3,445 $ 2,715 $ (47 ) $ 2,668 Credit Agreement On July 24, 2018, the Company entered into a new $1,000 revolving credit facility that is scheduled to mature on July 24, 2023 (the "Credit Agreement") and, in connection therewith, terminated the existing $1,000 revolving credit facility that was scheduled to mature on August 23, 2021 (the "Prior Credit Agreement"). The Credit Agreement bears interest at either (a) LIBOR plus a spread ranging from 1.00% to 1.75% or (b) Alternate Base Rate plus a spread ranging from 0.00% to 0.75% in each case depending on the credit rating of the Company. At December 31, 2019 , the Company had no borrowings outstanding under the Credit Agreement. As of December 31, 2019 , the Company had no outstanding letters of credit and borrowing availability of $1,000 under the Credit Agreement. The Credit Agreement contains certain affirmative and negative covenants, including a quarterly total leverage ratio financial maintenance covenant. As of December 31, 2019 , 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. None of the Company's subsidiaries are required to guarantee the obligations of the Company under the Credit Agreement. The Credit Agreement includes a $150 sub-limit for letters of credit, and any outstanding letters of credit will be deducted from availability under the facility. The Credit Agreement also provides for a discretionary $50 commitment for swingline loans to be provided on a same-day basis. The Company may also increase the size of the facility, in increments of at least $25 , up to a maximum of $500 , subject to certain conditions and if certain lenders agree to commit to such an increase. 3.60% Senior Notes due 2026 and 5.0% Senior Notes due 2046 In August 2016, the Company issued $750 aggregate principal amount of the 3.60% 2026 Senior Notes and $700 aggregate principal amount of the 5.0% 2046 Senior Notes . In March 2017, the Company commenced registered exchange offers to exchange the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes for new notes that are identical in all material respects to the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes , except that the offer and issuance of the new Securities and Exchange Commission ("SEC")-registered notes have been registered under the Securities Act of 1933, as amended (the "Securities Act"). The exchange offers expired on April 24, 2017, and approximately 99.97% of the 3.60% 2026 Senior Notes and 100% of the 5.0% 2046 Senior Notes were exchanged. The 3.60% 2026 Senior Notes that were not exchanged in the 3.60% 2026 Senior Notes exchange offer have not been registered under the Securities Act or any state securities laws and may not be offered or sold in the U.S. absent registration or an applicable exemption from registration requirements or a transaction not subject to the registration requirements of the Securities Act or any state securities law. 3.60% Senior Notes due 2022 In July 2012, the Company issued $250 aggregate principal amount of the 3.60% 2022 Senior Notes . The 3.60% 2022 Senior Notes are unsecured and were issued with an original issue discount of $1 . There is no sinking fund and no scheduled amortization of the 3.60% 2022 Senior Notes prior to maturity. The Company may optionally redeem the 3.60% 2022 Senior Notes in accordance with the terms of the 3.60% 2022 Senior Notes . 4 .375% Senior Notes due 2047 In November 2017, the Company completed the registered public offering of $500 aggregate principal amount of the 4.375% 2047 Senior Notes . The 4.375% 2047 Senior Notes are unsecured and mature on November 15, 2047. There is no sinking fund and no scheduled amortization of the 4.375% 2047 Senior Notes prior to maturity. The Company may optionally redeem the 4.375% 2047 Senior Notes in accordance with the terms of the 4.375% 2047 Senior Notes . 1.625% Senior Notes due 2029 On July 17, 2019 , the Company completed the registered public offering of €700 aggregate principal amount of 1.625% Senior Notes due July 17, 2029 (the " 1.625% 2029 Senior Notes"). The Company received approximately $779 of net proceeds from the offering. The 1.625% 2029 Senior Notes will accrue interest from July 17, 2019 at a rate of 1.625% per annum, payable annually in arrears on July 17 of each year, beginning July 17, 2020. The Company designated this euro-denominated debt as a non-derivative net investment hedge of a portion of the Company's net investments in euro functional-currency denominated subsidiaries to offset foreign currency fluctuations. The indenture and supplemental indentures governing the 3.60% 2026 Senior Notes , 5.0% 2046 Senior Notes , 3.60% 2022 Senior Notes , 4.375% 2047 Senior Notes and 1.625% Senior Notes contain customary events of default and covenants that will restrict the Company and certain of the Company's 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. IKE Zone Bonds In December 2010, the Louisiana Local Government Authority Environmental Facilities and Community Development Authority (the "Authority"), a political subdivision of the State of Louisiana, completed the offering of $65 of 6 ½% IKE Zone Bonds under Section 704 of the Emergency Economic Stabilization Act of 2008 (the "IKE Zone Act"). In connection with the issuance of the 6 ½% 2035 IKE Zone Bonds, the Company issued $65 of the 6 ½% 2035 IKE Zone Senior Notes. GO Zone Bonds In December 2010, the Authority issued $89 of 6 ½% tax-exempt revenue bonds due November 1, 2035 under the Gulf Opportunity Zone Act of 2005 (the "GO Zone Act") (the " 6 ½% 2035 GO Zone Bonds"). In connection with the issuance of the 6 ½% 2035 GO Zone Bonds, the Company issued $89 of the 6 ½% 2035 GO Zone Senior Notes . In July 2010, the Authority completed the reoffering of $100 of 6 ½% tax-exempt revenue bonds due August 1, 2029 under the GO Zone Act (the " 6 ½% 2029 GO Zone Bonds"). In connection with the reoffering of the 6 ½% 2029 GO Zone Bonds, the Company issued $100 of the 6 ½% 2029 GO Zone Senior Notes . Each series of the tax-exempt bonds is subject to redemption and the holders may require the bonds to be repurchased upon a change of control or a change in or loss of the current tax status of the bonds. In addition, the bonds are subject to optional redemption by the Authority upon the direction of the Company if certain events have occurred in connection with the operation of the projects for which the bond proceeds may be used, including if the Company has determined that the continued operation of any material portion of the projects would be impracticable, uneconomical or undesirable for any reason. In November 2017, the Authority completed the remarketing of $250 aggregate principal amount of 3.50% tax-exempt revenue refunding bonds due November 1, 2032 (the " 3.50% 2032 GO Zone Bonds"). In connection with the remarketing of the 3.50% 2032 GO Zone Bonds, the Company issued $250 of the 3.50% 2032 Senior Notes . The 3.50% 2032 GO Zone Bonds are subject to optional redemption by the Authority upon the direction of the Company at any time on or after November 1, 2027 , for 100% of the principal amount plus accrued interest. The indenture governing the 3.50% 2032 Senior Notes contains customary events of default and covenants that will restrict the Company and certain of the Company's subsidiaries' ability to (1) incur certain secured indebtedness, (2) engage in certain sale-leaseback transactions and (3) consolidate, merge or transfer all of substantially all of its assets. In connection with each offering of the tax-exempt bonds, the Company entered into a loan agreement with the Authority pursuant to which the Company agreed to pay all of the principal, premium, if any, and interest on the bonds and certain other amounts to the Authority. The net proceeds from the offerings were loaned by the Authority to the Company. The Company used the proceeds to expand, refurbish and maintain certain of its facilities in the Louisiana Parishes of Calcasieu and Ascension. The bonds are unsecured and rank equally in right of payment with other existing and future unsecured senior indebtedness. As of December 31, 2019 , the Company had drawn all proceeds from the tax-exempt bonds. In connection with each such offering of the tax-exempt bonds, the Company issued senior notes under a base indenture and supplemental indenture to collateralize its obligations under the loan agreement relating to such tax-exempt bonds (collectively, the "Tax-Exempt Bond Related Senior Notes"). The indentures governing the Tax-Exempt Bond Related Senior Notes excluding the 3.5% 2032 GO Zone Refunding Senior Notes contain customary covenants and events of default. Accordingly, these agreements generally impose significant operating and financial restrictions on the Company. These restrictions, among other things, provide limitations on incurrence of additional indebtedness, the payment of dividends, certain investments and acquisitions and sales of assets. However, the effectiveness of certain of these restrictions is currently suspended because the Tax-Exempt Bond Related Senior Notes are currently rated investment grade by at least two nationally recognized credit rating agencies. The most significant of these provisions, if it were currently effective, would restrict the Company from incurring additional debt, except specified permitted debt (including borrowings under its credit facility), when the Company's fixed charge coverage ratio is below 2.0 :1. These limitations are subject to a number of important qualifications and exceptions, including, without limitation, an exception for the payment of the Company's regular quarterly dividend of up to $0.10 per share. If the restrictions were currently effective, distributions in excess of $100 would not be allowed unless, after giving pro forma effect to the distribution, the Company's fixed charge coverage ratio is at least 2.0 :1 and such payment, together with the aggregate amount of all other distributions after January 13, 2006, is less than the sum of 50% of the Company's consolidated net income for the period from October 1, 2003 to the end of the most recent quarter for which financial statements have been filed, plus 100% of net cash proceeds received after October 1, 2003 as a contribution to the Company's common equity capital or from the issuance or sale of certain securities, plus several other adjustments. Revenue Bonds In December 1997, the Company entered into a loan agreement with a public trust established for public purposes for the benefit of the Parish of Calcasieu, Louisiana. The public trust issued $11 principal amount of tax-exempt waste disposal revenue bonds in order to finance the Company's construction of waste disposal facilities for an ethylene plant. The waste disposal revenue bonds expire in December 2027 and are subject to redemption and mandatory tender for purchase prior to maturity under certain conditions. The interest rate on the waste disposal revenue bonds at December 31, 2019 and 2018 was 1.78% and 1.85% , respectively. As of December 31, 2019 , the Company was in compliance with all of its long-term debt covenants. The weighted average interest rate on all long-term debt was 3.6% and 4.4% at December 31, 2019 and 2018 , respectively. Unamortized debt issuance costs on long-term debt were $30 and $25 at December 31, 2019 and 2018 , respectively. Aggregate scheduled maturities of long-term debt during the next five years consist of $250

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity The Company's Board of Directors has declared regular quarterly dividends to holders of its common stock aggregating $132 , $120 and $103 for the years ended December 31, 2019 , 2018 and 2017 , respectively. Common Stock Each share of common stock entitles the holder to one vote on all matters on which holders are permitted to vote, including the election of directors. There are no cumulative voting rights. Accordingly, holders of a majority of the total votes entitled to vote in an election of directors will be able to elect all of the directors standing for election. Subject to preferences that may be applicable to any outstanding preferred stock, the holders of the common stock will share equally on a per share basis any dividends when, as and if declared by the Board of Directors out of funds legally available for that purpose. If the Company is liquidated, dissolved or wound up, the holders of the Company's common stock will be entitled to a ratable share of any distribution to stockholders, after satisfaction of all the Company's liabilities and of the prior rights of any outstanding class of the Company's preferred stock. The Company's common stock has no preemptive or conversion rights or other subscription rights. There are no redemption or sinking fund provisions applicable to the Company's common stock. Preferred Stock The Company's charter authorizes the issuance of shares of preferred stock. The Company's Board of Directors has the authority, without shareholder approval, to issue preferred shares from time to time in one or more series, and to fix the number of shares and terms of each such series. The Board may determine the designations and other terms of each series including dividend rates, whether dividends will be cumulative or non-cumulative, redemption rights, liquidation rights, sinking fund provisions, conversion or exchange rights and voting rights. Stock Repurchase Program In November 2014, the Company's Board of Directors approved a $250 share repurchase program (the "2014 Program"). In November 2015, the Company's Board of Directors approved the expansion of the 2014 Program by an additional $150 . In August 2018, the Company's Board of Directors approved the expansion of the 2014 Program by an additional $150 . The number of shares repurchased by the Company under the 2014 Program was 517,712 , 1,368,881 and 0 for the years ended December 31, 2019, 2018 and 2017 , respectively. As of December 31, 2019 , the Company had repurchased a total of 6,080,191 shares of its common stock for an aggregate purchase price of approximately $365 . Any shares repurchased under the 2014 Program are held by the Company as treasury stock and may be used for general corporate purposes, including for the 2013 Omnibus Incentive Plan. In 2014, the Company began delivering treasury shares to employees and non-employee directors for options exercised and for the settlement of restricted stock units. The cost of treasury shares delivered is determined using the specific identification method.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) by component were as follows: Pension and Other Post-Retirement Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Total Balances at December 31, 2017 $ 43 $ (36 ) $ 7 Other comprehensive income (loss) before reclassifications (14 ) (57 ) (71 ) Amounts reclassified from accumulated other comprehensive income (loss) (11 ) — (11 ) Reclassification of certain tax effects to retained earnings (1) 9 4 13 Net other comprehensive loss attributable to Westlake Chemical Corporation (16 ) (53 ) (69 ) Balances at December 31, 2018 27 (89 ) (62 ) Other comprehensive income (loss) before reclassifications (24 ) 12 (12 ) Amounts reclassified from accumulated other comprehensive income (loss) — — — Net other comprehensive income (loss) attributable to Westlake Chemical Corporation (24 ) 12 (12 ) Balances at December 31, 2019 $ 3 $ (77 ) $ (74 ) ______________________________ (1) In 2018, the Company reclassified certain income tax effects to retained earnings upon adoption of ASU No. 2018-02. See Note 1 (Income taxes) for additional information. The following table provides the details of the amounts reclassified from accumulated other comprehensive income (loss) into net income in the consolidated statements of operations: Details about Accumulated Other Comprehensive Income (Loss) Components Location of Reclassification (Income (Expense)) in Consolidated Statements of Operations Year Ended December 31, 2019 2018 2017 Amortization of pension and other post-retirement net loss (1) $ — $ — $ (2 ) Pension settlement gain (1) — 14 — Income tax benefit (provision) on pension and other post-retirement benefits Provision for (benefit from) income taxes — (3 ) — Total reclassifications for the period $ — $ 11 $ (2 ) ______________________________ (1) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost and reflected in other income, net in the consolidated statements of operations. See Note 14 for additional information on the pension settlement gain recognized in 2018.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2019
Defined Benefit Plan [Abstract]
Employee Benefits	Employee Benefits Defined Contribution Plans U.S. Plans The Company has a defined contribution savings plan covering the eligible U.S. regular full-time and part-time employees, whereby eligible employees may elect to contribute up to 100% of their annual eligible compensation, subject to an annual plan limit in line with the annual elective contribution limit as determined by the Internal Revenue Service. The Company matches its employee's contribution up to a certain percentage of such employee's compensation, per the terms of the plan. The Company may, at its discretion and per the terms of the plan, make an additional non-matching contribution in an amount as the Board of Directors may determine. For the years ended December 31, 2019 , 2018 and 2017 , the Company recorded approximately $20 , $21 and $23 , respectively, to expense for these contributions. Further, within the plan, the Company also makes an annual retirement contribution to substantially all employees of certain subsidiaries. The Company's contributions to the plan are determined as a percentage of employees' pay. For the years ended December 31, 2019 , 2018 and 2017 , the Company charged approximately $32 , $31 and $29 , respectively, to expense for these contributions. Non-U.S. Plans The Company has defined contribution plans in several countries covering eligible employees of the Company. The Company's contributions to the plans are based on applicable laws in each country. Contributions to the Company's non-U.S. defined contribution plans are made by both the employee and the Company. For the years ended December 31, 2019 , 2018 and 2017 , the Company charged approximately $4 , $5 and $5 , respectively, to expense for its contributions to these plans. Defined Benefit Plans U.S. Plans The Company has noncontributory defined benefit pension plans that cover certain eligible salaried and wage employees of certain subsidiaries. However, eligibility for the Company's plans has been frozen. Benefits for salaried employees under these plans are based primarily on years of service and employees' pay near retirement. Benefits for wage employees are based upon years of service and a fixed amount as periodically adjusted. The Company recognizes the years of service prior to the Company's acquisition of the subsidiary's facilities for purposes of determining vesting, eligibility and benefit levels for certain employees of the subsidiary and for determining vesting and eligibility for certain other employees of the subsidiary. The measurement date for these plans is December 31. Non-U.S. Plans The Company has defined benefit pension plans covering current and former employees associated with the Company's operations. These pension plans are closed to new participants. Benefits for employees for these plans are based primarily on employees' pay near retirement. These pension plans are unfunded and have no plan assets. The measurement date for the non-U.S. plans is December 31. Details of the changes in benefit obligations, plan assets and funded status of the Company's pension plans are as follows: 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 648 $ 136 $ 807 $ 142 Service cost 3 2 3 2 Interest cost 23 3 24 3 Actuarial loss (gain) 80 14 (43 ) — Benefits paid (51 ) (4 ) (40 ) (4 ) Plan amendments — (4 ) — — Settlements — (1 ) (103 ) — Foreign exchange effects — (2 ) — (7 ) Benefit obligation, end of year $ 703 $ 144 $ 648 $ 136 Change in plan assets Fair value of plan assets, beginning of year $ 486 $ 17 $ 650 $ 18 Actual return 92 1 (22 ) — Employer contribution 2 — 3 1 Benefits paid (51 ) — (40 ) (1 ) Administrative expenses paid (3 ) — (2 ) — Settlements — — (103 ) — Foreign exchange effects — 1 — (1 ) Fair value of plan assets, end of year $ 526 $ 19 $ 486 $ 17 Funded status, end of year $ (177 ) $ (125 ) $ (162 ) $ (119 ) 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (2 ) $ (2 ) $ (2 ) $ (3 ) Noncurrent liabilities (175 ) (123 ) (160 ) (116 ) Net amount recognized $ (177 ) $ (125 ) $ (162 ) $ (119 ) 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income (loss) Net loss (gain) $ (16 ) $ 22 $ (36 ) $ 9 Prior service cost — (4 ) — — Total before tax (1) $ (16 ) $ 18 $ (36 ) $ 9 ______________________________ (1) After-tax totals for pension benefits were $0 and $22 for 2019 and 2018 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive income (loss). In the U.S., the Pension Protection Act of 2006 (the "Pension Protection Act") established a relationship between a qualified pension plan's funded status and the actual benefits that can be provided. Restrictions on plan benefits and additional funding and notice requirements are imposed when a plan's funded status is less than certain threshold levels. For the 2019 plan year, the funded status for the Company's U.S. pension plans are above 80% and, as such, are exempt from the Pension Protection Act's benefit restrictions. Pension plans with an accumulated benefit obligation in excess of plan assets at December 31 are as follows: 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Information for pension plans with an accumulated benefit obligation in excess of plan assets Projected benefit obligation $ (703 ) $ (143 ) $ (648 ) $ (128 ) Accumulated benefit obligation (703 ) (138 ) (648 ) (125 ) Fair value of plan assets 526 18 486 10 The following table provides the components of net periodic benefit costs, other changes in plan assets and benefit obligation recognized in other comprehensive income. Year Ended December 31, 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Components of net periodic benefit cost Service cost $ 3 $ 2 $ 3 $ 2 $ 3 $ 2 Administrative expenses 4 — 3 — 2 — Interest cost 23 3 24 3 25 2 Expected return on plan assets (33 ) (1 ) (42 ) (1 ) (40 ) (1 ) Net amortization — — (1 ) 1 1 1 Settlement gain — — (14 ) — — — Net periodic benefit cost (gain) $ (3 ) $ 4 $ (27 ) $ 5 $ (9 ) $ 4 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net loss (gain) emerging $ 20 $ 13 $ 20 $ 1 $ (18 ) $ — Settlement gain — — 14 — — — Effect of plan change — (4 ) — — — — Amortization of net gain (loss) — — 1 (1 ) (1 ) (1 ) Total recognized in OCI $ 20 $ 9 $ 35 $ — $ (19 ) $ (1 ) Total net periodic benefit cost and OCI $ 17 $ 13 $ 8 $ 5 $ (28 ) $ 3 The estimated prior service cost and net loss for the defined benefit plans to be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost during 2020 are expected to be zero and $1 , respectively. During 2018, the Company's U.S. pension plans settled portions of their projected benefit obligations through the purchase of annuities and lump sum payments to certain participants. In conjunction with the settlement, the Company also remeasured the pension obligations and plan assets of the affected plans, resulting in a $26 increase in accumulated other comprehensive income (loss) before tax and a corresponding decrease in net pension liabilities recorded in the consolidated balance sheets. During 2018, the Company recognized a $14 one-time settlement gain in other income, net, which was reclassified from accumulated other comprehensive income (loss). The weighted-average assumptions used to determine pension plan obligations and net periodic benefit costs for the plans are as follows: 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 3.0 % 1.3 % 4.1 % 2.0 % 3.4 % 1.8 % Rate of compensation increase — % 2.6 % — % 2.6 % — % 2.6 % Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 4.1 % 2.0 % 3.4 % 1.8 % 3.8 % 1.8 % Discount rate for service cost 4.2 % 2.2 % 3.8 % 2.0 % 4.1 % 1.9 % Discount rate for interest cost 3.7 % 2.2 % 3.3 % 2.0 % 3.2 % 2.0 % Expected return on plan assets 7.0 % 4.0 % 7.0 % 3.8 % 6.8 % 3.8 % Rate of compensation increase — % 2.6 % — % 2.6 % — % 2.6 % The discount rates for the Company's U.S. and non-U.S. plans are determined using a benchmark pension discount curve and applying spot rates from the curve to each year of expected benefit payments to determine the appropriate discount rate for the Company. The assumed long-term return on plan assets is estimated by considering factors such as the plan's overall investment strategy, current economic conditions and historical averages. The Company's U.S. pension plan investments are held in the Westlake Defined Benefit Plan. The Company's overall investment strategy for these pension plan assets is to achieve a balance between moderate income generation and capital appreciation. The investment strategy includes a mix of approximately 60% of investments for long-term growth, and 40% for near-term benefit payments with a diversification of asset types. These pension funds' investment policies target asset allocations from approximately 60% equity securities and 40% fixed income securities in order to pursue a balance between moderate income generation and capital appreciation. Equity securities primarily include investments in large-cap and small-cap companies located in the U.S. and international developed and emerging markets stocks. Fixed income securities are comprised of investment and non-investment grade bonds, including U.S. Treasuries and U.S. and non-U.S. corporate bonds of companies from diversified industries. Each pension fund investment policy allows a discretionary range in various asset classes within the asset allocation model of up to 10% . The Company does not believe that there are significant concentrations of risk in the pension plan assets due to its strategy of asset diversification. At December 31, 2019 , plan assets did not include direct ownership of the Company's common stock. Under the accounting guidance for fair value measurements, inputs used to measure fair value are classified in one of three levels: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data. The investments in the collective trust and mutual funds are valued using a market approach based on the net asset value of units held. The fair values of the Company's U.S. plan assets at December 31, by asset category, are as follows: 2019 U.S. Plans Non U.S. Plans Level 1 Level 2 Total Level 1 Level 2 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ 6 $ — $ 6 Common stock 15 — 15 — — — Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 49 112 161 — 1 1 Small-cap funds (2) 8 14 22 — — — International funds (3) 75 45 120 — 5 5 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 100 98 198 — 7 7 Short-term investment funds — 10 10 — — — $ 247 $ 279 $ 526 $ 6 $ 13 $ 19 2018 U.S. Plans Non U.S. Plans Level 1 Level 2 Total Level 1 Level 2 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ 5 $ — $ 5 Common stock 13 — 13 — — — Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 44 98 142 — 1 1 Small-cap funds (2) 6 13 19 — — — International funds (3) 64 38 102 — 5 5 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 96 102 198 — 6 6 Short-term investment funds — 12 12 — — — $ 223 $ 263 $ 486 $ 5 $ 12 $ 17 ______________________________ (1) Substantially all of the assets of these funds are invested in large-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (2) Substantially all of the assets of these funds are invested in small-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (3) Substantially all of the assets of these funds are invested in international companies in developed markets (excluding the U.S.). The remainder of the assets of these funds is invested in cash reserves. (4) This category represents investment grade bonds of U.S. issuers, including U.S. Treasury notes. The Company's funding policy for its U.S. plans is consistent with the minimum funding requirements of federal law and regulations, and based on preliminary estimates, the Company expects to make contributions of approximately $2 for the pension plans in 2020 . Multi-employer Plans Non-U.S. Plans The Company participates in two multi-employer plans, Pensionskasse der Mitarbeiter der Hoechst-Gruppe VVaG and Pensionskasse der Wacker-Chemie GmbH VVaG, which provide benefits to certain of the Company's employees in Germany. These multi-employer plans are closed to new participants. The benefit obligations are covered up to a certain salary threshold by contributions made by the Company and employees to the plans. Contributions to the Company's multi-employer plans are expensed as incurred and were as follows: Year Ended December 31, 2019 2018 2017 Non-U.S. Plans Non-U.S. Plans Non-U.S. Plans Contributions to multi-employer plans (1) $ 9 $ 7 $ 8 ______________________________ (1) The plan information for both the Pensionskasse der Mitarbeiter der Hoechst-Gruppe VVaG and Pensionskasse der Wacker-Chemie GmbH VVaG plans is publicly available. The plans provide fixed, monthly retirement payments on the basis of the credits earned by the participating employees. To the extent that the plans are underfunded, future contributions to the plans may increase and may be used to fund retirement benefits for employees related to other employers. The Company does not consider either of its multi-employer plans individually significant. Other Post-retirement Benefits In the U.S., the Company provides post-retirement healthcare and life insurance benefits for certain employees and their dependents who meet minimum age and service requirements. The Company has the right to modify or terminate some of these benefits. The Company also has a post-retirement plan in Canada which is unfunded and provides medical and life insurance benefits for certain employees and their dependents. The following table provides a reconciliation of the benefit obligations of the Company's unfunded post-retirement healthcare plans. 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 67 $ 3 $ 73 $ 3 Service cost 1 — 1 — Interest cost 2 — 2 — Actuarial loss (gain) 3 1 (1 ) — Benefits paid (8 ) — (8 ) — Benefit obligation, end of year $ 65 $ 4 $ 67 $ 3 Change in plan assets Fair value of plan assets, beginning of year $ — $ — $ — $ — Employer contribution 8 — 8 — Benefits paid (8 ) — (8 ) — Fair value of plan assets, end of year $ — $ — $ — $ — Funded status, end of year $ (65 ) $ (4 ) $ (67 ) $ (3 ) 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (8 ) $ — $ (8 ) $ — Noncurrent liabilities (57 ) (5 ) (59 ) (3 ) Net amount recognized $ (65 ) $ (5 ) $ (67 ) $ (3 ) 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income (loss) Net gain $ (3 ) $ — $ (6 ) $ — Total before tax (1) $ (3 ) $ — $ (6 ) $ — ______________________________ (1) After-tax totals for post-retirement healthcare benefits were $3 and $5 for 2019 and 2018 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive income (loss). The following table provides the components of net periodic benefit costs, other changes in plan assets and benefit obligation recognized in other comprehensive income. Year Ended December 31, 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Components of net periodic benefit cost Service cost $ 1 $ — $ 1 $ — $ 1 $ — Interest cost 2 — 2 — 2 — Net amortization — — — — — — Net periodic benefit cost $ 3 $ — $ 3 $ — $ 3 $ — Other changes in plan assets and benefit obligation recognized in OCI Net loss (gain) emerging $ 3 $ — $ (1 ) $ (1 ) $ (1 ) $ — Total recognized in OCI $ 3 $ — $ (1 ) $ (1 ) $ (1 ) $ — Total net periodic benefit cost and OCI $ 6 $ — $ 2 $ (1 ) $ 2 $ — The estimated prior service cost and net loss for the post-retirement healthcare benefit plans that will be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost during 2020 are both expected to be zero . The weighted-average assumptions used to determine post-retirement healthcare plan obligations and net periodic benefit costs for the plans are as follows: 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 2.5 % 3.2 % 3.7 % 3.9 % 3.0 % 4.0 % Health care cost trend rate - Initial rate 6.8 % 5.7 % 7.0 % 5.8 % 7.3 % 6.2 % - Ultimate rate 4.5 % 4.0 % 4.5 % 4.0 % 4.5 % 4.5 % - Years to ultimate 10 21 11 22 11 12 Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 3.7 % 3.9 % 3.0 % 3.6 % 3.3 % 3.3 % Discount rate for service cost 4.0 % 3.9 % 3.4 % 3.6 % 3.8 % 3.3 % Discount rate for interest cost 3.4 % 3.9 % 2.7 % 3.6 % 2.6 % 3.3 % Health care cost trend rate - Initial rate 7.0 % 5.8 % 7.0 % 6.1 % 6.8 % 6.8 % - Ultimate rate 4.5 % 4.0 % 4.5 % 4.5 % 4.6 % 4.5 % - Years to ultimate 10 21 10 11 11 12 The discount rate is determined using a benchmark pension discount curve and applying spot rates from the curve to each year of expected benefit payments to determine the appropriate discount rate for the Company. A one percentage-point increase or decrease in assumed healthcare trend rates would not have a significant effect on the amounts reported for the healthcare plans. Estimated Future Benefit Payments The following benefit payments are expected to be paid: Pension Benefits Other Post- retirement Benefits Estimated future benefit payments: Year 1 $ 45 $ 8 Year 2 45 8 Year 3 45 8 Year 4 47 8 Year 5 46 7 Years 6 to 10 233 22

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Compensation	Stock-Based Compensation Under the Westlake Chemical Corporation 2013 Omnibus Incentive Plan (as amended and restated in 2017, the "2013 Plan"), all employees and non-employee directors of the Company, as well as certain individuals who have agreed to become the Company's employees, are eligible for awards. Shares of common stock may be issued as authorized in the 2013 Plan. At the discretion of the administrator of the 2013 Plan, employees and non-employee directors may be granted awards in the form of stock options, stock appreciation rights, stock awards, restricted stock units or cash awards (any of which may be a performance award). Outstanding stock option awards have a 10 -year term and vest (1) ratably on an annual basis over a three-year period or (2) at the end of a five-year period. Outstanding restricted stock units and performance stock units vest either (1) ratably on an annual basis over a two to five-year period or (2) at the end of a three or six-year period. In accordance with accounting guidance related to share-based payments, stock-based compensation expense for all stock-based compensation awards is based on estimated grant-date fair value. The Company recognizes these stock-based compensation costs net of a forfeiture rate and on a straight-line basis over the requisite service period of the award for only those shares expected to vest. For the years ended December 31, 2019 , 2018 and 2017 , the total recognized stock-based compensation expense related to equity awards issued under the 2013 Plan was $24 , $18 and $14 , respectively. Option activity and changes during the year ended December 31, 2019 were as follows: Options Weighted Average Exercise Price Weighted Average Remaining Term (Years) Aggregate Intrinsic Value Outstanding at December 31, 2018 1,115,954 $ 54.82 Granted 296,598 79.83 Exercised (18,635 ) 35.04 Cancelled (7,969 ) 79.94 Outstanding at December 31, 2019 1,385,948 $ 60.29 5.9 $ 23 Exercisable at December 31, 2019 888,093 $ 47.64 4.5 $ 22 For options outstanding at December 31, 2019 , the options had the following range of exercise prices: Range of Prices Options Outstanding Weighted Average Remaining Contractual Life (Years) $10.26 - $30.05 264,334 1.0 $40.38 - $44.42 218,047 6.1 $45.70 - $61.87 295,620 6.5 $63.98 - $68.18 145,171 4.7 $79.83 - $107.75 462,776 8.8 The aggregate intrinsic value in the table above represents the total pretax intrinsic value (the difference between the Company's closing stock price on the last trading day of the year and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2019 . This amount changes based on the fair market value of the Company's common stock. For the years ended December 31, 2019 , 2018 and 2017 , the total intrinsic value of options exercised was $1 , $21 and $24 , respectively. As of December 31, 2019 , $6 of total unrecognized compensation cost related to stock options is expected to be recognized over a weighted-average period of 1.8 years. Income tax benefits of $0 , $4 and $8 were realized from the exercise of stock options during the years ended December 31, 2019 , 2018 and 2017 , respectively. The Company used the Black-Scholes option pricing model to value its options. The table below presents the weighted average value and assumptions used in determining each option's fair value. Volatility was calculated using historical trends of the Company's common stock price. Stock Option Grants Year Ended December 31, 2019 2018 2017 Weighted average fair value $ 21.02 $ 28.94 $ 15.84 Risk-free interest rate 2.5 % 2.7 % 2.1 % Expected life in years 5 5 5 Expected volatility 28.9 % 27.6 % 29.2 % Expected dividend yield 1.2 % 0.7 % 1.2 % Non-vested restricted stock units as of December 31, 2019 and changes during the year ended December 31, 2019 were as follows: Number of Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2018 702,789 $ 65.79 Granted 205,517 77.59 Vested (415,593 ) 56.70 Forfeited (29,430 ) 73.28 Non-vested at December 31, 2019 463,283 $ 78.69 As of December 31, 2019 , there was $15 of unrecognized stock-based compensation expense related to non-vested restricted stock units. This cost is expected to be recognized over a weighted-average period of 1.7 years. The total fair value of restricted stock units that vested during the years ended December 31, 2019 , 2018 and 2017 was $28 , $10 and $6 , respectively. Performance stock unit payout is based on the greater of the average annual economic-value added results for the Company (equal to net operating profit after tax less a capital charge based upon the weighted average cost of capital) and relative total shareholder return as compared to a peer group of companies. The units have payouts that range from zero to 200 percent of the target award. Non-vested performance stock units as of December 31, 2019 and changes during the year ended December 31, 2019 were as follows: Number of Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2018 — $ — Granted 78,328 114.38 Vested — — Forfeited (1,111 ) 114.38 Non-vested at December 31, 2019 77,217 $ 114.38 As of December 31, 2019 , there was $6 of unrecognized stock-based compensation expense related to non-vested performance stock units. This cost is expected to be recognized over a weighted-average period of 2.1 years. There were no such awards issued during the years ended December 31, 2018 and 2017 . The Company used a Monte Carlo simulation model to value the performance stock units on the grant date. The table below presents the assumptions used in determining grant date fair value. Volatility was calculated using historical trends of the Company's common stock price. Year Ended December 31, 2019 Performance Stock Units Risk-free interest rate 2.5 % Expected life in years 2.88 Expected volatility of Westlake Chemical Corporation common stock 30.3 % Expected volatility of peer companies 14.5% - 47.8% Average correlation coefficient of peer companies 0.49 Grant date fair value $ 114.38 Liability Classified Awards Certain of the Company's restricted stock unit awards are classified as liability awards for accounting purposes and are re-measured at each reporting date until they vest. Total stock-based compensation expense recognized related to these restricted stock units during the years ended December 31, 2019 , 2018 , and 2017 was $1 , $4 and $9 , respectively. Non-vested liability classified restricted stock awards as of December 31, 2019 and changes during the year ended December 31, 2019 were as follows: Number of Units Weighted Average Fair Value Non-vested at December 31, 2018 49,528 $ 66.46 Vested (49,292 ) 68.22 Cancelled (236 ) 76.77 Non-vested at December 31, 2019 — — As of December 31, 2019 , there was no unrecognized stock-based compensation expense related to non-vested liability classified restricted stock awards. The total fair value of liability classified restricted stock awards that vested during the years ended December 31, 2019 , 2018 and 2017 was $3 , $6 and $11 , respectively. The total fair value of liability classified restricted stock awards cancelled during the year ended December 31, 2019 was $0 . Westlake Chemical Partners LP Awards The Company's wholly-owned subsidiary and the general partner of Westlake Partners, Westlake Chemical Partners GP LLC ("Westlake Partners GP"), maintains a unit-based compensation plan for directors and employees of WLKP GP and Westlake Partners. The Westlake Partners 2014 Long-term Incentive Plan ("Westlake Partners 2014 Plan") permits various types of equity awards including but not limited to grants of phantom units and restricted units. Awards granted under the Westlake Partners 2014 Plan may be settled with Westlake Partners units or in cash or a combination thereof. Compensation expense for these awards was not material to the Company's consolidated financial statements for the years ended December 31, 2019 , 2018 and 2017 .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company has financial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and long-term debt, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Company's long-term debt at December 31, 2019 and 2018 are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy. 2019 2018 Carrying Value Fair Value Carrying Value Fair Value 3.60% 2022 Senior Notes $ 249 $ 255 $ 249 $ 248 3.60% 2026 Senior Notes 742 777 741 692 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 11 11 6 ½% 2029 GO Zone Senior Notes 99 103 99 106 6 ½% 2035 GO Zone Senior Notes 88 92 88 95 6 ½% 2035 IKE Zone Senior Notes 65 68 65 69 5.0% 2046 Senior Notes 677 761 676 641 4.375% 2047 Senior Notes 491 505 491 417 3.50% 2032 GO Zone Refunding Senior Notes 249 267 248 233 1.625% 2029 Senior Notes 774 785 — —

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income before income taxes are as follows: Year Ended December 31, 2019 2018 2017 Domestic $ 460 $ 1,087 $ 917 Foreign 110 247 164 $ 570 $ 1,334 $ 1,081 The Company's provision for (benefit from) income taxes consists of the following: Year Ended December 31, 2019 2018 2017 Current Federal $ 20 $ 158 $ 231 State 9 28 18 Foreign 25 52 27 Total current 54 238 276 Deferred Federal 69 59 (557 ) State 11 (2 ) 25 Foreign (26 ) 5 (2 ) Total deferred 54 62 (534 ) Total provision for (benefit from) income taxes $ 108 $ 300 $ (258 ) A reconciliation of taxes computed at the statutory rate to the Company's income tax expense is as follows: Year Ended December 31, 2019 2018 2017 Provision for federal income tax, at statutory rate $ 120 $ 280 $ 378 State income tax provision, net of federal income tax effect 10 28 26 Foreign income tax rate differential (6 ) 14 (36 ) Manufacturing deduction — — (23 ) Depletion (5 ) (4 ) (7 ) Noncontrolling interests (8 ) (6 ) (9 ) Tax Act related adjustment — — (591 ) Change in valuation allowance (17 ) (9 ) 3 Changes in state apportionment and other state adjustments 11 (6 ) 2 Other, net 3 3 (1 ) Total income tax expense (benefit) $ 108 $ 300 $ (258 ) The tax effects of the principal temporary differences between financial reporting and income tax reporting at December 31 are as follows: 2019 2018 Net operating loss carryforward $ 209 $ 50 Credit carryforward 25 24 Operating lease liabilities 96 — Accruals 65 64 Pension 83 76 Inventories 20 13 Other 26 17 Deferred taxes assets—total 524 244 Property, plant and equipment (1,017 ) (948 ) Intangibles (156 ) (148 ) Operating lease right-of-use asset (95 ) — Turnaround costs (21 ) (20 ) Consolidated partnerships (194 ) (202 ) Equity method investments (220 ) (13 ) Other (18 ) (14 ) Deferred tax liabilities—total (1,721 ) (1,345 ) Valuation allowance (30 ) (47 ) Total net deferred tax liabilities $ (1,227 ) $ (1,148 ) Balance sheet classifications Noncurrent deferred tax asset $ 28 $ 11 Noncurrent deferred tax liability (1,255 ) (1,159 ) Total net deferred tax liabilities $ (1,227 ) $ (1,148 ) At December 31, 2019 , the Company had federal, foreign and state net operating loss carryforwards ("NOLs") of approximately $539 , $217 and $613 , respectively. The increase in the federal and state NOLs is primarily due to bonus tax depreciation from the Company's investment in LACC accounted for as an equity method investment. The federal NOL and certain foreign and state NOLs do not expire, while certain other foreign and state NOLs expire in varying amounts between 2020 and 2039. Certain NOLs are subject to limitations on an annual basis. At December 31, 2019, the Company had various federal, foreign and state credits carryforwards of $2 , $4 and $19 , respectively, which either do not expire or expire in varying amounts between 2020 and 2033. Management believes the Company will realize the benefit of a portion of the net operating loss carryforwards before they expire, but to the extent that the full benefit may not be realized, a valuation allowance has been recorded. The valuation allowance decreased by $17 in 2019 , primarily due to a $19 release in valuation allowance resulting from a change in management judgment regarding the realizability of certain foreign deferred tax assets, including net operating loss and credit carryforwards, as a result of the change in expectations of income in future years. As result of the Tax Act, the Company recognized an income tax benefit of $591 in the 2017 consolidated financial statements for items such as a revaluation of deferred tax assets and liabilities, partially offset by a one-time U.S. tax on the mandatory deemed repatriation of the Company's post-1986 foreign earnings. The Company did not record any material measurement period adjustment in 2018. The accounting for the income tax effects of the Tax Act was completed in 2018. The Company files income tax returns in the U.S. federal jurisdiction, various states and foreign jurisdictions. The Company is no longer subject to examinations by tax authorities before the year 2012.

Earnings and Dividends per Shar

Earnings and Dividends per Share	12 Months Ended
	Dec. 31, 2019
Earnings and Dividends Per Share [Abstract]
Earnings per Share	Earnings and Dividends per Share The Company has unvested restricted stock units outstanding that are considered participating securities and, therefore, computes basic and diluted earnings per share under the two-class method. Basic earnings per share for the periods are based upon the weighted average number of shares of common stock outstanding during the periods. Diluted earnings per share include the effect of certain stock options and performance stock units. Year Ended December 31, 2019 2018 2017 Net income attributable to Westlake Chemical Corporation $ 421 $ 996 $ 1,304 Less: Net income attributable to participating securities (2 ) (5 ) (7 ) Net income attributable to common shareholders $ 419 $ 991 $ 1,297 The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Year Ended December 31, 2019 2018 2017 Weighted average common shares—basic 128,395,184 129,401,823 129,087,043 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 362,109 583,930 452,970 Weighted average common shares—diluted 128,757,293 129,985,753 129,540,013 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 3.26 $ 7.66 $ 10.05 Diluted $ 3.25 $ 7.62 $ 10.00 Excluded from the computation of diluted earnings per share for the years ended December 31, 2019 and 2018 are options to purchase 562,773 and 150,479 shares of common stock, respectively. There are no antidilutive options to purchase shares of common stock for the year ended December 31, 2017 . These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive. Dividends per Share Dividends per common share for the years ended December 31, 2019 , 2018 and 2017 were as follows: Year Ended December 31, 2019 2018 2017 Dividends per common share $ 1.0250 $ 0.9200 $ 0.8012

Supplemental Information

Supplemental Information	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Information	Supplemental Information Accrued Liabilities Accrued liabilities were $768 and $676 at December 31, 2019 and 2018 , respectively. Accrued rebates, which is a component of accrued liabilities, was $115 and $125 at December 31, 2019 and 2018 , respectively. Other than the lease liability disclosed in Note 7, no other component of accrued and other liabilities was more than five percent of total current liabilities. Accrued liabilities with related parties were $41 and $54 at December 31, 2019 and 2018 , respectively. Non-cash Investing Activity The change in capital expenditure accruals increasing additions to property, plant and equipment was $14 for the year ended December 31, 2019 . The change in capital expenditure accruals reducing additions to property, plant and equipment was $48 and $9 for the years ended December 31, 2018 and 2017 , respectively. Restructuring, Transaction and Integration-related Costs For the year ended December 31, 2019 , the restructuring, transaction and integration-related costs of $37 primarily consisted of restructuring expenses of $26 and acquisition costs. The restructuring expenses represent charges associated with the write-off of certain assets in the Vinyls segment. For the year ended December 31, 2018 , the restructuring, transaction and integration-related costs of $33 primarily consisted of integration-related consulting fees and acquisition costs. Other Income, Net For the year ended December 31, 2019 , other income, net included income from unconsolidated subsidiaries and interest income of $17 and $20 , respectively. For the year ended December 31, 2018 , other income, net included income from pension and post-retirement plans, including a one-time settlement gain, income from unconsolidated subsidiaries and interest income of $25 , $16 and $17 , respectively. For the year ended December 31, 2017 , other income, net included income from unconsolidated subsidiaries of $10 . No other components of other income, net were material to the statements of operations for the years ended December 31, 2019 , 2018 and 2017 . Operating Lease Supplemental Cash Flow Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2019 Operating cash flows from operating leases (1) $ 112 Right-of-use assets obtained in exchange for operating lease obligations 119 _____________ (1) Includes cash paid for amounts included in the measurement of operating lease liabilities recorded in the consolidated balance sheets. Cash Flow Information Year Ended December 31, 2019 2018 2017 Cash paid for: Interest paid, net of interest capitalized $ 116 $ 140 $ 154 Income taxes paid 77 376 84

Related Party and Affiliate Tra

Related Party and Affiliate Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related Party And Affiliate Transactions	Related Party and Affiliate Transactions The Company and Lotte have a joint venture, LACC, to design, build and operate an ethylene facility with 2.2 billion pounds per year of ethylene production capacity. See Note 9 for details of the Company's transactions with LACC. The Company leases office space for management and administrative services from an affiliate of the Company's principal stockholder. For each of the years ended December 31, 2019 , 2018 and 2017 , the Company incurred lease payments of approximately $3 . Cypress Interstate Pipeline L.L.C., a natural gas liquids pipeline joint venture company in which the Company owns a 50% equity stake, transports natural gas liquid feedstocks to the Company's Lake Charles complex through its pipeline. The Company accounts for its investments in Cypress Interstate Pipeline L.L.C. under the equity method of accounting. The investment in Cypress Interstate Pipeline L.L.C. at December 31, 2019 and 2018 was $8 and $8 , respectively. For the years ended December 31, 2019 , 2018 and 2017 , the Company incurred pipeline lease service fees of approximately $14 , $14 and $15 , respectively, payable to this joint venture for usage of the pipeline. The amounts due to this joint venture were $1 and $2 at December 31, 2019 and 2018 , respectively. The Company owns an approximately 20% interest in both YNCORIS GmbH & Co. KG (formerly known as InfraServ Knapsack GmbH & Co. KG) and InfraServ Gendorf GmbH & Co. KG (collectively "Infraserv"). The Company accounts for its investments in Infraserv under the equity method of accounting. The Company has service agreements with these entities, including contracts to provide electricity, technical and leasing services to certain of the Company's production facilities in Germany. The investment in Infraserv was $57 and $57 at December 31, 2019 and 2018 , respectively. For the years ended December 31, 2019 , 2018 and 2017 , the Company incurred charges aggregating approximately $155 , $145 and $133 , respectively, for these services. The amounts accrued for these related parties were approximately $36 and $48 at December 31, 2019 and 2018 , respectively. The Company owns a 50% interest in RS Cogen LLC ("RS Cogen"). RS Cogen operates a process steam, natural gas-fired cogeneration facility adjacent to the Lake Charles South Facility. The Company accounts for its investment in RS Cogen under the equity method of accounting. The investment in RS Cogen at December 31, 2019 and 2018 was $9 and $5 , respectively. For the years ended December 31, 2019 , 2018 and 2017 , the Company recorded purchases of approximately $26 , $25 and $26 from RS Cogen, respectively. The Company owns a 50% interest in Vinyl Solutions, LLC ("Vinyl Solutions"). The Company accounts for its investments in Vinyl Solutions under the equity method of accounting. Vinyl Solutions is a compounding manufacturer of specialty compounds. For the years ended December 31, 2019 , 2018 and 2017 , the Company recorded sales of $5 , $13 and $17 , respectively, to Vinyl Solutions. The amounts receivable from this related party were $2 and $3 at December 31, 2019 and 2018 , respectively. Dividends received from equity method investments were $11 , $5 and $6 for the years ended December 31, 2019 , 2018 and 2017 , respectively. One of the Company's directors serves as Chairman, Chief Executive Officer and President of American Air Liquide Holdings, Inc. and Executive Vice President of the Air Liquide Group ("Air Liquide"). The Company purchased oxygen, nitrogen and utilities and leased cylinders from various affiliates of American Air Liquide Holdings, Inc. including Airgas and subsidiaries that were acquired in 2016 by Air Liquide aggregating approximately $32 , $31 and $30 for the years ended December 31, 2019 , 2018 and 2017 , respectively. The Company also sold certain utilities to Air Liquide aggregating approximately $7 , $7 and $7 during the years ended December 31, 2019 , 2018 and 2017 , respectively. The amounts payable to Air Liquide were $2 and $4 at December 31, 2019 and 2018 , respectively, and the amounts receivable from Air Liquide were $0 and $1 at December 31, 2019 and 2018 , respectively.

Westlake Chemical Partners LP

Westlake Chemical Partners LP	12 Months Ended
	Dec. 31, 2019
Partners' Capital [Abstract]
Westlake Chemical Partners LP	Westlake Chemical Partners LP In 2014, the Company formed Westlake Partners to operate, acquire and develop ethylene production facilities and related assets. Also in 2014, Westlake Partners completed its initial public offering of 12,937,500 common units. On March 29, 2019, Westlake Partners purchased an additional 4.5% newly issued limited partner interests in OpCo for approximately $201 and completed a private placement of 2,940,818 common units at a price of $21.40 per common unit for total proceeds of approximately $63 . TTWF LP, the Company's principal stockholder and a related party, acquired 1,401,869 units out of the 2,940,818 common units issued in the private placement. At December 31, 2019 , Westlake Partners had a 22.8% limited partner interest in OpCo, and the Company retained a 77.2% limited partner interest in OpCo and a significant interest in Westlake Partners through the Company's ownership of Westlake Partners' general partner, 40.1% of the limited partner interests (consisting of 14,122,230 common units) and incentive distribution rights. On October 4, 2018, Westlake Partners and Westlake Partners GP, the general partner of Westlake Partners, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell Westlake Partners' common units, from time to time, up to an aggregate offering amount of $50 . No common units were issued under this program in 2019 and 2018.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies The Company is involved in a number of legal and regulatory matters, principally environmental in nature, that are incidental to the normal conduct of its business, including lawsuits, investigations and claims. The outcome of these matters are inherently unpredictable. The Company believes that, in the aggregate, the outcome of all known legal and regulatory matters will not have a material adverse effect on its consolidated financial statements; however, under certain circumstances, if required to recognize costs in a specific period, when combined with other factors, outcomes with respect to such matters may be material to the Company's consolidated statements of operations in such period. The Company's assessment of the potential impact of environmental matters, in particular, is subject to uncertainty due to the complex, ongoing and evolving process of investigation and remediation of such environmental matters, and the potential for technological and regulatory developments. In addition, the impact of evolving claims and programs, such as natural resource damage claims, industrial site reuse initiatives and state remediation programs creates further uncertainty of the ultimate resolution of these matters. The Company anticipates that the resolution of many legal and regulatory matters, and in particular environmental matters, will occur over an extended period of time. 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. Plaintiffs seek an unspecified amount of damages and injunctive relief. The Company has already moved to dismiss the majority of the lawsuits filed and plans to file similar motions with respect to the remaining lawsuits. 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 December 31, 2019 and 2018 , the Company had reserves for environmental contingencies totaling approximately $47 and $54 , 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, 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 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 are the subject of further litigation as 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 has until March 10, 2020 to appeal that order. At this time, the Company is not able to estimate the impact, if any, that the issuance of the final award in the arbitration proceeding, or any subsequent 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 . Other Commitments The Company has various unconditional purchase obligations, primarily to purchase goods and services, including commitments to purchase various utilities, feedstock, nitrogen, oxygen, product storage and pipeline usage. Unrecorded unconditional purchase obligations for the next five years are as follows: $584 , $621 , $497 , $461 and $360 in 2020 , 2021 , 2022 , 2023 and 2024

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment and Geographic Information	Segment and Geographic Information Segment 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. The Company's Olefins segment manufactures and markets polyethylene, styrene monomer and various ethylene co-products. The Company's ethylene production is used in the Company's polyethylene, styrene and VCM operations. In addition, the Company sells ethylene and ethylene co-products, primarily propylene, crude butadiene, pyrolysis gasoline and hydrogen, to external customers. No single customer accounted for more than 10% of sales in the Olefins segment for the years ended December 31, 2019 , 2018 or 2017 . The Company's Vinyl segment manufactures and markets PVC, VCM, ethylene dichloride ("EDC"), chlor-alkali (chlorine and caustic soda), chlorinated derivative products and ethylene. The Company also manufactures and sells building products fabricated primarily from PVC, including residential siding, trim and mouldings, pipe and fittings for various water, sewer and industrial applications, profiles for windows and doors, decking products, film for various inflatables, wall covering tapes, roofing applications and composite roof tiles. The Company's primary North American chemical manufacturing facilities are located in its Calvert City, Kentucky and Lake Charles, Plaquemine and Geismar, Louisiana sites. The Company also produces chlorine, caustic soda, hydrogen and chlorinated derivative products at its facilities in Natrium, Longview, Washington and Beauharnois, Quebec and PVC resin and PVC compounds at several facilities in Mississippi. In addition to North America, the Company also has manufacturing facilities in Europe and Asia. As of December 31, 2019 , the Company owned 36 building products and PVC compound facilities. The Company primarily uses its chlorine, VCM and PVC production to manufacture its building products. No single customer accounted for more than 10% of sales in the Vinyls segment for the years ended December 31, 2019 , 2018 or 2017 . The accounting policies of the individual segments are the same as those described in Note 1. Year Ended December 31, 2019 2018 2017 Net external sales Olefins Polyethylene $ 1,301 $ 1,519 $ 1,518 Styrene, feedstock and other 481 500 533 Total olefins 1,782 2,019 2,051 Vinyls PVC, caustic soda and other 5,068 5,359 4,769 Building products 1,268 1,257 1,221 Total vinyls 6,336 6,616 5,990 $ 8,118 $ 8,635 $ 8,041 Intersegment sales Olefins $ 324 $ 500 $ 393 Vinyls 1 2 1 $ 325 $ 502 $ 394 Income (loss) from operations Olefins $ 260 $ 573 $ 655 Vinyls 451 913 639 Corporate and other (55 ) (78 ) (69 ) $ 656 $ 1,408 $ 1,225 Depreciation and amortization Olefins $ 142 $ 138 $ 145 Vinyls 563 491 449 Corporate and other 8 12 7 $ 713 $ 641 $ 601 Other income, net Olefins $ 5 $ 4 $ 3 Vinyls 18 35 7 Corporate and other 15 13 5 $ 38 $ 52 $ 15 Provision for (benefit from) income taxes Olefins $ 60 $ 128 $ 63 Vinyls 40 212 (302 ) Corporate and other 8 (40 ) (19 ) $ 108 $ 300 $ (258 ) Capital expenditures Olefins $ 117 $ 110 $ 97 Vinyls 664 585 459 Corporate and other 6 7 21 $ 787 $ 702 $ 577 A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Year Ended December 31, 2019 2018 2017 Income from operations for reportable segments $ 656 $ 1,408 $ 1,225 Interest expense (124 ) (126 ) (159 ) Other income, net 38 52 15 Income before income taxes $ 570 $ 1,334 $ 1,081 December 31, 2019 December 31, 2018 Total assets Olefins $ 1,991 $ 2,024 Vinyls 10,597 8,879 Corporate and other 673 699 $ 13,261 $ 11,602 Geographic Information Year Ended December 31, 2019 2018 2017 Net sales to external customers (1) United States $ 5,530 $ 6,114 $ 5,739 Foreign Canada 573 649 653 Germany 478 500 432 China 175 155 104 Italy 119 105 96 Taiwan 84 102 96 Other 1,159 1,010 921 $ 8,118 $ 8,635 $ 8,041 December 31, 2019 December 31, 2018 Long-lived assets United States $ 6,012 $ 5,829 Foreign Germany 588 528 Other 312 238 $ 6,912 $ 6,595 ______________________________ (1) Net sales are attributed to countries based on location of customer.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	Quarterly Financial Information (Unaudited) Three Months Ended March 31, June 30, September 30, December 31, Net sales $ 2,025 $ 2,144 $ 2,066 $ 1,883 Gross profit 299 340 371 250 Income from operations 134 194 226 102 Net income 82 129 166 85 Net income attributable to Westlake Chemical Corporation 72 119 158 72 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 0.56 $ 0.92 $ 1.22 $ 0.56 Diluted $ 0.55 $ 0.92 $ 1.22 $ 0.56 Three Months Ended March 31, June 30, September 30, December 31, Net sales $ 2,150 $ 2,235 $ 2,255 $ 1,995 Gross profit 542 552 539 354 Income from operations 401 404 396 207 Net income 297 288 318 131 Net income attributable to Westlake Chemical Corporation 287 278 308 123 Earnings per common share attributable to Westlake Chemical Corporation: (1) Basic $ 2.21 $ 2.13 $ 2.36 $ 0.95 Diluted $ 2.20 $ 2.12 $ 2.35 $ 0.95 ______________________________ (1) Basic and diluted earnings per common share ("EPS") for each quarter is computed using the weighted average shares outstanding during that quarter, while EPS for the year is computed using the weighted average shares outstanding for the year. As a result, the sum of the EPS for each of the four quarters may not equal the EPS for the year.

Description of Business and S_2

Description of Business and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Westlake Chemical Corporation (the "Company") operates as an integrated global manufacturer and marketer of basic chemicals, vinyls, polymers and building products. These products include some of the most widely used chemicals in the world, which are fundamental to many diverse consumer and industrial markets, including flexible and rigid packaging, automotive products, coatings, residential and commercial construction as well as other durable and non-durable goods. The Company's customers range from large chemical processors and plastics fabricators to small construction contractors, municipalities and supply warehouses primarily throughout North America and Europe. The petrochemical industry is subject to price fluctuations and volatile feedstock pricing typical of a commodity-based industry, the effects of which may not be immediately passed along to customers.
Westlake Chemical Partners LP	Westlake Chemical Partners LP In 2014, the Company formed Westlake Chemical Partners LP ("Westlake Partners") to operate, acquire and develop ethylene production facilities and related assets. Westlake Partners' assets consist of a limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in OpCo. OpCo's assets include two ethylene production facilities at the Company's Lake Charles, Louisiana site, one ethylene production facility at the Company's Calvert City, Kentucky site and a 200 -mile common carrier ethylene pipeline that runs from Mont Belvieu, Texas to the Company's Longview, Texas site. As of December 31, 2019 , the Company held a 77.2% limited partner interest in OpCo and a controlling interest in Westlake Partners. The operations of Westlake Partners are consolidated in the Company's financial statements.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and subsidiaries in which the Company directly or indirectly owns more than a 50% voting interest and exercises control and, when applicable, entities for which the Company has a controlling financial interest or is the primary beneficiary. Investments in majority-owned companies where the Company does not exercise control and investments in nonconsolidated affiliates (20%-50% owned companies, joint ventures and partnerships) are accounted for using the equity method of accounting. Undistributed earnings from joint ventures included in retained earnings were immaterial as of December 31, 2019 . All intercompany transactions and balances are eliminated in consolidation. Certain reclassifications have been made to the prior-year financial statements to conform to the current-year presentation. Noncontrolling interests represent the direct equity interests held by investors in the Company's consolidated subsidiaries, Westlake Partners, Taiwan Chlorine Industries, Ltd. and Suzhou Huasu Plastics Co., Ltd.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents consist of highly liquid investments that are readily convertible into cash and have a maturity of three months or less at the date of acquisition.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments which potentially subject the Company to concentration of risk consist principally of trade receivables from customers engaged in manufacturing polyethylene products, polyvinyl chloride ("PVC") products and PVC pipe products. The Company performs periodic credit evaluations of the customers' financial condition and generally does not require collateral. The Company maintains allowances for potential losses.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The determination of the allowance for doubtful accounts is based on estimation of the amount of accounts receivable that the Company believes are unlikely to be collected. Estimating this amount requires analysis of the financial strength of the Company's customers, the use of historical experience, the Company's accounts receivable aged trial balance, and specific collectibility analysis. The allowance for doubtful accounts is reviewed quarterly. Past due balances over 90 days and high risk accounts as determined by the analysis of financial strength of customers are reviewed individually for collectibility.
Inventories	Inventories
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are carried at cost, net of accumulated depreciation. Cost includes expenditures for improvements and betterments that extend the useful lives of the assets and interest capitalized on significant capital projects. Capitalized interest was $9 , $7 and $4 for the years ended December 31, 2019 , 2018 and 2017 , respectively. Repair and maintenance costs are charged to operations as incurred. Gains and losses on the disposition or retirement of fixed assets are reflected in the consolidated statement of operations when the assets are sold or retired. Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 40 Plant and equipment 10-25 Other 3-15
Impairment of Long-Lived Assets and Impairment of Goodwill and Intangible Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Long-lived assets assessed for impairment are grouped at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net undiscounted cash flows expected to be generated by the asset. Assets are considered to be impaired if the carrying amount of an asset exceeds the future undiscounted cash flows. The impairment recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or estimated fair value less costs to sell. Impairment of Goodwill and Intangible Assets Goodwill is tested for impairment at least annually, or when events or changes in circumstances indicate the fair value of a reporting unit with goodwill has been reduced below its carrying value. The Company performed its annual impairment tests for the Olefins and Vinyls segments' goodwill in October 2019 and April 2019 , respectively, and the impairment tests indicated that the recorded goodwill was not impaired. There has been no impairment of the Olefins or Vinyls segments' goodwill since the goodwill was initially recorded. Other intangible assets with finite lives are amortized over their estimated useful lives and reviewed for impairment in accordance with the provisions of the accounting guidance. See Note 8 for more information on the Company's annual goodwill impairment tests.
Equity Method Investments	Equity Method Investments The Company accounts for investments using the equity method of accounting if the Company has the ability to exercise significant influence over, but not control of, an investee. Significant influence generally exists if the Company has an ownership interest representing between 20% and 50% of the voting rights. Under the equity method of accounting, investments are stated initially at cost and are adjusted for subsequent additional investments and the proportionate share of profit or losses and distributions. The Company records its share of the profits or losses of the equity investments, net of income taxes, in the consolidated statements of income. The equity method investments are evaluated for impairment when events or changes in circumstances indicate, in management's judgment, that the carrying value of such investments may have experienced an other-than-temporary decline in value. When evidence of loss in value has occurred, management compares the estimated fair value of investment to the carrying value of investment to determine whether an impairment has occurred. If the estimated fair value is less than the carrying value and management considers the decline in value to be other-than-temporary, the excess of the carrying value over the estimated fair value is recognized in the consolidated financial statements as an impairment.
Other Assets, Net	Other Assets, net Other assets, net include turnaround costs, investments in unconsolidated subsidiaries, restricted cash, deferred charges and other long-term assets. The Company accounts for turnaround costs under the deferral method. Turnarounds are the scheduled and required shutdowns of specific operating units in order to perform planned major maintenance activities. The costs related to the significant overhaul and refurbishment activities include maintenance materials, parts and direct labor costs. The costs of the turnaround are deferred when incurred at the time of the turnaround and amortized (within depreciation and amortization) on a straight-line basis until the next planned turnaround, which ranges from three to six years . Deferred turnaround costs are presented as a component of other assets, net. The cash outflows related to these costs are included in operating activities in the consolidated statement of cash flows.
Business Combinations	Business Combinations The Company records business combinations using the acquisition method of accounting. Under the acquisition method of accounting, identifiable assets acquired and liabilities assumed are recorded at their acquisition date fair values. The excess of the purchase price over the estimated fair value is recorded as goodwill. Changes in the estimated fair values of net assets recorded for acquisitions prior to the finalization of more detailed analysis, but not to exceed one year from the date of acquisition, will adjust the amount of the purchase price allocable to goodwill. Measurement period adjustments are reflected in the period in which they occur.
Income Taxes	Income Taxes The Company utilizes the liability method of accounting for deferred income taxes. Under the liability method, deferred tax assets or liabilities are recorded based upon temporary differences between the tax basis of assets and liabilities and their carrying values for financial reporting purposes. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities during the period. Valuation allowances are recorded against deferred tax assets when it is considered more likely than not that the deferred tax assets will not be realized. On December 22, 2017, the United States ("U.S.") Tax Cuts and Jobs Act (the "Tax Act") was signed into law. The Tax Act, among other changes, reduced the U.S. corporate income tax rate from 35% to 21%, effective January 1, 2018, and also required a one-time deemed repatriation of foreign earnings at specified rates. The Company provisionally recognized a $591 income tax benefit in the 2017 consolidated financial statements that was primarily comprised of the revaluation of deferred tax assets and liabilities partially offset by a one-time U.S. tax on the mandatory deemed repatriation of the Company's post-1986 foreign earnings. The Company did not record any material measurement period adjustment in 2018. The Company's accounting for the income tax effects of the Tax Act was completed in 2018. In February 2018, the FASB issued an accounting standards update, Income Statement — Reporting Comprehensive Income, to (1) allow reclassification from accumulated other comprehensive income (loss) to retained earnings for stranded tax effects resulting from the Tax Act; and (2) require certain disclosures about stranded tax effects. Certain tax effects become stranded in accumulated other comprehensive income (loss) when deferred tax balances originally recorded at the historical income tax rate are adjusted in income from operations based on the lower, newly-enacted income tax rate. The Company adopted the accounting standard effective October 1, 2018 and reclassified $13 of stranded tax effects relating to its pension benefits liability and cumulative effect of foreign exchange from accumulated other comprehensive income (loss) to retained earnings. As a result of the Tax Act, the Financial Accounting Standards Board ("FASB") concluded that Global Intangible Low-Taxed Income Tax ("GILTI tax") can be recognized in the financial statements, no later than December 22, 2018, per an accounting policy choice, by: (1) recording a period cost (permanent item) or (2) providing deferred income taxes stemming from certain basis differences that are expected to result in GILTI tax. The Company elected to record GILTI tax as a period cost. The GILTI tax recognized in 2019 and 2018 were not material to the consolidated financial statements.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of foreign subsidiaries are translated to U.S. dollars at the exchange rate as of the end of the year. Statement of operations items are translated at the average exchange rate for the year. The resulting translation adjustment is recorded as a separate component of stockholders' equity.
Revenue Recognition	Revenue Recognition Revenue is recognized when the Company transfers control of inventories to its customers. Amounts recognized as revenues reflect the consideration to which the Company expects to be entitled in exchange for those inventories. Provisions for discounts, rebates and returns are incorporated in the estimate of variable consideration and reflected as reduction to revenue in the same period as the related sales. Control of inventories generally transfers upon shipment for domestic sales. The Company excludes taxes collected on behalf of customers from the estimated contract price. For export contracts, the point at which control passes to the customer varies depending on the terms specified in the customer contract. The Company generally invoices customers and recognizes revenue and accounts receivable upon transferring control of inventories. In limited circumstances, the Company transfers control of inventories shortly before it has an unconditional right to receive consideration, resulting in recognition of contract assets. The Company also receives advance payments from certain customers, resulting in recognition of contract liabilities. Contract assets and liabilities are generally settled within the period and are not material to the consolidated balance sheets. The Company expenses sales commissions when incurred. These costs are recorded within selling, general and administrative expenses. Aside from the amounts disclosed within Note 9, the Company does not disclose the value of unsatisfied performance obligations because its contracts with customers (1) have an original expected duration of one year or less or (2) have only variable consideration that is calculated based on market prices at specified dates and is allocated to wholly unsatisfied performance obligations. The Company adopted ASU No. 2014-09, Revenue from Contracts with Customers ("ASC 606"), effective January 1, 2018. The Company applied the modified retrospective transition method to all contracts that were not completed as of the adoption date. Periods prior to January 1, 2018 were not adjusted and are reported under the accounting standards that were in place during those periods. The cumulative effects of changes to the Company's consolidated January 1, 2018 balance sheet for the adoption of this accounting standard were immaterial. The impact of ASC 606 adoption on the financial statements for the year ended December 31, 2018 as compared with the guidance that was in effect prior to January 1, 2018 was immaterial. ASC 606 requires disclosure of disaggregated revenue into categories that depict the nature of how the Company's revenue and cash flows are affected by economic factors. The Company discloses revenues by product and segment in Note 23. Prior to the adoption of ASC 606, the revenue was recognized when persuasive evidence of an arrangement existed, products were delivered to the customer, the sales price was fixed or determinable and collectability was reasonably assured. For domestic contracts, title and risk of loss had passed to the customer upon delivery under executed customer purchase orders or contracts. For export contracts, the title and risk of loss had passed to customers at the time specified by each contract.
Transportation and Freight	Transportation and Freight Amounts billed to customers for freight and handling costs on outbound shipments are included in net sales in the consolidated statements of operations. Transportation and freight costs incurred by the Company on outbound shipments are included in cost of sales in the consolidated statements of operations.
Price Risk Management	Price Risk Management The Company recognizes derivative instruments on the balance sheet at fair value, and changes in a derivative's fair value are currently recognized in earnings or comprehensive income, depending on the designation of the derivative. If the derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized in earnings. If the derivative is designated as a cash flow hedge, the effective portion of the change in the fair value of the derivative is recorded in comprehensive income and is recognized in the statement of operations when the hedged item affects earnings. Ineffective portions of changes in the fair value of cash flow hedges are recognized in earnings currently. The derivative instruments did not have a material impact on the Company's consolidated financial statements.
Asset Retirement Obligations	Asset Retirement Obligations The Company has conditional asset retirement obligations for the removal and disposal of hazardous materials from certain of the Company's manufacturing facilities. The Company recognizes asset retirement obligations in the period in which the liability becomes probable and reasonably estimable. Recognized asset retirement obligations are initially recorded at fair value and capitalized as a component of the carrying value of the long-lived asset to which the obligation relates. The liability is accreted to its future value each period, and the capitalized cost is depreciated over the estimated useful life of the related asset. Upon settlement of the liability, a gain or loss is recorded. As of December 31, 2019 , the Company had $7 and $20 of asset retirement obligations recorded as accrued liabilities and other liabilities, respectively. As of December 31, 2018 , the Company had $8 and $20 of asset retirement obligations recorded as accrued liabilities and other liabilities, respectively. The Company also has conditional asset retirement obligations that have not been recognized because the fair values of the conditional legal obligations cannot be measured due to the indeterminate settlement date of the obligations. Settlements of the unrecognized conditional asset retirement obligations are not expected to have a material adverse effect on the Company's financial condition, results of operations or cash flows in any individual reporting period.
Environmental Costs	Environmental Costs Environmental costs relating to current operations are expensed or capitalized, as appropriate, depending on whether such costs provide future economic benefits. Remediation liabilities are recognized when the costs are considered probable and can be reasonably estimated. Measurement of liabilities is based on currently enacted laws and regulations, existing technology and undiscounted site-specific costs. Environmental liabilities in connection with properties that are sold or closed are realized upon such sale or closure, to the extent they are probable and estimable and not previously reserved. Recognition of any joint and several liabilities is based upon the Company's best estimate of its final pro rata share of the liability.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Credit Losses (ASU No. 2016-13) In June 2016, the Financial Accounting Standards Board ("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 additional authoritative guidance related to credit losses. The accounting standard is effective for reporting periods beginning after December 15, 2019 and is not expected to 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 will be effective for reporting periods beginning after December 15, 2019 and is not expected to 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. The amendments are effective for periods beginning after December 15, 2019. 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 Company is in the process of assessing the impact of the standard on the Company's fair value disclosures. However, the standard is not expected to have an impact on the Company's consolidated financial position, results of operations and cash flows. Income Taxes (ASU No. 2019-12) In December 2019, the 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 its consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Leases (ASU No. 2016-02) In February 2016, the FASB issued an accounting standards update on lease accounting that supersedes the previously issued lease guidance. The new standard requires lessees to recognize assets and liabilities for all long-term operating leases. An asset is recognized for the right to use an underlying leased asset and a liability is recognized for the obligation to make payments over the lease term. The standard also requires expanded lease disclosures. The standard requires a modified retrospective adoption approach and allows for the election of certain transition expedients. The Company adopted the standard on January 1, 2019 using the optional transition method, which allows entities to recognize a cumulative adjustment to the opening balance sheet in the period of adoption. The Company elected the package of optional transition expedients and was not required to reassess (1) whether any existing contracts are or contain leases, (2) classification of existing leases as operating or capital or (3) whether initial direct costs for existing leases qualify for capitalization under the new accounting standard. The Company did not elect the use of hindsight to determine the lease term when considering lease renewal or termination options. Additionally, the Company elected to continue accounting for existing land easements under its accounting policies that were in effect prior to adoption of the new lease standard. The following amounts were recorded as a result of adopting the new lease standard on January 1, 2019: Operating Lease Assets and Liabilities Balance Sheet Location Amounts Recorded in the Consolidated Balance Sheet January 1, 2019 Right-of-use assets Operating lease right-of-use assets $ 421 Current lease liabilities Accrued and other liabilities (94 ) Non-current lease liabilities Operating lease liabilities (331 ) Deferred rent Other liabilities 4

Description of Business and S_3

Description of Business and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Estimated Useful Lives of Assets	Classification Years Buildings and improvements 40 Plant and equipment 10-25 Other 3-15

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	Cash $ 10 Accounts receivable 53 Inventories 40 Prepaid expenses and other current assets 7 Property, plant and equipment 75 Operating lease right-of-use assets 3 Intangible assets: Customer relationships (weighted average lives of 17 years) 65 Technology (weighted average lives of 14 years) 40 Trade name (life of 15 years) 25 Other assets 12 Total assets acquired 330 Accounts payable 57 Accrued and other liabilities 18 Deferred income taxes 31 Pension and other post-retirement benefits 4 Operating lease liabilities 3 Other long-term liabilities 8 Total liabilities assumed 121 Total identifiable net assets acquired 209 Goodwill 40 Total purchase consideration $ 249

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Schedule Of Accounts Receivable	Accounts receivable consist of the following at December 31: 2019 2018 Trade customers $ 948 $ 969 Related parties 12 6 Allowance for doubtful accounts (22 ) (23 ) 938 952 Federal and state taxes 59 57 Other 39 28 Accounts receivable, net $ 1,036 $ 1,037

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2019
Inventory, Net [Abstract]
Schedule Of Inventory	Inventories consist of the following at December 31: 2019 2018 Finished products $ 568 $ 657 Feedstock, additives, chemicals and other raw materials 210 203 Materials and supplies 158 154 Inventories $ 936 $ 1,014

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment, Net [Abstract]
Schedule Of Property, Plant And Equipment	Property, plant and equipment consist of the following at December 31: 2019 2018 Land $ 198 $ 193 Buildings and improvements 608 544 Plant and equipment 8,227 7,568 Other 496 437 9,529 8,742 Less: Accumulated depreciation (3,168 ) (2,720 ) 6,361 6,022 Construction in progress 551 573 Property, plant and equipment, net $ 6,912 $ 6,595

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lease related asset and liability	Lease-related asset and liability balances were as follows: December 31, Operating Leases Right-of-use assets $ 443 Accrued and other liabilities $ 93 Operating lease liabilities 355 Total operating lease liabilities $ 448 Weighted Average Remaining Term (in years) 8 Weighted Average Lease Discount Rate 3.5 %
Lease, Cost	The components of operating lease expense were as follows: December 31, Operating lease cost (1) $ 113 Short-term lease cost 58 Total operating lease cost $ 171 _____________________________ (1) Includes fixed lease payments for operating leases recorded in the consolidated balance sheet.
Lessee, Operating Lease, Liability, Maturity	Maturities of lease liabilities were as follows at December 31, 2019 : Operating Leases 2020 $ 106 2021 83 2022 69 2023 55 2024 43 Thereafter 189 Total lease payments 545 Less: imputed interest (97 ) Present value of lease liabilities $ 448
Schedule of Property Subject to or Available for Operating Lease	Future lease commitments for operating lease obligations were as follows at December 31, 2018 : Operating Leases 2019 $ 94 2020 89 2021 70 2022 56 2023 42 Thereafter 152 Total lease payments $ 503

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Intangible assets consisted of the following at December 31: 2019 2018 Weighted Average Life Cost Accumulated Amortization Net Cost Accumulated Amortization Net Customer relationships $ 832 $ (309 ) $ 523 $ 745 $ (220 ) $ 525 11 Other intangible assets: Licenses and intellectual property 172 (79 ) 93 122 (65 ) 57 13 Trademarks 120 (37 ) 83 90 (26 ) 64 13 Other 35 (24 ) 11 35 (22 ) 13 10 Total other intangible assets $ 327 $ (140 ) $ 187 $ 247 $ (113 ) $ 134
Schedule of Goodwill	The gross carrying amounts and changes in the carrying amount of goodwill for the years ended December 31, 2019 and 2018 are as follows: Olefins Segment Vinyls Segment Total Balance at December 31, 2017 $ 30 $ 982 $ 1,012 Effects of changes in foreign exchange rates — (10 ) (10 ) Balance at December 31, 2018 30 972 1,002 Goodwill acquired during the year — 67 67 Effects of changes in foreign exchange rates — 5 5 Balance at December 31, 2019 $ 30 $ 1,044 $ 1,074

Equity Method Investements (Tab

Equity Method Investements (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments [Table Text Block]	Changes in the Company's investment in LACC for the year ended December 31, 2019 were as follows: Investment in LACC Balance at December 31, 2018 $ 183 Cash contributions 45 Additional interest purchased 817 Depreciation and amortization (7 ) Balance at December 31, 2019 $ 1,038

Accounts and Notes Payable (Tab

Accounts and Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2019
Accounts and Notes Payable [Abstract]
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Accounts payable consist of the following: December 31, December 31, Accounts payable—third parties $ 435 $ 504 Accounts payable to related parties 12 2 Notes payable 26 1 Accounts payable $ 473 $ 507

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule Of Long-Term Debt	Long-term debt consisted of the following at December 31: December 31, 2019 December 31, 2018 Principal Amount Unamortized Discount and Debt Issuance Costs Net Long-Term Debt Principal Amount Unamortized Discount and Debt Issuance Costs Net Long-Term Debt 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 (8 ) 742 750 (9 ) 741 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 — 11 11 — 11 6 ½% senior notes due 2029 (the "6 ½% 2029 GO Zone Senior Notes") 100 (1 ) 99 100 (1 ) 99 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 (24 ) 676 4.375% senior notes due 2047 (the "4.375% 2047 Senior Notes") 500 (9 ) 491 500 (9 ) 491 3.50% senior notes due 2032 (the "3.50% 2032 GO Zone Refunding Senior Notes") 250 (1 ) 249 250 (2 ) 248 1.625% senior notes due 2029 (the "1.625% 2029 Senior Notes") 785 (11 ) 774 — — — Long-term debt $ 3,500 $ (55 ) $ 3,445 $ 2,715 $ (47 ) $ 2,668

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive income (loss) by component were as follows: Pension and Other Post-Retirement Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Total Balances at December 31, 2017 $ 43 $ (36 ) $ 7 Other comprehensive income (loss) before reclassifications (14 ) (57 ) (71 ) Amounts reclassified from accumulated other comprehensive income (loss) (11 ) — (11 ) Reclassification of certain tax effects to retained earnings (1) 9 4 13 Net other comprehensive loss attributable to Westlake Chemical Corporation (16 ) (53 ) (69 ) Balances at December 31, 2018 27 (89 ) (62 ) Other comprehensive income (loss) before reclassifications (24 ) 12 (12 ) Amounts reclassified from accumulated other comprehensive income (loss) — — — Net other comprehensive income (loss) attributable to Westlake Chemical Corporation (24 ) 12 (12 ) Balances at December 31, 2019 $ 3 $ (77 ) $ (74 ) ______________________________ (1) In 2018, the Company reclassified certain income tax effects to retained earnings upon adoption of ASU No. 2018-02. See Note 1 (Income taxes) for additional information.
Reclassification out of Accumulated Other Comprehensive Income	The following table provides the details of the amounts reclassified from accumulated other comprehensive income (loss) into net income in the consolidated statements of operations: Details about Accumulated Other Comprehensive Income (Loss) Components Location of Reclassification (Income (Expense)) in Consolidated Statements of Operations Year Ended December 31, 2019 2018 2017 Amortization of pension and other post-retirement net loss (1) $ — $ — $ (2 ) Pension settlement gain (1) — 14 — Income tax benefit (provision) on pension and other post-retirement benefits Provision for (benefit from) income taxes — (3 ) — Total reclassifications for the period $ — $ 11 $ (2 ) ______________________________ (1) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost and reflected in other income, net in the consolidated statements of operations. See Note 14 for additional information on the pension settlement gain recognized in 2018.

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule Of Accumulated Benefit Obligations In Excess Of Plan Assets	Pension plans with an accumulated benefit obligation in excess of plan assets at December 31 are as follows: 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Information for pension plans with an accumulated benefit obligation in excess of plan assets Projected benefit obligation $ (703 ) $ (143 ) $ (648 ) $ (128 ) Accumulated benefit obligation (703 ) (138 ) (648 ) (125 ) Fair value of plan assets 526 18 486 10
Schedule Of Net Benefit Costs And Amounts Recognized In Other Comprehensive Income	The following table provides the components of net periodic benefit costs, other changes in plan assets and benefit obligation recognized in other comprehensive income. Year Ended December 31, 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Components of net periodic benefit cost Service cost $ 3 $ 2 $ 3 $ 2 $ 3 $ 2 Administrative expenses 4 — 3 — 2 — Interest cost 23 3 24 3 25 2 Expected return on plan assets (33 ) (1 ) (42 ) (1 ) (40 ) (1 ) Net amortization — — (1 ) 1 1 1 Settlement gain — — (14 ) — — — Net periodic benefit cost (gain) $ (3 ) $ 4 $ (27 ) $ 5 $ (9 ) $ 4 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net loss (gain) emerging $ 20 $ 13 $ 20 $ 1 $ (18 ) $ — Settlement gain — — 14 — — — Effect of plan change — (4 ) — — — — Amortization of net gain (loss) — — 1 (1 ) (1 ) (1 ) Total recognized in OCI $ 20 $ 9 $ 35 $ — $ (19 ) $ (1 ) Total net periodic benefit cost and OCI $ 17 $ 13 $ 8 $ 5 $ (28 ) $ 3
Schedule Of Weighted Average Assumptions Used	The weighted-average assumptions used to determine pension plan obligations and net periodic benefit costs for the plans are as follows: 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 3.0 % 1.3 % 4.1 % 2.0 % 3.4 % 1.8 % Rate of compensation increase — % 2.6 % — % 2.6 % — % 2.6 % Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 4.1 % 2.0 % 3.4 % 1.8 % 3.8 % 1.8 % Discount rate for service cost 4.2 % 2.2 % 3.8 % 2.0 % 4.1 % 1.9 % Discount rate for interest cost 3.7 % 2.2 % 3.3 % 2.0 % 3.2 % 2.0 % Expected return on plan assets 7.0 % 4.0 % 7.0 % 3.8 % 6.8 % 3.8 % Rate of compensation increase — % 2.6 % — % 2.6 % — % 2.6 %
Schedule Of Fair Value Of Pension Plan Assets	The investments in the collective trust and mutual funds are valued using a market approach based on the net asset value of units held. The fair values of the Company's U.S. plan assets at December 31, by asset category, are as follows: 2019 U.S. Plans Non U.S. Plans Level 1 Level 2 Total Level 1 Level 2 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ 6 $ — $ 6 Common stock 15 — 15 — — — Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 49 112 161 — 1 1 Small-cap funds (2) 8 14 22 — — — International funds (3) 75 45 120 — 5 5 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 100 98 198 — 7 7 Short-term investment funds — 10 10 — — — $ 247 $ 279 $ 526 $ 6 $ 13 $ 19 2018 U.S. Plans Non U.S. Plans Level 1 Level 2 Total Level 1 Level 2 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ 5 $ — $ 5 Common stock 13 — 13 — — — Collective investment trust and mutual funds—Equity securities: Large-cap funds (1) 44 98 142 — 1 1 Small-cap funds (2) 6 13 19 — — — International funds (3) 64 38 102 — 5 5 Collective investment trust and mutual funds—Fixed income: Bond funds (4) 96 102 198 — 6 6 Short-term investment funds — 12 12 — — — $ 223 $ 263 $ 486 $ 5 $ 12 $ 17 ______________________________ (1) Substantially all of the assets of these funds are invested in large-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (2) Substantially all of the assets of these funds are invested in small-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves. (3) Substantially all of the assets of these funds are invested in international companies in developed markets (excluding the U.S.). The remainder of the assets of these funds is invested in cash reserves. (4) This category represents investment grade bonds of U.S. issuers, including U.S. Treasury notes.
Schedule of Multi-employer Plans	Non-U.S. Plans The Company participates in two multi-employer plans, Pensionskasse der Mitarbeiter der Hoechst-Gruppe VVaG and Pensionskasse der Wacker-Chemie GmbH VVaG, which provide benefits to certain of the Company's employees in Germany. These multi-employer plans are closed to new participants. The benefit obligations are covered up to a certain salary threshold by contributions made by the Company and employees to the plans. Contributions to the Company's multi-employer plans are expensed as incurred and were as follows: Year Ended December 31, 2019 2018 2017 Non-U.S. Plans Non-U.S. Plans Non-U.S. Plans Contributions to multi-employer plans (1) $ 9 $ 7 $ 8 ______________________________ (1) The plan information for both the Pensionskasse der Mitarbeiter der Hoechst-Gruppe VVaG and Pensionskasse der Wacker-Chemie GmbH VVaG plans is publicly available. The plans provide fixed, monthly retirement payments on the basis of the credits earned by the participating employees. To the extent that the plans are underfunded, future contributions to the plans may increase and may be used to fund retirement benefits for employees related to other employers. The Company does not consider either of its multi-employer plans individually significant.
Schedule Of Estimated Future Benefit Payments	The following benefit payments are expected to be paid: Pension Benefits Other Post- retirement Benefits Estimated future benefit payments: Year 1 $ 45 $ 8 Year 2 45 8 Year 3 45 8 Year 4 47 8 Year 5 46 7 Years 6 to 10 233 22
Defined Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan	Details of the changes in benefit obligations, plan assets and funded status of the Company's pension plans are as follows: 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 648 $ 136 $ 807 $ 142 Service cost 3 2 3 2 Interest cost 23 3 24 3 Actuarial loss (gain) 80 14 (43 ) — Benefits paid (51 ) (4 ) (40 ) (4 ) Plan amendments — (4 ) — — Settlements — (1 ) (103 ) — Foreign exchange effects — (2 ) — (7 ) Benefit obligation, end of year $ 703 $ 144 $ 648 $ 136 Change in plan assets Fair value of plan assets, beginning of year $ 486 $ 17 $ 650 $ 18 Actual return 92 1 (22 ) — Employer contribution 2 — 3 1 Benefits paid (51 ) — (40 ) (1 ) Administrative expenses paid (3 ) — (2 ) — Settlements — — (103 ) — Foreign exchange effects — 1 — (1 ) Fair value of plan assets, end of year $ 526 $ 19 $ 486 $ 17 Funded status, end of year $ (177 ) $ (125 ) $ (162 ) $ (119 )
Schedule of Amounts Recognized in Balance Sheet	2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (2 ) $ (2 ) $ (2 ) $ (3 ) Noncurrent liabilities (175 ) (123 ) (160 ) (116 ) Net amount recognized $ (177 ) $ (125 ) $ (162 ) $ (119 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income (loss) Net loss (gain) $ (16 ) $ 22 $ (36 ) $ 9 Prior service cost — (4 ) — — Total before tax (1) $ (16 ) $ 18 $ (36 ) $ 9 ______________________________ (1) After-tax totals for pension benefits were $0 and $22 for 2019 and 2018 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive income (loss).
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan	The following table provides a reconciliation of the benefit obligations of the Company's unfunded post-retirement healthcare plans. 2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 67 $ 3 $ 73 $ 3 Service cost 1 — 1 — Interest cost 2 — 2 — Actuarial loss (gain) 3 1 (1 ) — Benefits paid (8 ) — (8 ) — Benefit obligation, end of year $ 65 $ 4 $ 67 $ 3 Change in plan assets Fair value of plan assets, beginning of year $ — $ — $ — $ — Employer contribution 8 — 8 — Benefits paid (8 ) — (8 ) — Fair value of plan assets, end of year $ — $ — $ — $ — Funded status, end of year $ (65 ) $ (4 ) $ (67 ) $ (3 )
Schedule of Amounts Recognized in Balance Sheet	2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (8 ) $ — $ (8 ) $ — Noncurrent liabilities (57 ) (5 ) (59 ) (3 ) Net amount recognized $ (65 ) $ (5 ) $ (67 ) $ (3 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	2019 2018 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income (loss) Net gain $ (3 ) $ — $ (6 ) $ — Total before tax (1) $ (3 ) $ — $ (6 ) $ — ______________________________ (1) After-tax totals for post-retirement healthcare benefits were $3 and $5 for 2019 and 2018 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive income (loss).
Schedule Of Net Benefit Costs And Amounts Recognized In Other Comprehensive Income	The following table provides the components of net periodic benefit costs, other changes in plan assets and benefit obligation recognized in other comprehensive income. Year Ended December 31, 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Components of net periodic benefit cost Service cost $ 1 $ — $ 1 $ — $ 1 $ — Interest cost 2 — 2 — 2 — Net amortization — — — — — — Net periodic benefit cost $ 3 $ — $ 3 $ — $ 3 $ — Other changes in plan assets and benefit obligation recognized in OCI Net loss (gain) emerging $ 3 $ — $ (1 ) $ (1 ) $ (1 ) $ — Total recognized in OCI $ 3 $ — $ (1 ) $ (1 ) $ (1 ) $ — Total net periodic benefit cost and OCI $ 6 $ — $ 2 $ (1 ) $ 2 $ —
Schedule Of Weighted Average Assumptions Used	The weighted-average assumptions used to determine post-retirement healthcare plan obligations and net periodic benefit costs for the plans are as follows: 2019 2018 2017 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 2.5 % 3.2 % 3.7 % 3.9 % 3.0 % 4.0 % Health care cost trend rate - Initial rate 6.8 % 5.7 % 7.0 % 5.8 % 7.3 % 6.2 % - Ultimate rate 4.5 % 4.0 % 4.5 % 4.0 % 4.5 % 4.5 % - Years to ultimate 10 21 11 22 11 12 Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 3.7 % 3.9 % 3.0 % 3.6 % 3.3 % 3.3 % Discount rate for service cost 4.0 % 3.9 % 3.4 % 3.6 % 3.8 % 3.3 % Discount rate for interest cost 3.4 % 3.9 % 2.7 % 3.6 % 2.6 % 3.3 % Health care cost trend rate - Initial rate 7.0 % 5.8 % 7.0 % 6.1 % 6.8 % 6.8 % - Ultimate rate 4.5 % 4.0 % 4.5 % 4.5 % 4.6 % 4.5 % - Years to ultimate 10 21 10 11 11 12

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
Schedule Of Range Of Exercise Prices For Outstanding Options	For options outstanding at December 31, 2019 , the options had the following range of exercise prices: Range of Prices Options Outstanding Weighted Average Remaining Contractual Life (Years) $10.26 - $30.05 264,334 1.0 $40.38 - $44.42 218,047 6.1 $45.70 - $61.87 295,620 6.5 $63.98 - $68.18 145,171 4.7 $79.83 - $107.75 462,776 8.8
Schedule Of Option Activity And Changes	Option activity and changes during the year ended December 31, 2019 were as follows: Options Weighted Average Exercise Price Weighted Average Remaining Term (Years) Aggregate Intrinsic Value Outstanding at December 31, 2018 1,115,954 $ 54.82 Granted 296,598 79.83 Exercised (18,635 ) 35.04 Cancelled (7,969 ) 79.94 Outstanding at December 31, 2019 1,385,948 $ 60.29 5.9 $ 23 Exercisable at December 31, 2019 888,093 $ 47.64 4.5 $ 22
Schedule Of Weighted Average Value And Assumptions For Fair Value Of Options	The Company used the Black-Scholes option pricing model to value its options. The table below presents the weighted average value and assumptions used in determining each option's fair value. Volatility was calculated using historical trends of the Company's common stock price. Stock Option Grants Year Ended December 31, 2019 2018 2017 Weighted average fair value $ 21.02 $ 28.94 $ 15.84 Risk-free interest rate 2.5 % 2.7 % 2.1 % Expected life in years 5 5 5 Expected volatility 28.9 % 27.6 % 29.2 % Expected dividend yield 1.2 % 0.7 % 1.2 %
Schedule Of Non-Vested Restricted Stock Award Activity And Changes	Non-vested liability classified restricted stock awards as of December 31, 2019 and changes during the year ended December 31, 2019 were as follows: Number of Units Weighted Average Fair Value Non-vested at December 31, 2018 49,528 $ 66.46 Vested (49,292 ) 68.22 Cancelled (236 ) 76.77 Non-vested at December 31, 2019 — — Non-vested restricted stock units as of December 31, 2019 and changes during the year ended December 31, 2019 were as follows: Number of Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2018 702,789 $ 65.79 Granted 205,517 77.59 Vested (415,593 ) 56.70 Forfeited (29,430 ) 73.28 Non-vested at December 31, 2019 463,283 $ 78.69
Share-based Payment Arrangement, Performance Shares, Activity [Table Text Block]	Number of Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2018 — $ — Granted 78,328 114.38 Vested — — Forfeited (1,111 ) 114.38 Non-vested at December 31, 2019 77,217 $ 114.38
Share-based Compensation Arrangements by Share-based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block]	Year Ended December 31, 2019 Performance Stock Units Risk-free interest rate 2.5 % Expected life in years 2.88 Expected volatility of Westlake Chemical Corporation common stock 30.3 % Expected volatility of peer companies 14.5% - 47.8% Average correlation coefficient of peer companies 0.49 Grant date fair value $ 114.38

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule Of Carrying And Fair Values Of Long-Term Debt	The carrying and fair values of the Company's long-term debt at December 31, 2019 and 2018 are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy. 2019 2018 Carrying Value Fair Value Carrying Value Fair Value 3.60% 2022 Senior Notes $ 249 $ 255 $ 249 $ 248 3.60% 2026 Senior Notes 742 777 741 692 Loan related to tax-exempt waste disposal revenue bonds due 2027 11 11 11 11 6 ½% 2029 GO Zone Senior Notes 99 103 99 106 6 ½% 2035 GO Zone Senior Notes 88 92 88 95 6 ½% 2035 IKE Zone Senior Notes 65 68 65 69 5.0% 2046 Senior Notes 677 761 676 641 4.375% 2047 Senior Notes 491 505 491 417 3.50% 2032 GO Zone Refunding Senior Notes 249 267 248 233 1.625% 2029 Senior Notes 774 785 — —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Components of Income (Loss) Before Income Taxes	The components of income before income taxes are as follows: Year Ended December 31, 2019 2018 2017 Domestic $ 460 $ 1,087 $ 917 Foreign 110 247 164 $ 570 $ 1,334 $ 1,081
Schedule of The Provision For (Benefit From) Income Taxes	The Company's provision for (benefit from) income taxes consists of the following: Year Ended December 31, 2019 2018 2017 Current Federal $ 20 $ 158 $ 231 State 9 28 18 Foreign 25 52 27 Total current 54 238 276 Deferred Federal 69 59 (557 ) State 11 (2 ) 25 Foreign (26 ) 5 (2 ) Total deferred 54 62 (534 ) Total provision for (benefit from) income taxes $ 108 $ 300 $ (258 )
Reconciliation of Taxes Computed at the Statutory Rate to Income Tax Expense	A reconciliation of taxes computed at the statutory rate to the Company's income tax expense is as follows: Year Ended December 31, 2019 2018 2017 Provision for federal income tax, at statutory rate $ 120 $ 280 $ 378 State income tax provision, net of federal income tax effect 10 28 26 Foreign income tax rate differential (6 ) 14 (36 ) Manufacturing deduction — — (23 ) Depletion (5 ) (4 ) (7 ) Noncontrolling interests (8 ) (6 ) (9 ) Tax Act related adjustment — — (591 ) Change in valuation allowance (17 ) (9 ) 3 Changes in state apportionment and other state adjustments 11 (6 ) 2 Other, net 3 3 (1 ) Total income tax expense (benefit) $ 108 $ 300 $ (258 )
Schedule of Deferred Tax Assets And Liabilities	The tax effects of the principal temporary differences between financial reporting and income tax reporting at December 31 are as follows: 2019 2018 Net operating loss carryforward $ 209 $ 50 Credit carryforward 25 24 Operating lease liabilities 96 — Accruals 65 64 Pension 83 76 Inventories 20 13 Other 26 17 Deferred taxes assets—total 524 244 Property, plant and equipment (1,017 ) (948 ) Intangibles (156 ) (148 ) Operating lease right-of-use asset (95 ) — Turnaround costs (21 ) (20 ) Consolidated partnerships (194 ) (202 ) Equity method investments (220 ) (13 ) Other (18 ) (14 ) Deferred tax liabilities—total (1,721 ) (1,345 ) Valuation allowance (30 ) (47 ) Total net deferred tax liabilities $ (1,227 ) $ (1,148 ) Balance sheet classifications Noncurrent deferred tax asset $ 28 $ 11 Noncurrent deferred tax liability (1,255 ) (1,159 ) Total net deferred tax liabilities $ (1,227 ) $ (1,148 )

Earnings and Dividends per Sh_2

Earnings and Dividends per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings and Dividends Per Share [Abstract]
Schedule Of Net Income Attributable To Common Stockholders	Diluted earnings per share include the effect of certain stock options and performance stock units. Year Ended December 31, 2019 2018 2017 Net income attributable to Westlake Chemical Corporation $ 421 $ 996 $ 1,304 Less: Net income attributable to participating securities (2 ) (5 ) (7 ) Net income attributable to common shareholders $ 419 $ 991 $ 1,297
Reconciliation Of Denominator For Basic And Diluted Earnings (Loss) Per Share	The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Year Ended December 31, 2019 2018 2017 Weighted average common shares—basic 128,395,184 129,401,823 129,087,043 Plus incremental shares from: Assumed exercise of options and vesting of performance stock units 362,109 583,930 452,970 Weighted average common shares—diluted 128,757,293 129,985,753 129,540,013 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 3.26 $ 7.66 $ 10.05 Diluted $ 3.25 $ 7.62 $ 10.00
Dividends Per Share	Dividends per Share Dividends per common share for the years ended December 31, 2019 , 2018 and 2017 were as follows: Year Ended December 31, 2019 2018 2017 Dividends per common share $ 1.0250 $ 0.9200 $ 0.8012

Supplemental Information (Table

Supplemental Information (Tables)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Cash Flow Information	Operating Lease Supplemental Cash Flow Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2019 Operating cash flows from operating leases (1) $ 112 Right-of-use assets obtained in exchange for operating lease obligations 119 _____________ (1) Includes cash paid for amounts included in the measurement of operating lease liabilities recorded in the consolidated balance sheets. Cash Flow Information Year Ended December 31, 2019 2018 2017 Cash paid for: Interest paid, net of interest capitalized $ 116 $ 140 $ 154 Income taxes paid 77 376 84

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Reporting Information	Year Ended December 31, 2019 2018 2017 Net external sales Olefins Polyethylene $ 1,301 $ 1,519 $ 1,518 Styrene, feedstock and other 481 500 533 Total olefins 1,782 2,019 2,051 Vinyls PVC, caustic soda and other 5,068 5,359 4,769 Building products 1,268 1,257 1,221 Total vinyls 6,336 6,616 5,990 $ 8,118 $ 8,635 $ 8,041 Intersegment sales Olefins $ 324 $ 500 $ 393 Vinyls 1 2 1 $ 325 $ 502 $ 394 Income (loss) from operations Olefins $ 260 $ 573 $ 655 Vinyls 451 913 639 Corporate and other (55 ) (78 ) (69 ) $ 656 $ 1,408 $ 1,225 Depreciation and amortization Olefins $ 142 $ 138 $ 145 Vinyls 563 491 449 Corporate and other 8 12 7 $ 713 $ 641 $ 601 Other income, net Olefins $ 5 $ 4 $ 3 Vinyls 18 35 7 Corporate and other 15 13 5 $ 38 $ 52 $ 15 Provision for (benefit from) income taxes Olefins $ 60 $ 128 $ 63 Vinyls 40 212 (302 ) Corporate and other 8 (40 ) (19 ) $ 108 $ 300 $ (258 ) Capital expenditures Olefins $ 117 $ 110 $ 97 Vinyls 664 585 459 Corporate and other 6 7 21 $ 787 $ 702 $ 577
Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes	Year Ended December 31, 2019 2018 2017 Income from operations for reportable segments $ 656 $ 1,408 $ 1,225 Interest expense (124 ) (126 ) (159 ) Other income, net 38 52 15 Income before income taxes $ 570 $ 1,334 $ 1,081
Total Assets	December 31, 2019 December 31, 2018 Total assets Olefins $ 1,991 $ 2,024 Vinyls 10,597 8,879 Corporate and other 673 699 $ 13,261 $ 11,602
Geographic Information For Sales To External Customers And Long-Lived Assets	Geographic Information Year Ended December 31, 2019 2018 2017 Net sales to external customers (1) United States $ 5,530 $ 6,114 $ 5,739 Foreign Canada 573 649 653 Germany 478 500 432 China 175 155 104 Italy 119 105 96 Taiwan 84 102 96 Other 1,159 1,010 921 $ 8,118 $ 8,635 $ 8,041 December 31, 2019 December 31, 2018 Long-lived assets United States $ 6,012 $ 5,829 Foreign Germany 588 528 Other 312 238 $ 6,912 $ 6,595 ______________________________ (1) Net sales are attributed to countries based on location of customer.

Quarterly Financial Informati_2

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Summary Of Quarterly Financial Information	Three Months Ended March 31, June 30, September 30, December 31, Net sales $ 2,025 $ 2,144 $ 2,066 $ 1,883 Gross profit 299 340 371 250 Income from operations 134 194 226 102 Net income 82 129 166 85 Net income attributable to Westlake Chemical Corporation 72 119 158 72 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 0.56 $ 0.92 $ 1.22 $ 0.56 Diluted $ 0.55 $ 0.92 $ 1.22 $ 0.56 Three Months Ended March 31, June 30, September 30, December 31, Net sales $ 2,150 $ 2,235 $ 2,255 $ 1,995 Gross profit 542 552 539 354 Income from operations 401 404 396 207 Net income 297 288 318 131 Net income attributable to Westlake Chemical Corporation 287 278 308 123 Earnings per common share attributable to Westlake Chemical Corporation: (1) Basic $ 2.21 $ 2.13 $ 2.36 $ 0.95 Diluted $ 2.20 $ 2.12 $ 2.35 $ 0.95 ______________________________ (1) Basic and diluted earnings per common share ("EPS") for each quarter is computed using the weighted average shares outstanding during that quarter, while EPS for the year is computed using the weighted average shares outstanding for the year. As a result, the sum of the EPS for each of the four quarters may not equal the EPS for the year.

Description of Business and S_4

Description of Business and Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)plant	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Capitalized interest	$ 9	$ 7	$ 4
Provisional adjustment of income tax benefit			$ 591
Asset Retirement Obligation, Current	7	8
Asset Retirement Obligations, Noncurrent	$ 20	20
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Deferred Cost, Amortization Period	3 years
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Deferred Cost, Amortization Period	6 years
Westlake Chemical OpCo LP [Member] | Limited Partner [Member] | IPO [Member] | Subsidiary of Common Parent [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Limited partner interest (percent)	77.20%
Westlake Chemical OpCo LP [Member] | Subsidiaries [Member] | Louisiana
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of production facilities | plant	2
Westlake Chemical OpCo LP [Member] | Subsidiaries [Member] | Kentucky
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of production facilities | plant	1
Accumulated Other Comprehensive Income (Loss) [Member] | Accounting Standard Update 2018-02 [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax		$ 13

Description of Business and S_5

Description of Business and Significant Accounting Policies (Schedule Of Estimated Useful Lives Of Assets) (Details)	12 Months Ended
	Dec. 31, 2019
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	40 years
Minimum [Member] | Other Capitalized Property Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	3 years
Minimum [Member] | Plant And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	10 years
Maximum [Member] | Other Capitalized Property Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	15 years
Maximum [Member] | Plant And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	25 years

Description of Business and S_6

Description of Business and Significant Accounting Policies Changes Due to Lease Standard Adoption (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 443		$ 0
Operating Lease, Liability, Current	93
Operating lease liabilities	355		0
Other liabilities	$ 202		$ 179
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 421
Operating lease liabilities		(331)
Other Liabilities [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other liabilities		4
Accrued and Other Liabilities [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Liability, Current		$ (94)

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) - NAKAN [Member] $ in Millions	Jan. 02, 2019USD ($)
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 249
Goodwill, Acquired During Period	$ 40

Acquisitions Business Acquisiti

Acquisitions Business Acquisition (Details) - NAKAN [Member] $ in Millions	Jan. 02, 2019USD ($)
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	$ 10
Business Combination, Acquired Receivable, Fair Value	53
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	40
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets	7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	75
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease, Right-of-Use-Asset	3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets	12
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	330
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	57
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Liabilities	18
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent	31
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Pension and Other Post Retirement Obligations	4
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Operating Lease, Liability	3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities	8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	121
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	209
Goodwill, Acquired During Period	40
Business Combination, Consideration Transferred	249
Technology-Based Intangible Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	40
Trade Names [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	25
Customer Relationships [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 65

Acquisitions Acquisitions Phant

Acquisitions Acquisitions Phantom (Details)	Jan. 02, 2019	Dec. 31, 2019
Customer Relationships [Member]
Business Acquisition [Line Items]
Weighted Average Life		11 years
NAKAN [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Weighted Average Life	17 years
NAKAN [Member] | Technology-Based Intangible Assets [Member]
Business Acquisition [Line Items]
Weighted Average Life	14 years
NAKAN [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Weighted Average Life	15 years

Financial Instruments (Cash Equ

Financial Instruments (Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Held-to-maturity	$ 240	$ 10
Restricted cash and cash equivalents	$ 22	$ 22

Accounts Receivable (Schedule O

Accounts Receivable (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Trade customers	$ 948	$ 969
Related Party	12	6
Allowance for doubtful accounts	(22)	(23)
Accounts Receivable from trade customers, net	938	952
Federal and state taxes	59	57
Other	39	28
Accounts receivable, net	$ 1,036	$ 1,037

Inventories (Schedule Of Invent

Inventories (Schedule Of Inventory) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Inventory, Net [Abstract]
Finished products	$ 568	$ 657
Feedstock, additives, chemicals and other raw materials	210	203
Materials and supplies	158	154
Inventories	$ 936	$ 1,014

Property, Plant And Equipment_2

Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment, Net [Abstract]
Land	$ 198	$ 193
Buildings and improvements	608	544
Plant and equipment	8,227	7,568
Other	496	437
Property, Plant and Equipment, Gross	9,529	8,742
Less: Accumulated depreciation	(3,168)	(2,720)
Property, plant and equipment, net, before construction in progress	6,361	6,022
Construction in progress	551	573
Property, plant and equipment, net	$ 6,912	$ 6,595

Property, Plant And Equipment_3

Property, Plant And Equipment (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net [Abstract]
Depreciation expense on property, plant and equipment	$ 519	$ 478	$ 449

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use assets	$ 443	$ 0
Operating Lease, Liability, Current	93
Operating lease liabilities	355	0
Operating Lease, Liability	$ 448
Operating Lease, Weighted Average Remaining Lease Term	8 years
Operating Lease, Weighted Average Discount Rate, Percent	3.50%
Lease, Cost [Abstract]
Operating Lease, Cost	$ 113
Short-term Lease, Cost	58
Lease, Cost	171
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	106
Lessee, Operating Lease, Liability, Payments, Due Year Two	83
Lessee, Operating Lease, Liability, Payments, Due Year Three	69
Lessee, Operating Lease, Liability, Payments, Due Year Four	55
Lessee, Operating Lease, Liability, Payments, Due Year Five	43
Lessee, Operating Lease, Liability, Payments, Due after Year Five	189
Lessee, Operating Lease, Liability, Payments, Due	545
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(97)
Operating Leases, Future Minimum Payments Due, Next Twelve Months		94
Operating Leases, Future Minimum Payments, Due in Two Years		89
Operating Leases, Future Minimum Payments, Due in Three Years		70
Operating Leases, Future Minimum Payments, Due in Four Years		56
Operating Leases, Future Minimum Payments, Due in Five Years		42
Operating Leases, Future Minimum Payments, Due Thereafter		152
Operating Leases, Future Minimum Payments Due		$ 503
Affiliates [Member]
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use assets	50
Fixed Lease Payments [Member] | Affiliates [Member]
Lease, Cost [Abstract]
Operating Lease, Cost	$ 18

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Balance at beginning of year	$ 1,002	$ 1,012
Goodwill Acquired	67
Effects of changes in foreign exchange rates	5	(10)
Balance at end of year	1,074	1,002
Olefins [Member]
Goodwill [Roll Forward]
Balance at beginning of year	30	30
Goodwill Acquired	0
Effects of changes in foreign exchange rates	0	0
Balance at end of year	30	30
Vinyls [Member]
Goodwill [Roll Forward]
Balance at beginning of year	972	982
Goodwill Acquired	67
Effects of changes in foreign exchange rates	5	(10)
Balance at end of year	$ 1,044	$ 972

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Schedule of Finite-Lived Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Customer Relationships, Gross	$ 832	$ 745
Finite-Lived Intangible Assets, Net	523	525
Finite-Lived Intangible Assets, Accumulated Amortization	$ (309)	(220)
Weighted Average Life	11 years
Licensing Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Licenses and intellectual property, Gross	$ 172	122
Finite-Lived Intangible Assets, Net	93	57
Finite-Lived Intangible Assets, Accumulated Amortization	$ (79)	(65)
Weighted Average Life	13 years
Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Trademarks, Gross	$ 120	90
Finite-Lived Intangible Assets, Net	83	64
Finite-Lived Intangible Assets, Accumulated Amortization	$ (37)	(26)
Weighted Average Life	13 years
Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross	$ 35	35
Finite-Lived Intangible Assets, Net	11	13
Finite-Lived Intangible Assets, Accumulated Amortization	$ (24)	(22)
Weighted Average Life	10 years
Total Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	$ 187	134
Finite-Lived Intangible Assets, Accumulated Amortization	(140)	(113)
Finite-Lived Intangible Assets, Gross	$ 327	$ 247

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Amortization) (Details) $ in Millions	Dec. 31, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 120
2021	117
2022	104
2023	57
2024	$ 51

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets (Narrative) (Details) - Measurement Input, Discount Rate [Member] - Valuation Technique, Discounted Cash Flow [Member]	Dec. 31, 2019
Olefins [Member]
Goodwill [Line Items]
Alternative Investment, Measurement Input	0.095
Vinyls [Member] | Minimum [Member]
Goodwill [Line Items]
Alternative Investment, Measurement Input	0.09
Vinyls [Member] | Maximum [Member]
Goodwill [Line Items]
Alternative Investment, Measurement Input	0.125

Equity Method Investements (Det

Equity Method Investements (Details) lb in Millions, $ in Millions	Jun. 17, 2015lb	Dec. 31, 2019USD ($)lb	Nov. 12, 2019USD ($)	Oct. 28, 2019	Dec. 31, 2018USD ($)
Schedule of Equity Method Investments [Line Items]
Investments in joint ventures		$ 225
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity		166
Equity Method Investments		1,112			$ 253
LACC, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)			34.80%	12.00%
Increase in Equity Method Investment		$ 817	$ 817
Investments in and Advances to Affiliates, Proportionate Share Of Production, Mass | lb		215
Investments in and Advances to Affiliates, at Fair Value		$ 1,038			183
Investments in and Advances to Affiliates, at Fair Value, Gross Additions		45
Investments in and Advances to Affiliates, at Fair Value, Gross Reductions		(7)
other equity method investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments		$ 74			70
Affiliates [Member]
Schedule of Equity Method Investments [Line Items]
Plant capacity (in lbs) | lb	2,200
Lotte Chemical Corporation [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Reimbursement Agreement, Term		6 years 6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period		25 years
Revenue, Remaining Performance Obligation, Amount		$ 81
Contract with Customer, Liability		$ 7			0
LACC, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Reimbursement Agreement, Term		6 years 6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period		25 years
Revenue, Remaining Performance Obligation, Amount		$ 59
Contract with Customer, Liability		$ 5			$ 0

Accounts and Notes Payable (Det

Accounts and Notes Payable (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts and Notes Payable [Abstract]
Accounts Payable, Trade, Current	$ 435	$ 504
Accounts payable due to related parties	12	2
Notes Payable, Current	26	1
Accounts payable	$ 473	$ 507

Long-Term Debt (Schedule Of Lon

Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jul. 17, 2019	Dec. 31, 2018	Nov. 30, 2017	Aug. 10, 2016	Jul. 31, 2012	Dec. 31, 2010
Debt Instrument [Line Items]
Long-term Debt, Gross Excluding Current Maturities	$ 3,500		$ 2,715
Debt Instrument, Unamortized Premium (Discount) and Debt Issuance Cost, Net, Excluding Current Maturities	(55)		(47)
Long-term Debt, Excluding Current Maturities	$ 3,445		2,668
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2022
Stated interest rate (percent)	3.60%
Principal amount	$ 250		250			$ 250
Unamortized Premium (Discount) and Debt Issuance Costs	(1)		(1)
Long-term debt, net	$ 249		249
Senior Notes [Member] | 3.60% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2026
Stated interest rate (percent)	3.60%
Principal amount	$ 750		750		$ 750
Unamortized Premium (Discount) and Debt Issuance Costs	(8)		(9)
Long-term debt, net	$ 742		741
Senior Notes [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2027
Principal amount	$ 11		11
Unamortized Premium (Discount) and Debt Issuance Costs	0		0
Long-term debt, net	$ 11		11
Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2029
Stated interest rate (percent)	6.50%
Principal amount	$ 100		100
Unamortized Premium (Discount) and Debt Issuance Costs	(1)		(1)
Long-term debt, net	$ 99		99
Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2035 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2035
Stated interest rate (percent)	6.50%
Principal amount	$ 89		89				$ 89
Unamortized Premium (Discount) and Debt Issuance Costs	(1)		(1)
Long-term debt, net	$ 88		88
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2035
Stated interest rate (percent)	6.50%
Principal amount	$ 65		65				$ 65
Unamortized Premium (Discount) and Debt Issuance Costs	0		0
Long-term debt, net	$ 65		65
Senior Notes [Member] | 5.0% 2046 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2046
Stated interest rate (percent)	5.00%
Principal amount	$ 700		700		$ 700
Unamortized Premium (Discount) and Debt Issuance Costs	(23)		(24)
Long-term debt, net	$ 677		676
Senior Notes [Member] | 4.375% Senior Notes Due 2047 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2047
Stated interest rate (percent)	4.375%
Principal amount	$ 500		500	$ 500
Unamortized Premium (Discount) and Debt Issuance Costs	(9)		(9)
Long-term debt, net	$ 491		491
Senior Notes [Member] | 3.50% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Debt instrument maturity	2032
Stated interest rate (percent)	3.50%
Principal amount	$ 250		250
Unamortized Premium (Discount) and Debt Issuance Costs	(1)		(2)
Long-term debt, net	$ 249		248
Senior Notes [Member] | 1.625% Senior Notes Due 2029
Debt Instrument [Line Items]
Debt instrument maturity	2029
Stated interest rate (percent)	1.625%
Principal amount	$ 785		0
Unamortized Premium (Discount) and Debt Issuance Costs	(11)		0
Long-term debt, net	$ 774	$ 779	$ 0

Long-Term Debt (Credit Agreemen

Long-Term Debt (Credit Agreement (Details) - USD ($) $ in Millions	Jul. 24, 2018	Dec. 31, 2019	Jul. 23, 2018
New Credit Agreement [Member] | Minimum [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Line Of Credit Facility Permitted Increase	$ 25
New Credit Agreement [Member] | Maximum [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Line Of Credit Facility Permitted Increase	500
Revolving Credit Facility [Member] | New Credit Agreement [Member]
Credit Agreement [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity		$ 1,000
Revolving Credit Facility [Member] | New Credit Agreement [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000
Line of Credit Facility, Fair Value of Amount Outstanding		0
Letters of Credit Outstanding, Amount		$ 0
Revolving Credit Facility [Member] | New Credit Agreement [Member] | Minimum [Member] | LIBOR [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Revolving Credit Facility [Member] | New Credit Agreement [Member] | Minimum [Member] | Alternate Base Rate [Domain] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Revolving Credit Facility [Member] | New Credit Agreement [Member] | Maximum [Member] | LIBOR [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Revolving Credit Facility [Member] | New Credit Agreement [Member] | Maximum [Member] | Alternate Base Rate [Domain] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.75%
Revolving Credit Facility [Member] | Credit Agreement [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			$ 1,000
Letter of Credit [Member] | New Credit Agreement [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 150
Swingline Loan [Member] | New Credit Agreement [Member] | Senior Secured Revolving Credit Facility [Member]
Credit Agreement [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 50

Long-Term Debt (Senior Notes Du

Long-Term Debt (Senior Notes Due 2026 and 2046) (Details) - Senior Notes [Member] - USD ($) $ in Millions	Apr. 24, 2017	Dec. 31, 2019	Dec. 31, 2018	Aug. 10, 2016
3.60% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Principal amount		$ 750	$ 750	$ 750
Exchange Offer Percentage	99.97%
5.0% 2046 [Member]
Debt Instrument [Line Items]
Principal amount		$ 700	$ 700	$ 700
Exchange Offer Percentage	100.00%

Long-Term Debt (3.60% Senior No

Long-Term Debt (3.60% Senior Notes due 2022) (Details) - Senior Notes [Member] - 3.60% Senior Notes Due 2022 [Member] - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Jul. 31, 2012
Debt Instrument [Line Items]
Principal amount	$ 250	$ 250	$ 250
Debt Instrument, Unamortized Discount			$ 1

Long-Term Debt (4.375% Senior N

Long-Term Debt (4.375% Senior Notes due 2047) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Nov. 30, 2017
Senior Notes [Member] | 4.375% Senior Notes Due 2047 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500	$ 500	$ 500

Long-Term Debt (1.625% Senior N

Long-Term Debt (1.625% Senior Notes due 2029) (Details) - Senior Notes [Member] - 1.625% Senior Notes Due 2029 € in Millions, $ in Millions	Dec. 31, 2019USD ($)	Jul. 17, 2019EUR (€)	Jul. 17, 2019USD ($)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Debt Instrument, Face Amount | €		€ 700
Long-term Debt | $	$ 774		$ 779	$ 0

Long-Term Debt (IKE Zone Bonds)

Long-Term Debt (IKE Zone Bonds) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2010
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 65	$ 65	$ 65

Long-Term Debt (GO Zone Bonds)

Long-Term Debt (GO Zone Bonds) (Details) - Senior Notes [Member] $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Nov. 30, 2017USD ($)	Jul. 31, 2012USD ($)	Dec. 31, 2010USD ($)	Jul. 02, 2010USD ($)
6 1/2% GO Zone Senior Notes Due 2035 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 89	$ 89			$ 89
Debt Instrument, Face Amount					$ 89
Stated interest rate (percent)	6.50%
Fixed Charge Coverage Ratio	2
Maximum Unrestricted Quarterly Dividends Allowable Under Debt Covenants	0.10
Maximum Unrestricted Distributions Allowable Under Debt Covenants	$ 100
Maximum Percentage Of Income Distribution	50.00%
Maximum Distribution Percentage Of Specified Net Cash Proceeds	100.00%
6 1/2% GO Zone Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 100	100
Debt Instrument, Face Amount						$ 100
Stated interest rate (percent)	6.50%
Go Zone 3.50% Bonds Due 2032 [Member]
Debt Instrument [Line Items]
Amount of bonds remarketed			$ 250
Stated interest rate (percent)			3.50%
3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 250	250		$ 250
Stated interest rate (percent)	3.60%
3.50% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 250	$ 250
Stated interest rate (percent)	3.50%

Long-Term Debt (Revenue Bonds)

Long-Term Debt (Revenue Bonds) (Details) - Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] - Senior Notes [Member] - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 11	$ 11
Debt Instrument, Interest Rate, Effective Percentage	1.78%	1.85%

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Long-term Debt, Weighted Average Interest Rate, at Point in Time	3.60%	4.40%
Unamortized Debt Issuance Expense	$ 30	$ 25
Long-term Debt, Maturities, Repayments of Principal in Year Three	$ 250

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 31, 2018	Nov. 20, 2015	Nov. 30, 2014
Class of Stock [Line Items]
Dividends, Common Stock, Cash	$ 132	$ 120	$ 103
Common Stock, Voting Rights, Number of Votes Per Share	1
Common stock, sinking fund	$ 0
Stock repurchase program, authorized amount				$ 150	$ 150	$ 250
Stock Repurchase Program, Shares Repurchased, Gross	6,080,191
Treasury Stock Purchase Price, Repurchase Program	$ 365
Ordinary Dividend [Member]
Class of Stock [Line Items]
Dividends, Common Stock, Cash	$ 132	$ 120	$ 103
Treasury Stock [Member]
Class of Stock [Line Items]
Stock repurchased 2014 program, shares repurchase	517,712	1,368,881	0

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	$ 5,860	$ 5,590
Accumulated Other Comprehensive Income (Loss), Net of Tax	(74)	(62)	$ 7
Reclassification of certain tax effects to retained earnings		0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	3	27	43
Other comprehensive income (loss) before reclassifications	(24)	(14)
Amounts reclassified from accumulated other comprehensive income (loss)	0	(11)
Reclassification of certain tax effects to retained earnings		9
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(24)	(16)
Accumulated Foreign Currency Adjustment Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(77)	(89)	$ (36)
Other comprehensive income (loss) before reclassifications	12	(57)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Reclassification of certain tax effects to retained earnings		4
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	12	(53)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	(12)	(71)
Amounts reclassified from accumulated other comprehensive income (loss)	0	(11)
Reclassification of certain tax effects to retained earnings		13
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (12)	$ (69)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) Reclassifications in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	$ 0	$ 11	$ (2)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	0	11
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of pension and other post-retirement items	0	0	(2)
Settlement gain	0	14	0
Provision for (benefit from) income taxes	$ 0	$ (3)	$ 0

Employee Benefits (Narrative De

Employee Benefits (Narrative Defined Contribution Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
United States [Member]
Defined Contribution Plan [Line Items]
Maximum employee contribution as a percentage of annual compensation	100.00%
Employer contributions to plans	$ 20	$ 21	$ 23
Foreign Plan [Member]
Defined Contribution Plan [Line Items]
Employer Contributions to Plan	4	5	5
Defined Contribution Retirement Plan [Member] | United States [Member]
Defined Contribution Plan [Line Items]
Employer Contributions to Plan	$ 32	$ 31	$ 29

Employee Benefits (Schedule Of

Employee Benefits (Schedule Of Change In Benefit Obligation and Change In Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
United States [Member]
Change in plan assets
Fair value of plan assets, beginning of year	$ 486
Fair value of plan assets, end of year	526	$ 486
Foreign Plan [Member]
Change in plan assets
Fair value of plan assets, beginning of year	17
Fair value of plan assets, end of year	19	17
Pension Plan [Member] | United States [Member]
Change in benefit obligation
Benefit obligation, beginning of year	648	807
Service cost	3	3	$ 3
Interest Cost	23	24	25
Actuarial loss (gain)	80	(43)
Benefits paid	(51)	(40)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	0
Settlements	0	(103)
Foreign exchange effects	0	0
Benefit obligation, end of year	703	648	807
Change in plan assets
Fair value of plan assets, beginning of year	486	650
Actual return	92	(22)
Employer contribution	2	3
Benefits paid	(51)	(40)
Administrative expenses paid	(3)	(2)
Settlements	0	(103)
Foreign exchange effects	0	0
Fair value of plan assets, end of year	526	486	650
Funded status, end of year	(177)	(162)
Pension Plan [Member] | Foreign Plan [Member]
Change in benefit obligation
Benefit obligation, beginning of year	136	142
Service cost	2	2	2
Interest Cost	3	3	2
Actuarial loss (gain)	14	0
Benefits paid	(4)	(4)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	(4)	0
Settlements	(1)	0
Foreign exchange effects	(2)	(7)
Benefit obligation, end of year	144	136	142
Change in plan assets
Fair value of plan assets, beginning of year	17	18
Actual return	1	0
Employer contribution	0	1
Benefits paid	0	(1)
Administrative expenses paid	0	0
Settlements	0	0
Foreign exchange effects	1	(1)
Fair value of plan assets, end of year	19	17	18
Funded status, end of year	(125)	(119)
Other Postretirement Benefits Plan [Member] | United States [Member]
Change in benefit obligation
Benefit obligation, beginning of year	67	73
Service cost	1	1	1
Interest Cost	2	2	2
Actuarial loss (gain)	3	(1)
Benefits paid	(8)	(8)
Benefit obligation, end of year	65	67	73
Change in plan assets
Fair value of plan assets, beginning of year	0	0
Employer contribution	8	8
Benefits paid	(8)	(8)
Fair value of plan assets, end of year	0	0	0
Funded status, end of year	(65)	(67)
Other Postretirement Benefits Plan [Member] | Foreign Plan [Member]
Change in benefit obligation
Benefit obligation, beginning of year	3	3
Service cost	0	0	0
Interest Cost	0	0	0
Actuarial loss (gain)	1	0
Benefits paid	0	0
Benefit obligation, end of year	4	3	3
Change in plan assets
Fair value of plan assets, beginning of year	0	0
Employer contribution	0	0
Benefits paid	0	0
Fair value of plan assets, end of year	0	0	$ 0
Funded status, end of year	$ (4)	$ (3)

Employee Benefits (Schedule O_2

Employee Benefits (Schedule Of Amounts Recognized In The Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	$ (360)	$ (337)
Other Postretirement Benefits Plan [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(8)	(8)
Noncurrent liabilities	(57)	(59)
Net amount recognized	(65)	(67)
Other Postretirement Benefits Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	0	0
Noncurrent liabilities	(5)	(3)
Net amount recognized	(5)	(3)
Pension Plan [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(2)	(2)
Noncurrent liabilities	(175)	(160)
Net amount recognized	(177)	(162)
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(2)	(3)
Noncurrent liabilities	(123)	(116)
Net amount recognized	$ (125)	$ (119)

Employee Benefits (Schedule O_3

Employee Benefits (Schedule Of Amounts Recognized In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income (loss), benefits, net of tax	$ 0	$ (22)
Pension Plan [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	(16)	(36)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Reclassification Adjustment, before Tax	0	0
Total before tax	(16)	(36)
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	22	9
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Reclassification Adjustment, before Tax	(4)	0
Total before tax	18	9
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income (loss), benefits, net of tax	(3)	(5)
Other Postretirement Benefits Plan [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	(3)	(6)
Total before tax	(3)	(6)
Other Postretirement Benefits Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	0	0
Total before tax	$ 0	$ 0

Employee Benefits (Narrative _2

Employee Benefits (Narrative Defined Benefit Plan) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement		$ 26
Defined Benefit Plan, Target Allocation Percentage of Assets, Long-Term	60.00%
Defined Benefit Plan, Target Allocation Percentage of Assets, Short-Term	40.00%
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Discretionary Range	10.00%
Minimum [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funded Status, Percentage	80.00%
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	60.00%
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	40.00%
Pension Plan [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	$ 0	(14)	$ 0
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	2
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	0	0	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	$ 0	$ 14	$ 0

Employee Benefits (Schedule O_4

Employee Benefits (Schedule Of Accumulated Benefit Obligations In Excess Of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 526	$ 486
United States [Member] | Underfunded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	(703)	(648)
Accumulated benefit obligation	(703)	(648)
Fair value of plan assets	526	486
United States [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0	$ 0
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19	17
Foreign Plan [Member] | Underfunded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	(143)	(128)
Accumulated benefit obligation	(138)	(125)
Fair value of plan assets	18	10
Foreign Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0	$ 0

Employee Benefits (Schedule O_5

Employee Benefits (Schedule Of Net Benefit Costs, Other Changes in Plan Assets and Benefit Obligation Recognized In Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Settlement benefits		$ (25)
Amortization of net gain (loss)	$ 0	0	$ (2)
Expected net loss, Next Fiscal Year	0
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year	1
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected net loss, Next Fiscal Year	0
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year	0
United States [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	3
Administrative expenses	4	3	2
Interest Cost	23	24	25
Expected return on plan assets	(33)	(42)	(40)
Net amortization	0	(1)	1
Settlement benefits	0	(14)	0
Net periodic benefit cost (gain)	(3)	(27)	(9)
Net loss (gain) emerging	20	20	(18)
Settlement gain	0	14	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Effect on plan change, before tax	0	0	0
Amortization of net gain (loss)	0	1	(1)
Total recognized in OCI	20	35	(19)
Total net periodic benefit cost and OCI	17	8	(28)
United States [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	1
Interest Cost	2	2	2
Net amortization	0	0	0
Net periodic benefit cost (gain)	3	3	3
Net loss (gain) emerging	3	(1)	(1)
Total recognized in OCI	3	(1)	(1)
Total net periodic benefit cost and OCI	6	2	2
Foreign Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	2
Administrative expenses	0	0	0
Interest Cost	3	3	2
Expected return on plan assets	(1)	(1)	(1)
Net amortization	0	1	1
Settlement benefits	0	0	0
Net periodic benefit cost (gain)	4	5	4
Net loss (gain) emerging	13	1	0
Settlement gain	0	0	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Effect on plan change, before tax	(4)	0	0
Amortization of net gain (loss)	0	(1)	(1)
Total recognized in OCI	9	0	(1)
Total net periodic benefit cost and OCI	13	5	3
Foreign Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest Cost	0	0	0
Net amortization	0	0	0
Net periodic benefit cost (gain)	0	0	0
Net loss (gain) emerging	0	(1)	0
Total recognized in OCI	0	(1)	0
Total net periodic benefit cost and OCI	$ 0	$ (1)	$ 0

Employee Benefits (Schedule O_6

Employee Benefits (Schedule Of Weighted Average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.00%	4.10%	3.40%
Rate of compensation increase	0.00%	0.00%	0.00%
Discount rate for benefit obligations	4.10%	3.40%	3.80%
Discount rate for service cost	4.20%	3.80%	4.10%
Discount rate for interest cost	3.70%	3.30%	3.20%
Expected return on plan assets	7.00%	7.00%	6.80%
Rate of compensation increase	0.00%	0.00%	0.00%
United States [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.50%	3.70%	3.00%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	6.80%	7.00%	7.30%
Defined Benefit Plan, Defined Benefit Obligation, Ultimate Health Care Cost Trend Rate	4.50%	4.50%	4.50%
Defined Benefit Plan, Years To Health Care Cost Trend Rate Reaches Ultimate Trend Rate, Benefit Obligation	10 years	11 years	11 years
Discount rate for benefit obligations	3.70%	3.00%	3.30%
Discount rate for service cost	4.00%	3.40%	3.80%
Discount rate for interest cost	3.40%	2.70%	2.60%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Periodic Benefit Costs	7.00%	7.00%	6.80%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.50%	4.50%	4.60%
Defined Benefit Plan, Years To Health Care Cost Trend Rate Reaches Ultimate Trend Rate	10 years	10 years	11 years
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	1.30%	2.00%	1.80%
Rate of compensation increase	2.60%	2.60%	2.60%
Discount rate for benefit obligations	2.00%	1.80%	1.80%
Discount rate for service cost	2.20%	2.00%	1.90%
Discount rate for interest cost	2.20%	2.00%	2.00%
Expected return on plan assets	4.00%	3.80%	3.80%
Rate of compensation increase	2.60%	2.60%	2.60%
Foreign Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.20%	3.90%	4.00%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	5.70%	5.80%	6.20%
Defined Benefit Plan, Defined Benefit Obligation, Ultimate Health Care Cost Trend Rate	4.00%	4.00%	4.50%
Defined Benefit Plan, Years To Health Care Cost Trend Rate Reaches Ultimate Trend Rate, Benefit Obligation	21 years	22 years	12 years
Discount rate for benefit obligations	3.90%	3.60%	3.30%
Discount rate for service cost	3.90%	3.60%	3.30%
Discount rate for interest cost	3.90%	3.60%	3.30%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Periodic Benefit Costs	5.80%	6.10%	6.80%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.00%	4.50%	4.50%
Defined Benefit Plan, Years To Health Care Cost Trend Rate Reaches Ultimate Trend Rate	21 years	11 years	12 years

Employee Benefits (Schedule O_7

Employee Benefits (Schedule Of Fair Value Of Pension Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 526	$ 486
United States [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	247	223
United States [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	279	263
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19	17
Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	5
Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13	12
Pension Plan [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	526	486	$ 650
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19	17	$ 18
Cash and Cash Equivalents [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member] | United States [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member] | United States [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	5
Cash and Cash Equivalents [Member] | Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	5
Cash and Cash Equivalents [Member] | Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15	13
Common Stock | United States [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15	13
Common Stock | United States [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock | Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock | Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large-Cap Mutual Funds [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	161
Large-Cap Mutual Funds [Member] | United States [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		142
Large-Cap Mutual Funds [Member] | United States [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49
Large-Cap Mutual Funds [Member] | United States [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		44
Large-Cap Mutual Funds [Member] | United States [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	112
Large-Cap Mutual Funds [Member] | United States [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		98
Large-Cap Mutual Funds [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1
Small-Cap Mutual Funds [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22
Small-Cap Mutual Funds [Member] | United States [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		19
Small-Cap Mutual Funds [Member] | United States [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8
Small-Cap Mutual Funds [Member] | United States [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		6
Small-Cap Mutual Funds [Member] | United States [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14
Small-Cap Mutual Funds [Member] | United States [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		13
Small-Cap Mutual Funds [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
International Mutual Funds [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	120
International Mutual Funds [Member] | United States [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		102
International Mutual Funds [Member] | United States [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	75
International Mutual Funds [Member] | United States [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		64
International Mutual Funds [Member] | United States [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45
International Mutual Funds [Member] | United States [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		38
International Mutual Funds [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5
International Mutual Funds [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		5
International Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
International Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
International Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5
International Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		5
Bond Mutual Funds [Member] | United States [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	198	198
Bond Mutual Funds [Member] | United States [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	100	96
Bond Mutual Funds [Member] | United States [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	98	102
Bond Mutual Funds [Member] | Foreign Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	6
Bond Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Bond Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	6
Short Term Investment Funds [Member] | United States [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	12
Short Term Investment Funds [Member] | United States [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds [Member] | United States [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	12
Short Term Investment Funds [Member] | Foreign Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

Employee Benefits (Multiemploye

Employee Benefits (Multiemployer Plans) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)plan	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Multiemployer Plans [Line Items]
Number of multiemployer plans | plan	2
Foreign Plan [Member]
Multiemployer Plans [Line Items]
Contributions to multi-employer plans | $	$ 9	$ 7	$ 8

Employee Benefits (Schedule O_8

Employee Benefits (Schedule Of Estimated Future Benefit Payments) (Details) $ in Millions	Dec. 31, 2019USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Year 1	$ 45
Year 2	45
Year 3	45
Year 4	47
Year 5	46
Years 6 to 10	233
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Year 1	8
Year 2	8
Year 3	8
Year 4	8
Year 5	7
Years 6 to 10	$ 22

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense on restricted stock	$ 24	$ 18	$ 14
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	1	21	24
Share-based Payment Arrangement, Exercise of Option, Tax Benefit	0	4	8
Restructuring, transaction and integration-related costs	$ 37	33	29
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awards, term (in years)	10 years
Unrecognized compensation expense	$ 6
Unrecognized compensation expense, weighted-average period of recognition (in years)	1 year 9 months 18 days
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 15
Unrecognized compensation expense, weighted-average period of recognition (in years)	1 year 8 months 12 days
Total fair value of shares of restricted stock that vested	$ 28	10	6
Axiall Corporation [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense on restricted stock	1	4	9
Unrecognized compensation expense	0
Total fair value of shares of restricted stock that vested	3	$ 6	$ 11
Total fair value of shares of restricted stock that were cancelled	$ 0
Cliff Vest [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	3 years
Cliff Vest [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	6 years
Cliff Vest [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	5 years
Ratably On Annual Basis [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	2 years
Ratably On Annual Basis [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	5 years
Ratably On Annual Basis [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	3 years

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule Of Option Activity And Changes) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares
Options
Options, Outstanding, beginning balance | shares	1,115,954
Options, Granted | shares	296,598
Options, Exercised | shares	(18,635)
Options, Cancelled | shares	(7,969)
Options, Outstanding, ending balance | shares	1,385,948
Options, Exercisable, ending balance | shares	888,093
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding, beginning balance (in dollars per share) | $ / shares	$ 54.82
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	79.83
Weighted Average Exercise Price, Exercised (in dollars per share) | $ / shares	35.04
Weighted Average Exercise Price, Cancelled (in dollars per share) | $ / shares	79.94
Weighted Average Exercise Price, Outstanding, ending balance (in dollars per share) | $ / shares	60.29
Weighted Average Exercise Price, Exercisable, ending balance (in dollars per share) | $ / shares	$ 47.64
Weighted Average Remaining Term (Years) [Abstract]
Weighted Average Remaining Term (Years), Outstanding	5 years 10 months 24 days
Weighted Average Remaining Term (Years), Exercisable	4 years 6 months
Aggregate Intrinsic Value [Abstract]
Aggregate Intrinsic Value, Outstanding | $	$ 23
Aggregate Intrinsic Value, Exercisable | $	$ 22

Stock-Based Compensation (Sch_2

Stock-Based Compensation (Schedule Of Range Of Exercise Prices For Outstanding Options) (Details)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
$10.26 - $30.05
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 10.26
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 30.05
Options Outstanding | shares	264,334
Weighted Average Remaining Contractual Life (Years)	1 year
$40.38 - $44.42
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 40.38
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 44.42
Options Outstanding | shares	218,047
Weighted Average Remaining Contractual Life (Years)	6 years 1 month 6 days
$45.70 - $61.87
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 45.70
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 61.87
Options Outstanding | shares	295,620
Weighted Average Remaining Contractual Life (Years)	6 years 6 months
$63.98 - $68.18
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 63.98
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 68.18
Options Outstanding | shares	145,171
Weighted Average Remaining Contractual Life (Years)	4 years 8 months 12 days
$79.83 - $107.75
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	$ 79.83
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 107.75
Options Outstanding | shares	462,776
Weighted Average Remaining Contractual Life (Years)	8 years 9 months 18 days

Stock-Based Compensation (Sch_3

Stock-Based Compensation (Schedule Of Weighted Average Value And Assumptions For Fair Value Of Options) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 21.02	$ 28.94	$ 15.84
Risk-free interest rate	2.50%	2.70%	2.10%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	5 years	5 years	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	28.90%	27.60%	29.20%
Expected dividend yield	1.20%	0.70%	1.20%

Stock-Based Compensation (Sch_4

Stock-Based Compensation (Schedule Of Non-Vested Restricted Stock Award and RSU Activity and Changes) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $	$ 15
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 8 months 12 days
Number of Shares
Number of Shares, Non-vested, beginning balance | shares	702,789
Number of Shares, Granted | shares	205,517
Number of Shares, Vested | shares	(415,593)
Number of Shares, Forfeited | shares	(29,430)
Number of Shares, Non-vested, ending balance | shares	463,283
Weighted Average Grant Date Fair Value
Weighted Average Fair Value, Non-vested, beginning balance (in dollars per share) | $ / shares	$ 65.79
Weighted Average Fair Value, Granted (in dollars per share) | $ / shares	77.59
Weighted Average Fair Value, Vested (in dollars per share) | $ / shares	56.70
Weighted Average Fair Value, Forfeited (in dollars per share) | $ / shares	73.28
Weighted Average Fair Value, Non-vested, ending balance (in dollars per share) | $ / shares	$ 78.69
Axiall Corporation [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $	$ 0
Number of Shares
Number of Shares, Non-vested, beginning balance | shares	49,528
Number of Shares, Vested | shares	(49,292)
Number of Shares, Forfeited | shares	(236)
Number of Shares, Non-vested, ending balance | shares	0
Weighted Average Grant Date Fair Value
Weighted Average Fair Value, Non-vested, beginning balance (in dollars per share) | $ / shares	$ 66.46
Weighted Average Fair Value, Vested (in dollars per share) | $ / shares	68.22
Weighted Average Fair Value, Forfeited (in dollars per share) | $ / shares	76.77
Weighted Average Fair Value, Non-vested, ending balance (in dollars per share) | $ / shares	$ 0

Stock-Based Compensation (Sch_5

Stock-Based Compensation (Schedule of Non-Vested Performance Stock Award) (Details) - Performance Shares [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 114.38	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	77,217	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	78,328
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 114.38
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(1,111)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 114.38
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 6
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years 1 month 6 days

Stock-Based Compensation (Perfo

Stock-Based Compensation (Performance Stock Units Assumptions) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.50%	2.70%	2.10%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	5 years	5 years	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	28.90%	27.60%	29.20%
Share Base Compensation Average Correlation Coefficient of Peer Companies	0.49
Performance Shares [Member]
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.50%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	2 years 10 months 17 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	30.30%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 114.38
Minimum [Member] | Performance Shares [Member]
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share Based Compensation Arrangements Expected Volatility Rate of Peer Companies	14.50%
Maximum [Member] | Performance Shares [Member]
Schedule Of Share Based Payment Award Performance Share Units Valuation Assumptions [Line Items]
Share Based Compensation Arrangements Expected Volatility Rate of Peer Companies	47.80%

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Carrying And Fair Values Of Long-Term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jul. 17, 2019	Dec. 31, 2018
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 249		$ 249
Debt instrument maturity	2022
Stated interest rate (percent)	3.60%
Senior Notes [Member] | 3.60% Senior Notes Due 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 742		741
Debt instrument maturity	2026
Stated interest rate (percent)	3.60%
Senior Notes [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 11		11
Debt instrument maturity	2027
Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 99		99
Debt instrument maturity	2029
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2035 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 88		88
Debt instrument maturity	2035
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 65		65
Debt instrument maturity	2035
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 5.0% 2046 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 677		676
Debt instrument maturity	2046
Stated interest rate (percent)	5.00%
Senior Notes [Member] | 4.375% Senior Notes Due 2047 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 491		491
Debt instrument maturity	2047
Stated interest rate (percent)	4.375%
Senior Notes [Member] | 3.50% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 249		248
Debt instrument maturity	2032
Stated interest rate (percent)	3.50%
Senior Notes [Member] | 1.625% Senior Notes Due 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 774	$ 779	0
Debt instrument maturity	2029
Stated interest rate (percent)	1.625%
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	$ 255		248
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 3.60% Senior Notes Due 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	777		692
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	103		106
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 6 1/2% GO Zone Senior Notes Due 2035 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	92		95
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	68		69
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 5.0% 2046 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	761		641
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 4.375% Senior Notes Due 2047 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	505		417
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 3.50% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	267		233
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 1.625% Senior Notes Due 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	785		0
Estimate of Fair Value Measurement [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	$ 11		$ 11

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in valuation allowance	$ (17)	$ (9)	$ 3
Provisional adjustment of income tax benefit			$ 591
Domestic Tax Authority [Member]
Tax Credit Carryforward, Amount	2
Operating Loss Carryforwards	539
Foreign Tax Authority [Member]
Tax Credit Carryforward, Amount	4
Change in valuation allowance	19
Operating Loss Carryforwards	217
State and Local Jurisdiction [Member]
Tax Credit Carryforward, Amount	19
Operating Loss Carryforwards	$ 613

Income Taxes (Components Of Inc

Income Taxes (Components Of Income (Loss) Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Domestic	$ 460	$ 1,087	$ 917
Foreign	110	247	164
Income before income taxes	$ 570	$ 1,334	$ 1,081

Income Taxes (Schedule Of The P

Income Taxes (Schedule Of The Provision For (Benefit From) Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current
Federal	$ 20	$ 158	$ 231
State	9	28	18
Foreign	25	52	27
Total Current	54	238	276
Deferred
Federal	69	59	(557)
State	11	(2)	25
Foreign	(26)	5	(2)
Total Deferred	54	62	(534)
Provision for (benefit from) income taxes	$ 108	$ 300	$ (258)

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Taxes Computed At The Statutory Rate To Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provision for federal income tax, at statutory rate	$ 120	$ 280	$ 378
State income tax provision, net of federal income tax effect	10	28	26
Foreign income tax rate differential	(6)	14	(36)
Manufacturing deduction	0	0	(23)
Depletion	(5)	(4)	(7)
Noncontrolling interests	(8)	(6)	(9)
Tax Act related adjustment	0	0	(591)
Change in valuation allowance	(17)	(9)	3
Changes in state apportionment and other state adjustments	11	(6)	2
Other, net	3	3	(1)
Provision for (benefit from) income taxes	$ 108	$ 300	$ (258)

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ 209	$ 50
Credit carryforward	25	24
Operating lease liabilities	96	0
Accruals	65	64
Pension	83	76
Inventories	20	13
Other	26	17
Deferred taxes assets—total	524	244
Property, plant and equipment	(1,017)	(948)
Intangibles	(156)	(148)
Operating lease right-of-use asset	(95)	0
Turnaround costs	(21)	(20)
Consolidated partnerships	(194)	(202)
Equity method investments	(220)	(13)
Other	(18)	(14)
Deferred tax liabilities—total	(1,721)	(1,345)
Valuation allowance	(30)	(47)
Total net deferred tax liabilities	(1,227)	(1,148)
Balance sheet classifications
Noncurrent deferred tax asset	28	11
Noncurrent deferred tax liability	$ (1,255)	$ (1,159)

Earnings and Dividends per Sh_3

Earnings and Dividends per Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings and Dividends Per Share [Abstract]
Number of options excluded from computation of diluted earnings per share	562,773	150,479	0

Earnings and Dividends per Sh_4

Earnings and Dividends per Share (Schedule Of Net Income Attributable To Common Stockholders) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings and Dividends Per Share [Abstract]
Net income attributable to Westlake Chemical Corporation	$ 72	$ 158	$ 119	$ 72	$ 123	$ 308	$ 278	$ 287	$ 421	$ 996	$ 1,304
Net income attributable to participating securities									(2)	(5)	(7)
Net income attributable to common shareholders									$ 419	$ 991	$ 1,297

Earnings and Dividends per Sh_5

Earnings and Dividends per Share (Reconciliation Of Denominator For Basic And Diluted Earnings (Loss) Per Share) (Details) - $ / shares	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings and Dividends Per Share [Abstract]
Weighted average common shares—basic									128,395,184	129,401,823	129,087,043
Weighted Average Number Diluted Shares Outstanding Adjustment									362,109	583,930	452,970
Weighted average common shares—diluted									128,757,293	129,985,753	129,540,013
Basic (in dollars per share)	$ 0.56	$ 1.22	$ 0.92	$ 0.56	$ 0.95	$ 2.36	$ 2.13	$ 2.21	$ 3.26	$ 7.66	$ 10.05
Diluted (in dollars per share)	$ 0.56	$ 1.22	$ 0.92	$ 0.55	$ 0.95	$ 2.35	$ 2.12	$ 2.20	$ 3.25	$ 7.62	$ 10

Earnings and Dividends per Sh_6

Earnings and Dividends per Share Dividends Per Share (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings and Dividends Per Share [Abstract]
Dividends Per Common Share (in usd per share)	$ 1.0250	$ 0.9200	$ 0.8012

Supplemental Information (Detai

Supplemental Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest Paid, Excluding Capitalized Interest, Operating Activities	$ 116	$ 140	$ 154
Accrued Liabilities
Accrued and other liabilities	768	676
Accrued rebates	115	125
Due to Related Parties, Current	41	54
Non-Cash Investing Activity [Abstract]
Increase (Decrease) in Capital Expenditure Accrual	(14)	48	9
Restructuring and Related Activities [Abstract]
Restructuring, transaction and integration-related costs	37	33	29
Business Acquisition, Transaction Costs	26
Other Income and Expenses [Abstract]
Income (Loss) from Subsidiaries, Net of Tax	17	16	10
Interest Income, Other	20	17
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement		25
Operating Lease, Payments	112
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	119
Income Taxes Paid, Net	$ 77	$ 376	$ 84

Related Party and Affiliate T_2

Related Party and Affiliate Transactions (Details) $ in Millions, lb in Billions	Jun. 17, 2015lb	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Investments in joint ventures		$ 225
Related party receivable		12	$ 6
Dividends received from equity method investments		11	5	$ 6
Accounts payable due to related parties		12	2
Affiliates [Member]
Related Party Transaction [Line Items]
Plant capacity (in lbs) | lb	2.2
Incurred and paid lease payments		3	3	3
Pipeline Fees For Transport Of Natural Gas Liquid Feedstocks [Member] | Cypress Interstate Pipeline L.L.C [Member] | Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Purchases from related parties		14	14	15
Accounts payable due to affiliate		$ 1	2
Cypress Interstate Pipeline L.L.C [Member] | Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%
Investments in joint ventures		$ 8	8
YNCORIS GmbH & Co. KG [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		20.00%
Investments in joint ventures		$ 57	57
YNCORIS GmbH & Co. KG [Member] | Electricity And Technical Services [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Purchases from related parties		155	145	133
Accounts payable due to affiliate		$ 36	48
RS Cogen LLC [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%
Investments in joint ventures		$ 9	5
Purchases from related parties		$ 26	25	26
Vinyl Solutions, LLC [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%
Sales to related parties		$ 5	13	17
Related party receivable		2	3
American Air Liquide Holdings [Member] | American Air Liquide Holdings, Inc. [Member]
Related Party Transaction [Line Items]
Sales to related parties		7	7	7
Related party receivable		0	1
Purchases and lease expense to related parties		32	31	$ 30
Accounts payable due to related parties		$ 2	$ 4

Westlake Chemical Partners LP (

Westlake Chemical Partners LP (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 29, 2019	Oct. 04, 2018	Aug. 04, 2014	Dec. 31, 2019
Related Party Transaction [Line Items]
Partners' Capital Account, Units, Sold in Public Offering			12,937,500
Partners' Capital Account, Units, Sold in Private Placement	2,940,818
Sale of Unit Price Per Unit	$ 21.40
Proceeds from Issuance of Private Placement	$ 63
Partners' Units, Maximum Aggregate Offering Amount, ATM		$ 50
Westlake Chemical OpCo LP [Member]
Related Party Transaction [Line Items]
Payments to Acquire Limited Partnership Interests	$ 201
Westlake Chemical OpCo LP [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited Partnership Ownership Percentage Increase	4.50%
Principal Owner [Member] | TTWF LP [Member]
Related Party Transaction [Line Items]
Partners' Capital Account, Units, Acquisitions	1,401,869
Subsidiary of Common Parent [Member] | Westlake Chemical OpCo LP [Member] | IPO [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest				22.80%
Limited partner interest (percent)				77.20%
Subsidiary of Common Parent [Member] | Westlake Chemical Partners LP [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Partners' Capital Account, Units				14,122,230
Subsidiary of Common Parent [Member] | Westlake Chemical Partners LP [Member] | IPO [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited partner interest (percent)				40.10%

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	May 22, 2019	Jun. 18, 2018	May 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Environmental Loss Contingencies [Line Items]
Environmental loss contingency accrual				$ 47	$ 54
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 Loss				$ 130
PolyOne [Member]
Environmental Loss Contingencies [Line Items]
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties	100.00%
PolyOne [Member] | Pending Litigation [Member]
Environmental Loss Contingencies [Line Items]
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties				100.00%
Loss Contingency, Damages Sought, Value			$ 11
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 Cost				$ 1
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Maximum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Anticipated Cost				$ 3

Commitments and Contingencies_2

Commitments and Contingencies (Minimum Purchase Obligations) (Details) $ in Millions	Dec. 31, 2019USD ($)
Unconditional purchase obligations
2020	$ 584
2021	621
2022	497
2023	461
2024	$ 360

Segment and Geographic Inform_3

Segment and Geographic Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2019plantcustomerSegment	Dec. 31, 2018customer	Dec. 31, 2017customer
Segment Reporting Information [Line Items]
Number of segments | Segment	2
Number of Building Product Facilities | plant	36
Olefins [Member]
Segment Reporting Information [Line Items]
Number of major customers	0	0	0
Vinyls [Member]
Segment Reporting Information [Line Items]
Number of major customers	0	0	0

Segment and Geographic Inform_4

Segment and Geographic Information (Segment Reporting Information) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 1,883	$ 2,066	$ 2,144	$ 2,025	$ 1,995	$ 2,255	$ 2,235	$ 2,150	$ 8,118	$ 8,635	$ 8,041
Income from operations	$ 102	$ 226	$ 194	$ 134	$ 207	$ 396	$ 404	$ 401	656	1,408	1,225
Depreciation and amortization									713	641	601
Other income, net									38	52	15
Provision for (benefit from) income taxes									108	300	(258)
Payments to Acquire Property, Plant, and Equipment									787	702	577
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales									8,118	8,635	8,041
Operating Segments [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales									1,782	2,019	2,051
Income from operations									260	573	655
Depreciation and amortization									142	138	145
Other income, net									5	4	3
Provision for (benefit from) income taxes									60	128	63
Payments to Acquire Property, Plant, and Equipment									117	110	97
Operating Segments [Member] | Olefins [Member] | Polyethylene [Member]
Segment Reporting Information [Line Items]
Net sales									1,301	1,519	1,518
Operating Segments [Member] | Olefins [Member] | Styrene, Feedstock And Other [Member]
Segment Reporting Information [Line Items]
Net sales									481	500	533
Operating Segments [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net sales									6,336	6,616	5,990
Income from operations									451	913	639
Depreciation and amortization									563	491	449
Other income, net									18	35	7
Provision for (benefit from) income taxes									40	212	(302)
Payments to Acquire Property, Plant, and Equipment									664	585	459
Operating Segments [Member] | Vinyls [Member] | PVC, Caustic Soda And Other [Member]
Segment Reporting Information [Line Items]
Net sales									5,068	5,359	4,769
Operating Segments [Member] | Vinyls [Member] | Building Products [Member]
Segment Reporting Information [Line Items]
Net sales									1,268	1,257	1,221
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Income from operations									(55)	(78)	(69)
Depreciation and amortization									8	12	7
Other income, net									15	13	5
Provision for (benefit from) income taxes									8	(40)	(19)
Payments to Acquire Property, Plant, and Equipment									6	7	21
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales									325	502	394
Intersegment Eliminations [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net sales									324	500	393
Intersegment Eliminations [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net sales									$ 1	$ 2	$ 1

Segment and Geographic Inform_5

Segment and Geographic Information (Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Income from operations for reportable segments	$ 102	$ 226	$ 194	$ 134	$ 207	$ 396	$ 404	$ 401	$ 656	$ 1,408	$ 1,225
Interest expense									(124)	(126)	(159)
Other income, net									38	52	15
Income before income taxes									$ 570	$ 1,334	$ 1,081

Segment and Geographic Inform_6

Segment and Geographic Information (Total Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total assets	$ 13,261	$ 11,602
Operating Segments [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Total assets	1,991	2,024
Operating Segments [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Total assets	10,597	8,879
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 673	$ 699

Segment and Geographic Inform_7

Segment and Geographic Information (Geographic Information for Sales to External Customers and Long-lived Assets) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 1,883	$ 2,066	$ 2,144	$ 2,025	$ 1,995	$ 2,255	$ 2,235	$ 2,150	$ 8,118	$ 8,635	$ 8,041
Long-lived assets	6,912				6,595				6,912	6,595
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									5,530	6,114	5,739
Long-lived assets	6,012				5,829				6,012	5,829
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									573	649	653
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									478	500	432
Long-lived assets	588				528				588	528
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									175	155	104
Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									119	105	96
TAIWAN, PROVINCE OF CHINA
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									84	102	96
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									1,159	1,010	$ 921
Long-lived assets	$ 312				$ 238				$ 312	$ 238

Quarterly Financial Informati_3

Quarterly Financial Information (Unaudited) (Summary Of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 1,883	$ 2,066	$ 2,144	$ 2,025	$ 1,995	$ 2,255	$ 2,235	$ 2,150	$ 8,118	$ 8,635	$ 8,041
Gross profit	250	371	340	299	354	539	552	542	1,260	1,987	1,761
Income from operations	102	226	194	134	207	396	404	401	656	1,408	1,225
Net income	85	166	129	82	131	318	288	297	462	1,034	1,339
Net income attributable to Westlake Chemical Corporation	$ 72	$ 158	$ 119	$ 72	$ 123	$ 308	$ 278	$ 287	$ 421	$ 996	$ 1,304
Basic (in dollars per share)	$ 0.56	$ 1.22	$ 0.92	$ 0.56	$ 0.95	$ 2.36	$ 2.13	$ 2.21	$ 3.26	$ 7.66	$ 10.05
Diluted (in dollars per share)	$ 0.56	$ 1.22	$ 0.92	$ 0.55	$ 0.95	$ 2.35	$ 2.12	$ 2.20	$ 3.25	$ 7.62	$ 10