Westlake (WLK) 10-K 22 Feb 17 2016 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Feb. 15, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Entity Registrant Name	WESTLAKE CHEMICAL CORP
Entity Central Index Key	1,262,823
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		128,925,003
Entity Public Float			$ 1.6

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 459,453	$ 662,525
Marketable securities	0	520,144
Accounts receivable, net	938,743	508,532
Inventories	801,100	434,060
Prepaid expenses and other current assets	48,493	14,489
Restricted cash	160,527	0
Deferred income taxes	0	35,439
Total current assets	2,408,316	2,175,189
Property, plant and equipment, net	6,420,062	3,004,067
Other assets, net
Goodwill	946,553	62,016
Deferred charges and other assets, net	327,868	176,625
Total other assets, net	2,061,875	390,029
Total assets	10,890,253	5,569,285
Current liabilities
Accounts and notes payable	496,259	235,329
Accrued liabilities	537,483	287,313
Term loan	149,341	0
Total current liabilities	1,183,083	522,642
Long-term debt, net	3,678,654	758,148
Deferred income taxes	1,650,575	575,603
Pension and other post-retirement benefits	364,819	122,821
Other liabilities	121,077	28,140
Total liabilities	6,998,208	2,007,354
Commitments and contingencies (Notes 9, 10 and 23)
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 134,663,244 shares issued at December 31, 2016 and 2015, respectively (Note 11)	1,347	1,347
Common stock, held in treasury, at cost; 5,726,377 and 4,444,898 shares at December 31, 2016 and 2015, respectively (Note 11)	(319,339)	(258,312)
Additional paid-in capital	550,641	542,148
Retained earnings	3,412,286	3,109,987
Accumulated other comprehensive loss	(121,306)	(129,292)
Total Westlake Chemical Corporation stockholders' equity	3,523,629	3,265,878
Noncontrolling interests	368,416	296,053
Total equity	3,892,045	3,561,931
Total liabilities and equity	10,890,253	5,569,285
Customer relationships [Member]
Other assets, net
Intangible assets, net	611,615	52,677
Other Intangible Assets, Net [Member]
Other assets, net
Intangible assets, net	$ 175,839	$ 98,711

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
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 issued	134,651,380	134,663,244
Common stock, held in treasury	5,726,377	4,444,898

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net sales	$ 5,075,456	$ 4,463,336	$ 4,415,350
Cost of sales	4,094,894	3,278,145	3,098,000
Gross profit	980,562	1,185,191	1,317,350
Selling, general and administrative expenses	295,436	225,364	183,745
Transaction and integration-related costs	103,672	0	9,614
Income from operations	581,454	959,827	1,123,991
Other income (expense)
Interest expense	(79,473)	(34,656)	(37,352)
Other income (expense), net	56,398	38,270	(2,721)
Income before income taxes	558,379	963,441	1,083,918
Provision for income taxes	138,520	298,396	398,902
Net income	419,859	665,045	685,016
Net income attributable to noncontrolling interests	21,000	19,035	6,493
Net income attributable to Westlake Chemical Corporation	$ 398,859	$ 646,010	$ 678,523
Earnings per common share attributable to Westlake Chemical Corporation (Note 18):
Basic (in dollars per share)	$ 3.07	$ 4.88	$ 5.09
Diluted (in dollars per share)	$ 3.06	$ 4.86	$ 5.07
Weighted average shares outstanding (Note 18)
Basic (in shares)	129,367,712	131,823,707	133,111,230
Diluted (in shares)	129,974,822	132,301,812	133,643,414
Dividends per common share (Note 11) (in dollars per share)	$ 0.7442	$ 0.6930	$ 0.5820

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 419,859	$ 665,045	$ 685,016
Pension and other post-retirement benefits liability
Pension and other post-retirement reserves adjustment (excluding amortization)	59,546	18,260	(25,766)
Curtailment	364	0	0
Settlement benefits	371	355	0
Amortization of benefits liability	1,429	2,663	924
Income tax (provision) benefit on pension and other post-retirement benefits liability	(24,158)	(6,443)	8,096
Foreign currency translation adjustments	(34,512)	(59,466)	(60,128)
Available-for-sale investments
Unrealized holding gains on investments	61,438	(4,362)	1,301
Reclassification of net realized gains to net income	(53,720)	(3,798)	(1,212)
Income tax benefit (provision) on available-for-sale investments	(2,772)	2,932	(32)
Other comprehensive income (loss)	7,986	(49,859)	(76,817)
Comprehensive income	427,845	615,186	608,199
Comprehensive income attributable to noncontrolling interests, net of tax of $279 for 2016 and $0 for 2015 and 2014	21,000	19,035	6,493
Comprehensive income attributable to Westlake Chemical Corporation	$ 406,845	$ 596,151	$ 601,706

Consolidated Statements Of Com6

Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Comprehensive income (loss) including portion attributable to noncontrolling interest, tax	$ 279	$ 0	$ 0

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Common Stock, Held In Treasury [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Benefits Liability Net of Tax [Member]	Cumulative Foreign Currency Exchange [Member]	Net Unrealized Holding Gains on Investments, Net of Tax [Member]	Noncontrolling Interests [Member]
Number of shares, beginning balance at Dec. 31, 2013		134,580,208	1,252,922
Total equity, beginning balance at Dec. 31, 2013	$ 2,418,603	$ 1,346	$ (46,220)	$ 511,432	$ 1,954,661	$ (6,696)	$ 3,904	$ 176	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	685,016				678,523				6,493
Other comprehensive income (loss)	(76,817)					(16,746)	(60,128)	57	0
Common stock repurchased, shares			671,791
Common stock repurchased	(52,630)		$ (52,630)						0
Shares issued—stock- based compensation, shares		98,856	(137,167)
Shares issued—stock- based compensation	5,524	$ 1	$ 2,478	3,045
Stock-based compensation, net of tax on stock options exercised	15,964			15,964
Dividends paid	(77,656)				(77,656)
Distributions to noncontrolling interests	(2,204)								(2,204)
Noncontrolling interest in acquired business	286,088								286,088
Number of shares, ending balance at Dec. 31, 2014		134,679,064	1,787,546
Total equity, ending balance at Dec. 31, 2014	3,201,888	$ 1,347	$ (96,372)	530,441	2,555,528	(23,442)	(56,224)	233	290,377
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	665,045				646,010				19,035
Other comprehensive income (loss)	(49,859)					14,835	(59,466)	(5,228)	0
Common stock repurchased, shares			2,701,937
Common stock repurchased	(163,138)		$ (163,138)						0
Shares issued—stock- based compensation, shares		15,820	(44,585)
Shares issued—stock- based compensation	1,063	$ 0	$ 1,198	(135)
Stock-based compensation, net of tax on stock options exercised	11,842			11,842
Dividends paid	(91,551)				(91,551)
Distributions to noncontrolling interests	(14,956)								(14,956)
Noncontrolling interest in acquired business	1,597								1,597
Number of shares, ending balance at Dec. 31, 2015		134,663,244	4,444,898
Total equity, ending balance at Dec. 31, 2015	3,561,931	$ 1,347	$ (258,312)	542,148	3,109,987	(8,607)	(115,690)	(4,995)	296,053
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	419,859				398,859				21,000
Other comprehensive income (loss)	7,986					37,552	(34,512)	4,946	0
Common stock repurchased, shares			1,511,109
Common stock repurchased	(66,727)		$ (66,727)						0
Shares issued—stock- based compensation, shares		11,864	(117,019)
Shares issued—stock- based compensation	$ 7,728	$ 0	$ 2,938	4,790
Stock-based compensation, net of tax on stock options exercised (in shares)	(112,611)		(112,611)
Stock-based compensation, net of tax on stock options exercised	$ 6,465		$ 2,762	3,703
Dividends paid	(96,560)				(96,560)
Distributions to noncontrolling interests	(16,637)								(16,637)
Noncontrolling interest in acquired business	68,000								68,000
Number of shares, ending balance at Dec. 31, 2016		134,651,380	5,726,377
Total equity, ending balance at Dec. 31, 2016	$ 3,892,045	$ 1,347	$ (319,339)	$ 550,641	$ 3,412,286	$ 28,945	$ (150,202)	$ (49)	$ 368,416

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net income	$ 419,859	$ 665,045	$ 685,016
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	377,666	245,757	208,486
Provision for doubtful accounts	4,095	956	301
Amortization of debt issuance costs	3,159	2,004	1,673
Stock-based compensation expense	14,193	10,196	9,261
Loss from disposition of property, plant and equipment	8,629	10,891	4,181
Gains realized on previously held shares of Axiall common stock and from sales of securities	(53,754)	(3,798)	(1,212)
Gain on acquisition, net of loss on the fair value remeasurement of preexisting equity interest	0	(21,045)	0
Impairment of equity method investments	0	4,925	6,747
Deferred income taxes	100,677	39,784	58,967
Windfall tax benefits from share-based payment arrangements	(2,624)	(1,646)	(6,704)
Loss (income) from equity method investments, net of dividends	1,503	(632)	(424)
Other (gains) losses, net	(1,050)	362	1,487
Changes in operating assets and liabilities, net of effect of business acquisitions
Accounts receivable	50,291	62,722	33,161
Inventories	(61,985)	99,430	51,087
Prepaid expenses and other current assets	11,370	(4,257)	7,461
Accounts payable	11,950	(21,604)	(97,237)
Accrued liabilities	48,316	(7,640)	74,989
Other, net	(98,443)	(2,614)	(4,864)
Net cash provided by operating activities	833,852	1,078,836	1,032,376
Cash flows from investing activities
Acquisition of business, net of cash acquired	(2,437,829)	15,782	(611,087)
Additions to property, plant and equipment	(628,483)	(491,426)	(431,104)
Additions to cost method investment	(17,000)	0	0
Proceeds from disposition of assets	1,207	49	181
Proceeds from disposition of equity method investment	0	27,865	0
Proceeds from repayment of loan acquired	0	0	45,923
Proceeds from sales and maturities of securities	662,938	48,900	342,045
Purchase of securities	(138,422)	(605,098)	(117,332)
Settlements of derivative instruments	(5,211)	(2,248)	(1,831)
Net cash used for investing activities	(2,562,800)	(1,006,176)	(773,205)
Cash flows from financing activities
Debt issuance costs	(35,773)	0	(1,186)
Dividends paid	(96,560)	(91,551)	(77,656)
Distributions to noncontrolling interests	(16,637)	(14,856)	(2,204)
Proceeds from senior notes issuance	1,428,512	0	0
Proceeds from term loan and drawdown of revolver	600,000	0	0
Net proceeds from WLKP LP common stock units	0	0	286,088
Proceeds from exercise of stock options	2,179	1,063	5,524
Restricted cash associated with term loan	(154,000)	0	0
Repayment of revolver	(125,000)	0	0
Proceeds from issuance of notes payable	8,324	52,960	0
Repayment of notes payable	(13,046)	(73,615)	0
Repurchase of common stock for treasury	(67,406)	(162,459)	(52,630)
Windfall tax benefits from share-based payment arrangements	2,624	1,646	6,704
Net cash provided (used for) by financing activities	1,533,217	(286,812)	164,640
Effect of exchange rate changes on cash and cash equivalents	(7,341)	(3,924)	(4,511)
Net (decrease) increase in cash and cash equivalents	(203,072)	(218,076)	419,300
Cash and cash equivalents at beginning of the year	662,525	880,601	461,301
Cash and cash equivalents at end of the year	$ 459,453	$ 662,525	$ 880,601

Description Of Business And Sig

Description Of Business And Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
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. Acquisition of Axiall Corporation On August 31, 2016, the Company completed the acquisition of Axiall Corporation ("Axiall") for $33.00 per share in an all-cash transaction (the "Merger"), pursuant to the terms of the Agreement and Plan of Merger (the "Merger Agreement"), dated as of June 10, 2016, by and among Westlake, Axiall and Lagoon Merger Sub, Inc., a wholly-owned subsidiary of Westlake. During the third quarter of 2016, in order to finance a portion of the consideration and related fees and expenses, and for other general corporate purposes, the Company issued $1,450,000 aggregate principal amount of senior notes. In addition, the Company entered into a $1,000,000 unsecured revolving credit facility (the "Credit Agreement"). Formation and Initial Public Offering of a Master Limited Partnership In 2014, the Company formed Westlake Chemical Partners LP ("Westlake Partners") to operate, acquire and develop ethylene production facilities and related assets. Also in 2014, Westlake Partners completed an initial public offering of 12,937,500 common units (the "Westlake Partners IPO"). As of December 31, 2016 , Westlake Partners' assets consist of a 13.3% 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, 2016 , the Company held an 86.7% 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, 2016 . Certain prior period amounts have been reclassified in the consolidated balance sheets and consolidated statements of operations to conform to current presentation. 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. Investments Investments in debt and equity securities are classified as trading, available-for-sale or held-to-maturity. Investments classified as trading are carried at estimated fair value with changes in fair value currently recognized in earnings. Investments classified as available-for-sale are carried at estimated fair value with unrealized gains and losses recorded as a component of accumulated other comprehensive income. Investments classified as held-to-maturity are carried at amortized cost. The Company periodically reviews its available-for-sale and held-to-maturity securities for other-than-temporary declines in fair value below the cost basis, and when events or changes in circumstances indicate the carrying value of an asset may not be recoverable, the investment is written down to fair value, establishing a new cost basis. 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 market. 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 $10,388 , $10,449 and $7,059 for the years ended December 31, 2016 , 2015 and 2014 , 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. The accounting guidance for asset retirement obligations requires the recording of liabilities equal to the fair value of asset retirement obligations and corresponding additional asset costs, when there is a legal asset retirement obligation as a result of existing or enacted law, statute or contract. Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 25 Plant and equipment 25 Ethylene pipeline 35 Other 3-10 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, 2016, the Company had $4,421 and $17,004 of asset retirement obligations recorded as accrued liabilities and other liabilities, respectively. There was no asset retirement obligation recorded as of December 31, 2015. The Company also has conditional asset retirement obligations that have not been recognized because the fair value of the conditional legal obligations cannot be measured due to the indeterminate settlement date of the obligation. Settlement of the unrecognized conditional asset retirement obligations is not expected to have a material adverse effects on the Company's financial condition, results of operations or cash flows in any individual reporting period. The asset retirement obligations activity for the year ended December 31, 2016 is as follows: Year Ended December 31, 2016 Beginning balance, January 1, $ — Acquisitions (1) 21,174 Accretion expense 251 Ending balance, December 31, $ 21,425 _______________________________ (1) See Note 2, "Acquisitions" for additional information on the Company's acquisition activities. Fair Value Estimates The Company develops estimates of fair value to allocate the purchase price paid to acquire a business to the assets acquired and liabilities assumed in an acquisition, to assess impairment of long-lived assets, goodwill and intangible assets and to record marketable securities, derivative instruments and pension plan assets. The Company uses all available information to make these fair value determinations, including the engagement of third-party consultants. 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. Impairment of Long-Lived Assets The accounting guidance for the impairment or disposal of long-lived assets requires that the Company review 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 Intangible Assets The accounting guidance for goodwill and intangible assets requires that goodwill and indefinite-lived intangible assets are tested for impairment at least annually. Other intangible assets with finite lives are amortized over their estimated useful life and reviewed for impairment in accordance with the provisions of the accounting guidance. As of December 31, 2016 , the Company's recorded goodwill was $946,553 . See Note 7 for more information on the Company's annual goodwill impairment tests. Turnaround Costs 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. Exchanges The Company enters into inventory exchange transactions with third parties, which involve fungible commodities. These exchanges are settled in like-kind quantities and are valued at lower of cost or market. Cost is determined using the FIFO method. 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. 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. 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. Revenue Recognition Revenue is recognized when persuasive evidence of an arrangement exists, products are delivered to the customer, the sales price is fixed or determinable and collectability is reasonably assured. For domestic contracts, title and risk of loss passes to the customer upon delivery under executed customer purchase orders or contracts. For export contracts, the title and risk of loss passes to customers at the time specified by each contract. Provisions for discounts, rebates and returns are provided for in the same period as the related sales are recorded. 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. Earnings per Share The accounting guidance for earnings per share requires the Company to present basic earnings per share and diluted earnings per share. Basic earnings per share excludes dilution and is computed by dividing income available to common stockholders by the weighted average number of shares outstanding for the period. Diluted earnings per share reflects the dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock. Price Risk Management The accounting guidance for derivative instruments and hedging activities requires that the Company recognize all derivative instruments on the balance sheet at fair value, and changes in the derivative's fair value must be 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 Company utilizes commodity price swaps to reduce price risks by entering into price swaps with counterparties and by purchasing or selling futures on established exchanges. The Company takes both fixed and variable positions, depending upon anticipated future physical purchases and sales of these commodities. The fair value of derivative financial instruments is estimated using quoted market prices in active markets and observable market-based inputs or unobservable inputs that are corroborated by market data when active markets are not available. The Company assesses both counterparty as well as its own nonperformance risk when measuring the fair value of derivative liabilities. The Company does not consider its nonperformance risk to be significant. See Note 16 for a summary of the fair value of derivative instruments. 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. Fair Value of Financial Instruments The amounts reported in the balance sheet for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The fair value of the Company's debt at December 31, 2016 differs from the carrying value due to the Company's fixed rate senior notes. The fair value of financial instruments is estimated using quoted market prices in active markets and observable market-based inputs or unobservable inputs that are corroborated by market data when active markets are not available. See Note 16 for more information on the fair value of financial instruments. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. Warranty Costs We provide warranties for certain building products against defects in material, performance and workmanship. We accrue for warranty claims at the time of sale based on historical warranty claims experience. Our warranty liabilities are included in accrued liabilities and other liabilities in the consolidated balance sheets. The warranty liabilities activity for the years ended December 31, 2016, 2015 and 2014 is as follows: Year Ended December 31, 2016 2015 2014 Beginning balance, January 1, $ 2,879 $ 1,833 $ 1,219 Estimated fair value of warranty liability assumed in acquisition (1) 14,564 — 612 Warranty provisions 3,009 1,987 632 Effects of changes in foreign exchange rates (196 ) (97 ) (79 ) Warranty claims paid (3,186 ) (844 ) (551 ) Ending balance, December 31, $ 17,070 $ 2,879 $ 1,833 ______________________________ (1) See Note 2, "Acquisitions" for additional information on the Company's acquisition activities. Other Amortization of debt issuance costs is computed on a basis which approximates the interest method over the term of the related debt. Certain other assets (see Note 7) are amortized over periods ranging from one to 30 years using the straight-line method. Recent Accounting Pronouncements Revenue from Contracts with Customers (ASU No. 2014-09) In May 2014, the Financial Accounting Standards Board ("FASB") issued an accounting standards update on a comprehensive new revenue recognition standard that will supersede the existing revenue recognition guidance. The new accounting guidance creates a framework by which an entity will allocate the transaction price to separate performance obligations and recognize revenue when each performance obligation is satisfied. Under the new standard, entities will be required to use judgment and make estimates, including identifying performance obligations in a contract, estimating the amount of variable consideration to include in the transaction price, allocating the transaction price to each separate performance obligation and determining when an entity satisfies its performance obligations. The standard allows for either "full retrospective" adoption, meaning that the standard is applied to all of the periods presented with a cumulative catch-up as of the earliest period presented, or "modified retrospective" adoption, meaning the standard is applied only to the most current period presented in the financial statements with a cumulative catch-up as of the current period. In July and December 2016, the FASB issued various additional authoritative guidance for the new revenue recognition standard. The accounting standard will be effective for reporting periods beginning after December 15, 2017. The Company is in the process of evaluating the impact that the new accounting standard will have on its consolidated financial position, results of operations and cash flows. Recognition and Measurement of Financial Assets and Financial Liabilities (ASU No. 2016-01) In January 2016, the FASB issued an accounting standards update making certain changes principally to the current guidance for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. Among other things, the guidance (1) requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value, with changes in fair value recognized in net income; (2) provide entities with a policy election to record equity investments without readily determinable fair values at cost, less impairment, and subsequent adjustments for observable price changes (changes in the basis of these equity investments to be reported in net income); (3) requires an entity that has elected the fair value option for financial liabilities to recognize changes in fair value due to instrument-specific credit risk separately in other comprehensive income; (4) clarified current guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities; and (5) requires specific disclosure pertaining to financial assets and financial liabilities in the financial statements. The accounting standard will be effective for reporting periods beginning after December 15, 2017. 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. Leases (ASU No. 2016-02) In February 2016, the FASB issued an accounting standards update on a new lease standard that will supersede the existing lease guidance. The standard requires a lessee to recognize assets and liabilities related to long-term leases that are classified as operating leases under current guidance on its balance sheet. An asset would be recognized related to the right to use the underlying asset and a liability would be recognized related to the obligation to make lease payments over the term of the lease. The standard also requires expanded disclosures related to leases. The accounting standard will be effective for reporting periods beginning after December 15, 2018. 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. Investments-Equity Method and Joint Ventures (ASU No. 2016-07) In March 2016, the FASB issued an accounting standards update providing new guidance for the accounting for equity method investments. The new guidance eliminates the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. In addition, the guidance requires that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor's previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The accounting standard is effective for reporting its periods beginning after December 15, 2016. The Company does not expect the new guidance to have a significant impact on its consolidated financial position, results of operations and cash flows. The Company will adopt the accounting change prospectively; therefore, historical amounts will not be affected. Stock Compensation (ASU No. 2016-09) In March 2016, the FASB issued an accounting standards update to simplify several aspects of the accounting for share-based payment transactions, including income tax consequences, classifications of awards as either equity or liabilities and certain related classifications on the statement of cash flows. In addition, the new guidance permits entities to make an accounting policy election for the impact of forfeitures on the recognition of expense for share-based payment awards. Forfeitures can be estimated, as required today, or recognized when they occur. The accounting standard is effective for reporting periods beginning after December 15, 2016 and is not expected to have a material impact on the Company's consolidated financial position, results of operations and cash flows. Credit Losses (ASU No. 2016-13) In June 2016, the FASB issued an accounting standards update providing new guidance for the accounting for credit losses on loans and other financial instruments. The new guidance introduces an approach based on expected losses to estimate credit losses on 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. The accounting standard will be effective for reporting periods beginning after December 15, 2019. 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. Cash Flows (ASU No. 2016-15) In August 2016, the FASB issued an accounting standards update providing new guidance on the classification of certain cash receipts and payments including debt extinguishment costs, debt prepayment costs, settlement of zero-coupon debt instruments, contingent consideration payments, proceeds from the settlement of insurance claims and life insurance policies and distributions received from equity method investees in the statement of cash flows. This update is required to be applied using the retrospective transition method to each period presented unless it is impracticable to be applied retrospectively. In such situation, this guidance is to be applied prospectively. The accounting standard will be effective for reporting periods beginning after December 15, 2017. 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. Amendments to the Consolidation Analysis (ASU No. 2016-17) In October 2016, the FASB issued an accounting standards update making certain changes to the current consolidation guidance. The amendments affect reporting entities that are required to evaluate whether they should consolidate a variable interest entity in certain situations involving entities under common control. Specifically, the amendments change the evaluation of whether a reporting entity is the primary beneficiary of a variable interest entity by changing how a reporting entity that is a single decision maker of a variable interest entity treats indirect interests in the entity held through related parties that are under common control with the reporting entity. The amendments will be effective for annual periods beginning after December 15, 2016. 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. Cash Flows (ASU No. 2016-18) In November 2016, the FASB issued an accounting standards update to clarify certain existing principles in ASC 230, including providing additional guidance related to transfers between cash and restricted cash and how entities present, in their statement of cash flows, the cash receipts and cash payments that directly affect the restricted cash accounts. The accounting standard will be effective for reporting periods beginning December 1, 2018 and is not expected to have a material impact on the Company's consolidated financial position, results of operations and cash flows. Business Combinations (ASU No. 2017-01) In January 2017, the FASB issued an accounting standard update to assist entities with evaluating when a set of transferred assets and activities is a business. The guidance requires an entity to evaluate if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of transferred assets and activities is not a business. The guidance also requires a business to include at least one substantive process and narrows the definition of outputs by more closely aligning it with how outputs are described in ASC 606. The accounting standard will be effective for reporting periods beginning after December 15, 2017. 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. Intangibles-Goodwill and Other (ASU No. 2017-04) In January 2017, the FASB issued an accounting standard 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. 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 Going Concern (ASU No. 2014-15) In August 2014, the FASB issued an accounting standard update providing guidance related to evaluating whether there is substantial doubt about the reporting entity's ability to continue as a going concern and about related financial statement note disclosures. Disclosures are required if there is substantial doubt as to the Company's continuation as a going concern within one year after the issue date of financial statements. The standard provides guidance for making the assessment, including consideration of management's plans which may alleviate doubt regarding the Company's ability to continue as a going concern. The accounting standard became effective for the annual reporting period ending after December 15, 2016, and all annual and interim periods thereafter. The Company adopted this accounting standard effective December 31, 2016 and the adoption did not have an impact on the Company's consolidated financial position, results of operations and cash flows. Amendments to the Consolidation Analysis (ASU No. 2015-02) In February 2015, the FASB issued an accounting standards update making certain changes to the current consolidation guidance. The amendments affect both the variable interest entity and

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Acquisitions	Acquisitions Axiall Corporation On August 31, 2016, the Company completed its acquisition of, and acquired all the remaining equity interest in, Axiall Corporation ("Axiall"), a Delaware corporation. Prior to the acquisition, the Company held 3.1 million shares in Axiall. Pursuant to the terms of the Agreement and Plan of Merger, dated as of June 10, 2016, by and among Westlake, Axiall and Lagoon Merger Sub, Inc., a Delaware corporation that is a wholly-owned subsidiary of Westlake ("Merger Sub"), the Company acquired all of the remaining issued and outstanding shares of common stock of Axiall for $33.00 per share in cash. Pursuant to the Merger Agreement, Merger Sub was merged with and into Axiall, and Axiall survived the Merger as a wholly-owned subsidiary of the Company. The combined company is the third-largest global chlor-alkali producer and the third-largest global polyvinyl chloride ("PVC") producer. The Company's management believes that this strategic acquisition will enhance its strategy of integration and will further strengthen its role in the North American markets. Axiall produces a highly integrated chain of chlor-alkali and derivative products, including chlorine, caustic soda, vinyl chloride monomer ("VCM"), PVC resin, PVC compounds and chlorinated derivative products. Axiall also manufactures and sells building products, including siding, trim, mouldings, pipe and pipe fittings. Total consideration transferred for the Merger was $2,539,360 . The Merger is being accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed and the results of operations of the acquired business are included in the Company's Vinyls segment. The acquired business contributed net sales and net loss of $975,605 and $95,663 , respectively, to the Company for the period from August 31, 2016 to December 31, 2016. The net loss for the period from August 31, 2016 to December 31, 2016 included integration-related costs and the negative impact of selling higher cost Axiall inventory recorded at fair value. The following unaudited consolidated pro forma information presents consolidated information as if the Merger had occurred on January 1, 2015: Pro Forma Year Ended December 31, 2016 2015 Net sales $ 7,080,545 $ 7,793,086 Net income (1) $ 398,826 $ 662,750 Net income (loss) attributable to noncontrolling interest 22,748 (1,665 ) Net income attributable to Westlake Chemical Corporation (1) $ 376,078 $ 664,415 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 2.89 $ 5.02 Diluted $ 2.88 $ 5.00 ______________________________ (1) The 2016 pro forma net income amounts include Axiall's historical pre-tax charges recorded during the eight-month period prior to the closing of the Merger for (1) divestitures; (2) restructuring; and (3) legal and settlement claims, net, of $26,666 , $22,881 and $23,376 , respectively. These nonrecurring costs are included in the pro forma results because they were not directly attributable to the Merger. The pro forma amounts above have been calculated after applying the Company's accounting policies and adjusting the Axiall results to reflect (1) the increase to depreciation and amortization that would have been charged assuming the fair value adjustments to property, plant and equipment and intangible assets had been applied from January 1, 2015; (2) the elimination of net sales and cost of sales between the Company and Axiall; (3) additional pension service costs; (4) amortization of debt premium and accretion of asset retirement obligations as part of the Company's adjustments to fair value; (5) incremental interest expense that would have been incurred assuming the financing arrangements entered by the Company and repayment of a portion of Axiall's outstanding debt had occurred on January 1, 2015; (6) the elimination of transaction-related costs; (7) the elimination of Axiall's goodwill impairment charges during 2015; and (8) an adjustment to tax-effect the aforementioned pro forma adjustments using an estimated aggregate statutory income tax rate of the jurisdictions to which the above adjustments relate. The pro forma amounts do not include any potential synergies, cost savings or other expected benefits of the Merger, are presented for illustrative purposes only and are not necessarily indicative of results that would have been achieved if the Merger had occurred as of January 1, 2015 or of future operating performance. The Company recognized $103,672 of transaction and integration-related costs during 2016. This included acquisition-related costs of $49,262 for advisory, consulting and professional fees and other expenses. Transaction and integration-related costs also included $54,410 related to settlement of Axiall share-based awards, retention agreement costs and severance benefits provided to former Axiall executives in connection with the Merger during 2016. The following table summarizes the consideration transferred and the estimated fair value of identified assets acquired and liabilities assumed at the date of acquisition. The preliminary allocation of the consideration transferred is based on management's estimates, judgments and assumptions. When determining the fair values of assets acquired, liabilities assumed and noncontrolling interests of the acquiree, management made significant estimates, judgments and assumptions. These estimates, judgments and assumptions are subject to change upon final valuation and should be treated as preliminary values. Management estimated that consideration paid exceeded the fair value of the net assets acquired. Therefore, goodwill of $887,491 was recorded. The goodwill recognized is primarily attributable to synergies related to the Company's vinyls integration strategy that are expected to arise from the Merger. All of the goodwill is assigned to the Company's Vinyls segment. As a portion of the goodwill arising from the Merger is attributable to foreign operations, there will be a continuing foreign currency impact to goodwill on the financial statements. Final Purchase Consideration as of August 31, 2016 Closing stock purchase: Offer per share $ 33.00 Multiplied by number of shares outstanding at acquisition 67,277 Fair value of Axiall shares outstanding purchased by the Company $ 2,220,141 Plus: Axiall debt repaid at acquisition 247,135 Seller's transaction costs paid by the Company (1) 47,458 Total fair value of consideration transferred $ 2,514,734 Fair value of Axiall share-based awards attributed to pre-combination service (2) $ 11,346 Additional settlement value of shares acquired 13,280 Purchase consideration $ 2,539,360 Fair value of previously held equity interest in Axiall (3) 102,300 Total fair value allocated to net assets acquired $ 2,641,660 ______________________________ (1) Transactions costs incurred by the seller included legal and advisory costs incurred for the benefit of Axiall's former shareholders and board of directors to evaluate the Company's initial Merger proposals, explore strategic alternatives and negotiate the purchase price. (2) The fair value of share-based awards attributable to pre-combination service includes the ratio of the pre-combination service performed to the original service period of the Axiall restricted share units and options, including related dividend equivalent rights. (3) Prior to the Merger, the Company owned 3.1 million shares in Axiall. The investment in Axiall was carried at estimated fair value with unrealized gains recorded as a component of accumulated other comprehensive loss on the consolidated balance sheet. The Company recognized a $49,080 gain for the investment in other income, net in the consolidated statement of operations upon gaining control. The final allocation of purchase consideration, based on final valuations, could include changes in the estimated fair value of inventories, property, plant and equipment, equity investments, customer relationships, trade names, developed technologies and other intangibles, deferred income taxes, all contingencies, asset retirement obligations and noncontrolling interests. The assumed contingencies relate to environmental liabilities, legal liabilities, asset retirement obligations and warranty reserves. The information below represents the preliminary purchase price allocation: Cash $ 88,251 Accounts receivable (1) 422,459 Income tax receivable 55,193 Inventories 306,158 Prepaid expenses and other current assets 55,462 Property, plant and equipment (2) 3,134,741 Customer relationships (weighted average lives of 10.7 years) (3) 590,000 Other intangible assets: Trade name (weighted average lives of 6.8 years) 50,000 Technology (weighted average lives of 5.4 years) 41,500 Supply contracts and leases (weighted average lives of 6.3 years) 27,288 Other assets 98,708 Total assets acquired $ 4,869,760 Accounts and notes payable 255,232 Interest payable 8,154 Income tax payable 967 Accrued compensation 44,186 Accrued liabilities 152,550 Deferred income taxes 985,128 Tax reserve non-current 3,130 Pension and other post-retirement obligations 311,106 Other liabilities 99,848 Long-term debt 1,187,290 Total liabilities assumed $ 3,047,591 Total identifiable net assets acquired $ 1,822,169 Noncontrolling interest (68,000 ) Goodwill 887,491 Total fair value allocated to net assets acquired $ 2,641,660 ______________________________ (1) The fair value of accounts receivable acquired is $422,459 , with the gross contractual amount being $434,834 . The Company expects $12,375 to be uncollectible. (2) The Company obtained additional information related to its property plant and equipment balances which led to a decrease in property plant and equipment of $54,841 and a corresponding increase in goodwill. (3) The Company obtained additional information related to its customer relationship balances which led to an increase in customer relationship of $30,000 and a corresponding decrease in goodwill. Suzhou Huasu Plastics Co., Ltd. On June 1, 2015, the Company acquired an additional 35.7% equity interest in Suzhou Huasu Plastics Co., Ltd. ("Huasu") from INEOS Chlor Vinyls Holdings B.V., increasing its interest in Huasu to 95.0% . Huasu is a PVC joint venture based near Shanghai, in the People's Republic of China and has a combined annual capacity of 300 million pounds of PVC resin and 145 million pounds of PVC film and sheet. Prior to the acquisition of this 35.7% interest, the Company owned a 59.3% interest in Huasu. The Company accounted for the investment using the equity method of accounting because Huasu did not meet the definition of a variable interest entity and because contractual arrangements giving certain substantive participatory rights to minority shareholders prevented the Company from exercising a controlling financial interest over Huasu. As a result of the Company obtaining control over Huasu, the Company's 59.3% interest was remeasured to fair value, resulting in a loss of $1,505 , which is included in other income (expense), net in the consolidated statement of operations for the year ended December 31, 2015. The closing date purchase price of $5,518 was paid with available cash on hand. The acquisition was accounted for under the acquisition method of accounting. The transaction resulted in a bargain purchase acquisition-date gain of $22,550 and is recognized in other income (expense), net in the consolidated statement of operations. The Company believes there are several factors that contributed to this transaction resulting in a bargain purchase acquisition-date gain, including the slowdown in the growth of, and current weakness in, the Chinese economy. The assets acquired and liabilities assumed and the results of operations of this acquired business are included in the Vinyls segment. Vinnolit Holdings GmbH and Subsidiary Companies On July 31, 2014, the Company acquired all the equity interests in German-based Vinnolit Holdings GmbH and its subsidiary companies ("Vinnolit") from several entities associated with Advent International Corporation (the "Sellers"). Vinnolit is headquartered in Ismaning, Germany and is an integrated global leader in specialty PVC resins, with a combined annual capacity of 1.7 billion pounds of PVC, including specialty paste and suspension grades, 1.5 billion pounds of VCM and 1.0 billion pounds of caustic soda. The Vinnolit acquisition included six production facilities located in Burghausen, Gendorf, Cologne, Knapsack and Schkopau in Germany and Hillhouse in the United Kingdom. The Company also acquired Vinnolit's technical centers, including a research and development facility in Gendorf and an applications laboratory in Burghausen. The Company's management believes that this strategic acquisition will enhance its strategy of integration and expansion into new markets and specialty products, in addition to growing the Company's global presence with a footprint in Europe and surrounding markets. The purchase price of $736,224 was paid with available cash on hand. The acquisition was accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed and the results of operations of this acquired business are included in the Vinyls segment.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Financial Instruments	Financial Instruments Cash Equivalents The Company had no held-to-maturity securities, classified as cash equivalents, at December 31, 2016 . The Company had $221,918 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, 2015 . The Company's investments in held-to-maturity securities were held at amortized cost, which approximates fair value. Restricted Cash The Company had restricted cash and cash equivalents of $186,216 at December 31, 2016, which are primarily related to the balances deposited with and held as security by the lender under the Company's current term loan facility and for distributions to certain of Axiall's current and former employees. The current portion of restricted cash and cash equivalents was $160,527 . The non-current portion of $25,689 is reflected under Deferred charges and other assets, net on the consolidated balance sheet. The Company had no restricted cash balances at December 31, 2015. Available-for-Sale Marketable Securities The Company had no available-for-sale securities at December 31, 2016 . Investments in available-for-sale securities at December 31, 2015 were classified as follows: December 31, 2015 Current $ 520,144 Non-current 48,081 Total available-for-sale securities $ 568,225 The cost, gross unrealized gains, gross unrealized losses and fair value of the Company's available-for-sale securities were as follows: December 31, 2015 Cost Gross Gross (1) Fair Value Debt securities Corporate bonds $ 336,665 $ 55 $ (1,076 ) $ 335,644 U.S. government debt (2) 135,226 2 (374 ) 134,854 Asset-backed securities 49,759 2 (115 ) 49,646 Equity securities $ 54,371 $ 466 $ (6,756 ) $ 48,081 Total available-for-sale securities $ 576,021 $ 525 $ (8,321 ) $ 568,225 ______________________________ (1) All unrealized loss positions were held at a loss for less than 12 months. (2) U.S. Treasury obligations, U.S. government agency obligations and U.S government agency mortgage-backed securities. As of December 31, 2015 , net unrealized losses on the Company's available-for-sale securities was $4,995 , net of income tax benefit of $2,801 , which were recorded in accumulated other comprehensive income. See Note 16 for the fair value hierarchy of the Company's available-for-sale securities. The proceeds from sales and maturities of available-for-sale securities included in the consolidated statements of cash flows and the gross realized gains and losses included in the consolidated statements of operations are reflected in the table below. The cost of securities sold was determined using the specific identification method. Year Ended December 31, 2016 2015 2014 Proceeds from sales and maturities of securities $ 662,938 $ 48,900 $ 342,045 Gross realized gains 53,754 3,830 1,311 Gross realized losses (35 ) (32 ) (99 )

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Accounts Receivable	Accounts Receivable Accounts receivable consist of the following at December 31: 2016 2015 Trade customers $ 827,721 $ 438,538 Allowance for doubtful accounts (17,991 ) (14,095 ) 809,730 424,443 Federal and state taxes 90,414 60,748 Other 38,599 23,341 Accounts receivable, net $ 938,743 $ 508,532 Activity in our allowance for doubtful accounts during the years ended December 31, 2016 , 2015 and 2014 is set forth in the table below: Year Ended December 31, 2016 2015 2014 Balance at Beginning of Year, January 1 $ 14,095 $ 13,468 $ 11,741 Charged to Expense 4,095 956 301 Additions/(Deductions) (1) (199 ) (329 ) 1,426 Balance at End of Year, December 31 $ 17,991 $ 14,095 $ 13,468 ______________________________ (1) Deductions primarily represent accounts receivable written off during the period.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2016
Inventory, Net [Abstract]
Inventories	Inventories Inventories consist of the following at December 31: 2016 2015 Finished products $ 500,861 $ 253,338 Feedstock, additives and chemicals 216,877 106,435 Materials and supplies 83,362 74,287 Inventories $ 801,100 $ 434,060

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
	Dec. 31, 2016
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: 2016 2015 Land $ 194,137 $ 33,051 Building and improvements 464,570 266,214 Plant and equipment 6,913,721 3,632,416 Other 377,466 241,829 7,949,894 4,173,510 Less: Accumulated depreciation (1,919,229 ) (1,685,255 ) 6,030,665 2,488,255 Construction in progress 389,397 515,812 Property, plant and equipment, net $ 6,420,062 $ 3,004,067 Depreciation expense on property, plant and equipment of $305,273 , $209,271 and $174,173 is included in cost of sales in the consolidated statements of operations for the years ended December 31, 2016 , 2015 and 2014 , respectively.

Other Assets

Other Assets	12 Months Ended
	Dec. 31, 2016
Other Assets [Abstract]
Other Assets	Other Assets Other assets consist of the following at December 31: 2016 2015 Weighted Average Life Cost Accumulated Amortization Net Cost Accumulated Amortization Net Goodwill $ 946,553 $ — $ 946,553 $ 62,016 $ — $ 62,016 Customer relationships 662,080 (50,465 ) 611,615 75,249 (22,572 ) 52,677 10 Other intangible assets: Licenses and intellectual property 120,992 (44,035 ) 76,957 79,699 (38,643 ) 41,056 13 Trademarks 87,927 (6,841 ) 81,086 39,085 (2,602 ) 36,483 12 Other 31,038 (13,242 ) 17,796 29,320 (8,148 ) 21,172 11 Total other intangible assets 239,957 (64,118 ) 175,839 148,104 (49,393 ) 98,711 Deferred charges and other assets Cost-method investments 108,938 — 108,938 51,334 — 51,334 Equity-method investments 21,522 — 21,522 9,208 — 9,208 Restricted cash 25,689 — 25,689 — — — Turnaround costs 168,501 (74,671 ) 93,830 111,078 (74,943 ) 36,135 5 Deferred Taxes 12,526 — 12,526 — — — Debt issuance costs 3,055 (210 ) 2,845 11,915 (10,762 ) 1,153 5 Other 82,287 (19,769 ) 62,518 99,763 (20,968 ) 78,795 8 Total deferred charges and other assets 422,518 (94,650 ) 327,868 283,298 (106,673 ) 176,625 Other assets, net $ 2,271,108 $ (209,233 ) $ 2,061,875 $ 568,667 $ (178,638 ) $ 390,029 Amortization expense on other assets of $73,757 , $37,998 and $35,496 is included in the consolidated statements of operations for the years ended December 31, 2016 , 2015 and 2014 , respectively. Scheduled amortization of intangible assets for the next five years is as follows: $99,011 , $98,669 , $97,648 , $95,717 and $94,214 in 2017 , 2018 , 2019 , 2020 and 2021 , respectively. Goodwill Goodwill is tested for impairment at least annually, or when events or changes in circumstances indicate the fair value of a reporting unit with goodwill has been reduced below its carrying value. The Company performed its annual impairment tests for the Olefins and Vinyls segments' goodwill in October 2016 and April 2016 , 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. The gross carrying amounts of goodwill for the years ended December 31, 2016 and 2015 are as follows: Olefins Segment Vinyls Segment Total Balance at December 31, 2014 $ 29,990 $ 32,026 $ 62,016 Balance at December 31, 2015 29,990 32,026 62,016 Goodwill acquired during the year — 887,491 887,491 Effects of changes in foreign exchange rates — (2,954 ) (2,954 ) Balance at December 31, 2016 $ 29,990 $ 916,563 $ 946,553 Olefins Segment Goodwill The fair value of the Olefins segment, the reporting unit assessed, was calculated using both a discounted cash flow methodology and a market value methodology. The discounted cash flow projections were based on a nine -year forecast, from 2017 to 2025 , to reflect the cyclicality of the Company's olefins business. The forecast was based on (1) prices and spreads projected by IHS Chemical, a chemical industry organization offering market and business advisory services for the chemical market, for the same period, and (2) estimates by management, including its strategic and operational plans. Other significant assumptions used in the discounted cash flow projection included sales volumes based on current capacities. The future cash flows were discounted to present value using a discount rate of 8.8% . The significant assumptions used in determining the fair value of the reporting unit using the market value methodology include the determination of appropriate market comparables and the estimated multiples of EBITDA a willing buyer is likely to pay. Even if the fair value of the Olefins segment decreased by 10% , the carrying value of the Olefins segment would not exceed its fair value. Vinyls Segment Goodwill The fair value of the pipe and foundation building products business, the reporting unit assessed during the April 2016 impairment test, was calculated using both a discounted cash flow methodology and a market value methodology. The discounted cash flow projections were based on a nine -year forecast, from 2016 to 2024, to reflect the cyclicality of the North American housing and construction markets as the Company's North American Vinyls business is significantly influenced by said markets. The forecast was based on historical results and estimates by management, including its strategic and operational plans, and assumed a gradual increase in financial performance based on a housing market recovery in the United States. The future cash flows were discounted to present value using a discount rate of 11.5% . The significant assumptions used in determining the fair value of the reporting unit using the market value methodology include the determination of appropriate market comparables and the estimated multiples of EBITDA a willing buyer is likely to pay. Even if the fair value of the reporting unit decreased by 10% , the carrying value of the reporting unit would not have exceeded its fair value.

Accounts and Notes Payable

Accounts and Notes Payable	12 Months Ended
	Dec. 31, 2016
Accounts and Notes Payable [Abstract]
Accounts and Notes Payable	Accounts and Notes Payable Accounts and notes payable consist of the following at December 31: 2016 2015 Accounts payable $ 494,743 $ 229,219 Notes payable to banks 1,516 6,110 Accounts and notes payable $ 496,259 $ 235,329

Term Loan

Term Loan	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Term Loan	Term Loan On August 10, 2016, an indirect subsidiary of the Company, Westlake International Holdings II C.V., a limited partnership organized under the laws of the Netherlands (the "CV Borrower"), entered into a credit agreement with Bank of America, N.A., as agent and lender, providing the CV Borrower with a $150,000 term loan facility. The term loan facility had a maturity date of March 31, 2017. The term loan was fully repaid in January 2017. The loans thereunder bore interest at a floating interest rate equal to LIBOR plus 2% per annum, payable in arrears on the last day of each three-month period following the date of funding and at maturity. The interest rate on the outstanding term loan was 2.68% at December 31, 2016. The facility contained customary covenants and events of default that imposed certain operating and financial restrictions on the CV Borrower and certain of its subsidiaries. These restrictions, among other things, provided limitations on the incurrence of additional indebtedness and liens and the ability to engage in certain transactions with affiliates. Pursuant to the credit agreement, all of the non-U.S. subsidiaries of the Company were to remain owned, directly or indirectly, by the CV Borrower and its wholly owned subsidiary, Westlake International II LLC, a Delaware limited liability company ("WII LLC"). The CV Borrower was also required, together with its subsidiaries, to maintain at all times unencumbered cash and cash equivalents in a U.S. dollar equivalent of not less than $150,000 , which amount would be increased by 5% to the extent maintained in non-U.S. currencies. In connection therewith, an amount of cash and cash equivalents for the period (a) from the closing date until the date 30 days thereafter, not less than $50,000 , and (b) thereafter, not less than $75,000 , was required to be maintained by the CV Borrower and its subsidiaries in accounts at Bank of America, N.A., in accordance with cash management agreements. Obligations under the term loan facility were secured by a pledge of 65% of the membership interests of WII LLC as well as rights under the partnership agreement of Westlake International Holdings C.V., a limited partnership organized under the laws of the Netherlands, held by WII LLC and the CV Borrower.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt The Company adopted an accounting standards update to simplify the presentation of debt issuance costs effective January 1, 2016. The standard requires, on a retrospective basis, all costs incurred to issue debt, excluding line-of-credit arrangements, to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt liability. As a result of this retrospective adoption and reclassification of equity-method investment of $9,208 to other assets for comparative purposes, Other assets, net—Deferred charges and other assets, net and Long-term debt, net on the consolidated balance sheet as of December 31, 2015 have been adjusted to $176,625 and $758,148 , respectively, from the originally reported $173,384 and $764,115 , respectively, to reflect the retrospective application of the new accounting guidance. Long-term debt consists of the following at December 31: December 31, 2016 December 31, 2015 Principal Amount Unamortized Premium, Discount and Debt Issuance Costs (1) Net Long-Term Debt Principal Amount Unamortized Discount and Debt Issuance Costs (1) Net Long-Term Debt Revolving credit facility $ 325,000 $ — $ 325,000 $ — $ — $ — 4.625% senior notes due 2021 (the "4.625% Westlake 2021 Senior Notes") 624,793 26,837 651,630 — — — 4.625% senior notes due 2021 (the "4.625% Subsidiary 2021 Senior Notes") 63,207 2,862 66,069 — — — 3.60% senior notes due 2022 250,000 (1,891 ) 248,109 250,000 (2,232 ) 247,768 4.875% senior notes due 2023 (the "4.875% Westlake 2023 Senior Notes") 433,793 13,431 447,224 — — — 4.875% senior notes due 2023 (the "4.875% Subsidiary 2023 Senior Notes") 16,207 540 16,747 — — — 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750,000 (10,757 ) 739,243 — — — Loan related to tax-exempt waste disposal revenue bonds due 2027 10,889 — 10,889 10,889 — 10,889 6 ½% senior notes due 2029 100,000 (916 ) 99,084 100,000 (989 ) 99,011 6 ¾% senior notes due 2032 250,000 (1,883 ) 248,117 250,000 (2,002 ) 247,998 6 ½% senior notes due 2035 (the "6 ½% 89,000 (839 ) 88,161 89,000 (884 ) 88,116 6 ½% senior notes due 2035 (the "6 ½% 65,000 (602 ) 64,398 65,000 (634 ) 64,366 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700,000 (26,017 ) 673,983 — — — Long-term debt, net $ 3,677,889 $ 765 $ 3,678,654 $ 764,889 $ (6,741 ) $ 758,148 ______________________________ (1) Includes unamortized debt issuance costs of $24,113 and $5,967 at December 31, 2016 and December 31, 2015 , respectively. Credit Agreement On August 23, 2016, the Company and certain of its subsidiaries entered into an unsecured revolving credit facility (the "Credit Agreement"), by and among the Company, the other borrowers and guarantors referred to therein, the lenders from time to time party thereto (collectively, the "Lenders"), the issuing banks party thereto and JPMorgan Chase Bank, National Association, as Administrative Agent. Under the Credit Agreement, the Lenders have committed to provide an unsecured five -year revolving credit facility in an aggregate principal amount of up to $1,000,000 . The Credit Agreement replaced the Company's existing $400,000 senior secured third amended and restated credit facility, dated as of July 17, 2014, by and among the Company, the financial institutions party thereto, as lenders, Bank of America, N.A., as agent, and the Company and certain of its subsidiaries, as borrowers. The Credit Agreement includes a $150,000 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 $50,000 commitment for swing line loans to be provided on a same-day basis. The Company may also increase the size of the facility, in increments of at least $25,000 , up to a maximum of $500,000 , subject to certain conditions and if certain Lenders agree to commit to such an increase. At December 31, 2016 , the Company had $325,000 of borrowings outstanding under the Credit Agreement. Borrowings under the Credit Agreement will bear interest, at the Company's option, at either (a) LIBOR plus a spread ranging from 1.00% to 1.75% that will vary depending on the credit rating of the Company or (b) Alternate Base Rate plus a spread ranging from 0.00% to 0.75% that will vary depending on the credit rating of the Company. The Credit Agreement also requires an undrawn commitment fee ranging from 0.10% to 0.25% that will vary depending on the credit rating of the Company. The interest rate on the outstanding revolving credit facility was 2.19% at December 31, 2016 . The Credit Agreement matures on August 23, 2021. As of December 31, 2016 , the Company had outstanding letters of credit totaling $76,535 and borrowing availability of $598,465 under the Credit Agreement. The obligations of the Company under the Credit Agreement are guaranteed by current and future material domestic subsidiaries of the Company, subject to certain exceptions. The Credit Agreement contains certain affirmative and negative covenants, including a quarterly total leverage ratio financial maintenance covenant. The Credit Agreement also contains certain events of default and if and for so long as an event of default has occurred and is continuing, any 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. As of December 31, 2016 , the Company is in compliance with the total leverage ratio financial maintenance covenant. 3.60% Senior Notes due 2026 and 5.0% Senior Notes due 2046 On August 10, 2016, the Company completed its private offering of $750,000 aggregate principal amount of 3.60% senior notes due 2026 (the " 3.60% 2026 Senior Notes ") and $700,000 aggregate principal amount of 5.0% senior notes due 2046 (the " 5.0% 2046 Senior Notes "). The 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes are the Company's senior obligations and are guaranteed on a senior basis by certain of the Company's existing and future domestic subsidiaries. The 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes and guarantees are unsecured and rank equally with the Company's existing and future senior unsecured obligations and each guarantor's existing and future senior unsecured obligations. The Company has entered into a registration rights agreement in which it has agreed to file an exchange offer registration statement or, under specified circumstances, a shelf registration statement, with the SEC with respect to the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes . The net proceeds from the offering were used to finance the Merger and to repay amounts under the term loan facility dated February 27, 2015 entered into by Axiall Holdco, Inc. (a wholly-owned subsidiary of Axiall), as the borrower, with the financial institutions party thereto. The indenture governing the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes contains customary events of default and covenants that will restrict the Company's and certain of its subsidiaries' ability to (1) incur certain secured indebtedness, (2) engage in certain sale-leaseback transactions and (3) consolidate, merge or transfer all or substantially all of the Company's or their assets. Exchange Offers On September 7, 2016, the Company completed offers to exchange (the "Axiall Exchange Offers") any and all of the $688,000 aggregate principal amount of the outstanding 4.625% senior notes due 2021 (the " 4.625% Subsidiary 2021 Senior Notes ") issued by Eagle Spinco Inc. ("Eagle Spinco"), a wholly-owned subsidiary of Axiall, and the $450,000 aggregate principal amount of the outstanding 4.875% senior notes due 2023 (the " 4.875% Subsidiary 2023 Senior Notes " and, together with the 4.625% Subsidiary 2021 Senior Notes , the "Subsidiary Notes") issued by Axiall for new senior notes issued by the Company having the same maturity and interest rates as the Subsidiary Notes. The 4.625% Subsidiary 2021 Senior Notes and the 4.875% Subsidiary 2023 Senior Notes were assumed at fair value, which resulted in a premium on the Subsidiary Notes of $33,540 and $15,750 , respectively. In the Axiall Exchange Offers, $624,793 aggregate principal amount of the 4.625% Subsidiary 2021 Senior Notes and $433,793 aggregate principal amount of the 4.875% Subsidiary 2023 Senior Notes were exchanged, respectively, for $624,793 aggregate principal amount of 4.625% Subsidiary 2021 Senior Notes (the " 4.625% Westlake 2021 Senior Notes ") and $433,793 aggregate principal amount of 4.875% senior notes due 2023 (the " 4.875% Westlake 2023 Senior Notes ") issued by the Company, leaving outstanding $63,207 aggregate principal amount of the 4.625% Subsidiary 2021 Senior Notes and $16,207 aggregate principal amount of the 4.875% Subsidiary 2023 Senior Notes . The remaining 4.625% Subsidiary 2021 Senior Notes and the remaining 4.875% Subsidiary 2023 Senior Notes are the senior unsecured obligations of Axiall and Eagle Spinco, respectively. The 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes are the Company's senior obligations and are guaranteed on a senior basis by certain of the Company's existing and future domestic subsidiaries. The 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes and guarantees are unsecured and rank equally with the Company's existing and future senior unsecured obligations and each guarantor's existing and future senior unsecured obligations. The Company has entered into a registration rights agreement in which it has agreed to file an exchange offer registration statement or, under specified circumstances, a shelf registration statement, with the SEC with respect to the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes . The indenture governing the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes contains customary events of default and covenants that will restrict the Company's and certain of its subsidiaries' ability to (1) incur certain secured indebtedness, (2) engage in certain sale-leaseback transactions and (3) consolidate, merge or transfer all or substantially all of the Company's or their assets. 3.60% Senior Notes due 2022 In July 2012, the Company issued $250,000 aggregate principal amount of its 3.60% senior notes due 2022 (the "3.60% Notes Due 2022"). The 3.60% Notes Due 2022 are unsecured and were issued with an original issue discount of $1,183 . There is no sinking fund and no scheduled amortization of the 3.60% Notes Due 2022 prior to maturity. The Company may optionally redeem the 3.60% Notes Due 2022 at any time and from time to time prior to April 15, 2022 (three months prior to the maturity date) for 100% of the principal plus accrued interest and a discounted "make whole" payment. On or after April 15, 2022, the Company may optionally redeem the 3.60% Notes Due 2022 for 100% of the principal plus accrued interest. The holders of the 3.60% Notes Due 2022 may require the Company to repurchase the 3.60% Notes Due 2022 at a price of 101% of their principal amount, plus accrued and unpaid interest to the date of repurchase, upon the occurrence of both a "change of control" and, within 60 days of such change of control, a "below investment grade rating event" (as such terms are defined in the indenture governing the 3.60% Notes Due 2022). All domestic subsidiaries of the Company that guarantee other indebtedness of the Company or of another guarantor of the 3.60% Notes Due 2022 in excess of $5,000 are guarantors of the 3.60% Notes Due 2022.The indenture governing the 3.60% Notes Due 2022 contains customary events of default and covenants that will restrict the Company's and certain of its subsidiaries' ability to (1) incur certain secured indebtedness, (2) engage in certain sale-leaseback transactions and (3) consolidate, merge or transfer all or substantially all of the Company's assets. GO Zone Bonds In December 2010, the Louisiana Local Government Environmental Facility and Development Authority (the "Authority"), a political subdivision of the State of Louisiana, completed the offering of $89,000 of 6 ½% tax-exempt revenue bonds due November 1, 2035 under the Gulf Opportunity Zone Act of 2005 (the "GO Zone Act"). The bonds are subject to optional redemption by the Authority upon the direction of the Company at any time prior to November 1, 2020 for 100% of the principal plus accrued interest and a discounted "make whole" payment. On or after November 1, 2020, the bonds are subject to optional redemption by the Authority upon the direction of the Company for 100% of the principal plus accrued interest. In July 2010, the Authority completed the reoffering of $100,000 of 6 ½% tax-exempt revenue bonds due August 1, 2029 under the GO Zone Act. The bonds are subject to optional redemption by the Authority upon the direction of the Company at any time prior to August 1, 2020 for 100% of the principal plus accrued interest and a discounted "make whole" payment. On or after August 1, 2020, the bonds are subject to optional redemption by the Authority upon the direction of the Company for 100% of the principal plus accrued interest. In December 2007, the Authority issued $250,000 of 6 ¾% tax-exempt revenue bonds due November 1, 2032 under the GO Zone Act. The bonds are subject to optional redemption by the Authority upon the direction of the Company at any time prior to November 1, 2017 for 100% of the principal plus accrued interest and a discounted "make whole" payment. On or after November 1, 2017, the bonds are subject to optional redemption by the Authority upon the direction of the Company for 100% of the principal plus accrued interest. Each series of the 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 connection with each offering of the 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. All domestic restricted subsidiaries that guarantee other debt of the Company or of another guarantor of the 6 ½% senior notes due 2029, the 6 ¾% senior notes due 2032 and the 6 ½% 2035 GO Zone Senior Notes (collectively, and including the 6 ½% 2035 IKE Zone Senior Notes, the "Senior Notes") in excess of $5,000 are guarantors of the bonds. As of December 31, 2016 , the Company had drawn all the proceeds from the 6 ½% bonds due 2029, 6 ¾% bonds due 2032 and 6 ½% 2035 GO Zone Senior Notes. IKE Zone Bonds In December 2010, the Authority completed the offering of $65,000 of 6 ½% tax-exempt revenue bonds due November 1, 2035 under Section 704 of the Emergency Economic Stabilization Act of 2008. The bonds are subject to optional redemption by the Authority upon the direction of the Company at any time prior to November 1, 2020 for 100% of the principal plus accrued interest and a discounted "make whole" payment. On or after November 1, 2020, the bonds are subject to optional redemption by the Authority upon the direction of the Company for 100% of the principal plus accrued interest. The bonds are subject to redemption, repurchase by the holders upon a change of control or a change in or loss of the current tax status of the bonds and optional redemption by the Authority under terms substantially similar to the terms for the GO Zone Bonds. In connection with the offering of the 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 offering 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 Parish of Calcasieu. The 6 ½% 2035 IKE Zone Senior Notes are unsecured and rank equally in right of payment with other existing and future unsecured senior indebtedness. All domestic restricted subsidiaries that guarantee other debt of the Company or of another guarantor of the Senior Notes in excess of $5,000 are guarantors of the 6 ½% 2035 IKE Zone Senior Notes. As of December 31, 2016 , the Company had drawn all the proceeds from the 6 ½% 2035 IKE Zone Senior Notes. The indentures governing the 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 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 $100,000 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 $10,889 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. Interest on the waste disposal revenue bonds accrues at a rate determined by a remarketing agent and is payable quarterly. The interest rate on the waste disposal revenue bonds at December 31, 2016 and 2015 was 0.79% and 0.07% , respectively. Bridge Loan Agreement In June 2016, in connection with the Axiall acquisition, the Company entered into a commitment letter with various lenders pursuant to which such lenders agreed to provide for a senior unsecured bridge loan facility of up to $1,765,000 in the aggregate. Also in June 2016, the Company paid structuring and other fees of approximately $9,700 in connection with the senior unsecured bridge loan facility. On August 26, 2016, the Company terminated the senior unsecured bridge loan facility. This structuring and other fees is included in other income, net, in the consolidated statements of operations for the year ended December 31, 2016 . As of December 31, 2016 , the Company was in compliance with all of the covenants with respect to the Credit Agreement, 3.60% 2026 Senior Notes , 5.0% 2046 Senior Notes , 4.625% Westlake 2021 Senior Notes , 4.875% Westlake 2023 Senior Notes , 3.60% Senior Notes Due 2022 and the waste disposal revenue bonds. The weighted average interest rate on all long-term debt was 4.4% at December 31, 2016 and 5.5% at December 31, 2015 . As of December 31, 2016 , the Company had no maturities of long-term debt until 2021.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity The Company's Board of Directors has declared regular quarterly dividends to holders of its common stock aggregating $96,560 , $91,551 and $77,656 for the years ended December 31, 2016 , 2015 and 2014 , 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. On February 14, 2014, the Company's Board of Directors authorized a two -for-one split of the Company's common stock. Stockholders of record as of February 28, 2014 were entitled to one additional share for every share outstanding, which was distributed on March 18, 2014. The total number of authorized common stock shares and associated par value were unchanged by this stock split. In 2014, the stockholders of the Company approved an amendment to the Company's Amended and Restated Certificate of Incorporation to increase the Company's authorized shares of common stock from 150,000,000 shares to 300,000,000 shares, par value $0.01 per share. The Company issued 134,651,380 and 134,663,244 shares of common stock as of December 31, 2016 and 2015 , respectively. 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 August 2011, the Company's Board of Directors authorized a stock repurchase program of the Company's common stock totaling $100,000 (the "2011 Program"). As of March 31, 2015, the Company had repurchased 1,944,161 shares of its common stock for an aggregate purchase price of approximately $100,000 under the 2011 Program, the full amount of the 2011 Program. In November 2014, the Company's Board of Directors approved a new $250,000 share repurchase program (the "2014 Program"). On November 20, 2015, the Company's Board of Directors approved the expansion of the 2014 Program by an additional $150,000 . The total number of shares repurchased by the Company under the 2014 Program was 1,511,109 and 2,682,489 for the years ended December 31, 2016 and 2015, respectively. Any shares repurchased under the 2011 and 2014 Programs are held by the Company as treasury stock and may be used for general corporate purposes, including for the 2013 Omnibus Incentive Plan. Beginning in 2014, the Company began delivering treasury shares to employees and nonemployee directors for options exercised and for the settlement of restricted stock units. The cost of treasury shares delivered was determined using the specific identification method.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) by component were as follows: Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange Net Unrealized Holding Gains on Investments, Net of Tax Total Balances at December 31, 2014 $ (23,442 ) $ (56,224 ) $ 233 $ (79,433 ) Other comprehensive income (loss) before reclassifications 12,877 (59,466 ) (2,795 ) (49,384 ) Amounts reclassified from accumulated other comprehensive loss 1,958 — (2,433 ) (475 ) Net other comprehensive income (loss) for the year 14,835 (59,466 ) (5,228 ) (49,859 ) Balances at December 31, 2015 (8,607 ) (115,690 ) (4,995 ) (129,292 ) Other comprehensive income (loss) before reclassifications 36,211 (34,512 ) 57,004 58,703 Amounts reclassified from accumulated other comprehensive loss 1,341 — (52,058 ) (50,717 ) Net other comprehensive income (loss) for the year 37,552 (34,512 ) 4,946 7,986 Balances at December 31, 2016 $ 28,945 $ (150,202 ) $ (49 ) $ (121,306 ) 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, 2016 2015 2014 Amortization of pension and other post-retirement items Prior service costs (1) $ — $ — $ (347 ) Net loss (1) (1,429 ) (2,663 ) (577 ) Curtailment (1) (364 ) — — Settlement benefits (1) (371 ) (355 ) — (2,164 ) (3,018 ) (924 ) Provision for income taxes 823 1,060 356 (1,341 ) (1,958 ) (568 ) Net unrealized gains on available-for- sale investments Realized gain on available- for-sale investments Other income, net 53,720 3,798 1,212 Provision for income taxes (1,662 ) (1,365 ) (435 ) 52,058 2,433 777 Total reclassifications for the period $ 50,717 $ 475 $ 209 ______________________________ (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, see Note 13.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Employee Benefits	Employee Benefits Defined Contribution Plans U.S. Plans The Company has defined contribution savings plans 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 respective plans. The Company may, at its discretion and per the terms of the respective plans, make an additional non-matching contribution in an amount as the Board of Directors may determine. For the years ended December 31, 2016 , 2015 and 2014 , the Company recorded approximately $10,697 , $7,594 and $6,856 , respectively, to expense for these contributions. The Company's charge for the year ended December 31, 2016 includes company contribution pertaining to Axiall's defined contribution savings plans for the four-month period since the completion of the Merger. Further, within a defined contribution savings plan, the Company also makes an annual retirement contribution to substantially all employees of one subsidiary who have completed one year of service. The Company's contributions to the plan are determined as a percentage of employees' base and overtime pay. For the years ended December 31, 2016 , 2015 and 2014 , the Company charged approximately $16,766 , $11,715 and $8,309 , respectively, to expense for these contributions. Non-U.S. Plans The Company has various defined contribution plans in Germany, the United Kingdom, Italy and Belgium covering eligible employees of our European operations. 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, 2016 , 2015 and 2014, the Company charged approximately $2,028 , $1,912 and $416 , 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. In December 2014, the Company announced a plan amendment to one of the Company's defined benefit pension plans. Under the plan amendment, no additional benefits may be earned by participants after January 31, 2015 and participants' accrued benefits will freeze at the levels earned as of January 31, 2015. In addition, the amendment added a lump sum payment option effective February 1, 2015. The Company made a similar plan amendment to another of its defined benefit pension plans in 2012. In conjunction with both of the defined benefit pension plans' amendments, the Company amended, in 2014 and 2012, its defined contribution savings plan to allow participants impacted by the amendments to participate in the Company's annual retirement contribution program. In connection with the Merger, the Company assumed certain U.S. pension plans and other post-retirement benefit plans covering Axiall employees. The Axiall pension plans are closed to new participants and provide benefits to certain employees and retirees. The other post-retirement benefit plans are unfunded and provide medical and life insurance benefits for certain employees and their dependents. Non-U.S. Plans The Company has defined benefit pension plans covering current and former employees associated with our European operations. These pension plans are closed to new participants and are for employees in Germany who commenced employment before July 1, 2007. Benefits for employees for these plans are based primarily on employees' pay near retirement. The non-U.S. plans are unfunded as no contributions have been made to the plans and therefore, have no plan assets. The measurement date for these plans is December 31. In connection with the Merger, the Company assumed certain defined benefit pension plans. These pension plans are for employees outside of the U.S., namely in Canada and Taiwan. Details of the changes in benefit obligations, plan assets and funded status of the Company's pension plans are as follows: 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 62,192 $ 94,821 $ 67,010 $ 122,701 Benefit obligation assumed with acquisition 818,602 20,895 — — Service cost 975 1,459 29 1,661 Interest cost 8,832 2,441 2,015 2,110 Actuarial (gain) loss (74,262 ) 12,705 (2,330 ) (17,310 ) Benefits paid (17,081 ) (2,571 ) (4,532 ) (2,139 ) Other — (61 ) — — Foreign exchange effects — (4,537 ) — (12,202 ) Benefit obligation, end of year $ 799,258 $ 125,152 $ 62,192 $ 94,821 Change in plan assets Fair value of plan assets, beginning of year $ 50,763 $ — $ 53,415 $ — Acquisition 575,865 16,298 — — Actual return 7,334 27 (268 ) — Employer contribution 456 2,609 2,148 2,139 Benefits paid (17,081 ) (2,571 ) (4,532 ) (2,139 ) Experience gain 136 — — — Administrative expenses paid (3,204 ) — — — Foreign exchange effects — (371 ) — — Fair value of plan assets, end of year $ 614,269 $ 15,992 $ 50,763 $ — Funded status, end of year $ (184,989 ) $ (109,160 ) $ (11,429 ) $ (94,821 ) 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Noncurrent assets $ — $ 233 $ — $ — Current liabilities (1,691 ) (2,583 ) — — Noncurrent liabilities (183,298 ) (106,810 ) (11,429 ) (94,821 ) Net amount recognized $ (184,989 ) $ (109,160 ) $ (11,429 ) $ (94,821 ) 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income Net (gain) loss $ (53,302 ) $ 7,990 $ 14,755 $ (4,919 ) Foreign exchange effects — (15 ) — 1,986 Total before tax (1) $ (53,302 ) $ 7,975 $ 14,755 $ (2,933 ) ______________________________ (1) After-tax totals for pension benefits were $30,287 and $6,812 for 2016 and 2015 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive loss. In the United States, 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 2016 plan year, the funded status for the Company's U.S. pension plans are above 80% , with all plans' funded status above 100% . Accordingly, the Company's U.S. pension plans 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: 2016 2015 Information for pension plans with an accumulated benefit obligation in excess of plan assets U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Projected benefit obligation $ (799,258 ) $ (113,286 ) $ (62,192 ) $ (94,821 ) Accumulated benefit obligation (799,258 ) (109,837 ) (62,192 ) (93,231 ) Fair value of plan assets 614,269 4,627 50,763 — 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, 2016 2015 2014 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 $ 1,261 $ 1,459 $ 29 $ 1,661 $ 334 $ 602 Administrative expenses 2,919 — — — — — Interest cost 8,832 2,441 2,015 2,110 2,322 1,366 Expected return on plan assets (15,354 ) (199 ) (2,960 ) — (3,140 ) — Net amortization 1,307 — 1,270 1,048 571 — Settlement benefits 371 — 355 — — — Net periodic benefit (gain) cost $ (664 ) $ 3,701 $ 709 $ 4,819 $ 87 $ 1,968 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net loss (gain) emerging $ (66,379 ) $ 12,893 $ 898 $ (17,310 ) $ 9,352 $ 15,425 Amortization of net loss (1,307 ) — (1,270 ) (1,048 ) (274 ) — Amortization of prior service cost — — — — (297 ) — Settlement benefits (371 ) — (355 ) — — — Total recognized in OCI $ (68,057 ) $ 12,893 $ (727 ) $ (18,358 ) $ 8,781 $ 15,425 Total net periodic benefit cost and OCI $ (68,721 ) $ 16,594 $ (18 ) $ (13,539 ) $ 8,868 $ 17,393 The estimated prior service cost and net loss for the defined benefit plans that will be amortized from accumulated other comprehensive income into net periodic benefit cost during 2017 are expected to be zero and $1,761 , respectively. The weighted-average assumptions used to determine pension plan obligations and net periodic benefit costs for the plans are as follows: 2016 2015 2014 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 3.8 % 1.8 % 4.0 % 2.4 % 3.5 % 1.9 % Rate of compensation increase — % 2.6 % — % 2.5 % — % 2.5 % Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 3.2 % 2.4 % 3.5 % 1.9 % 4.5 % 2.6 % Discount rate for service cost 3.4 % 2.4 % — % — % — % — % Discount rate for interest cost 2.9 % 2.4 % — % — % — % — % Expected return on plan assets 6.8 % 4.6 % 7.0 % — % 7.0 % — % Rate of compensation increase — % 2.6 % — % 2.5 % — % 2.5 % 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 Company pension plans' investments are held in the Westlake U.S. Salaried Plan, the Westlake U.S. Union Plan, the Axiall U.S. Salaried Plan and the Axiall Union U.S. Plan. The Company's overall investment strategy for its pension plan assets is to achieve a balance between moderate income generation and capital appreciation. The investment strategy includes a mix of approximately 55% to 65% of investments for long-term growth, and 35% to 45% for near-term benefit payments with a diversification of asset types. These pension funds' investment policies target asset allocations from approximately 55% to 65% equity securities and 35% to 45% 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 United States 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% or 15% . 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, 2016, 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 bank 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: 2016 2015 U.S. Plans Non U.S. Plans U.S. Plans Level 1 Level 2 Total Level 1 Level 2 Total Level 2 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ 4,627 $ — $ 4,627 $ — $ — Common stock 16,546 — 16,546 — — — — — Bank collective trust and mutual funds—Equity securities: Large-cap funds (1) 50,143 166,604 216,747 — 1,609 1,609 18,384 18,384 Small-cap funds (2) 8,379 23,407 31,786 — — — 4,069 4,069 International funds (3) 53,422 53,629 107,051 — 4,370 4,370 8,181 8,181 Bank collective trust funds—Fixed income: Bond funds (4) 61,778 165,657 227,435 — 5,386 5,386 19,624 19,624 Short-term investment funds — 14,704 14,704 — — — 505 505 $ 190,268 $ 424,001 $ 614,269 $ 4,627 $ 11,365 $ 15,992 $ 50,763 $ 50,763 ______________________________ (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 United States). 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 $2,254 for the pension plans in 2017 . 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, 2016 2015 2014 Non-U.S. Plans Non-U.S. Plans Non-U.S. Plans Contributions to multi-employer plans (1) $ 4,952 $ 4,489 $ 2,295 ______________________________ (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 benefits to the employees of two subsidiaries who meet certain minimum age and service requirements. The Company has the right to modify or terminate some of these benefits. In conjunction with the Axiall acquisition, the Company assumed postretirement plans in the U.S. and Canada which are unfunded and provide 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. 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 17,815 $ — $ 20,177 Benefit obligation assumed with acquisition 69,650 3,324 — Service cost 289 5 22 Interest cost 1,000 12 571 Actuarial (gain) loss (6,151 ) 91 (1,848 ) Benefits paid (2,355 ) (9 ) (1,107 ) Curtailment (364 ) — — Plan participants' contributions 35 — — Foreign exchange effects — (82 ) — Benefit obligation, end of year $ 79,919 $ 3,341 $ 17,815 Change in plan assets Fair value of plan assets, beginning of year $ — $ — $ — Employer contribution 2,320 9 1,107 Plan participants' contributions 35 — — Benefits paid (2,355 ) (9 ) (1,107 ) Fair value of plan assets, end of year $ — $ — $ — Funded status, end of year $ (79,919 ) $ (3,341 ) $ (17,815 ) 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (8,447 ) $ (102 ) $ (1,244 ) Noncurrent liabilities (71,472 ) (3,239 ) (16,571 ) Net amount recognized $ (79,919 ) $ (3,341 ) $ (17,815 ) 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Amounts recognized in accumulated other comprehensive income Net loss $ (3,659 ) $ 91 $ 2,978 Total before tax (1) $ (3,659 ) $ 91 $ 2,978 ______________________________ (1) After-tax totals for post-retirement healthcare benefits were a loss of $1,342 and a gain of $1,795 for 2016 and 2015 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive 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, 2016 2015 2014 U.S. Plans Non-U.S. Plans U.S. Plans U.S. Plans Components of net periodic benefit cost Service cost $ 289 $ 5 $ 22 $ 22 Interest cost 1,000 12 571 733 Net amortization 122 — 345 353 Net periodic benefit cost $ 1,411 $ 17 $ 938 $ 1,108 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net (gain) loss emerging $ (6,151 ) $ 91 $ (1,848 ) $ 989 Curtailment (364 ) — — — Amortization of net loss (122 ) — (345 ) (303 ) Amortization of prior service cost — — — (50 ) Total recognized in OCI $ (6,637 ) $ 91 $ (2,193 ) $ 636 Total net periodic benefit cost and OCI $ (5,226 ) $ 108 $ (1,255 ) $ 1,744 The estimated prior service cost and net loss for the post-retirement healthcare benefit plans that will be amortized from accumulated other comprehensive income into net periodic benefit cost during 2017 are expected to be zero and $56,446 , respectively. The weighted-average assumptions used to determine post-retirement healthcare plan obligations and net periodic benefit costs for the plans are as follows: 2016 2015 2014 U.S. Plans Non-U.S. Plans U.S. Plans U.S. Plans Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 3.3 % 4.0 % 3.5 % 3.3 % Health care cost trend rate - Initial rate 7.3 % 6.2 % — % — % - Ultimate rate 4.5 % 4.5 % — % — % - Years to ultimate 11 12 — — Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 2.6 % 3.3 % 3.3 % 4.0 % Discount rate for service cost 3.1 % 3.3 % — % — % Discount rate for interest cost 2.8 % 3.3 % — % — % Health care cost trend rate - Initial rate 7.0 % 6.8 % — % — % - Ultimate rate 4.5 % 4.5 % — % — % - Years to ultimate 12 13 — — 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 Post- retirement Healthcare Estimated future benefit payments: Year 1 $ 51,324 $ 8,663 Year 2 49,626 8,460 Year 3 51,163 8,302 Year 4 51,554 8,185 Year 5 51,715 8,122 Years 6 to 10 267,024 34,681

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2016
Share-based Compensation [Abstract]
Stock-Based Compensation	Stock-Based Compensation Under the Westlake Chemical Corporation 2013 Omnibus Incentive Plan (as amended and restated, 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 either (1) ratably on an annual basis over a one to four -year period or (2) at the end of a five to 9.5 -year period. Current outstanding restricted stock awards vest on the 9.5 -year anniversary of the award date. Outstanding restricted stock units vest either (1) ratably on an annual basis over a three -year period or (2) at the end of a one to 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, 2016 , 2015 and 2014 , the total recognized stock-based compensation expense related to the 2013 Plan was $14,193 , $10,196 and $9,261 , respectively. Option activity and changes during the year ended December 31, 2016 were as follows: Options Weighted Average Exercise Price Weighted Average Remaining Term (Years) Aggregate Intrinsic Value Outstanding at December 31, 2015 1,267,790 $ 30.07 Granted 292,448 44.42 Exercised (112,611 ) 19.33 Cancelled (42,893 ) 35.07 Outstanding at December 31, 2016 1,404,734 $ 33.76 5.3 $ 34,368 Exercisable at December 31, 2016 940,314 $ 24.29 3.7 $ 31,009 For options outstanding at December 31, 2016 , the options had the following range of exercise prices: Range of Prices Options Outstanding Weighted Average Remaining Contractual Life (Years) $7.12 - $9.65 304,200 1.7 $10.26 - $18.05 235,916 2.3 $22.92 - $30.05 174,082 4.7 $40.38 - $52.35 391,083 8.4 $63.98 - $68.18 299,453 7.7 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, 2016 . This amount changes based on the fair market value of the Company's common stock. For the years ended December 31, 2016 , 2015 and 2014 , the total intrinsic value of options exercised was $3,630 , $1,145 and $14,534 , respectively. As of December 31, 2016 , $3,708 of total unrecognized compensation cost related to stock options is expected to be recognized over a weighted-average period of 1.5 years. Income tax benefits of $1,090 , $78 and $4,512 were realized from the exercise of stock options during the years ended December 31, 2016 , 2015 and 2014 , 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, 2016 2015 2014 Weighted average fair value $ 11.67 $ 20.21 $ 20.49 Risk-free interest rate 1.4 % 1.7 % 1.6 % Expected life in years 5 5 5 Expected volatility 32.9 % 34.2 % 35.7 % Expected dividend yield 1.6 % 0.9 % 0.7 % Non-vested restricted stock awards as of December 31, 2016 and changes during the year ended December 31, 2016 were as follows: Number of Shares Weighted Average Grant Date Fair Value Non-vested at December 31, 2015 64,856 $ 15.81 Granted 28,142 51.53 Vested (81,134 ) 28.19 Forfeited (11,864 ) 15.81 Non-vested at December 31, 2016 — $ — As of December 31, 2016 , there was no unrecognized stock-based compensation expense related to non-vested restricted stock awards. The total fair value of shares of restricted stock that vested during the years ended December 31, 2016 , 2015 and 2014 was $4,260 , $8,363 and $8,831 , respectively. Non-vested restricted stock unit as of December 31, 2016 and changes during the year ended December 31, 2016 were as follows: Number of Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2015 498,872 $ 57.61 Granted 204,642 48.64 Vested (88,877 ) 48.28 Forfeited (17,078 ) 67.47 Non-vested at December 31, 2016 597,559 $ 55.64 As of December 31, 2016 , there was $16,110 of unrecognized stock-based compensation expense related to non-vested restricted stock units. This cost is expected to be recognized over a weighted-average period of 2.2 years. The total fair value of restricted stock units that vested during the years ended December 31, 2016 , 2015 and 2014 was $4,031 , $725 and $371 , respectively. Axiall Awards Assumed in the Merger Under the Merger Agreement, all outstanding Axiall restricted stock units were assumed by the Company and converted into restricted stock units in respect of the Company's common stock, with the same terms and conditions except that upon settlement the award holders will receive the greater of (1) the value of $33.00 per Axiall restricted stock unit that was converted into a restricted stock unit in respect of the Company's common stock and (2) the value of the Company's common stock. The awards are classified as liability awards for accounting purposes and are re-measured at each reporting date until they vest. The portion of the replacement award that is attributable to pre-combination service by the employee is included in the measure of consideration transferred to acquire Axiall. The remaining fair value of the replacement awards will be recognized as stock-based compensation expense over the remaining vesting period. Total stock-based compensation expense recognized related to Axiall restricted stock units that were assumed by the Company and converted into restricted stock units during the year ended December 31, 2016 was $38,031 , of which $32,644 is included in transaction and integration-related costs in the consolidated statement of operations. The Company estimates the fair value of these awards using the Company's common stock price and a pricing model to estimate the value attributable to the $33.00 minimum price per Axiall restricted stock unit converted into a restricted stock unit in respect of the Company's common stock. The table below presents the assumptions used in determining each liability classified restricted stock unit's fair value. Volatility was calculated using historical trends of the Company's common stock price. Liability Classified Restricted Stock Awards Year Ended December 31, 2016 Weighted average vesting period in years 1.2 Risk-free interest rate 0.9 % Expected volatility 28.2 % Expected dividend yield 1.4 % Non-vested liability classified restricted stock awards as of December 31, 2016 and changes during the year ended December 31, 2016 were as follows: Number of Units Weighted Average Fair Value Non-vested at August 31, 2016 340,413 $ 51.82 Vested (54,266 ) 52.88 Non-vested at December 31, 2016 286,147 $ 60.77 As of December 31, 2016, there was $ 11,707 of unrecognized stock-based compensation expense related to non-vested liability classified restricted stock awards. This cost is expected to be recognized over a weighted-average period of 1.2 years. The total fair value of liability classified restricted stock awards that vested during the year ended December 31, 2016 was $2,870 . Westlake Chemical Partners LP Awards Our wholly-owned subsidiary and the general partner of Westlake Partners, Westlake Chemical Partners GP LLC ("WLKPGP"), maintains a unit-based compensation plan for directors and employees of WLKPGP 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 our consolidated financial statements for the years ended December 31, 2016 , 2015 and 2014 .

Derivative Commodity Instrument

Derivative Commodity Instruments	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedges, Assets [Abstract]
Derivative Commodity Instruments	Derivative Commodity Instruments Commodity Risk Management The Company uses derivative instruments to reduce price volatility risk on commodities, primarily natural gas and ethane, from time to time. The Company does not use derivative instruments to engage in speculative activities. The Company had no derivative instruments that were designated as fair value hedges during the years ended December 31, 2016 , 2015 and 2014 . Gains and losses from changes in the fair value of derivative instruments that are not designated as hedging instruments were included in cost of sales in the consolidated statements of operations for the years ended December 31, 2016 , 2015 and 2014 . The exposure on commodity derivatives used for price risk management includes the risk that the counterparty will not pay if the market declines below the established fixed price. In such case, the Company would lose the benefit of the derivative differential on the volume of the commodities covered. In any event, the Company would continue to receive the market price on the actual volume hedged. The Company also bears the risk that it could lose the benefit of market improvements over the fixed derivative price for the term and volume of the derivative instruments (as such improvements would accrue to the benefit of the counterparty). The Company had non-hedge designated feedstock forward contracts for approximately 257,000,000 gallons and 8,500,000 MMBtu as of December 31, 2016 and for approximately 171,000,000 gallons and 8,000,000 MMBtu as of December 31, 2015. The fair values of derivative instruments in the Company's consolidated balance sheets were as follows: Asset Derivatives Balance Sheet Location Fair Value as of December 31, 2016 2015 Not designated as hedging instruments Commodity forward contracts Accounts receivable, net $ 7,727 $ 3,465 Commodity forward contracts Deferred charges and other assets, net 7,259 2,088 Total asset derivatives $ 14,986 $ 5,553 Liability Derivatives Balance Sheet Location Fair Value as of December 31, 2016 2015 Not designated as hedging instruments Commodity forward contracts Accrued liabilities $ 1,487 $ 9,325 Commodity forward contracts Other liabilities 5,734 12,437 Total liability derivatives $ 7,221 $ 21,762 The impact of derivative instruments that have not been designated as hedges on the Company's consolidated statements of operations were as follows: Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative Year Ended December 31, 2016 2015 2014 Commodity forward contracts Cost of sales $ 19,696 $ (11,395 ) $ (9,678 ) See Note 16 for the fair value of the Company's derivative instruments.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company reports certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The following tables summarize, by level within the fair value hierarchy, the Company's assets and liabilities at December 31 that were accounted for at fair value on a recurring basis: 2016 Level 1 Level 2 Total Derivative instruments Risk management assets—Commodity forward contracts $ 878 $ 14,108 $ 14,986 Risk management liabilities—Commodity forward contracts (6,854 ) (367 ) (7,221 ) 2015 Level 1 Level 2 Total Derivative instruments Risk management assets—Commodity forward contracts $ 5,553 $ — $ 5,553 Risk management liabilities—Commodity forward contracts (11,648 ) (10,114 ) (21,762 ) Marketable securities Available-for-sale securities 48,081 520,144 568,225 The Level 2 measurements for the Company's commodity contracts are derived using forward curves supplied by industry recognized and unrelated third-party services. The Level 2 measurements for the Company's available-for-sale securities are derived using market-based pricing provided by unrelated third-party services. There were no transfers in and out of Levels 1 and 2 of the fair value hierarchy in 2016 and 2015 . In addition to the assets and liabilities above, the Company has other 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, 2016 and 2015 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. 2016 2015 Carrying Value Fair Value Carrying Value Fair Value Revolving credit facility $ 325,000 $ 325,000 $ — $ — 4.625% Westlake Senior Notes 2021 651,630 650,847 — — 4.625% Subsidiary Senior Notes 2021 66,069 65,775 — — 3.60% senior notes due 2022 248,109 251,725 247,768 244,828 4.875% Westlake Senior 2023 Notes 447,224 451,301 — — 4.875% Subsidiary 2023 Senior Notes 16,747 16,501 — — 3.60% 2026 Senior Notes 739,243 722,055 — — Loan related to tax-exempt waste disposal revenue bonds due 2027 10,889 10,889 10,889 10,889 6 ½% senior notes due 2029 99,084 112,433 99,011 117,153 6 ¾% senior notes due 2032 248,117 258,818 247,998 268,490 6 ½% 2035 GO Zone Senior Notes 88,161 100,323 88,116 106,491 6 ½% 2035 IKE Zone Senior Notes 64,398 73,270 64,366 76,741 5.0% 2046 Senior Notes 673,983 691,712 — —

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company elected to early adopt an accounting standards update requiring the noncurrent classification of all deferred tax assets and liabilities, along with any related valuation allowance, effective January 1, 2016. As a result, the Company's deferred tax assets and liabilities have been classified, by jurisdiction, as a net noncurrent deferred tax asset or liability on the consolidated balance sheet. Consistent with the prospective application of this accounting standard, prior period comparative information was not adjusted. The components of income (loss) before income taxes are as follows: Year Ended December 31, 2016 2015 2014 Domestic $ 476,423 $ 880,044 $ 1,102,101 Foreign 81,956 83,397 (18,183 ) $ 558,379 $ 963,441 $ 1,083,918 The Company's provision for (benefit from) income taxes consists of the following: Year Ended December 31, 2016 2015 2014 Current Federal $ 8,156 $ 225,617 $ 300,610 State 8,967 23,966 37,351 Foreign 20,720 9,029 1,974 37,843 258,612 339,935 Deferred Federal 136,206 29,820 40,950 State (33,681 ) 2,807 22,714 Foreign (1,848 ) 7,157 (4,697 ) 100,677 39,784 58,967 Total provision $ 138,520 $ 298,396 $ 398,902 A reconciliation of taxes computed at the statutory rate to the Company's income tax expense is as follows: Year Ended December 31, 2016 2015 2014 Provision for federal income tax, at statutory rate $ 195,432 $ 337,204 $ 379,371 State income tax provision, net of federal income tax effect 1,408 17,403 40,012 Foreign income tax rate differential (7,594 ) (13,002 ) 3,640 Manufacturing deduction (2,371 ) (24,185 ) (24,465 ) Depletion (2,298 ) — — Contingent tax liability 2,172 — (1,626 ) Noncontrolling interests (6,940 ) (6,662 ) (2,255 ) Tax on previously held shares of Axiall Corporation and certain other acquisition related items (12,924 ) — — Changes in state apportionment and other state adjustments (16,929 ) — — Research and development expenditures and adjustments related to prior years' tax returns (8,344 ) Other, net (3,092 ) (12,362 ) 4,225 $ 138,520 $ 298,396 $ 398,902 The tax effects of the principal temporary differences between financial reporting and income tax reporting at December 31 are as follows: 2016 2015 Net operating loss carryforward $ 69,790 $ 17,679 Credit carryforward 23,932 746 Accruals 66,694 57,811 Pension 113,644 4,393 Allowance for doubtful accounts 12,039 4,617 Inventories 13,257 8,663 Other 36,624 7,747 Deferred taxes assets—total 335,980 101,656 Property, plant and equipment (1,374,095 ) (408,374 ) Intangibles (220,489 ) (15,007 ) Turnaround costs (701 ) (1,467 ) Basis difference—consolidated partnerships (308,361 ) (200,627 ) Other (17,377 ) — Deferred tax liabilities—total (1,921,023 ) (625,475 ) Valuation allowance (53,006 ) (16,345 ) Total net deferred tax liabilities $ (1,638,049 ) $ (540,164 ) Balance sheet classifications Current deferred tax asset $ — $ 35,439 Noncurrent deferred tax asset 12,526 — Noncurrent deferred tax liability (1,650,575 ) (575,603 ) Total net deferred tax liabilities $ (1,638,049 ) $ (540,164 ) At December 31, 2016 , the Company had foreign and state net operating loss carryforwards of approximately $564,896 , which will expire in varying amounts between 2017 and 2036 and are subject to certain limitations on an annual basis. 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 increased by $36,661 in 2016 as a result of the Axiall Corporation acquisition and due to the creation of additional state and foreign net operating loss carryforwards. For the year ended December 31, 2016 , the Company is not permanently reinvested with respect to the outside basis difference for all of its foreign subsidiaries. The Company is asserting under ASC 740-30 that the unremitted earnings of some of its foreign subsidiaries are permanently reinvested outside the U.S. For these foreign subsidiaries, the earnings and profits (E&P) is estimated to be $209,791 at December 31, 2016 . If no assertion were made to permanently reinvest any of these unremitted foreign earnings, U.S. income tax expense of approximately $32,319 relating to U.S. tax would be recorded. Such expense takes into account utilization of foreign tax credits. The Company is not asserting under ASC 740-30 for certain other foreign subsidiaries. As such, the Company recorded a deferred tax liability (and related tax expense) of $2,218 . Of this amount, $1,448 has been recorded to recognize the foreign taxes that would result if earnings in lower-tier foreign subsidiaries would be distributed up the foreign ownership chain to a subsidiary where an assertion is made, and $770 is attributable to the U.S. tax related to the distribution from the Taiwanese subsidiary which is expected to be made to the Company annually. A reconciliation of unrecognized tax benefits for the year ended December 31, 2016 is set forth in the table below: Beginning balance at January 1, 2016 $ — Amounts attributable to Axiall pre-acquisition 5,030 Additions during the year ended December 31, 2016 3,398 Reductions due to statutes of limitations expiring (1,184 ) Effects of changes in foreign exchange rates $ (56 ) Ending balance at December 31, 2016 $ 7,188 There were unrecognized tax benefits of $7,188 and $0 as of December 31, 2016 and 2015 , respectively. The Company recognizes penalties and interest accrued related to unrecognized tax benefits in income tax expense. If recognized, $4,571 of the unrecognized tax benefits would lower the effective tax rate. The majority of the total unrecognized tax benefits relate to historical balances reported by Axiall prior to the Merger. As of December 31, 2016 and 2015, our tax liability for interest and penalties was $328 and $0 , respectively. For the year ended December 31, 2016 , the Company accrued interest and penalties in the amount of $253 related to uncertain tax positions. It is reasonably possible that our existing liabilities for unrecognized tax benefits may increase or decrease within the next twelve months primarily due to open audits and the expiration of statutes of limitation. However, we cannot reasonably estimate a range of potential changes in our existing liabilities for unrecognized tax benefits due to the uncertainties of the open audits. 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 2010.

Earnings per Share

Earnings per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share The Company has unvested shares of restricted stock and 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. Year Ended December 31, 2016 2015 2014 Net income attributable to Westlake Chemical Corporation $ 398,859 $ 646,010 $ 678,523 Less: Net income attributable to participating securities (1,784 ) (2,825 ) (1,502 ) Net income attributable to common shareholders $ 397,075 $ 643,185 $ 677,021 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, 2016 2015 2014 Weighted average common shares—basic 129,367,712 131,823,707 133,111,230 Plus incremental shares from: Assumed exercise of options 607,110 478,105 532,184 Weighted average common shares—diluted 129,974,822 132,301,812 133,643,414 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 3.07 $ 4.88 $ 5.09 Diluted $ 3.06 $ 4.86 $ 5.07 Excluded from the computation of diluted earnings per share for the years ended December 31, 2016 , 2015 and 2014 are options to purchase 318,259 , 301,969 and 126,091 shares of common stock, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive.

Supplemental Information

Supplemental Information	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Information	Supplemental Information Accrued Liabilities Accrued liabilities were $537,483 and $287,313 at December 31, 2016 and 2015 , respectively. Accrued rebates, which is a component of accrued liabilities, was $77,985 and $46,460 at December 31, 2016 and December 31, 2015 , respectively. No other component of accrued liabilities was more than five percent of total current liabilities. Other Income (Expense), Net The components of other income (expense), net are as follows: Year Ended December 31, 2016 2015 2014 Interest income $ 8,421 $ 6,034 $ 3,468 Dividend income 4,821 3,559 532 Acquisition-related financing costs (12,453 ) — — Foreign exchange currency gains (losses), net (1) 122 1,828 (7,382 ) Income from equity method investments 3,613 6,242 5,883 Impairment of equity method investments — (4,925 ) (6,747 ) Gain realized on previously held shares of Axiall common stock 49,080 — — Gain on acquisition and related expenses, net — 20,430 — Gain from sales of securities, net 4,640 3,798 1,212 Other (1,846 ) 1,304 313 Other income (expense), net $ 56,398 $ 38,270 $ (2,721 ) ______________________________ (1) Aggregate foreign exchange currency gains and losses included in the consolidated statements of operations for the years ended December 31, 2016 , 2015 and 2014 . Cash Flow Information Year Ended December 31, 2016 2015 2014 Cash paid for: Interest paid, net of interest capitalized $ 45,534 $ 31,946 $ 35,336 Income taxes paid 3,066 314,186 314,745

Related Party And Affiliate Tra

Related Party And Affiliate Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party And Affiliate Transactions	Related Party and Affiliate Transactions The Company leases office space for management and administrative services from an affiliate of the Company's principal stockholder. For the years ended December 31, 2016 , 2015 and 2014 , the Company incurred lease payments of approximately $3,024 , $2,148 and $2,001 , respectively. The amounts due to this affiliate were $236 and $196 at December 31, 2016 and 2015 , respectively. 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 investment in Cypress Interstate Pipeline L.L.C at December 31, 2016 and 2015 was $9,098 and $9,208 , respectively. For the years ended December 31, 2016 , 2015 and 2014 , the Company incurred pipeline fees of approximately $13,748 , $14,110 and $14,206 , respectively, payable to this joint venture for usage of the pipeline. The amounts due to this joint venture were $1,018 and $991 at December 31, 2016 and 2015, respectively. EPS Ethylene Pipeline Süd GmbH & Co. KG, an ethylene pipeline company in which the Company owns a 10% equity stake, transports ethylene feedstocks to the Company's Gendorf, Germany production facility through its pipeline. For the years ended December 31, 2016 , 2015 and 2014, the Company incurred pipeline fees of approximately $797 , $1,022 and $548 , respectively, for usage of the pipeline. There were no outstanding amounts due to this related party at December 31, 2016 and 2015. The Company owns a 15% and an 11% equity stake in InfraServ Knapsack GmbH & Co. KG and InfraServ Gendorf GmbH & Co. KG, respectively. The Company has service agreements with these entities, including contracts to provide electricity and technical services to certain of the Company's production facilities in Germany. The investment in Infraserv was $49,532 and $51,333 at December 31, 2016 and 2015 , respectively. For the years ended December 31, 2016 , 2015 and 2014, the Company incurred charges aggregating approximately $130,840 , $115,961 and $55,400 , respectively, for these services. The amounts payable to these related parties were approximately $24,708 and $22,931 at December 31, 2016 and 2015 , respectively. The Company owns 50% interest in Shriram Axiall Private Limited ("SAPL"), which the Company acquired as a result of the Merger. SAPL is a joint venture formed in April 2014 to facilitate the manufacture and sale of certain compound products in India. The investment in SAPL at December 31, 2016 was $1,974 . For the period from August 31, 2016 to December 31, 2016, the Company recorded sales of approximately $49 to SAPL. The amount receivable from this related party was approximately $80 at December 31, 2016. The Company owns a 50% interest in RS Cogen LLC ("RS Cogen"), which the Company acquired as a result of the Merger. RS Cogen operates a process steam, natural gas-fired cogeneration facility adjacent to the Lake Charles South Facility. The daily operations of the cogeneration facility are the activities of RS Cogen that most significantly impact its economic performance. These activities are directed by a management team with oversight by a management committee that has equal representation from the Company and Entergy Corporation. By the terms of the joint venture agreement, all decisions of the management committee require approval by a majority of its members. Accordingly, the power to direct the activities of RS Cogen is equally shared between RS Cogen's two owners and, thus, the Company does not consider itself to be the joint venture's primary beneficiary. Accordingly, the Company accounts for its investment in RS Cogen under the equity method of accounting. The investment in and net advances to RS Cogen at December 31, 2016 were $9,949 . For the period from August 31, 2016 to December 31, 2016, the Company recorded purchases of approximately $8,623 from RS Cogen. The amount payable to this related party was approximately $1,159 at December 31, 2016 . The Company owns a 50% interest in Vinyl Solutions, LLC ("Vinyl Solutions"), which the Company acquired as a result of the Merger. Vinyl Solutions is a compounding manufacturer of specialty compounds. The investment in Vinyl Solutions at December 31, 2016 was $500 . For the period from August 31, 2016 to December 31, 2016, the Company recorded sales of $6,218 to Vinyl Solutions. The amount receivable from this related party was $4,855 at December 31, 2016. On June 17, 2015, Eagle US 2 LLC ("Eagle" ) , a wholly-owned subsidiary of Axiall, entered into an amended and restated limited liability company agreement with Lotte Chemical USA Corporation (" Lotte") related to the formation of LACC, which was formed by Eagle and Lotte to design, build and operate a 1 billion ton per year ethylene plant. Pursuant to a contribution and subscription agreement, dated as of June 17, 2015, between Eagle and LACC, Eagle has agreed to make a maximum capital commitment to LACC of up to $225,000 to fund the construction costs of the plant, representing a 10% interest in LACC. Eagle and Lotte also entered into a call option agreement, dated as of June 17, 2015, pursuant to which Eagle has the right, but not the obligation, until the third anniversary of the substantial completion of the plant, to acquire up to a 50% ownership interest in LACC from Lotte. The construction of the plant commenced in January 2016. The plant is being built adjacent to the Company's largest chlor-alkali chemical facility, located in Lake Charles, to take advantage of the Company's existing infrastructure, access to competitive feedstock resources and ethylene distribution infrastructure. The anticipated start-up for the plant is expected to be in the first quarter of 2019 . The Company acquired this investment as a result of the Merger. As of December 31, 2016, the Company's investment in LACC is $59,405 . Total funding by the Company in LACC from August 31, 2016 to December 31, 2016 amounted to $17,000 . The amount receivable from LACC at December 31, 2016 was approximately $820 . The Company's investment in LACC is accounted for under the cost method. Dividends received from equity method investments were $5,116 , $5,610 and $5,459 for the years ended December 31, 2016 , 2015 and 2014 , respectively. One of the Company's directors serves as Chairman and Chief Executive Officer of American Air Liquide Holdings, Inc. and as a Senior Vice President of the Air Liquide Group. 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 Group ("Air Liquide") aggregating approximately $22,167 , $10,345 and $13,862 for the years ended December 31, 2016 , 2015 and 2014 , respectively. The Company also sold certain utilities to Air Liquide aggregating approximately $3,988 during the year ended December 31, 2016. The amount payable to Air Liquide was $3,724 and $762 at December 31, 2016 and 2015, respectively, and the amount receivable from Air Liquide was $664 and $0 at December 31, 2016 and 2015, respectively.

Insurance Recovery

Insurance Recovery	12 Months Ended
	Dec. 31, 2016
Insurance Recovery [Abstract]
Insurance Recovery	Insurance Recovery During the second and third quarters of 2015, the Company's production rates and operating costs at its Knapsack, Germany and Cologne, Germany facilities were negatively impacted due to an interruption of feedstock supply as a result of a fire at a third-party supplier's ethylene production facility. During the year ended December 31, 2016 , the Company received a final insurance recovery of approximately $2,670 related to business interruption costs. The insurance recovery is included in cost of sales in the consolidated statement of operations. The Company had received and recognized approximately $7,809 as a partial insurance recovery during the year ended December 31, 2015.

Westlake Chemical Partners LP

Westlake Chemical Partners LP	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Westlake Chemical Partners LP	Westlake Chemical Partners LP Westlake Partners is a publicly traded master limited partnership that was formed by the Company to operate, acquire and develop ethylene production facilities and related assets. Initial Public Offering of Westlake Partners On August 4, 2014, Westlake Partners completed its initial public offering of 12,937,500 common units at a price of $24.00 per unit, which included 1,687,500 units purchased by the underwriters pursuant to the exercise in full of their over-allotment option. Net proceeds to Westlake Partners from the sale of the units was approximately $286,088 , net of underwriting discounts, structuring fees and offering expenses (the "Offering Costs") of approximately $24,412 . At the time of the initial public offering, Westlake Partners' assets consisted of a 10.6% limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in OpCo. At the time of the initial public offering, the Company retained an 89.4% limited partner interest in OpCo, a 52.2% limited partner interest in Westlake Partners (common and subordinated units), a general partner interest in Westlake Partners and incentive distribution rights. The Company consolidates Westlake Partners for financial reporting purposes as the Company has a controlling financial interest. The initial public offering represented the sale of 47.8% of the common units in Westlake Partners. OpCo used the net proceeds from the purchase of its limited partner interest to establish a cash reserve of approximately $55,419 for turnaround expenditures, to reimburse approximately $151,729 for capital expenditures incurred by the Company with respect to certain of the assets contributed to OpCo and to repay intercompany debt to the Company of approximately $78,940 . The following table is a reconciliation of proceeds from the initial public offering: Total proceeds from the initial public offering $ 310,500 Less: Offering Costs (24,412 ) Net proceeds from the initial public offering 286,088 Less: Cash retained by OpCo (55,419 ) Net proceeds distributed to the Company from the initial public offering $ 230,669

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2016
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, specific outcomes with respect to such matters may be material to the Company's consolidated statements of operations in any particular period in which costs, if any, are recognized. 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. Environmental. As of December 31, 2016 and December 31, 2015 , the Company had reserves for environmental contingencies totaling approximately $48,817 (primarily as a result of the Axiall acquisition) and $5,368 , 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. From time to time the Company receives notices or inquiries from government entities regarding alleged violations of environmental laws and regulations pertaining to, among other things, the disposal, emission and storage of chemical substances, including hazardous wastes. Item 103 of the SEC's Regulation S-K requires disclosure of certain environmental matters when a governmental authority is a party to the proceedings and the proceedings involve potential monetary sanctions, unless the Company reasonably believes such sanctions would not exceed $100 . • In May 2013, an amendment to an existing consent order agreed to by the West Virginia Department of Environmental Protection and a predecessor of Axiall required that it, among other things, pay a penalty in the amount of $449 and continue certain corrective action associated with discharges of hexachlorocyclohexane (commonly referred to as BHC) from the Natrium, West Virginia facility's effluent discharge outfalls. The penalty was paid and corrective actions required under the amendment to the consent order are on-going. • In May 2013 and September 2013, the Environmental Protection Agency (the "EPA") conducted inspections at the Company's Plaquemine, Louisiana facility pursuant to requirements of the federal Clean Air Act Section 112(r) Risk Management Program and Title V. As a result of the inspections, the EPA identified areas of concern and the Company has subsequently engaged in negotiations, which are anticipated to result in sanctions of $167 . • The LDEQ has issued notices of violations ("NOVs") regarding the Company's olefins facilities in Lake Charles, Louisiana for various air and water compliance issues. The Company is working with the LDEQ to settle these claims, and a global settlement of all claims is being discussed. The Company has reached a verbal agreement with the LDEQ to settle certain of the NOVs in two separate settlements for a combined $192 in civil penalties. • During September 2010, the Company's vinyls facilities in north Lake Charles and Plaquemine each received a Consolidated Compliance Order and Notice of Potential Penalty, alleging violations of various requirements of those facilities' air permits, based largely on self-reported permit deviations related to record-keeping violations. The Company has been negotiating a possible global settlement of these and several other matters with the LDEQ. The Company believes the resolution of these matters may require the payment of a monetary sanction in excess of $100 . • In April 2015, Axiall received a communication from the EPA related to, among other things, the EPA's investigation of the 2012 and 2013 fires that occurred at its VCM plant in Lake Charles. In late 2015, Axiall settled this matter with the EPA, with such settlement including on-going supplemental environmental projects and a payment of $900 . • For several years, the EPA has been conducting an enforcement initiative against petroleum refineries and petrochemical plants with respect to emissions from flares. On April 21, 2014, the Company received a Clean Air Act Section 114 Information Request from the EPA which sought information regarding flares at the Calvert City, Kentucky facility and certain Lake Charles facilities. The EPA has informed the Company that the information provided leads the EPA to believe that some of the flares are out of compliance with applicable standards. The EPA has indicated that it is seeking a consent decree that would obligate the Company to take corrective actions relating to the alleged noncompliance. The Company believes the resolution of these matters may require the payment of a monetary sanction in excess of $100 . The Company does not believe that the resolution of any or all of these matters will have a material adverse effect on the Company's financial condition, results of operations or cash flows. 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 $40,000 to $80,000 . Other Commitments The Company is obligated under various long-term and short-term noncancelable operating leases, primarily related to rail car leases and land. Several of the leases provide for renewal terms and, in certain leases, purchase options. At December 31, 2016 , future minimum lease commitments for operating lease obligations and capital lease obligations were as follows: Operating Leases Capital Leases 2017 $ 86,910 $ 3,713 2018 78,941 3,627 2019 60,885 3,367 2020 48,395 3,367 2021 39,626 2,610 Thereafter 603,621 13,943 Total minimum lease payments $ 918,378 $ 30,627 Less: Imputed interest costs (10,681 ) Present value of net minimum lease payments $ 19,946 Operating lease rental expense was approximately $87,323 , $69,455 and $56,014 for the years ended December 31, 2016 , 2015 and 2014 , respectively. 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: $307,768 , $304,129 , $284,894 , $266,989 and $188,372 in 2017 , 2018 , 2019 , 2020 and 2021 , respectively.

Segment And Geographic Informat

Segment And Geographic Information	12 Months Ended
	Dec. 31, 2016
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 vinyl chloride monomer ("VCM") operations. In addition, the Company sells ethylene and ethylene co-products, primarily propylene, crude butadiene, pyrolysis gasoline and hydrogen, to external customers. The majority of sales in the Company's Olefins business are made under long-term agreements where contract volumes are established within a range (typically, more than one year). Earlier terminations may occur if the parties fail to agree on price and deliveries are suspended for a period of several months. In most cases, these contracts also contemplate extension of the term unless specifically terminated by one of the parties. No single customer accounted for more than 10% of sales in the Olefins segment for the years ended December 31, 2016 , 2015 or 2014 . The Company's Vinyl segment manufactures and markets PVC, VCM, EDC, chlor-alkali (chlorine and caustic soda), chlorinated derivative products and ethylene. The Company also manufactures and sells building products fabricated from PVC, including siding, pipe, fittings, profiles, trim, mouldings, fence and decking products, window and door components and film and sheet products. 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, the Company has manufacturing facilities in Germany, the United Kingdom, Taiwan and the People's Republic of China. As of December 31, 2016 , the Company owned 26 building products facilities. The Company 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, 2016 , 2015 or 2014 . The accounting policies of the individual segments are the same as those described in Note 1. Year Ended December 31, 2016 2015 2014 Net external sales Olefins Polyethylene $ 1,462,407 $ 1,650,964 $ 1,922,535 Styrene, feedstock and other 431,227 609,149 801,155 Total olefins 1,893,634 2,260,113 2,723,690 Vinyls PVC, caustic soda and other 2,492,562 1,718,359 1,203,332 Building products 689,260 484,864 488,328 Total vinyls 3,181,822 2,203,223 1,691,660 $ 5,075,456 $ 4,463,336 $ 4,415,350 Intersegment sales Olefins $ 165,266 $ 106,861 $ 146,539 Vinyls 25,809 1,493 1,385 $ 191,075 $ 108,354 $ 147,924 Income (loss) from operations Olefins $ 557,806 $ 747,436 $ 1,013,825 Vinyls 174,141 254,452 142,740 Corporate and other (150,493 ) (42,061 ) (32,574 ) $ 581,454 $ 959,827 $ 1,123,991 Depreciation and amortization Olefins $ 136,500 $ 110,684 $ 106,244 Vinyls 237,588 134,546 101,666 Corporate and other 3,578 527 576 $ 377,666 $ 245,757 $ 208,486 Other income (expense), net Olefins $ 5,156 $ 4,656 $ 6,102 Vinyls 3,138 8,540 2,680 Corporate and other 48,104 25,074 (11,503 ) $ 56,398 $ 38,270 $ (2,721 ) Provision for (benefit from) income taxes Olefins $ 175,394 $ 242,516 $ 354,159 Vinyls 24,695 64,456 52,249 Corporate and other (61,569 ) (8,576 ) (7,506 ) $ 138,520 $ 298,396 $ 398,902 Capital expenditures Olefins $ 323,590 $ 304,873 $ 188,729 Vinyls 302,208 176,582 237,992 Corporate and other 2,685 9,971 4,383 $ 628,483 $ 491,426 $ 431,104 December 31, 2016 December 31, 2015 Total assets Olefins $ 2,092,617 $ 1,869,888 Vinyls 8,287,204 2,638,833 Corporate and other 510,432 1,060,564 $ 10,890,253 $ 5,569,285 A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Year Ended December 31, 2016 2015 2014 Income from operations for reportable segments $ 581,454 $ 959,827 $ 1,123,991 Interest expense (79,473 ) (34,656 ) (37,352 ) Other income (expense), net 56,398 38,270 (2,721 ) Income before income taxes $ 558,379 $ 963,441 $ 1,083,918 Geographic Information Year Ended December 31, 2016 2015 2014 Sales to external customers (1) United States $ 3,525,492 $ 3,133,395 $ 3,596,091 Foreign Germany 401,950 394,459 198,921 Canada 317,083 195,790 217,567 Switzerland 101,320 106,750 89,214 China 87,118 46,451 6,515 Italy 84,359 90,237 36,823 Belgium 50,662 41,542 24,082 France 50,371 58,727 27,521 Other 457,101 395,985 218,616 $ 5,075,456 $ 4,463,336 $ 4,415,350 December 31, 2016 December 31, 2015 Long-lived assets United States $ 5,782,796 $ 2,588,366 Foreign Germany 401,572 379,262 Other 235,694 36,439 $ 6,420,062 $ 3,004,067 ______________________________ (1) Revenues are attributed to countries based on location of customer.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Subsequent events were evaluated through the date on which the financial statements were issued.

Guarantor Disclosures

Guarantor Disclosures	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Guarantor Disclosures	Guarantor Disclosures The Company's payment obligations under the 3.60% senior notes due 2022 are fully and unconditionally guaranteed by each of its current and future domestic subsidiaries that guarantee other debt of the Company or of another guarantor of the 3.60% senior notes due 2022 in excess of $5,000 (the "Guarantor Subsidiaries"). In October 2016, the Company executed a Joinder Agreement with the Administrative Agent of the Credit Agreement, whereby certain subsidiaries of the Company were added as Guarantor Subsidiaries. Each Guarantor Subsidiary is 100% owned by Westlake Chemical Corporation (the " 100% Owned Guarantor Subsidiaries"). These guarantees are the joint and several obligations of the Guarantor Subsidiaries. The following condensed consolidating financial information presents the financial condition, results of operations and cash flows of Westlake Chemical Corporation, the 100% owned Guarantor Subsidiaries and the remaining subsidiaries that do not guarantee the 3.60% senior notes due 2022 and the Credit Agreement (the "Non-Guarantor Subsidiaries"), together with consolidating eliminations necessary to present the Company's results on a consolidated basis. In August 2016, certain of the Company's subsidiary guarantors were released from their guarantees of the Company's 3.60% senior notes due 2022 in connection with the replacement of the Company's revolving credit facility. Westlake Chemical OpCo LP, which was previously separately presented as a less than 100% owned guarantor, and certain of the Company's other 100% owned subsidiaries that were previously presented as guarantors, are now reflected as Non-Guarantor Subsidiaries in the condensed consolidating guarantor financial information. Prior periods were retrospectively adjusted to conform to the current presentation of Guarantor Subsidiaries and Non-Guarantor Subsidiaries. ondensed Consolidating Financial Information as of December 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Balance Sheet Current assets Cash and cash equivalents $ 146,990 $ 53,006 $ 259,457 $ — $ 459,453 Accounts receivable, net 2,117,540 3,329,871 323,931 (4,832,599 ) 938,743 Inventories — 597,819 203,281 — 801,100 Prepaid expenses and other current assets 30,748 41,755 12,494 (36,504 ) 48,493 Restricted cash — — 160,527 — 160,527 Total current assets 2,295,278 4,022,451 959,690 (4,869,103 ) 2,408,316 Property, plant and equipment, net — 4,475,943 1,944,119 — 6,420,062 Other assets, net 9,170,042 2,264,597 1,484,871 (10,857,635 ) 2,061,875 Total assets $ 11,465,320 $ 10,762,991 $ 4,388,680 $ (15,726,738 ) $ 10,890,253 Current liabilities Accounts and notes payable $ 4,330,375 $ 748,364 $ 225,300 $ (4,807,780 ) $ 496,259 Accrued liabilities 26,367 389,216 183,223 (61,323 ) 537,483 Term loan — — 149,341 — 149,341 Total current liabilities 4,356,742 1,137,580 557,864 (4,869,103 ) 1,183,083 Long-term debt 3,584,949 4,090,775 — (3,997,070 ) 3,678,654 Deferred income taxes — 1,581,260 91,809 (22,494 ) 1,650,575 Pension and other liabilities — 360,622 125,274 — 485,896 Total liabilities 7,941,691 7,170,237 774,947 (8,888,667 ) 6,998,208 Total Westlake Chemical Corporation stockholders' equity 3,523,629 3,592,754 3,245,317 (6,838,071 ) 3,523,629 Noncontrolling interests — — 368,416 — 368,416 Total equity 3,523,629 3,592,754 3,613,733 (6,838,071 ) 3,892,045 Total liabilities and equity $ 11,465,320 $ 10,762,991 $ 4,388,680 $ (15,726,738 ) $ 10,890,253 Condensed Consolidating Financial Information as of December 31, 2015 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Balance Sheet Current assets Cash and cash equivalents $ 303,131 $ 6,818 $ 352,576 $ — $ 662,525 Marketable securities 520,144 — — — 520,144 Accounts receivable, net 10,943 2,474,963 190,384 (2,167,758 ) 508,532 Inventories — 287,114 146,946 — 434,060 Prepaid expenses and other current assets 2,201 10,186 4,981 (2,879 ) 14,489 Deferred income taxes 702 28,325 6,412 — 35,439 Total current assets 837,121 2,807,406 701,299 (2,170,637 ) 2,175,189 Property, plant and equipment, net — 1,476,642 1,527,425 — 3,004,067 Other assets, net 5,003,096 914,823 1,442,436 (6,970,326 ) 390,029 Total assets $ 5,840,217 $ 5,198,871 $ 3,671,160 $ (9,140,963 ) $ 5,569,285 Current liabilities Accounts payable $ 1,817,963 $ 374,468 $ 185,931 $ (2,143,033 ) $ 235,329 Accrued liabilities 9,117 163,167 142,633 (27,604 ) 287,313 Total current liabilities 1,827,080 537,635 328,564 (2,170,637 ) 522,642 Long-term debt 747,259 744,405 — (733,516 ) 758,148 Deferred income taxes — 513,692 68,478 (6,567 ) 575,603 Pension and other liabilities — 49,202 101,759 — 150,961 Total liabilities 2,574,339 1,844,934 498,801 (2,910,720 ) 2,007,354 Total Westlake Chemical Corporation stockholders' equity 3,265,878 3,353,937 2,876,306 (6,230,243 ) 3,265,878 Noncontrolling interests — — 296,053 — 296,053 Total equity 3,265,878 3,353,937 3,172,359 (6,230,243 ) 3,561,931 Total liabilities and equity $ 5,840,217 $ 5,198,871 $ 3,671,160 $ (9,140,963 ) $ 5,569,285 Condensed Consolidating Financial Information for the Year Ended December 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 4,009,891 $ 2,444,878 $ (1,379,313 ) $ 5,075,456 Cost of sales — 3,532,638 1,919,598 (1,357,342 ) 4,094,894 Gross profit — 477,253 525,280 (21,971 ) 980,562 Selling, general and administrative expenses 3,488 204,353 109,566 (21,971 ) 295,436 Transaction and integration-related costs — 103,226 446 — 103,672 (Loss) income from operations (3,488 ) 169,674 415,268 — 581,454 Interest expense (82,908 ) (75,907 ) (2,578 ) 81,920 (79,473 ) Other income (expense), net 77,151 (14,247 ) 75,414 (81,920 ) 56,398 (Loss) income before income taxes (9,245 ) 79,520 488,104 — 558,379 (Benefit from) provision for income taxes (8,047 ) 115,457 31,110 — 138,520 Equity in net income of subsidiaries 400,057 — — (400,057 ) — Net income (loss) 398,859 (35,937 ) 456,994 (400,057 ) 419,859 Net income attributable to noncontrolling interests — — 21,000 — 21,000 Net income (loss) attributable to Westlake Chemical Corporation $ 398,859 $ (35,937 ) $ 435,994 $ (400,057 ) $ 398,859 Comprehensive income (loss) attributable to Westlake Chemical Corporation $ 406,845 $ 11,695 $ 395,682 $ (407,377 ) $ 406,845 Condensed Consolidating Financial Information for the Year Ended December 31, 2015 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 3,557,806 $ 2,286,407 $ (1,380,877 ) $ 4,463,336 Cost of sales — 2,842,466 1,796,734 (1,361,055 ) 3,278,145 Gross profit — 715,340 489,673 (19,822 ) 1,185,191 Selling, general and administrative expenses 2,478 150,968 91,740 (19,822 ) 225,364 (Loss) income from operations (2,478 ) 564,372 397,933 — 959,827 Interest expense (42,197 ) (34,667 ) — 42,208 (34,656 ) Other income (expense), net 19,614 5,576 55,288 (42,208 ) 38,270 (Loss) income before income taxes (25,061 ) 535,281 453,221 — 963,441 Provision for (benefit from) income taxes (7,237 ) 275,687 29,946 — 298,396 Equity in net income of subsidiaries 663,834 — — (663,834 ) — Net income (loss) 646,010 259,594 423,275 (663,834 ) 665,045 Net income attributable to noncontrolling interests — — 19,035 — 19,035 Net income (loss) attributable to Westlake Chemical Corporation $ 646,010 $ 259,594 $ 404,240 $ (663,834 ) $ 646,010 Comprehensive income attributable to Westlake Chemical Corporation $ 596,151 $ 261,392 $ 334,447 $ (595,839 ) $ 596,151 Condensed Consolidating Financial Information for the Year Ended December 31, 2014 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 3,617,627 $ 2,492,099 $ (1,694,376 ) $ 4,415,350 Cost of sales — 3,056,659 1,714,415 (1,673,074 ) 3,098,000 Gross profit — 560,968 777,684 (21,302 ) 1,317,350 Selling, general and administrative expenses 2,082 121,182 81,783 (21,302 ) 183,745 Transaction and integration-related costs — 7,411 2,203 — 9,614 (Loss) income from operations (2,082 ) 432,375 693,698 — 1,123,991 Interest expense (39,763 ) (26,218 ) — 28,629 (37,352 ) Other income (expense), net 21,001 (4,278 ) 9,185 (28,629 ) (2,721 ) (Loss) income before income taxes (20,844 ) 401,879 702,883 — 1,083,918 (Benefit from) provision for income taxes 248 192,659 205,995 — 398,902 Equity in net income of subsidiaries 699,615 — — (699,615 ) — Net income (loss) 678,523 209,220 496,888 (699,615 ) 685,016 Net income attributable to noncontrolling interests — — 6,493 — 6,493 Net income (loss) attributable to Westlake Chemical Corporation $ 678,523 $ 209,220 $ 490,395 $ (699,615 ) $ 678,523 Comprehensive income attributable to Westlake Chemical Corporation $ 601,706 $ 203,428 $ 419,313 $ (622,741 ) $ 601,706 Condensed Consolidating Financial Information for the Year Ended December 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income (loss) $ 398,859 $ (35,937 ) $ 456,994 $ (400,057 ) $ 419,859 Adjustments to reconcile net income to net cash (used for) provided by operating activities Depreciation and amortization — 216,374 161,292 — 377,666 Deferred income taxes 1,214 103,315 (3,852 ) — 100,677 Net changes in working capital and other (437,148 ) 90,183 (117,442 ) 400,057 (64,350 ) Net cash (used for) provided by operating activities (37,075 ) 373,935 496,992 — 833,852 Cash flows from investing activities Acquisition of business, net of cash acquired — (2,502,018 ) 64,189 — (2,437,829 ) Additions to cost method investments — (17,000 ) — — (17,000 ) Additions to property, plant and equipment — (274,564 ) (353,919 ) — (628,483 ) Proceeds from disposition of assets — 1,037 170 — 1,207 Proceeds from sales and maturities of securities 658,338 — 4,600 — 662,938 Purchase of securities (138,422 ) — — — (138,422 ) Settlements of derivative instruments — (5,211 ) — — (5,211 ) Net cash provided by (used for) investing activities 519,916 (2,797,756 ) (284,960 ) — (2,562,800 ) Cash flows from financing activities Intercompany financing (2,199,148 ) 2,207,119 (7,971 ) — — Capitalized debt issuance costs (34,183 ) — (1,590 ) — (35,773 ) Dividends paid (96,560 ) — — — (96,560 ) Distributions paid — 262,890 (279,527 ) — (16,637 ) Proceeds from debt issuance 1,428,512 — — 1,428,512 Proceeds from exercise of stock options 2,179 — — — 2,179 Proceeds from issuance of notes payable — — 8,324 — 8,324 Proceeds from term loan and drawdown of revolver 450,000 — 150,000 — 600,000 Restricted cash associated with term loan — — (154,000 ) — (154,000 ) Repayment of debt — — (13,046 ) — (13,046 ) Repayment of revolver (125,000 ) — — — (125,000 ) Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Repurchase of common stock for treasury $ (67,406 ) $ — $ — $ — $ (67,406 ) Windfall tax benefits from share-based payment arrangements 2,624 — — — 2,624 Net cash (used for) provided by financing activities (638,982 ) 2,470,009 (297,810 ) — 1,533,217 Effect of exchange rate changes on cash and cash equivalents — — (7,341 ) — (7,341 ) Net (decrease) increase in cash and cash equivalents (156,141 ) 46,188 (93,119 ) — (203,072 ) Cash and cash equivalents at beginning of the year 303,131 6,818 352,576 — 662,525 Cash and cash equivalents at end of the year $ 146,990 $ 53,006 $ 259,457 $ — $ 459,453 Condensed Consolidating Financial Information for the Year Ended December 31, 2015 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income (loss) $ 646,010 $ 259,594 $ 423,275 $ (663,834 ) $ 665,045 Adjustments to reconcile net income to net cash (used for) provided by operating activities Depreciation and amortization — 113,575 132,182 — 245,757 Deferred income taxes (285 ) 38,680 1,389 — 39,784 Net changes in working capital and other (658,773 ) 93,633 29,556 663,834 128,250 Net cash (used for) provided by operating activities (13,048 ) 505,482 586,402 — 1,078,836 Cash flows from investing activities Acquisition of business, net of cash acquired — — 15,782 — 15,782 Additions to property, plant and equipment — (215,405 ) (276,021 ) — (491,426 ) Proceeds from disposition of assets — 18 31 — 49 Proceeds from disposition of equity method investment — 27,865 — — 27,865 Proceeds from sales and maturities of securities 48,900 — — — 48,900 Purchase of securities (556,211 ) (48,887 ) — — (605,098 ) Settlements of derivative instruments — (2,248 ) — — (2,248 ) Net cash (used for) provided by investing activities (507,311 ) (238,657 ) (260,208 ) — (1,006,176 ) Cash flows from financing activities Intercompany financing 418,844 (590,114 ) 171,270 — — Dividends paid (91,551 ) — — — (91,551 ) Distributions paid — 327,060 (341,916 ) — (14,856 ) Proceeds from exercise of stock options 1,063 — — — 1,063 Proceeds from issuance of notes payable — — 52,960 — 52,960 Repayment of notes payable — — (73,615 ) — (73,615 ) Repurchase of common stock for treasury (162,459 ) — — — (162,459 ) Windfall tax benefits from share-based payment arrangements 1,646 — — — 1,646 Net cash provided by (used for) financing activities $ 167,543 $ (263,054 ) $ (191,301 ) $ — $ (286,812 ) Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Effect of exchange rate changes on cash and cash equivalents $ — $ — $ (3,924 ) $ — $ (3,924 ) Net increase (decrease) in cash and cash equivalents (352,816 ) 3,771 130,969 — (218,076 ) Cash and cash equivalents at beginning of the year 655,947 3,047 221,607 — 880,601 Cash and cash equivalents at end of the year $ 303,131 $ 6,818 $ 352,576 $ — $ 662,525 Condensed Consolidating Financial Information for the Year Ended December 31, 2014 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income (loss) $ 678,523 $ 209,220 $ 496,888 $ (699,615 ) $ 685,016 Adjustments to reconcile net income (loss) to net cash (used for) provided by operating activities Depreciation and amortization — 101,779 106,707 — 208,486 Deferred income taxes (288 ) 47,692 11,563 — 58,967 Net changes in working capital and other (704,370 ) (560,996 ) 645,658 699,615 79,907 Net cash (used for) provided by operating activities (26,135 ) (202,305 ) 1,260,816 — 1,032,376 Cash flows from investing activities Acquisition of business — — (611,087 ) — (611,087 ) Additions to property, plant and equipment — (209,111 ) (221,993 ) — (431,104 ) Proceeds from disposition of assets — 180 1 — 181 Proceeds from repayment of loan to affiliate — — 45,923 — 45,923 Proceeds from sales and maturities of securities 342,045 — — — 342,045 Purchase of securities (117,332 ) — — — (117,332 ) Settlements of derivative instruments — (1,698 ) (133 ) — (1,831 ) Net cash used for investing activities 224,713 (210,629 ) (787,289 ) — (773,205 ) Cash flows from financing activities Intercompany financing 155,665 (244,122 ) 88,457 — — Net distributions prior to Westlake Partners initial public offering — 448,101 (448,101 ) — — Capitalized debt issuance costs (1,186 ) — — — (1,186 ) Dividends paid (77,656 ) 151,729 (151,729 ) — (77,656 ) Distributions paid — 54,060 (56,264 ) — (2,204 ) Net proceeds from issuance of Westlake Partners common units — — 286,088 — 286,088 Proceeds from exercise of stock options 5,524 — — — 5,524 Repurchase of common stock for treasury (52,630 ) — — — (52,630 ) Windfall tax benefits from share-based payment arrangements 6,704 — — — 6,704 Net cash provided (used for) by financing activities $ 36,421 $ 409,768 $ (281,549 ) $ — $ 164,640 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Effect of exchange rate changes on cash and cash equivalents $ — $ — $ (4,511 ) $ — $ (4,511 ) Net (decrease) increase in cash and cash equivalents 234,999 (3,166 ) 187,467 — 419,300 Cash and cash equivalents at beginning of the year 420,948 6,213 34,140 — 461,301 Cash and cash equivalents at end of the year $ 655,947 $ 3,047 $ 221,607 $ — $ 880,601

Quarterly Financial Information

Quarterly Financial Information	12 Months Ended
	Dec. 31, 2016
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 $ 975,187 $ 1,086,061 $ 1,279,028 $ 1,735,180 Gross profit 255,585 241,366 202,133 281,478 Income from operations 202,276 179,938 46,563 152,677 Net income 128,936 115,620 70,014 105,289 Net income attributable to Westlake Chemical Corporation 123,128 111,124 65,662 98,945 Earnings per common share attributable to (1) Basic $ 0.94 $ 0.85 $ 0.51 $ 0.76 Diluted $ 0.94 $ 0.85 $ 0.51 $ 0.76 Three Months Ended March 31, June 30, September 30, December 31, Net sales $ 1,103,531 $ 1,185,002 $ 1,188,037 $ 986,766 Gross profit 284,546 353,181 311,276 236,188 Income from operations 229,280 295,374 254,028 181,145 Net income 150,407 210,061 188,420 116,157 Net income attributable to Westlake Chemical Corporation 146,342 205,095 183,604 110,969 Earnings per common share attributable to (1) Basic $ 1.10 $ 1.55 $ 1.39 $ 0.85 Diluted $ 1.10 $ 1.54 $ 1.39 $ 0.84 ______________________________ (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 S36

Description Of Business And Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
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.
Acquisition of Axiall Corporation	Acquisition of Axiall Corporation On August 31, 2016, the Company completed the acquisition of Axiall Corporation ("Axiall") for $33.00 per share in an all-cash transaction (the "Merger"), pursuant to the terms of the Agreement and Plan of Merger (the "Merger Agreement"), dated as of June 10, 2016, by and among Westlake, Axiall and Lagoon Merger Sub, Inc., a wholly-owned subsidiary of Westlake. During the third quarter of 2016, in order to finance a portion of the consideration and related fees and expenses, and for other general corporate purposes, the Company issued $1,450,000 aggregate principal amount of senior notes. In addition, the Company entered into a $1,000,000 unsecured revolving credit facility (the "Credit Agreement").
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, 2016 . Certain prior period amounts have been reclassified in the consolidated balance sheets and consolidated statements of operations to conform to current presentation.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents consist of highly liquid investments that are readily convertible into cash and have a maturity of three months or less at the date of acquisition.
Investments	Investments Investments in debt and equity securities are classified as trading, available-for-sale or held-to-maturity. Investments classified as trading are carried at estimated fair value with changes in fair value currently recognized in earnings. Investments classified as available-for-sale are carried at estimated fair value with unrealized gains and losses recorded as a component of accumulated other comprehensive income. Investments classified as held-to-maturity are carried at amortized cost. The Company periodically reviews its available-for-sale and held-to-maturity securities for other-than-temporary declines in fair value below the cost basis, and when events or changes in circumstances indicate the carrying value of an asset may not be recoverable, the investment is written down to fair value, establishing a new cost basis.
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 Inventories primarily include product, material and supplies. Inventories are stated at lower of cost or market. Cost is determined using the first-in, first-out ("FIFO") or average method.
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 $10,388 , $10,449 and $7,059 for the years ended December 31, 2016 , 2015 and 2014 , 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. The accounting guidance for asset retirement obligations requires the recording of liabilities equal to the fair value of asset retirement obligations and corresponding additional asset costs, when there is a legal asset retirement obligation as a result of existing or enacted law, statute or contract. Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 25 Plant and equipment 25 Ethylene pipeline 35 Other 3-10
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, 2016, the Company had $4,421 and $17,004 of asset retirement obligations recorded as accrued liabilities and other liabilities, respectively. There was no asset retirement obligation recorded as of December 31, 2015. The Company also has conditional asset retirement obligations that have not been recognized because the fair value of the conditional legal obligations cannot be measured due to the indeterminate settlement date of the obligation. Settlement of the unrecognized conditional asset retirement obligations is not expected to have a material adverse effects on the Company's financial condition, results of operations or cash flows in any individual reporting period.
Fair Value Estimates	Fair Value Estimates The Company develops estimates of fair value to allocate the purchase price paid to acquire a business to the assets acquired and liabilities assumed in an acquisition, to assess impairment of long-lived assets, goodwill and intangible assets and to record marketable securities, derivative instruments and pension plan assets. The Company uses all available information to make these fair value determinations, including the engagement of third-party consultants.
Impairment of Long-Lived Assets and Impairment of Intangible Assets	Impairment of Long-Lived Assets The accounting guidance for the impairment or disposal of long-lived assets requires that the Company review 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 Intangible Assets The accounting guidance for goodwill and intangible assets requires that goodwill and indefinite-lived intangible assets are tested for impairment at least annually. Other intangible assets with finite lives are amortized over their estimated useful life and reviewed for impairment in accordance with the provisions of the accounting guidance.
Turnaround Costs	Turnaround Costs 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.
Exchanges	Exchanges The Company enters into inventory exchange transactions with third parties, which involve fungible commodities. These exchanges are settled in like-kind quantities and are valued at lower of cost or market. Cost is determined using the FIFO method.
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.
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.
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.
Revenue Recognition	Revenue Recognition Revenue is recognized when persuasive evidence of an arrangement exists, products are delivered to the customer, the sales price is fixed or determinable and collectability is reasonably assured. For domestic contracts, title and risk of loss passes to the customer upon delivery under executed customer purchase orders or contracts. For export contracts, the title and risk of loss passes to customers at the time specified by each contract. Provisions for discounts, rebates and returns are provided for in the same period as the related sales are recorded.
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.
Earnings Per Share	Earnings per Share The accounting guidance for earnings per share requires the Company to present basic earnings per share and diluted earnings per share. Basic earnings per share excludes dilution and is computed by dividing income available to common stockholders by the weighted average number of shares outstanding for the period. Diluted earnings per share reflects the dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock.
Price Risk Management	Price Risk Management The accounting guidance for derivative instruments and hedging activities requires that the Company recognize all derivative instruments on the balance sheet at fair value, and changes in the derivative's fair value must be 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 Company utilizes commodity price swaps to reduce price risks by entering into price swaps with counterparties and by purchasing or selling futures on established exchanges. The Company takes both fixed and variable positions, depending upon anticipated future physical purchases and sales of these commodities. The fair value of derivative financial instruments is estimated using quoted market prices in active markets and observable market-based inputs or unobservable inputs that are corroborated by market data when active markets are not available. The Company assesses both counterparty as well as its own nonperformance risk when measuring the fair value of derivative liabilities. The Company does not consider its nonperformance risk to be significant. See Note 16 for a summary of the fair value of derivative instruments.
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.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The amounts reported in the balance sheet for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The fair value of the Company's debt at December 31, 2016 differs from the carrying value due to the Company's fixed rate senior notes. The fair value of financial instruments is estimated using quoted market prices in active markets and observable market-based inputs or unobservable inputs that are corroborated by market data when active markets are not available. See Note 16 for more information on the fair value of financial instruments.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.
Warranty Costs	Warranty Costs We provide warranties for certain building products against defects in material, performance and workmanship. We accrue for warranty claims at the time of sale based on historical warranty claims experience. Our warranty liabilities are included in accrued liabilities and other liabilities in the consolidated balance sheets.
Other	Other Amortization of debt issuance costs is computed on a basis which approximates the interest method over the term of the related debt. Certain other assets (see Note 7) are amortized over periods ranging from one to 30 years using the straight-line method.
New Accounting Pronouncements	Recent Accounting Pronouncements Revenue from Contracts with Customers (ASU No. 2014-09) In May 2014, the Financial Accounting Standards Board ("FASB") issued an accounting standards update on a comprehensive new revenue recognition standard that will supersede the existing revenue recognition guidance. The new accounting guidance creates a framework by which an entity will allocate the transaction price to separate performance obligations and recognize revenue when each performance obligation is satisfied. Under the new standard, entities will be required to use judgment and make estimates, including identifying performance obligations in a contract, estimating the amount of variable consideration to include in the transaction price, allocating the transaction price to each separate performance obligation and determining when an entity satisfies its performance obligations. The standard allows for either "full retrospective" adoption, meaning that the standard is applied to all of the periods presented with a cumulative catch-up as of the earliest period presented, or "modified retrospective" adoption, meaning the standard is applied only to the most current period presented in the financial statements with a cumulative catch-up as of the current period. In July and December 2016, the FASB issued various additional authoritative guidance for the new revenue recognition standard. The accounting standard will be effective for reporting periods beginning after December 15, 2017. The Company is in the process of evaluating the impact that the new accounting standard will have on its consolidated financial position, results of operations and cash flows. Recognition and Measurement of Financial Assets and Financial Liabilities (ASU No. 2016-01) In January 2016, the FASB issued an accounting standards update making certain changes principally to the current guidance for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. Among other things, the guidance (1) requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value, with changes in fair value recognized in net income; (2) provide entities with a policy election to record equity investments without readily determinable fair values at cost, less impairment, and subsequent adjustments for observable price changes (changes in the basis of these equity investments to be reported in net income); (3) requires an entity that has elected the fair value option for financial liabilities to recognize changes in fair value due to instrument-specific credit risk separately in other comprehensive income; (4) clarified current guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities; and (5) requires specific disclosure pertaining to financial assets and financial liabilities in the financial statements. The accounting standard will be effective for reporting periods beginning after December 15, 2017. 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. Leases (ASU No. 2016-02) In February 2016, the FASB issued an accounting standards update on a new lease standard that will supersede the existing lease guidance. The standard requires a lessee to recognize assets and liabilities related to long-term leases that are classified as operating leases under current guidance on its balance sheet. An asset would be recognized related to the right to use the underlying asset and a liability would be recognized related to the obligation to make lease payments over the term of the lease. The standard also requires expanded disclosures related to leases. The accounting standard will be effective for reporting periods beginning after December 15, 2018. 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. Investments-Equity Method and Joint Ventures (ASU No. 2016-07) In March 2016, the FASB issued an accounting standards update providing new guidance for the accounting for equity method investments. The new guidance eliminates the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. In addition, the guidance requires that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor's previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The accounting standard is effective for reporting its periods beginning after December 15, 2016. The Company does not expect the new guidance to have a significant impact on its consolidated financial position, results of operations and cash flows. The Company will adopt the accounting change prospectively; therefore, historical amounts will not be affected. Stock Compensation (ASU No. 2016-09) In March 2016, the FASB issued an accounting standards update to simplify several aspects of the accounting for share-based payment transactions, including income tax consequences, classifications of awards as either equity or liabilities and certain related classifications on the statement of cash flows. In addition, the new guidance permits entities to make an accounting policy election for the impact of forfeitures on the recognition of expense for share-based payment awards. Forfeitures can be estimated, as required today, or recognized when they occur. The accounting standard is effective for reporting periods beginning after December 15, 2016 and is not expected to have a material impact on the Company's consolidated financial position, results of operations and cash flows. Credit Losses (ASU No. 2016-13) In June 2016, the FASB issued an accounting standards update providing new guidance for the accounting for credit losses on loans and other financial instruments. The new guidance introduces an approach based on expected losses to estimate credit losses on 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. The accounting standard will be effective for reporting periods beginning after December 15, 2019. 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. Cash Flows (ASU No. 2016-15) In August 2016, the FASB issued an accounting standards update providing new guidance on the classification of certain cash receipts and payments including debt extinguishment costs, debt prepayment costs, settlement of zero-coupon debt instruments, contingent consideration payments, proceeds from the settlement of insurance claims and life insurance policies and distributions received from equity method investees in the statement of cash flows. This update is required to be applied using the retrospective transition method to each period presented unless it is impracticable to be applied retrospectively. In such situation, this guidance is to be applied prospectively. The accounting standard will be effective for reporting periods beginning after December 15, 2017. 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. Amendments to the Consolidation Analysis (ASU No. 2016-17) In October 2016, the FASB issued an accounting standards update making certain changes to the current consolidation guidance. The amendments affect reporting entities that are required to evaluate whether they should consolidate a variable interest entity in certain situations involving entities under common control. Specifically, the amendments change the evaluation of whether a reporting entity is the primary beneficiary of a variable interest entity by changing how a reporting entity that is a single decision maker of a variable interest entity treats indirect interests in the entity held through related parties that are under common control with the reporting entity. The amendments will be effective for annual periods beginning after December 15, 2016. 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. Cash Flows (ASU No. 2016-18) In November 2016, the FASB issued an accounting standards update to clarify certain existing principles in ASC 230, including providing additional guidance related to transfers between cash and restricted cash and how entities present, in their statement of cash flows, the cash receipts and cash payments that directly affect the restricted cash accounts. The accounting standard will be effective for reporting periods beginning December 1, 2018 and is not expected to have a material impact on the Company's consolidated financial position, results of operations and cash flows. Business Combinations (ASU No. 2017-01) In January 2017, the FASB issued an accounting standard update to assist entities with evaluating when a set of transferred assets and activities is a business. The guidance requires an entity to evaluate if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of transferred assets and activities is not a business. The guidance also requires a business to include at least one substantive process and narrows the definition of outputs by more closely aligning it with how outputs are described in ASC 606. The accounting standard will be effective for reporting periods beginning after December 15, 2017. 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. Intangibles-Goodwill and Other (ASU No. 2017-04) In January 2017, the FASB issued an accounting standard 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. 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 Going Concern (ASU No. 2014-15) In August 2014, the FASB issued an accounting standard update providing guidance related to evaluating whether there is substantial doubt about the reporting entity's ability to continue as a going concern and about related financial statement note disclosures. Disclosures are required if there is substantial doubt as to the Company's continuation as a going concern within one year after the issue date of financial statements. The standard provides guidance for making the assessment, including consideration of management's plans which may alleviate doubt regarding the Company's ability to continue as a going concern. The accounting standard became effective for the annual reporting period ending after December 15, 2016, and all annual and interim periods thereafter. The Company adopted this accounting standard effective December 31, 2016 and the adoption did not have an impact on the Company's consolidated financial position, results of operations and cash flows. Amendments to the Consolidation Analysis (ASU No. 2015-02) In February 2015, the FASB issued an accounting standards update making certain changes to the current consolidation guidance. The amendments affect both the variable interest entity and voting interest entity consolidation models. The new standard changes the consideration of substantive rights, related party interests and fees paid to the decision maker when applying the variable interest entity consolidation model and eliminates certain guidance for limited partnerships and similar entities under the voting interest consolidation model. The accounting standard is effective for annual periods beginning after December 15, 2015. The Company adopted this accounting standard effective January 1, 2016 and the adoption did not have an impact on the Company's consolidated financial position, results of operations and cash flows. Simplifying the Presentation of Debt Issuance Costs (ASU No. 2015-03) In April 2015, the FASB issued an accounting standards update on simplifying the presentation of debt issuance costs, which requires all costs incurred to issue debt to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt liability, consistent with the presentation of a debt discount. The accounting standard is effective for reporting periods beginning after December 15, 2015. The Company adopted this accounting standard effective January 1, 2016. As a result of this retrospective adoption and reclassification of equity-method investment of $9,208 to other assets for comparative purposes, Other assets, net—Deferred charges and other assets, net and Long-term debt on the consolidated balance sheet as of December 31, 2015 have been adjusted to $176,625 and $758,148 , respectively, from the originally reported $173,384 and $764,115 , respectively, to reflect the retrospective application of the new accounting guidance. The adoption of this accounting standard did not have an impact on the Company's results of operations and cash flows. Intangibles-Goodwill and Other-Internal use software (ASU No. 2015-05) In April 2015, the FASB issued an accounting standards update to provide clarification on accounting for cloud computing arrangements which include a software license. The accounting standard is effective for annual periods beginning after December 15, 2015. The Company adopted this accounting standard, to be applied prospectively, effective January 1, 2016. Consistent with the prospective application of this accounting standard, prior period comparative information was not adjusted. The adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. Simplifying the Accounting for Measurement-Period Adjustments (ASU No. 2015-16) In September 2015, the FASB issued an accounting standards update that requires an acquirer to recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The guidance requires that the acquirer record, in the same period's financial statements, the effect on earnings of changes in depreciation, amortization or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. The new guidance further requires specific disclosure pertaining to the measurement period adjustments. The accounting standard is effective for reporting periods beginning after December 15, 2015. The Company adopted this accounting standard effective January 1, 2016, and the adoption did not have an impact on the Company's consolidated financial position, results of operations and cash flows. Balance Sheet Classification of Deferred Taxes (ASU No. 2015-17) In November 2015, the FASB issued an accounting standards update that requires all deferred tax assets and liabilities, along with any related valuation allowance, to be classified as noncurrent on the balance sheet. As a result, each jurisdiction will now only have one net noncurrent deferred tax asset or liability. The new guidance does not change the existing requirement that only permits offsetting within a jurisdiction. The accounting standard is required to be adopted for reporting periods beginning after December 15, 2016; however, early adoption of this standard is permitted. The Company elected to early adopt this accounting standard, to be applied prospectively, effective January 1, 2016. Consistent with the prospective application of this accounting standard, prior period comparative information was not adjusted. The early adoption of this accounting standard did not have an impact on the Company's results of operations and cash flows.

Description Of Business And S37

Description Of Business And Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Estimated Useful Lives of Assets	Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows: Classification Years Buildings and improvements 25 Plant and equipment 25 Ethylene pipeline 35 Other 3-10
Schedule of Change in Asset Retirement Obligation	The asset retirement obligations activity for the year ended December 31, 2016 is as follows: Year Ended December 31, 2016 Beginning balance, January 1, $ — Acquisitions (1) 21,174 Accretion expense 251 Ending balance, December 31, $ 21,425 _______________________________ (1) See Note 2, "Acquisitions" for additional information on the Company's acquisition activities.
Schedule of Product Warranty Liability	The warranty liabilities activity for the years ended December 31, 2016, 2015 and 2014 is as follows: Year Ended December 31, 2016 2015 2014 Beginning balance, January 1, $ 2,879 $ 1,833 $ 1,219 Estimated fair value of warranty liability assumed in acquisition (1) 14,564 — 612 Warranty provisions 3,009 1,987 632 Effects of changes in foreign exchange rates (196 ) (97 ) (79 ) Warranty claims paid (3,186 ) (844 ) (551 ) Ending balance, December 31, $ 17,070 $ 2,879 $ 1,833 ______________________________ (1) See Note 2, "Acquisitions" for additional information on the Company's acquisition activities.

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Pro Forma Information	The following unaudited consolidated pro forma information presents consolidated information as if the Merger had occurred on January 1, 2015: Pro Forma Year Ended December 31, 2016 2015 Net sales $ 7,080,545 $ 7,793,086 Net income (1) $ 398,826 $ 662,750 Net income (loss) attributable to noncontrolling interest 22,748 (1,665 ) Net income attributable to Westlake Chemical Corporation (1) $ 376,078 $ 664,415 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 2.89 $ 5.02 Diluted $ 2.88 $ 5.00 ______________________________ (1) The 2016 pro forma net income amounts include Axiall's historical pre-tax charges recorded during the eight-month period prior to the closing of the Merger for (1) divestitures; (2) restructuring; and (3) legal and settlement claims, net, of $26,666 , $22,881 and $23,376 , respectively. These nonrecurring costs are included in the pro forma results because they were not directly attributable to the Merger.
Schedule of Business Acquisitions	As a portion of the goodwill arising from the Merger is attributable to foreign operations, there will be a continuing foreign currency impact to goodwill on the financial statements. Final Purchase Consideration as of August 31, 2016 Closing stock purchase: Offer per share $ 33.00 Multiplied by number of shares outstanding at acquisition 67,277 Fair value of Axiall shares outstanding purchased by the Company $ 2,220,141 Plus: Axiall debt repaid at acquisition 247,135 Seller's transaction costs paid by the Company (1) 47,458 Total fair value of consideration transferred $ 2,514,734 Fair value of Axiall share-based awards attributed to pre-combination service (2) $ 11,346 Additional settlement value of shares acquired 13,280 Purchase consideration $ 2,539,360 Fair value of previously held equity interest in Axiall (3) 102,300 Total fair value allocated to net assets acquired $ 2,641,660 ______________________________ (1) Transactions costs incurred by the seller included legal and advisory costs incurred for the benefit of Axiall's former shareholders and board of directors to evaluate the Company's initial Merger proposals, explore strategic alternatives and negotiate the purchase price. (2) The fair value of share-based awards attributable to pre-combination service includes the ratio of the pre-combination service performed to the original service period of the Axiall restricted share units and options, including related dividend equivalent rights. (3) Prior to the Merger, the Company owned 3.1 million shares in Axiall. The investment in Axiall was carried at estimated fair value with unrealized gains recorded as a component of accumulated other comprehensive loss on the consolidated balance sheet. The Company recognized a $49,080 gain for the investment in other income, net in the consolidated statement of operations upon gaining control.
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The information below represents the preliminary purchase price allocation: Cash $ 88,251 Accounts receivable (1) 422,459 Income tax receivable 55,193 Inventories 306,158 Prepaid expenses and other current assets 55,462 Property, plant and equipment (2) 3,134,741 Customer relationships (weighted average lives of 10.7 years) (3) 590,000 Other intangible assets: Trade name (weighted average lives of 6.8 years) 50,000 Technology (weighted average lives of 5.4 years) 41,500 Supply contracts and leases (weighted average lives of 6.3 years) 27,288 Other assets 98,708 Total assets acquired $ 4,869,760 Accounts and notes payable 255,232 Interest payable 8,154 Income tax payable 967 Accrued compensation 44,186 Accrued liabilities 152,550 Deferred income taxes 985,128 Tax reserve non-current 3,130 Pension and other post-retirement obligations 311,106 Other liabilities 99,848 Long-term debt 1,187,290 Total liabilities assumed $ 3,047,591 Total identifiable net assets acquired $ 1,822,169 Noncontrolling interest (68,000 ) Goodwill 887,491 Total fair value allocated to net assets acquired $ 2,641,660 ______________________________ (1) The fair value of accounts receivable acquired is $422,459 , with the gross contractual amount being $434,834 . The Company expects $12,375 to be uncollectible. (2) The Company obtained additional information related to its property plant and equipment balances which led to a decrease in property plant and equipment of $54,841 and a corresponding increase in goodwill. (3) The Company obtained additional information related to its customer relationship balances which led to an increase in customer relationship of $30,000 and a corresponding decrease in goodwill.

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Investments in available-for-sale securities at December 31, 2015 were classified as follows: December 31, 2015 Current $ 520,144 Non-current 48,081 Total available-for-sale securities $ 568,225
Available-for-sale Securities	The cost, gross unrealized gains, gross unrealized losses and fair value of the Company's available-for-sale securities were as follows: December 31, 2015 Cost Gross Gross (1) Fair Value Debt securities Corporate bonds $ 336,665 $ 55 $ (1,076 ) $ 335,644 U.S. government debt (2) 135,226 2 (374 ) 134,854 Asset-backed securities 49,759 2 (115 ) 49,646 Equity securities $ 54,371 $ 466 $ (6,756 ) $ 48,081 Total available-for-sale securities $ 576,021 $ 525 $ (8,321 ) $ 568,225 ______________________________ (1) All unrealized loss positions were held at a loss for less than 12 months. (2) U.S. Treasury obligations, U.S. government agency obligations and U.S government agency mortgage-backed securities.
Schedule of Realized Gain (Loss)	The cost of securities sold was determined using the specific identification method. Year Ended December 31, 2016 2015 2014 Proceeds from sales and maturities of securities $ 662,938 $ 48,900 $ 342,045 Gross realized gains 53,754 3,830 1,311 Gross realized losses (35 ) (32 ) (99 )

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Schedule Of Accounts Receivable	Accounts receivable consist of the following at December 31: 2016 2015 Trade customers $ 827,721 $ 438,538 Allowance for doubtful accounts (17,991 ) (14,095 ) 809,730 424,443 Federal and state taxes 90,414 60,748 Other 38,599 23,341 Accounts receivable, net $ 938,743 $ 508,532
Activity in Allowance for Doubtful Accounts	Activity in our allowance for doubtful accounts during the years ended December 31, 2016 , 2015 and 2014 is set forth in the table below: Year Ended December 31, 2016 2015 2014 Balance at Beginning of Year, January 1 $ 14,095 $ 13,468 $ 11,741 Charged to Expense 4,095 956 301 Additions/(Deductions) (1) (199 ) (329 ) 1,426 Balance at End of Year, December 31 $ 17,991 $ 14,095 $ 13,468 ______________________________ (1) Deductions primarily represent accounts receivable written off during the period.

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2016
Inventory, Net [Abstract]
Schedule Of Inventory	Inventories consist of the following at December 31: 2016 2015 Finished products $ 500,861 $ 253,338 Feedstock, additives and chemicals 216,877 106,435 Materials and supplies 83,362 74,287 Inventories $ 801,100 $ 434,060

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment, Net [Abstract]
Schedule Of Property, Plant And Equipment	Property, plant and equipment consist of the following at December 31: 2016 2015 Land $ 194,137 $ 33,051 Building and improvements 464,570 266,214 Plant and equipment 6,913,721 3,632,416 Other 377,466 241,829 7,949,894 4,173,510 Less: Accumulated depreciation (1,919,229 ) (1,685,255 ) 6,030,665 2,488,255 Construction in progress 389,397 515,812 Property, plant and equipment, net $ 6,420,062 $ 3,004,067

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Other Assets [Abstract]
Schedule Of Other Assets	Other assets consist of the following at December 31: 2016 2015 Weighted Average Life Cost Accumulated Amortization Net Cost Accumulated Amortization Net Goodwill $ 946,553 $ — $ 946,553 $ 62,016 $ — $ 62,016 Customer relationships 662,080 (50,465 ) 611,615 75,249 (22,572 ) 52,677 10 Other intangible assets: Licenses and intellectual property 120,992 (44,035 ) 76,957 79,699 (38,643 ) 41,056 13 Trademarks 87,927 (6,841 ) 81,086 39,085 (2,602 ) 36,483 12 Other 31,038 (13,242 ) 17,796 29,320 (8,148 ) 21,172 11 Total other intangible assets 239,957 (64,118 ) 175,839 148,104 (49,393 ) 98,711 Deferred charges and other assets Cost-method investments 108,938 — 108,938 51,334 — 51,334 Equity-method investments 21,522 — 21,522 9,208 — 9,208 Restricted cash 25,689 — 25,689 — — — Turnaround costs 168,501 (74,671 ) 93,830 111,078 (74,943 ) 36,135 5 Deferred Taxes 12,526 — 12,526 — — — Debt issuance costs 3,055 (210 ) 2,845 11,915 (10,762 ) 1,153 5 Other 82,287 (19,769 ) 62,518 99,763 (20,968 ) 78,795 8 Total deferred charges and other assets 422,518 (94,650 ) 327,868 283,298 (106,673 ) 176,625 Other assets, net $ 2,271,108 $ (209,233 ) $ 2,061,875 $ 568,667 $ (178,638 ) $ 390,029
Schedule of Goodwill	The gross carrying amounts of goodwill for the years ended December 31, 2016 and 2015 are as follows: Olefins Segment Vinyls Segment Total Balance at December 31, 2014 $ 29,990 $ 32,026 $ 62,016 Balance at December 31, 2015 29,990 32,026 62,016 Goodwill acquired during the year — 887,491 887,491 Effects of changes in foreign exchange rates — (2,954 ) (2,954 ) Balance at December 31, 2016 $ 29,990 $ 916,563 $ 946,553

Accounts and Notes Payable (Tab

Accounts and Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2016
Accounts and Notes Payable [Abstract]
Accounts and Notes Payable	Accounts and notes payable consist of the following at December 31: 2016 2015 Accounts payable $ 494,743 $ 229,219 Notes payable to banks 1,516 6,110 Accounts and notes payable $ 496,259 $ 235,329

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule Of Long-Term Debt	Long-term debt consists of the following at December 31: December 31, 2016 December 31, 2015 Principal Amount Unamortized Premium, Discount and Debt Issuance Costs (1) Net Long-Term Debt Principal Amount Unamortized Discount and Debt Issuance Costs (1) Net Long-Term Debt Revolving credit facility $ 325,000 $ — $ 325,000 $ — $ — $ — 4.625% senior notes due 2021 (the "4.625% Westlake 2021 Senior Notes") 624,793 26,837 651,630 — — — 4.625% senior notes due 2021 (the "4.625% Subsidiary 2021 Senior Notes") 63,207 2,862 66,069 — — — 3.60% senior notes due 2022 250,000 (1,891 ) 248,109 250,000 (2,232 ) 247,768 4.875% senior notes due 2023 (the "4.875% Westlake 2023 Senior Notes") 433,793 13,431 447,224 — — — 4.875% senior notes due 2023 (the "4.875% Subsidiary 2023 Senior Notes") 16,207 540 16,747 — — — 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750,000 (10,757 ) 739,243 — — — Loan related to tax-exempt waste disposal revenue bonds due 2027 10,889 — 10,889 10,889 — 10,889 6 ½% senior notes due 2029 100,000 (916 ) 99,084 100,000 (989 ) 99,011 6 ¾% senior notes due 2032 250,000 (1,883 ) 248,117 250,000 (2,002 ) 247,998 6 ½% senior notes due 2035 (the "6 ½% 89,000 (839 ) 88,161 89,000 (884 ) 88,116 6 ½% senior notes due 2035 (the "6 ½% 65,000 (602 ) 64,398 65,000 (634 ) 64,366 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700,000 (26,017 ) 673,983 — — — Long-term debt, net $ 3,677,889 $ 765 $ 3,678,654 $ 764,889 $ (6,741 ) $ 758,148 ______________________________ (1) Includes unamortized debt issuance costs of $24,113 and $5,967 at December 31, 2016 and December 31, 2015 , respectively.

Accumulated Other Comprehensi46

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive income (loss) by component were as follows: Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange Net Unrealized Holding Gains on Investments, Net of Tax Total Balances at December 31, 2014 $ (23,442 ) $ (56,224 ) $ 233 $ (79,433 ) Other comprehensive income (loss) before reclassifications 12,877 (59,466 ) (2,795 ) (49,384 ) Amounts reclassified from accumulated other comprehensive loss 1,958 — (2,433 ) (475 ) Net other comprehensive income (loss) for the year 14,835 (59,466 ) (5,228 ) (49,859 ) Balances at December 31, 2015 (8,607 ) (115,690 ) (4,995 ) (129,292 ) Other comprehensive income (loss) before reclassifications 36,211 (34,512 ) 57,004 58,703 Amounts reclassified from accumulated other comprehensive loss 1,341 — (52,058 ) (50,717 ) Net other comprehensive income (loss) for the year 37,552 (34,512 ) 4,946 7,986 Balances at December 31, 2016 $ 28,945 $ (150,202 ) $ (49 ) $ (121,306 )
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, 2016 2015 2014 Amortization of pension and other post-retirement items Prior service costs (1) $ — $ — $ (347 ) Net loss (1) (1,429 ) (2,663 ) (577 ) Curtailment (1) (364 ) — — Settlement benefits (1) (371 ) (355 ) — (2,164 ) (3,018 ) (924 ) Provision for income taxes 823 1,060 356 (1,341 ) (1,958 ) (568 ) Net unrealized gains on available-for- sale investments Realized gain on available- for-sale investments Other income, net 53,720 3,798 1,212 Provision for income taxes (1,662 ) (1,365 ) (435 ) 52,058 2,433 777 Total reclassifications for the period $ 50,717 $ 475 $ 209 ______________________________ (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, see Note 13.

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2016
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: 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 62,192 $ 94,821 $ 67,010 $ 122,701 Benefit obligation assumed with acquisition 818,602 20,895 — — Service cost 975 1,459 29 1,661 Interest cost 8,832 2,441 2,015 2,110 Actuarial (gain) loss (74,262 ) 12,705 (2,330 ) (17,310 ) Benefits paid (17,081 ) (2,571 ) (4,532 ) (2,139 ) Other — (61 ) — — Foreign exchange effects — (4,537 ) — (12,202 ) Benefit obligation, end of year $ 799,258 $ 125,152 $ 62,192 $ 94,821 Change in plan assets Fair value of plan assets, beginning of year $ 50,763 $ — $ 53,415 $ — Acquisition 575,865 16,298 — — Actual return 7,334 27 (268 ) — Employer contribution 456 2,609 2,148 2,139 Benefits paid (17,081 ) (2,571 ) (4,532 ) (2,139 ) Experience gain 136 — — — Administrative expenses paid (3,204 ) — — — Foreign exchange effects — (371 ) — — Fair value of plan assets, end of year $ 614,269 $ 15,992 $ 50,763 $ — Funded status, end of year $ (184,989 ) $ (109,160 ) $ (11,429 ) $ (94,821 )
Schedule of Amounts Recognized in Balance Sheet	2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Noncurrent assets $ — $ 233 $ — $ — Current liabilities (1,691 ) (2,583 ) — — Noncurrent liabilities (183,298 ) (106,810 ) (11,429 ) (94,821 ) Net amount recognized $ (184,989 ) $ (109,160 ) $ (11,429 ) $ (94,821 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Amounts recognized in accumulated other comprehensive income Net (gain) loss $ (53,302 ) $ 7,990 $ 14,755 $ (4,919 ) Foreign exchange effects — (15 ) — 1,986 Total before tax (1) $ (53,302 ) $ 7,975 $ 14,755 $ (2,933 ) ______________________________ (1) After-tax totals for pension benefits were $30,287 and $6,812 for 2016 and 2015 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive loss.
Schedule Of Accumulated Benefit Obligations In Excess Of Plan Assets	Pension plans with an accumulated benefit obligation in excess of plan assets at December 31 are as follows: 2016 2015 Information for pension plans with an accumulated benefit obligation in excess of plan assets U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans Projected benefit obligation $ (799,258 ) $ (113,286 ) $ (62,192 ) $ (94,821 ) Accumulated benefit obligation (799,258 ) (109,837 ) (62,192 ) (93,231 ) Fair value of plan assets 614,269 4,627 50,763 —
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, 2016 2015 2014 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 $ 1,261 $ 1,459 $ 29 $ 1,661 $ 334 $ 602 Administrative expenses 2,919 — — — — — Interest cost 8,832 2,441 2,015 2,110 2,322 1,366 Expected return on plan assets (15,354 ) (199 ) (2,960 ) — (3,140 ) — Net amortization 1,307 — 1,270 1,048 571 — Settlement benefits 371 — 355 — — — Net periodic benefit (gain) cost $ (664 ) $ 3,701 $ 709 $ 4,819 $ 87 $ 1,968 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net loss (gain) emerging $ (66,379 ) $ 12,893 $ 898 $ (17,310 ) $ 9,352 $ 15,425 Amortization of net loss (1,307 ) — (1,270 ) (1,048 ) (274 ) — Amortization of prior service cost — — — — (297 ) — Settlement benefits (371 ) — (355 ) — — — Total recognized in OCI $ (68,057 ) $ 12,893 $ (727 ) $ (18,358 ) $ 8,781 $ 15,425 Total net periodic benefit cost and OCI $ (68,721 ) $ 16,594 $ (18 ) $ (13,539 ) $ 8,868 $ 17,393
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: 2016 2015 2014 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 3.8 % 1.8 % 4.0 % 2.4 % 3.5 % 1.9 % Rate of compensation increase — % 2.6 % — % 2.5 % — % 2.5 % Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 3.2 % 2.4 % 3.5 % 1.9 % 4.5 % 2.6 % Discount rate for service cost 3.4 % 2.4 % — % — % — % — % Discount rate for interest cost 2.9 % 2.4 % — % — % — % — % Expected return on plan assets 6.8 % 4.6 % 7.0 % — % 7.0 % — % Rate of compensation increase — % 2.6 % — % 2.5 % — % 2.5 %
Schedule Of Fair Value Of Pension Plan Assets	The investments in the bank 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: 2016 2015 U.S. Plans Non U.S. Plans U.S. Plans Level 1 Level 2 Total Level 1 Level 2 Total Level 2 Total Cash and common stock: Cash and cash equivalents $ — $ — $ — $ 4,627 $ — $ 4,627 $ — $ — Common stock 16,546 — 16,546 — — — — — Bank collective trust and mutual funds—Equity securities: Large-cap funds (1) 50,143 166,604 216,747 — 1,609 1,609 18,384 18,384 Small-cap funds (2) 8,379 23,407 31,786 — — — 4,069 4,069 International funds (3) 53,422 53,629 107,051 — 4,370 4,370 8,181 8,181 Bank collective trust funds—Fixed income: Bond funds (4) 61,778 165,657 227,435 — 5,386 5,386 19,624 19,624 Short-term investment funds — 14,704 14,704 — — — 505 505 $ 190,268 $ 424,001 $ 614,269 $ 4,627 $ 11,365 $ 15,992 $ 50,763 $ 50,763 ______________________________ (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 United States). 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	Contributions to the Company's multi-employer plans are expensed as incurred and were as follows: Year Ended December 31, 2016 2015 2014 Non-U.S. Plans Non-U.S. Plans Non-U.S. Plans Contributions to multi-employer plans (1) $ 4,952 $ 4,489 $ 2,295 ______________________________ (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 Post- retirement Healthcare Estimated future benefit payments: Year 1 $ 51,324 $ 8,663 Year 2 49,626 8,460 Year 3 51,163 8,302 Year 4 51,554 8,185 Year 5 51,715 8,122 Years 6 to 10 267,024 34,681
Post-Retirement Healthcare 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	The following table provides a reconciliation of the benefit obligations of the Company's unfunded post-retirement healthcare plans. 2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Change in benefit obligation Benefit obligation, beginning of year $ 17,815 $ — $ 20,177 Benefit obligation assumed with acquisition 69,650 3,324 — Service cost 289 5 22 Interest cost 1,000 12 571 Actuarial (gain) loss (6,151 ) 91 (1,848 ) Benefits paid (2,355 ) (9 ) (1,107 ) Curtailment (364 ) — — Plan participants' contributions 35 — — Foreign exchange effects — (82 ) — Benefit obligation, end of year $ 79,919 $ 3,341 $ 17,815 Change in plan assets Fair value of plan assets, beginning of year $ — $ — $ — Employer contribution 2,320 9 1,107 Plan participants' contributions 35 — — Benefits paid (2,355 ) (9 ) (1,107 ) Fair value of plan assets, end of year $ — $ — $ — Funded status, end of year $ (79,919 ) $ (3,341 ) $ (17,815 )
Schedule of Amounts Recognized in Balance Sheet	2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Amounts recognized in the consolidated balance sheet at December 31 Current liabilities $ (8,447 ) $ (102 ) $ (1,244 ) Noncurrent liabilities (71,472 ) (3,239 ) (16,571 ) Net amount recognized $ (79,919 ) $ (3,341 ) $ (17,815 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	2016 2015 U.S. Plans Non-U.S. Plans U.S. Plans Amounts recognized in accumulated other comprehensive income Net loss $ (3,659 ) $ 91 $ 2,978 Total before tax (1) $ (3,659 ) $ 91 $ 2,978 ______________________________ (1) After-tax totals for post-retirement healthcare benefits were a loss of $1,342 and a gain of $1,795 for 2016 and 2015 , respectively, and are reflected in stockholders' equity as accumulated other comprehensive 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, 2016 2015 2014 U.S. Plans Non-U.S. Plans U.S. Plans U.S. Plans Components of net periodic benefit cost Service cost $ 289 $ 5 $ 22 $ 22 Interest cost 1,000 12 571 733 Net amortization 122 — 345 353 Net periodic benefit cost $ 1,411 $ 17 $ 938 $ 1,108 Other changes in plan assets and benefit obligation recognized in other comprehensive income (OCI) Net (gain) loss emerging $ (6,151 ) $ 91 $ (1,848 ) $ 989 Curtailment (364 ) — — — Amortization of net loss (122 ) — (345 ) (303 ) Amortization of prior service cost — — — (50 ) Total recognized in OCI $ (6,637 ) $ 91 $ (2,193 ) $ 636 Total net periodic benefit cost and OCI $ (5,226 ) $ 108 $ (1,255 ) $ 1,744
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: 2016 2015 2014 U.S. Plans Non-U.S. Plans U.S. Plans U.S. Plans Weighted average assumptions used to determine benefit obligations at December 31 Discount rate 3.3 % 4.0 % 3.5 % 3.3 % Health care cost trend rate - Initial rate 7.3 % 6.2 % — % — % - Ultimate rate 4.5 % 4.5 % — % — % - Years to ultimate 11 12 — — Weighted average assumptions used to determine net periodic benefit costs for years ended December 31 Discount rate for benefit obligations 2.6 % 3.3 % 3.3 % 4.0 % Discount rate for service cost 3.1 % 3.3 % — % — % Discount rate for interest cost 2.8 % 3.3 % — % — % Health care cost trend rate - Initial rate 7.0 % 6.8 % — % — % - Ultimate rate 4.5 % 4.5 % — % — % - Years to ultimate 12 13 — —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Option Activity And Changes	Option activity and changes during the year ended December 31, 2016 were as follows: Options Weighted Average Exercise Price Weighted Average Remaining Term (Years) Aggregate Intrinsic Value Outstanding at December 31, 2015 1,267,790 $ 30.07 Granted 292,448 44.42 Exercised (112,611 ) 19.33 Cancelled (42,893 ) 35.07 Outstanding at December 31, 2016 1,404,734 $ 33.76 5.3 $ 34,368 Exercisable at December 31, 2016 940,314 $ 24.29 3.7 $ 31,009
Schedule Of Range Of Exercise Prices For Outstanding Options	For options outstanding at December 31, 2016 , the options had the following range of exercise prices: Range of Prices Options Outstanding Weighted Average Remaining Contractual Life (Years) $7.12 - $9.65 304,200 1.7 $10.26 - $18.05 235,916 2.3 $22.92 - $30.05 174,082 4.7 $40.38 - $52.35 391,083 8.4 $63.98 - $68.18 299,453 7.7
Schedule Of Weighted Average Value And Assumptions For Fair Value Of 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, 2016 2015 2014 Weighted average fair value $ 11.67 $ 20.21 $ 20.49 Risk-free interest rate 1.4 % 1.7 % 1.6 % Expected life in years 5 5 5 Expected volatility 32.9 % 34.2 % 35.7 % Expected dividend yield 1.6 % 0.9 % 0.7 %
Schedule Of Non-Vested Restricted Stock Award Activity And Changes	Non-vested restricted stock awards as of December 31, 2016 and changes during the year ended December 31, 2016 were as follows: Number of Shares Weighted Average Grant Date Fair Value Non-vested at December 31, 2015 64,856 $ 15.81 Granted 28,142 51.53 Vested (81,134 ) 28.19 Forfeited (11,864 ) 15.81 Non-vested at December 31, 2016 — $ — Non-vested restricted stock unit as of December 31, 2016 and changes during the year ended December 31, 2016 were as follows: Number of Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2015 498,872 $ 57.61 Granted 204,642 48.64 Vested (88,877 ) 48.28 Forfeited (17,078 ) 67.47 Non-vested at December 31, 2016 597,559 $ 55.64
Axiall Corporation [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Weighted Average Value And Assumptions For Fair Value Of Options	Volatility was calculated using historical trends of the Company's common stock price. Liability Classified Restricted Stock Awards Year Ended December 31, 2016 Weighted average vesting period in years 1.2 Risk-free interest rate 0.9 % Expected volatility 28.2 % Expected dividend yield 1.4 %
Schedule Of Non-Vested Restricted Stock Award Activity And Changes	Non-vested liability classified restricted stock awards as of December 31, 2016 and changes during the year ended December 31, 2016 were as follows: Number of Units Weighted Average Fair Value Non-vested at August 31, 2016 340,413 $ 51.82 Vested (54,266 ) 52.88 Non-vested at December 31, 2016 286,147 $ 60.77

Derivative Commodity Instrume49

Derivative Commodity Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedges, Assets [Abstract]
Fair Values Of Derivative Instruments In Consolidated Balance Sheets	The fair values of derivative instruments in the Company's consolidated balance sheets were as follows: Asset Derivatives Balance Sheet Location Fair Value as of December 31, 2016 2015 Not designated as hedging instruments Commodity forward contracts Accounts receivable, net $ 7,727 $ 3,465 Commodity forward contracts Deferred charges and other assets, net 7,259 2,088 Total asset derivatives $ 14,986 $ 5,553 Liability Derivatives Balance Sheet Location Fair Value as of December 31, 2016 2015 Not designated as hedging instruments Commodity forward contracts Accrued liabilities $ 1,487 $ 9,325 Commodity forward contracts Other liabilities 5,734 12,437 Total liability derivatives $ 7,221 $ 21,762
Impact Of Derivative Instruments Not Designated As Fair Value Hedges	The impact of derivative instruments that have not been designated as hedges on the Company's consolidated statements of operations were as follows: Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative Year Ended December 31, 2016 2015 2014 Commodity forward contracts Cost of sales $ 19,696 $ (11,395 ) $ (9,678 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Schedule Of Assets And Liabilities On A Recurring Basis	The following tables summarize, by level within the fair value hierarchy, the Company's assets and liabilities at December 31 that were accounted for at fair value on a recurring basis: 2016 Level 1 Level 2 Total Derivative instruments Risk management assets—Commodity forward contracts $ 878 $ 14,108 $ 14,986 Risk management liabilities—Commodity forward contracts (6,854 ) (367 ) (7,221 ) 2015 Level 1 Level 2 Total Derivative instruments Risk management assets—Commodity forward contracts $ 5,553 $ — $ 5,553 Risk management liabilities—Commodity forward contracts (11,648 ) (10,114 ) (21,762 ) Marketable securities Available-for-sale securities 48,081 520,144 568,225
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, 2016 and 2015 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. 2016 2015 Carrying Value Fair Value Carrying Value Fair Value Revolving credit facility $ 325,000 $ 325,000 $ — $ — 4.625% Westlake Senior Notes 2021 651,630 650,847 — — 4.625% Subsidiary Senior Notes 2021 66,069 65,775 — — 3.60% senior notes due 2022 248,109 251,725 247,768 244,828 4.875% Westlake Senior 2023 Notes 447,224 451,301 — — 4.875% Subsidiary 2023 Senior Notes 16,747 16,501 — — 3.60% 2026 Senior Notes 739,243 722,055 — — Loan related to tax-exempt waste disposal revenue bonds due 2027 10,889 10,889 10,889 10,889 6 ½% senior notes due 2029 99,084 112,433 99,011 117,153 6 ¾% senior notes due 2032 248,117 258,818 247,998 268,490 6 ½% 2035 GO Zone Senior Notes 88,161 100,323 88,116 106,491 6 ½% 2035 IKE Zone Senior Notes 64,398 73,270 64,366 76,741 5.0% 2046 Senior Notes 673,983 691,712 — —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Components of Income (Loss) Before Income Taxes	The components of income (loss) before income taxes are as follows: Year Ended December 31, 2016 2015 2014 Domestic $ 476,423 $ 880,044 $ 1,102,101 Foreign 81,956 83,397 (18,183 ) $ 558,379 $ 963,441 $ 1,083,918
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, 2016 2015 2014 Current Federal $ 8,156 $ 225,617 $ 300,610 State 8,967 23,966 37,351 Foreign 20,720 9,029 1,974 37,843 258,612 339,935 Deferred Federal 136,206 29,820 40,950 State (33,681 ) 2,807 22,714 Foreign (1,848 ) 7,157 (4,697 ) 100,677 39,784 58,967 Total provision $ 138,520 $ 298,396 $ 398,902
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, 2016 2015 2014 Provision for federal income tax, at statutory rate $ 195,432 $ 337,204 $ 379,371 State income tax provision, net of federal income tax effect 1,408 17,403 40,012 Foreign income tax rate differential (7,594 ) (13,002 ) 3,640 Manufacturing deduction (2,371 ) (24,185 ) (24,465 ) Depletion (2,298 ) — — Contingent tax liability 2,172 — (1,626 ) Noncontrolling interests (6,940 ) (6,662 ) (2,255 ) Tax on previously held shares of Axiall Corporation and certain other acquisition related items (12,924 ) — — Changes in state apportionment and other state adjustments (16,929 ) — — Research and development expenditures and adjustments related to prior years' tax returns (8,344 ) Other, net (3,092 ) (12,362 ) 4,225 $ 138,520 $ 298,396 $ 398,902
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: 2016 2015 Net operating loss carryforward $ 69,790 $ 17,679 Credit carryforward 23,932 746 Accruals 66,694 57,811 Pension 113,644 4,393 Allowance for doubtful accounts 12,039 4,617 Inventories 13,257 8,663 Other 36,624 7,747 Deferred taxes assets—total 335,980 101,656 Property, plant and equipment (1,374,095 ) (408,374 ) Intangibles (220,489 ) (15,007 ) Turnaround costs (701 ) (1,467 ) Basis difference—consolidated partnerships (308,361 ) (200,627 ) Other (17,377 ) — Deferred tax liabilities—total (1,921,023 ) (625,475 ) Valuation allowance (53,006 ) (16,345 ) Total net deferred tax liabilities $ (1,638,049 ) $ (540,164 ) Balance sheet classifications Current deferred tax asset $ — $ 35,439 Noncurrent deferred tax asset 12,526 — Noncurrent deferred tax liability (1,650,575 ) (575,603 ) Total net deferred tax liabilities $ (1,638,049 ) $ (540,164 )
Schedule of Changes in Gross Unrecognized Tax Benefits	A reconciliation of unrecognized tax benefits for the year ended December 31, 2016 is set forth in the table below: Beginning balance at January 1, 2016 $ — Amounts attributable to Axiall pre-acquisition 5,030 Additions during the year ended December 31, 2016 3,398 Reductions due to statutes of limitations expiring (1,184 ) Effects of changes in foreign exchange rates $ (56 ) Ending balance at December 31, 2016 $ 7,188

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Schedule Of Net Income Attributable To Common Stockholders	Diluted earnings per share include the effect of certain stock options. Year Ended December 31, 2016 2015 2014 Net income attributable to Westlake Chemical Corporation $ 398,859 $ 646,010 $ 678,523 Less: Net income attributable to participating securities (1,784 ) (2,825 ) (1,502 ) Net income attributable to common shareholders $ 397,075 $ 643,185 $ 677,021
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, 2016 2015 2014 Weighted average common shares—basic 129,367,712 131,823,707 133,111,230 Plus incremental shares from: Assumed exercise of options 607,110 478,105 532,184 Weighted average common shares—diluted 129,974,822 132,301,812 133,643,414 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 3.07 $ 4.88 $ 5.09 Diluted $ 3.06 $ 4.86 $ 5.07

Supplemental Information (Table

Supplemental Information (Tables)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule Of Other Income, Net	The components of other income (expense), net are as follows: Year Ended December 31, 2016 2015 2014 Interest income $ 8,421 $ 6,034 $ 3,468 Dividend income 4,821 3,559 532 Acquisition-related financing costs (12,453 ) — — Foreign exchange currency gains (losses), net (1) 122 1,828 (7,382 ) Income from equity method investments 3,613 6,242 5,883 Impairment of equity method investments — (4,925 ) (6,747 ) Gain realized on previously held shares of Axiall common stock 49,080 — — Gain on acquisition and related expenses, net — 20,430 — Gain from sales of securities, net 4,640 3,798 1,212 Other (1,846 ) 1,304 313 Other income (expense), net $ 56,398 $ 38,270 $ (2,721 ) ______________________________ (1) Aggregate foreign exchange currency gains and losses included in the consolidated statements of operations for the years ended December 31, 2016 , 2015 and 2014 .
Schedule of Cash Flow Information	Cash Flow Information Year Ended December 31, 2016 2015 2014 Cash paid for: Interest paid, net of interest capitalized $ 45,534 $ 31,946 $ 35,336 Income taxes paid 3,066 314,186 314,745

Westlake Chemical Partners LP (

Westlake Chemical Partners LP (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Reconciliation Of Proceeds From Initial Public Offering	The following table is a reconciliation of proceeds from the initial public offering: Total proceeds from the initial public offering $ 310,500 Less: Offering Costs (24,412 ) Net proceeds from the initial public offering 286,088 Less: Cash retained by OpCo (55,419 ) Net proceeds distributed to the Company from the initial public offering $ 230,669

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Commitments	Several of the leases provide for renewal terms and, in certain leases, purchase options. At December 31, 2016 , future minimum lease commitments for operating lease obligations and capital lease obligations were as follows: Operating Leases Capital Leases 2017 $ 86,910 $ 3,713 2018 78,941 3,627 2019 60,885 3,367 2020 48,395 3,367 2021 39,626 2,610 Thereafter 603,621 13,943 Total minimum lease payments $ 918,378 $ 30,627 Less: Imputed interest costs (10,681 ) Present value of net minimum lease payments $ 19,946

Segment And Geographic Inform56

Segment And Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Reporting Information	Year Ended December 31, 2016 2015 2014 Net external sales Olefins Polyethylene $ 1,462,407 $ 1,650,964 $ 1,922,535 Styrene, feedstock and other 431,227 609,149 801,155 Total olefins 1,893,634 2,260,113 2,723,690 Vinyls PVC, caustic soda and other 2,492,562 1,718,359 1,203,332 Building products 689,260 484,864 488,328 Total vinyls 3,181,822 2,203,223 1,691,660 $ 5,075,456 $ 4,463,336 $ 4,415,350 Intersegment sales Olefins $ 165,266 $ 106,861 $ 146,539 Vinyls 25,809 1,493 1,385 $ 191,075 $ 108,354 $ 147,924 Income (loss) from operations Olefins $ 557,806 $ 747,436 $ 1,013,825 Vinyls 174,141 254,452 142,740 Corporate and other (150,493 ) (42,061 ) (32,574 ) $ 581,454 $ 959,827 $ 1,123,991 Depreciation and amortization Olefins $ 136,500 $ 110,684 $ 106,244 Vinyls 237,588 134,546 101,666 Corporate and other 3,578 527 576 $ 377,666 $ 245,757 $ 208,486 Other income (expense), net Olefins $ 5,156 $ 4,656 $ 6,102 Vinyls 3,138 8,540 2,680 Corporate and other 48,104 25,074 (11,503 ) $ 56,398 $ 38,270 $ (2,721 ) Provision for (benefit from) income taxes Olefins $ 175,394 $ 242,516 $ 354,159 Vinyls 24,695 64,456 52,249 Corporate and other (61,569 ) (8,576 ) (7,506 ) $ 138,520 $ 298,396 $ 398,902 Capital expenditures Olefins $ 323,590 $ 304,873 $ 188,729 Vinyls 302,208 176,582 237,992 Corporate and other 2,685 9,971 4,383 $ 628,483 $ 491,426 $ 431,104
Total Assets	December 31, 2016 December 31, 2015 Total assets Olefins $ 2,092,617 $ 1,869,888 Vinyls 8,287,204 2,638,833 Corporate and other 510,432 1,060,564 $ 10,890,253 $ 5,569,285
Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes	A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Year Ended December 31, 2016 2015 2014 Income from operations for reportable segments $ 581,454 $ 959,827 $ 1,123,991 Interest expense (79,473 ) (34,656 ) (37,352 ) Other income (expense), net 56,398 38,270 (2,721 ) Income before income taxes $ 558,379 $ 963,441 $ 1,083,918
Geographic Information For Sales To External Customers And Long-Lived Assets	Geographic Information Year Ended December 31, 2016 2015 2014 Sales to external customers (1) United States $ 3,525,492 $ 3,133,395 $ 3,596,091 Foreign Germany 401,950 394,459 198,921 Canada 317,083 195,790 217,567 Switzerland 101,320 106,750 89,214 China 87,118 46,451 6,515 Italy 84,359 90,237 36,823 Belgium 50,662 41,542 24,082 France 50,371 58,727 27,521 Other 457,101 395,985 218,616 $ 5,075,456 $ 4,463,336 $ 4,415,350 December 31, 2016 December 31, 2015 Long-lived assets United States $ 5,782,796 $ 2,588,366 Foreign Germany 401,572 379,262 Other 235,694 36,439 $ 6,420,062 $ 3,004,067 ______________________________ (1) Revenues are attributed to countries based on location of customer.

Guarantor Disclosures (Tables)

Guarantor Disclosures (Tables)	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Financial Information Balance Sheet	Condensed Consolidating Financial Information as of December 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Balance Sheet Current assets Cash and cash equivalents $ 146,990 $ 53,006 $ 259,457 $ — $ 459,453 Accounts receivable, net 2,117,540 3,329,871 323,931 (4,832,599 ) 938,743 Inventories — 597,819 203,281 — 801,100 Prepaid expenses and other current assets 30,748 41,755 12,494 (36,504 ) 48,493 Restricted cash — — 160,527 — 160,527 Total current assets 2,295,278 4,022,451 959,690 (4,869,103 ) 2,408,316 Property, plant and equipment, net — 4,475,943 1,944,119 — 6,420,062 Other assets, net 9,170,042 2,264,597 1,484,871 (10,857,635 ) 2,061,875 Total assets $ 11,465,320 $ 10,762,991 $ 4,388,680 $ (15,726,738 ) $ 10,890,253 Current liabilities Accounts and notes payable $ 4,330,375 $ 748,364 $ 225,300 $ (4,807,780 ) $ 496,259 Accrued liabilities 26,367 389,216 183,223 (61,323 ) 537,483 Term loan — — 149,341 — 149,341 Total current liabilities 4,356,742 1,137,580 557,864 (4,869,103 ) 1,183,083 Long-term debt 3,584,949 4,090,775 — (3,997,070 ) 3,678,654 Deferred income taxes — 1,581,260 91,809 (22,494 ) 1,650,575 Pension and other liabilities — 360,622 125,274 — 485,896 Total liabilities 7,941,691 7,170,237 774,947 (8,888,667 ) 6,998,208 Total Westlake Chemical Corporation stockholders' equity 3,523,629 3,592,754 3,245,317 (6,838,071 ) 3,523,629 Noncontrolling interests — — 368,416 — 368,416 Total equity 3,523,629 3,592,754 3,613,733 (6,838,071 ) 3,892,045 Total liabilities and equity $ 11,465,320 $ 10,762,991 $ 4,388,680 $ (15,726,738 ) $ 10,890,253 Condensed Consolidating Financial Information as of December 31, 2015 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Balance Sheet Current assets Cash and cash equivalents $ 303,131 $ 6,818 $ 352,576 $ — $ 662,525 Marketable securities 520,144 — — — 520,144 Accounts receivable, net 10,943 2,474,963 190,384 (2,167,758 ) 508,532 Inventories — 287,114 146,946 — 434,060 Prepaid expenses and other current assets 2,201 10,186 4,981 (2,879 ) 14,489 Deferred income taxes 702 28,325 6,412 — 35,439 Total current assets 837,121 2,807,406 701,299 (2,170,637 ) 2,175,189 Property, plant and equipment, net — 1,476,642 1,527,425 — 3,004,067 Other assets, net 5,003,096 914,823 1,442,436 (6,970,326 ) 390,029 Total assets $ 5,840,217 $ 5,198,871 $ 3,671,160 $ (9,140,963 ) $ 5,569,285 Current liabilities Accounts payable $ 1,817,963 $ 374,468 $ 185,931 $ (2,143,033 ) $ 235,329 Accrued liabilities 9,117 163,167 142,633 (27,604 ) 287,313 Total current liabilities 1,827,080 537,635 328,564 (2,170,637 ) 522,642 Long-term debt 747,259 744,405 — (733,516 ) 758,148 Deferred income taxes — 513,692 68,478 (6,567 ) 575,603 Pension and other liabilities — 49,202 101,759 — 150,961 Total liabilities 2,574,339 1,844,934 498,801 (2,910,720 ) 2,007,354 Total Westlake Chemical Corporation stockholders' equity 3,265,878 3,353,937 2,876,306 (6,230,243 ) 3,265,878 Noncontrolling interests — — 296,053 — 296,053 Total equity 3,265,878 3,353,937 3,172,359 (6,230,243 ) 3,561,931 Total liabilities and equity $ 5,840,217 $ 5,198,871 $ 3,671,160 $ (9,140,963 ) $ 5,569,285
Condensed Consolidating Financial Information Statement Of Operations	Condensed Consolidating Financial Information for the Year Ended December 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 4,009,891 $ 2,444,878 $ (1,379,313 ) $ 5,075,456 Cost of sales — 3,532,638 1,919,598 (1,357,342 ) 4,094,894 Gross profit — 477,253 525,280 (21,971 ) 980,562 Selling, general and administrative expenses 3,488 204,353 109,566 (21,971 ) 295,436 Transaction and integration-related costs — 103,226 446 — 103,672 (Loss) income from operations (3,488 ) 169,674 415,268 — 581,454 Interest expense (82,908 ) (75,907 ) (2,578 ) 81,920 (79,473 ) Other income (expense), net 77,151 (14,247 ) 75,414 (81,920 ) 56,398 (Loss) income before income taxes (9,245 ) 79,520 488,104 — 558,379 (Benefit from) provision for income taxes (8,047 ) 115,457 31,110 — 138,520 Equity in net income of subsidiaries 400,057 — — (400,057 ) — Net income (loss) 398,859 (35,937 ) 456,994 (400,057 ) 419,859 Net income attributable to noncontrolling interests — — 21,000 — 21,000 Net income (loss) attributable to Westlake Chemical Corporation $ 398,859 $ (35,937 ) $ 435,994 $ (400,057 ) $ 398,859 Comprehensive income (loss) attributable to Westlake Chemical Corporation $ 406,845 $ 11,695 $ 395,682 $ (407,377 ) $ 406,845 Condensed Consolidating Financial Information for the Year Ended December 31, 2015 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 3,557,806 $ 2,286,407 $ (1,380,877 ) $ 4,463,336 Cost of sales — 2,842,466 1,796,734 (1,361,055 ) 3,278,145 Gross profit — 715,340 489,673 (19,822 ) 1,185,191 Selling, general and administrative expenses 2,478 150,968 91,740 (19,822 ) 225,364 (Loss) income from operations (2,478 ) 564,372 397,933 — 959,827 Interest expense (42,197 ) (34,667 ) — 42,208 (34,656 ) Other income (expense), net 19,614 5,576 55,288 (42,208 ) 38,270 (Loss) income before income taxes (25,061 ) 535,281 453,221 — 963,441 Provision for (benefit from) income taxes (7,237 ) 275,687 29,946 — 298,396 Equity in net income of subsidiaries 663,834 — — (663,834 ) — Net income (loss) 646,010 259,594 423,275 (663,834 ) 665,045 Net income attributable to noncontrolling interests — — 19,035 — 19,035 Net income (loss) attributable to Westlake Chemical Corporation $ 646,010 $ 259,594 $ 404,240 $ (663,834 ) $ 646,010 Comprehensive income attributable to Westlake Chemical Corporation $ 596,151 $ 261,392 $ 334,447 $ (595,839 ) $ 596,151 Condensed Consolidating Financial Information for the Year Ended December 31, 2014 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 3,617,627 $ 2,492,099 $ (1,694,376 ) $ 4,415,350 Cost of sales — 3,056,659 1,714,415 (1,673,074 ) 3,098,000 Gross profit — 560,968 777,684 (21,302 ) 1,317,350 Selling, general and administrative expenses 2,082 121,182 81,783 (21,302 ) 183,745 Transaction and integration-related costs — 7,411 2,203 — 9,614 (Loss) income from operations (2,082 ) 432,375 693,698 — 1,123,991 Interest expense (39,763 ) (26,218 ) — 28,629 (37,352 ) Other income (expense), net 21,001 (4,278 ) 9,185 (28,629 ) (2,721 ) (Loss) income before income taxes (20,844 ) 401,879 702,883 — 1,083,918 (Benefit from) provision for income taxes 248 192,659 205,995 — 398,902 Equity in net income of subsidiaries 699,615 — — (699,615 ) — Net income (loss) 678,523 209,220 496,888 (699,615 ) 685,016 Net income attributable to noncontrolling interests — — 6,493 — 6,493 Net income (loss) attributable to Westlake Chemical Corporation $ 678,523 $ 209,220 $ 490,395 $ (699,615 ) $ 678,523 Comprehensive income attributable to Westlake Chemical Corporation $ 601,706 $ 203,428 $ 419,313 $ (622,741 ) $ 601,706
Condensed Consolidating Financial Information Statement Of Cash Flows	Condensed Consolidating Financial Information for the Year Ended December 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income (loss) $ 398,859 $ (35,937 ) $ 456,994 $ (400,057 ) $ 419,859 Adjustments to reconcile net income to net cash (used for) provided by operating activities Depreciation and amortization — 216,374 161,292 — 377,666 Deferred income taxes 1,214 103,315 (3,852 ) — 100,677 Net changes in working capital and other (437,148 ) 90,183 (117,442 ) 400,057 (64,350 ) Net cash (used for) provided by operating activities (37,075 ) 373,935 496,992 — 833,852 Cash flows from investing activities Acquisition of business, net of cash acquired — (2,502,018 ) 64,189 — (2,437,829 ) Additions to cost method investments — (17,000 ) — — (17,000 ) Additions to property, plant and equipment — (274,564 ) (353,919 ) — (628,483 ) Proceeds from disposition of assets — 1,037 170 — 1,207 Proceeds from sales and maturities of securities 658,338 — 4,600 — 662,938 Purchase of securities (138,422 ) — — — (138,422 ) Settlements of derivative instruments — (5,211 ) — — (5,211 ) Net cash provided by (used for) investing activities 519,916 (2,797,756 ) (284,960 ) — (2,562,800 ) Cash flows from financing activities Intercompany financing (2,199,148 ) 2,207,119 (7,971 ) — — Capitalized debt issuance costs (34,183 ) — (1,590 ) — (35,773 ) Dividends paid (96,560 ) — — — (96,560 ) Distributions paid — 262,890 (279,527 ) — (16,637 ) Proceeds from debt issuance 1,428,512 — — 1,428,512 Proceeds from exercise of stock options 2,179 — — — 2,179 Proceeds from issuance of notes payable — — 8,324 — 8,324 Proceeds from term loan and drawdown of revolver 450,000 — 150,000 — 600,000 Restricted cash associated with term loan — — (154,000 ) — (154,000 ) Repayment of debt — — (13,046 ) — (13,046 ) Repayment of revolver (125,000 ) — — — (125,000 ) Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Repurchase of common stock for treasury $ (67,406 ) $ — $ — $ — $ (67,406 ) Windfall tax benefits from share-based payment arrangements 2,624 — — — 2,624 Net cash (used for) provided by financing activities (638,982 ) 2,470,009 (297,810 ) — 1,533,217 Effect of exchange rate changes on cash and cash equivalents — — (7,341 ) — (7,341 ) Net (decrease) increase in cash and cash equivalents (156,141 ) 46,188 (93,119 ) — (203,072 ) Cash and cash equivalents at beginning of the year 303,131 6,818 352,576 — 662,525 Cash and cash equivalents at end of the year $ 146,990 $ 53,006 $ 259,457 $ — $ 459,453 Condensed Consolidating Financial Information for the Year Ended December 31, 2015 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income (loss) $ 646,010 $ 259,594 $ 423,275 $ (663,834 ) $ 665,045 Adjustments to reconcile net income to net cash (used for) provided by operating activities Depreciation and amortization — 113,575 132,182 — 245,757 Deferred income taxes (285 ) 38,680 1,389 — 39,784 Net changes in working capital and other (658,773 ) 93,633 29,556 663,834 128,250 Net cash (used for) provided by operating activities (13,048 ) 505,482 586,402 — 1,078,836 Cash flows from investing activities Acquisition of business, net of cash acquired — — 15,782 — 15,782 Additions to property, plant and equipment — (215,405 ) (276,021 ) — (491,426 ) Proceeds from disposition of assets — 18 31 — 49 Proceeds from disposition of equity method investment — 27,865 — — 27,865 Proceeds from sales and maturities of securities 48,900 — — — 48,900 Purchase of securities (556,211 ) (48,887 ) — — (605,098 ) Settlements of derivative instruments — (2,248 ) — — (2,248 ) Net cash (used for) provided by investing activities (507,311 ) (238,657 ) (260,208 ) — (1,006,176 ) Cash flows from financing activities Intercompany financing 418,844 (590,114 ) 171,270 — — Dividends paid (91,551 ) — — — (91,551 ) Distributions paid — 327,060 (341,916 ) — (14,856 ) Proceeds from exercise of stock options 1,063 — — — 1,063 Proceeds from issuance of notes payable — — 52,960 — 52,960 Repayment of notes payable — — (73,615 ) — (73,615 ) Repurchase of common stock for treasury (162,459 ) — — — (162,459 ) Windfall tax benefits from share-based payment arrangements 1,646 — — — 1,646 Net cash provided by (used for) financing activities $ 167,543 $ (263,054 ) $ (191,301 ) $ — $ (286,812 ) Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Effect of exchange rate changes on cash and cash equivalents $ — $ — $ (3,924 ) $ — $ (3,924 ) Net increase (decrease) in cash and cash equivalents (352,816 ) 3,771 130,969 — (218,076 ) Cash and cash equivalents at beginning of the year 655,947 3,047 221,607 — 880,601 Cash and cash equivalents at end of the year $ 303,131 $ 6,818 $ 352,576 $ — $ 662,525 Condensed Consolidating Financial Information for the Year Ended December 31, 2014 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income (loss) $ 678,523 $ 209,220 $ 496,888 $ (699,615 ) $ 685,016 Adjustments to reconcile net income (loss) to net cash (used for) provided by operating activities Depreciation and amortization — 101,779 106,707 — 208,486 Deferred income taxes (288 ) 47,692 11,563 — 58,967 Net changes in working capital and other (704,370 ) (560,996 ) 645,658 699,615 79,907 Net cash (used for) provided by operating activities (26,135 ) (202,305 ) 1,260,816 — 1,032,376 Cash flows from investing activities Acquisition of business — — (611,087 ) — (611,087 ) Additions to property, plant and equipment — (209,111 ) (221,993 ) — (431,104 ) Proceeds from disposition of assets — 180 1 — 181 Proceeds from repayment of loan to affiliate — — 45,923 — 45,923 Proceeds from sales and maturities of securities 342,045 — — — 342,045 Purchase of securities (117,332 ) — — — (117,332 ) Settlements of derivative instruments — (1,698 ) (133 ) — (1,831 ) Net cash used for investing activities 224,713 (210,629 ) (787,289 ) — (773,205 ) Cash flows from financing activities Intercompany financing 155,665 (244,122 ) 88,457 — — Net distributions prior to Westlake Partners initial public offering — 448,101 (448,101 ) — — Capitalized debt issuance costs (1,186 ) — — — (1,186 ) Dividends paid (77,656 ) 151,729 (151,729 ) — (77,656 ) Distributions paid — 54,060 (56,264 ) — (2,204 ) Net proceeds from issuance of Westlake Partners common units — — 286,088 — 286,088 Proceeds from exercise of stock options 5,524 — — — 5,524 Repurchase of common stock for treasury (52,630 ) — — — (52,630 ) Windfall tax benefits from share-based payment arrangements 6,704 — — — 6,704 Net cash provided (used for) by financing activities $ 36,421 $ 409,768 $ (281,549 ) $ — $ 164,640 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Effect of exchange rate changes on cash and cash equivalents $ — $ — $ (4,511 ) $ — $ (4,511 ) Net (decrease) increase in cash and cash equivalents 234,999 (3,166 ) 187,467 — 419,300 Cash and cash equivalents at beginning of the year 420,948 6,213 34,140 — 461,301 Cash and cash equivalents at end of the year $ 655,947 $ 3,047 $ 221,607 $ — $ 880,601

Quarterly Financial Informati58

Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Summary Of Quarterly Financial Information	Three Months Ended March 31, June 30, September 30, December 31, Net sales $ 975,187 $ 1,086,061 $ 1,279,028 $ 1,735,180 Gross profit 255,585 241,366 202,133 281,478 Income from operations 202,276 179,938 46,563 152,677 Net income 128,936 115,620 70,014 105,289 Net income attributable to Westlake Chemical Corporation 123,128 111,124 65,662 98,945 Earnings per common share attributable to (1) Basic $ 0.94 $ 0.85 $ 0.51 $ 0.76 Diluted $ 0.94 $ 0.85 $ 0.51 $ 0.76 Three Months Ended March 31, June 30, September 30, December 31, Net sales $ 1,103,531 $ 1,185,002 $ 1,188,037 $ 986,766 Gross profit 284,546 353,181 311,276 236,188 Income from operations 229,280 295,374 254,028 181,145 Net income 150,407 210,061 188,420 116,157 Net income attributable to Westlake Chemical Corporation 146,342 205,095 183,604 110,969 Earnings per common share attributable to (1) Basic $ 1.10 $ 1.55 $ 1.39 $ 0.85 Diluted $ 1.10 $ 1.54 $ 1.39 $ 0.84 ______________________________ (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 S59

Description Of Business And Significant Accounting Policies (Narrative) (Details)	Aug. 04, 2014shares	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)plant	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)shares	Aug. 31, 2016USD ($)$ / shares	Aug. 23, 2016USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Aggregate principal amount of senior notes		$ 1,450,000,000
Capitalized interest			$ 10,388,000	$ 10,449,000	$ 7,059,000
Asset Retirement Obligation, Current			4,421,000
Asset Retirement Obligations, Noncurrent			17,004,000
Asset Retirement Obligation			21,425,000	0
Goodwill			946,553,000	62,016,000	$ 62,016,000
Equity-method investments			$ 21,522,000	9,208,000
Subsidiaries [Member] | Limited Partner [Member] | IPO [Member] | Westlake Chemical Partners LP [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of units sold in public offering | shares	12,937,500				12,937,500
Westlake Chemical OpCo LP [Member] | Limited Partner [Member] | IPO [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Limited partner interest (percent)	89.40%		86.70%
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
Westlake Chemical OpCo LP [Member] | Subsidiaries [Member] | Limited Partner [Member] | IPO [Member] | Subsidiary of Common Parent [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Limited partner interest (percent)	10.60%		13.30%
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Amortization period (in years)			3 years
Other assets amortization period (in years)			1 year
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Amortization period (in years)			6 years
Other assets amortization period (in years)			30 years
Axiall Corporation [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Share price (in dollars per share) | $ / shares						$ 33
Goodwill						$ 887,491,000
Revolving Credit Facility [Member] | Senior Secured Revolving Credit Facility [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Maximum borrowing capacity		$ 1,000,000,000					$ 1,000,000,000
Accounting Standards Update 2015-03 [Member] | Other Assets [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity-method investments				9,208,000
Debt issuance costs, net				176,625,000
Accounting Standards Update 2015-03 [Member] | Long-term Debt [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Debt issuance costs, net				758,148,000
Scenario, Previously Reported [Member] | Accounting Standards Update 2015-03 [Member] | Other Assets [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Debt issuance costs, net				173,384,000
Scenario, Previously Reported [Member] | Accounting Standards Update 2015-03 [Member] | Long-term Debt [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Debt issuance costs, net				$ 764,115,000

Description Of Business And S60

Description Of Business And Significant Accounting Policies (Schedule Of Estimated Useful Lives Of Assets) (Details)	12 Months Ended
	Dec. 31, 2016
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	25 years
Plant And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	25 years
Ethylene Pipeline [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	35 years
Minimum [Member] | Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	3 years
Maximum [Member] | Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life, minimum (in years)	10 years

Description Of Business And S61

Description Of Business And Significant Accounting Policies (Activity in Asset Retirement Obligations) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	$ 0
Acquisitions	21,174
Accretion expense	251
Ending balance	$ 21,425

Description Of Business And S62

Description Of Business And Significant Accounting Policies (Activity in Warranty Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Beginning balance	$ 2,879	$ 1,833	$ 1,219
Estimated fair value of warranty liability assumed in acquisition	14,564	0	612
Warranty provisions	3,009	1,987	632
Effects of changes in foreign exchange rates	(196)	(97)	(79)
Warranty claims paid	(3,186)	(844)	(551)
Ending balance	$ 17,070	$ 2,879	$ 1,833

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) $ / shares in Units, $ in Thousands, shares in Millions, lb in Millions	Aug. 31, 2016USD ($)$ / shares	Aug. 30, 2016shares	Jun. 01, 2015USD ($)lb	Jul. 31, 2014USD ($)facilitylb	Dec. 31, 2016USD ($)	Aug. 30, 2016USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	May 31, 2015
Business Acquisition [Line Items]
Transaction and integration-related costs							$ 103,672	$ 0	$ 9,614
Goodwill					$ 946,553		946,553	62,016	$ 62,016
Axiall Corporation [Member]
Business Acquisition [Line Items]
Equity interest in acquiree held prior to combination, shares | shares		3.1
Offer price per share (usd per share) | $ / shares	$ 33
Purchase price	$ 2,539,360
Contribution to net sales					975,605
Contribution to net loss					95,663
Divestitures						$ 26,666
Restructuring						22,881
Legal and settlement claims, net						$ 23,376
Transaction and integration-related costs							103,672
Professional fees					$ 49,262		49,262
Change-in-control severance and other benefit costs							$ 54,410
Goodwill	887,491
Step acquisition, equity interest in acquiree, remeasurement gain (loss), net	49,080
Fair value of acquired accounts receivables	422,459
Gross contractual amount of acquired accounts receivables	434,834
Uncollectible accounts receivable	12,375
Decrease to property, plant, and equipment	54,841
Axiall Corporation [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Increase to customer relationship balances	$ 30,000
Suzhou Huasu Plastics Company Ltd [Member]
Business Acquisition [Line Items]
Step acquisition, equity interest in acquiree, remeasurement gain (loss), net								$ 1,505
Fair value of consideration transferred-cash			$ 5,518
Bargain purchase gain on acquisition			$ 22,550
Suzhou Huasu Plastics Company Ltd [Member] | PVC Resin [Member]
Business Acquisition [Line Items]
Combined annual capacity (in lb's) | lb			300
Suzhou Huasu Plastics Company Ltd [Member] | PVC Film [Member]
Business Acquisition [Line Items]
Combined annual capacity (in lb's) | lb			145
Suzhou Huasu Plastics Company Ltd [Member] | Affiliates [Member]
Business Acquisition [Line Items]
Percentage of interests acquired			35.70%							35.70%
Ownership interest (in percent)										59.30%
Percentage of interest			95.00%
Vinnolit [Member]
Business Acquisition [Line Items]
Number of production facilities | facility				6
Fair value of consideration transferred-cash				$ 736,224
Vinnolit [Member] | PVC Resin [Member]
Business Acquisition [Line Items]
Combined annual capacity (in lb's) | lb				1,700
Vinnolit [Member] | Vinyl Chloride Monomer [Member]
Business Acquisition [Line Items]
Combined annual capacity (in lb's) | lb				1,500
Vinnolit [Member] | Caustic Soda [Member]
Business Acquisition [Line Items]
Combined annual capacity (in lb's) | lb				1,000

Acquisitions (Pro Forma Informa

Acquisitions (Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
Net sales	$ 7,080,545	$ 7,793,086
Net income	398,826	662,750
Net income (loss) attributable to noncontrolling interest	22,748	(1,665)
Net income attributable to Westlake Chemical Corporation	$ 376,078	$ 664,415
Basic (in dollars per share)	$ 2.89	$ 5.02
Diluted (in dollars per share)	$ 2.88	$ 5

Acquisitions (Allocation of Pur

Acquisitions (Allocation of Purchase Consideration) (Details) - Axiall Corporation [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Aug. 31, 2016	Aug. 30, 2016
Business Acquisition [Line Items]
Offer price per share (usd per share)	$ 33
Multiplied by number of shares outstanding at acquisition	67,277
Fair value of Axiall shares outstanding purchased by the Company	$ 2,220,141
Axiall debt repaid at acquisition	247,135
Seller's transaction costs paid by the Company	47,458
Total fair value of consideration transferred	2,514,734
Fair value of Axiall share-based awards attributed to pre-combination service	11,346
Additional settlement value of shares acquired	13,280
Purchase consideration	2,539,360
Fair value of previously held equity interest in Axiall	102,300
Total fair value allocated to net assets acquired	$ 2,641,660
Equity interest in acquiree held prior to combination, shares		3,100

Acquisitions (Purchase Price Al

Acquisitions (Purchase Price Allocation) (Details) - USD ($) $ in Thousands	Aug. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill		$ 946,553	$ 62,016	$ 62,016
Customer relationships [Member]
Business Acquisition [Line Items]
Weighted average useful life	10 years 8 months 12 days
Trade Name [Member]
Business Acquisition [Line Items]
Weighted average useful life	6 years 9 months 18 days
Technology [Member]
Business Acquisition [Line Items]
Weighted average useful life	5 years 4 months 24 days
Supply Contracts and Leases [Member]
Business Acquisition [Line Items]
Weighted average useful life	6 years 3 months 18 days
Axiall Corporation [Member]
Business Acquisition [Line Items]
Cash	$ 88,251
Accounts receivable	422,459
Income tax receivable	55,193
Inventories	306,158
Prepaid expenses and other current assets	55,462
Property, plant and equipment	3,134,741
Other assets	98,708
Total assets acquired	4,869,760
Accounts and notes payable	255,232
Interest payable	8,154
Income tax payable	967
Accrued compensation	44,186
Accrued liabilities	152,550
Deferred income taxes	985,128
Tax reserve non-current	3,130
Pension and other post retirement obligations	311,106
Other liabilities	99,848
Long-term debt	1,187,290
Total liabilities assumed	3,047,591
Total identifiable net assets acquired	1,822,169
Noncontrolling interest	(68,000)
Goodwill	887,491
Total purchase consideration	2,641,660
Axiall Corporation [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles	590,000
Axiall Corporation [Member] | Trade Name [Member]
Business Acquisition [Line Items]
Finite-lived intangibles	50,000
Axiall Corporation [Member] | Technology [Member]
Business Acquisition [Line Items]
Finite-lived intangibles	41,500
Axiall Corporation [Member] | Supply Contracts and Leases [Member]
Business Acquisition [Line Items]
Finite-lived intangibles	$ 27,288

Financial Instruments (Cash Equ

Financial Instruments (Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Equivalents [Line Items]
Restricted cash	$ 186,216	$ 0
Restricted cash current	160,527
Restricted cash	$ 25,689	0
Held-to-maturity Securities [Member]
Cash Equivalents [Line Items]
Cash equivalents		$ 0	$ 221,918

Financial Instruments (Marketab

Financial Instruments (Marketable Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Current		$ 520,144
Non-current		48,081
Total Available-for-sale Securities	$ 0	$ 568,225

Financial Instruments (Availabl

Financial Instruments (Available-for-sale Securities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost		$ 576,021
Gross Unrealized Gains		525
Gross Unrealized Losses		(8,321)
Fair Value	$ 0	568,225
Net unrealized (losses) gains on AFS securities		(4,995)
Income tax (benefit) expense on net unrealized (losses) gains on AFS securities		(2,801)
Proceeds from sales and maturities of securities	662,938	48,900	$ 342,045
Gross realized gains	53,754	3,830	1,311
Gross realized losses	$ (35)	(32)	$ (99)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost		54,371
Gross Unrealized Gains		466
Gross Unrealized Losses		(6,756)
Fair Value		48,081
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost		336,665
Gross Unrealized Gains		55
Gross Unrealized Losses		(1,076)
Fair Value		335,644
US Government Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost		135,226
Gross Unrealized Gains		2
Gross Unrealized Losses		(374)
Fair Value		134,854
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost		49,759
Gross Unrealized Gains		2
Gross Unrealized Losses		(115)
Fair Value		$ 49,646

Accounts Receivable (Schedule O

Accounts Receivable (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Trade customers	$ 827,721	$ 438,538
Allowance for doubtful accounts	(17,991)	(14,095)
Receivables from trade customers and affiliates, net	809,730	424,443
Federal and state taxes	90,414	60,748
Other	38,599	23,341
Accounts receivable, net	$ 938,743	$ 508,532

Accounts Receivable (Activity i

Accounts Receivable (Activity in Allowance for Doubtful Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at Beginning of Year	$ 14,095	$ 13,468	$ 11,741
Charged to Expense	4,095	956	301
Additions/(Deductions)	(199)	(329)	1,426
Balance at End of Year	$ 17,991	$ 14,095	$ 13,468

Inventories (Schedule Of Invent

Inventories (Schedule Of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Inventory, Net [Abstract]
Finished products	$ 500,861	$ 253,338
Feedstock, additives and chemicals	216,877	106,435
Materials and supplies	83,362	74,287
Inventories	$ 801,100	$ 434,060

Property, Plant And Equipment73

Property, Plant And Equipment (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment, Net [Abstract]
Depreciation expense on property, plant and equipment	$ 305,273	$ 209,271	$ 174,173

Property, Plant And Equipment74

Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment, Net [Abstract]
Land	$ 194,137	$ 33,051
Building and improvements	464,570	266,214
Plant and equipment	6,913,721	3,632,416
Other	377,466	241,829
Property, plant and equipment, gross	7,949,894	4,173,510
Less: Accumulated depreciation	(1,919,229)	(1,685,255)
Property, plant and equipment, net, before construction in progress	6,030,665	2,488,255
Construction in progress	389,397	515,812
Property, plant and equipment, net	$ 6,420,062	$ 3,004,067

Other Assets (Narrative) (Detai

Other Assets (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Oct. 31, 2015	Apr. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Assets [Line Items]
Amortization expense of other assets			$ 73,757	$ 37,998	$ 35,496
Future amortization expense, 2017			99,011
Future amortization expense, 2018			98,669
Future amortization expense, 2019			97,648
Future amortization expense, 2020			95,717
Future amortization expense, 2021			94,214
Impairment since goodwill was initially recorded			$ 0
Olefins [Member]
Other Assets [Line Items]
Number of years forecasted to test for impairment of goodwill	9 years
Rate used to discount future cash flows for goodwill impairment test	8.80%
Percentage future cash flows of segment could decrease by and not be impaired	10.00%
Vinyls [Member]
Other Assets [Line Items]
Number of years forecasted to test for impairment of goodwill	9 years
Rate used to discount future cash flows for goodwill impairment test		11.50%
Percentage future cash flows of segment could decrease by and not be impaired		10.00%

Other Assets (Schedule Of Other

Other Assets (Schedule Of Other Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Cost	$ 946,553	$ 62,016
Goodwill, Net	946,553	62,016	$ 62,016
Cost-method investments	108,938	51,334
Equity-method investments	21,522	9,208
Restricted cash	25,689	0
Turnaround costs	168,501	111,078
Turnaround costs, Accumulated Amortization	(74,671)	(74,943)
Turnaround costs, Net	93,830	36,135
Deferred Taxes	12,526	0
Debt issuance costs, Cost	3,055	11,915
Debt issuance costs, Accumulated Amortization	(210)	(10,762)
Debt issuance costs, Net	2,845	1,153
Other, Costs	82,287	99,763
Other, Accumulated Amortization	(19,769)	(20,968)
Other, Net	62,518	78,795
Other assets, Cost	2,271,108	568,667
Other assets, Accumulated Amortization	(209,233)	(178,638)
Other assets, net	(2,061,875)	(390,029)
Total deferred charges and other assets, Cost	422,518	283,298
Total deferred charges and other assets, Accumulated Amortization	(94,650)	(106,673)
Total deferred charges and other assets, Net	$ 327,868	176,625
Turnaround Costs [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Weighted Average Life	5 years
Debt Issuance Costs [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Weighted Average Life	5 years
Other, Net [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Weighted Average Life	8 years
Customer relationships [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets, Cost	$ 662,080	75,249
Intangible assets, Accumulated Amortization	(50,465)	(22,572)
Intangible assets, Net	$ 611,615	52,677
Weighted Average Life	10 years
Licenses and intellectual property [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets, Cost	$ 120,992	79,699
Intangible assets, Accumulated Amortization	(44,035)	(38,643)
Intangible assets, Net	$ 76,957	41,056
Weighted Average Life	13 years
Trademarks [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets, Cost	$ 87,927	39,085
Intangible assets, Accumulated Amortization	(6,841)	(2,602)
Intangible assets, Net	$ 81,086	36,483
Weighted Average Life	12 years
Other Sundry Intangible Assets [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets, Cost	$ 31,038	29,320
Intangible assets, Accumulated Amortization	(13,242)	(8,148)
Intangible assets, Net	17,796	21,172
Other [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets, Cost	239,957	148,104
Intangible assets, Accumulated Amortization	(64,118)	(49,393)
Intangible assets, Net	$ 175,839	$ 98,711
Weighted Average Life	11 years

Other Assets (Goodwill) (Detail

Other Assets (Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2014
Goodwill [Line Items]
Impairment since goodwill was initially recorded		$ 0
Balance at end of year	$ 62,016	946,553	$ 62,016
Goodwill [Roll Forward]
Balance at beginning of year	62,016
Goodwill acquired during the year	887,491
Effects of changes in foreign exchange rates	(2,954)
Balance at end of year	946,553
Olefins [Member]
Goodwill [Line Items]
Balance at end of year	29,990	29,990	29,990
Goodwill [Roll Forward]
Balance at beginning of year	29,990
Goodwill acquired during the year	0
Effects of changes in foreign exchange rates	0
Balance at end of year	29,990
Vinyls [Member]
Goodwill [Line Items]
Balance at end of year	32,026	$ 916,563	$ 32,026
Goodwill [Roll Forward]
Balance at beginning of year	32,026
Goodwill acquired during the year	887,491
Effects of changes in foreign exchange rates	(2,954)
Balance at end of year	$ 916,563

Accounts and Notes Payable (Det

Accounts and Notes Payable (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts and Notes Payable [Abstract]
Accounts payable	$ 494,743	$ 229,219
Notes payable to banks	1,516	6,110
Accounts and notes payable	$ 496,259	$ 235,329

Term Loan (Narrative) (Details)

Term Loan (Narrative) (Details) - USD ($)	Aug. 10, 2016	Dec. 31, 2016	Sep. 10, 2016	Sep. 09, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Restricted cash		$ 186,216,000			$ 0
Senior Secured Revolving Credit Facility [Member] | Term Loan Facility Maturing March 31, 2017 [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 150,000,000
Interest rate on outstanding term loan (percent)		2.68%
Restricted cash	$ 150,000,000
Percent increase In restricted cash based on non-u.s. dollar based deposits	5.00%
Percent of pledged membership interests	65.00%
Senior Secured Revolving Credit Facility [Member] | Term Loan Facility Maturing March 31, 2017 [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Percentage added to basis to find interest rate	2.00%
Senior Secured Revolving Credit Facility [Member] | Term Loan Facility Maturing March 31, 2017 [Member] | Bank of America, N.A. [Member]
Line of Credit Facility [Line Items]
Restricted cash			$ 75,000,000	$ 50,000,000
Period to increase bank deposits	30 days

Long-Term Debt (Schedule Of Lon

Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 07, 2016	Sep. 06, 2016	Dec. 31, 2015	Jul. 17, 2012	Dec. 02, 2010
Debt Instrument [Line Items]
Equity-method investments	$ 21,522			$ 9,208
Deferred charges and other assets, net	327,868			176,625
Principal Amount	3,677,889			764,889
Unamortized Premium and Debt Issuance Costs	765			(6,741)
Long-term debt, net	3,678,654			758,148
Unamortized debt issuance costs	24,113			5,967
Scenario, Previously Reported [Member]
Debt Instrument [Line Items]
Deferred charges and other assets, net				173,384
Long-term debt, net				764,115
Accounting Standards Update 2015-03 [Member] | Other Assets [Member]
Debt Instrument [Line Items]
Equity-method investments				9,208
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal Amount	325,000			0
Unamortized Premium and Debt Issuance Costs	0			0
Long-term debt, net	325,000			0
Senior Notes [Member] | 4.625% Westlake Senior Notes 2021 [Member]
Debt Instrument [Line Items]
Principal Amount	624,793			0
Unamortized Premium and Debt Issuance Costs	26,837			0
Long-term debt, net	$ 651,630			0
Stated interest rate (percent)	4.625%		4.625%
Senior Notes [Member] | 4.625 Subsidiary Senior Notes 2021 [Member]
Debt Instrument [Line Items]
Principal Amount	$ 63,207	$ 624,793	$ 688,000	0
Unamortized Premium and Debt Issuance Costs	2,862			0
Long-term debt, net	$ 66,069			0
Stated interest rate (percent)	4.625%		4.625%
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Principal Amount	$ 250,000			250,000
Unamortized Premium and Debt Issuance Costs	(1,891)			(2,232)
Long-term debt, net	$ 248,109			$ 247,768
Stated interest rate (percent)	3.60%			3.60%	3.60%
Senior Notes [Member] | 4.875% Westlake Senior 2023 Notes [Member]
Debt Instrument [Line Items]
Principal Amount	$ 433,793			$ 0
Unamortized Premium and Debt Issuance Costs	13,431			0
Long-term debt, net	$ 447,224			0
Stated interest rate (percent)	4.875%	4.875%
Senior Notes [Member] | 4.875% Subsidiary 2023 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	$ 16,207	$ 433,793	$ 450,000	0
Unamortized Premium and Debt Issuance Costs	540			0
Long-term debt, net	$ 16,747			0
Stated interest rate (percent)	4.875%	4.875%
Senior Notes [Member] | 3.60% 2026 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	$ 750,000			0
Unamortized Premium and Debt Issuance Costs	(10,757)			0
Long-term debt, net	$ 739,243			0
Stated interest rate (percent)	3.60%
Senior Notes [Member] | Waste Disposal Revenue Bonds Due 2027 [Member]
Debt Instrument [Line Items]
Principal Amount	$ 10,889			10,889
Unamortized Premium and Debt Issuance Costs	0			0
Long-term debt, net	10,889			10,889
Senior Notes [Member] | GO Zone 6 1/2% Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Principal Amount	100,000			100,000
Unamortized Premium and Debt Issuance Costs	(916)			(989)
Long-term debt, net	$ 99,084			99,011
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 6.75% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Principal Amount	$ 250,000			250,000
Unamortized Premium and Debt Issuance Costs	(1,883)			(2,002)
Long-term debt, net	$ 248,117			247,998
Stated interest rate (percent)	6.75%
Senior Notes [Member] | GO Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member]
Debt Instrument [Line Items]
Principal Amount	$ 89,000			89,000
Unamortized Premium and Debt Issuance Costs	(839)			(884)
Long-term debt, net	$ 88,161			88,116
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	$ 65,000			65,000
Unamortized Premium and Debt Issuance Costs	(602)			(634)
Long-term debt, net	$ 64,398			64,366
Stated interest rate (percent)	6.50%					6.50%
Senior Notes [Member] | 5.0% 2046 [Member]
Debt Instrument [Line Items]
Principal Amount	$ 700,000			0
Unamortized Premium and Debt Issuance Costs	(26,017)			0
Long-term debt, net	$ 673,983			$ 0
Stated interest rate (percent)	5.00%

Long-Term Debt (Senior Secured

Long-Term Debt (Senior Secured Revolving Credit Facility) (Details) - Senior Secured Revolving Credit Facility [Member] - USD ($)	Aug. 23, 2016	Dec. 31, 2016	Sep. 30, 2016	Aug. 22, 2016
Debt Instrument [Line Items]
Term of debt instrument	5 years
Minimum [Member]
Debt Instrument [Line Items]
Increase in credit facility borrowings	$ 25,000,000
Maximum [Member]
Debt Instrument [Line Items]
Increase in credit facility borrowings	500,000,000
Bridge Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	50,000,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	150,000,000
Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 400,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,000,000,000		$ 1,000,000,000
Long-term line of credit		$ 325,000,000
Interest rate at end of period (percent)		2.19%
Letters of credit outstanding		$ 76,535,000
Remaining borrowing capacity		$ 598,465,000
Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of commitment on borrowing availability		0.10%
Revolving Credit Facility [Member] | Minimum [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate		1.00%
Revolving Credit Facility [Member] | Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate		0.00%
Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of commitment on borrowing availability		0.25%
Revolving Credit Facility [Member] | Maximum [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate		1.75%
Revolving Credit Facility [Member] | Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate		0.75%

Long-Term Debt (Senior Notes Du

Long-Term Debt (Senior Notes Due 2026 and 2046) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Aug. 10, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Principal amount	$ 3,677,889		$ 764,889
3.60% Senior Notes Due 2026 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount		$ 750,000
Stated interest rate (percent)		3.60%
5.0% Senior Notes Due 2046 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount		$ 700,000
Stated interest rate (percent)		5.00%

Long-Term Debt (Exchange Offers

Long-Term Debt (Exchange Offers) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 07, 2016	Sep. 06, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Principal amount	$ 3,677,889			$ 764,889
Senior Notes [Member] | 4.625 Subsidiary Senior Notes 2021 [Member]
Debt Instrument [Line Items]
Principal amount	$ 63,207	$ 624,793	$ 688,000	0
Unamortized premium		33,540
Stated interest rate (percent)	4.625%		4.625%
Senior Notes [Member] | 4.875% Subsidiary 2023 Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount	$ 16,207	433,793	$ 450,000	0
Unamortized premium		$ 15,750
Stated interest rate (percent)	4.875%	4.875%
Senior Notes [Member] | 4.625% Westlake Senior Notes 2021 [Member]
Debt Instrument [Line Items]
Principal amount	$ 624,793			0
Stated interest rate (percent)	4.625%		4.625%
Senior Notes [Member] | 4.875% Westlake Senior 2023 Notes [Member]
Debt Instrument [Line Items]
Principal amount	$ 433,793			$ 0
Stated interest rate (percent)	4.875%	4.875%

Long-Term Debt (Senior Notes 84

Long-Term Debt (Senior Notes due 2022 and GO Zone Bonds) (Details) - USD ($)	Jul. 17, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2010	Dec. 02, 2010	Jul. 02, 2010	Dec. 13, 2007
Debt Instrument [Line Items]
Minimum debt amount guaranteed by subsidiaries			$ 5,000,000
GO Zone 6 1/2% Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Senior notes, principal amount issued						$ 100,000,000
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Senior notes, principal amount issued	$ 250,000,000
Stated interest rate (percent)	3.60%	3.60%	3.60%
Senior notes, original discount issue	$ 1,183,000
Senior notes, minimum debt amount guaranteed by subsidiaries	$ 5,000,000		$ 5,000,000
Senior notes, repurchase price as percentage of principal amount upon change of control and below investment grade rating event	101.00%
Senior notes, maximum number of days from change of control for below investment grade rating event	60 days
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member] | Prior to April Fifteenth Twenty Twenty Two
Debt Instrument [Line Items]
Senior notes, redemption price as percentage of principal amount	100.00%
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member] | On or After April Fifteenth Twenty Twenty Two
Debt Instrument [Line Items]
Senior notes, redemption price as percentage of principal amount	100.00%
Senior Notes [Member] | GO Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member]
Debt Instrument [Line Items]
Stated interest rate (percent)		6.50%
Senior Notes [Member] | GO Zone 6 1/2% Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Stated interest rate (percent)		6.50%
Senior Notes [Member] | 6.75% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Stated interest rate (percent)		6.75%
GO Zone Act [Member] | Redeemed On Or After November 1, 2017 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called		100.00%
GO Zone Act [Member] | GO Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member]
Debt Instrument [Line Items]
Senior notes, principal amount issued					$ 89,000,000
Stated interest rate (percent)				6.50%
GO Zone Act [Member] | GO Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member] | Redeemed prior to November 1, 2020 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called		100.00%
GO Zone Act [Member] | GO Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member] | Redeemed on or After November 1, 2020 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called		100.00%
GO Zone Act [Member] | GO Zone 6 1/2% Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Stated interest rate (percent)						6.50%
GO Zone Act [Member] | GO Zone 6 1/2% Senior Notes Due 2029 [Member] | Redeemed Prior To August 1, 2020 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called		100.00%
GO Zone Act [Member] | GO Zone 6 1/2% Senior Notes Due 2029 [Member] | Redeemed on or After August 1, 2020 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called		100.00%
GO Zone Act [Member] | 6.75% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Senior notes, principal amount issued							$ 250,000,000
Stated interest rate (percent)							6.75%
GO Zone Act [Member] | 6.75% Senior Notes Due 2032 [Member] | Redeemed Prior To November 1, 2017 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called		100.00%

Long-Term Debt (IKE Zone Bonds)

Long-Term Debt (IKE Zone Bonds) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesagency	Dec. 31, 2015USD ($)	Dec. 02, 2010USD ($)
Debt Instrument [Line Items]
Minimum debt amount guaranteed by subsidiaries		$ 5,000,000
Number of credit rating agencies | agency	2
Maximum unrestricted distributions allowable	$ 100,000,000
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member]
Debt Instrument [Line Items]
Senior notes, principal amount issued			$ 65,000,000
Stated interest rate (percent)	6.50%		6.50%
Minimum debt amount guaranteed by subsidiaries	$ 5,000,000
Maximum unrestricted quarterly dividends allowable under debt covenants (in dollars per share) | $ / shares	0.10
Maximum percentage of income distribution	50.00%
Maximum distribution percentage of specified net cash proceeds	100.00%
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Fixed charge coverage ratio for debt covenant	2
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member] | Redeemed prior to November 1, 2020 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called	100.00%
Senior Notes [Member] | 6.5% 2035 IKE Zone Senior Notes [Member] | Redeemed on or After November 1, 2020 [Member]
Debt Instrument [Line Items]
Percentage of principal required if called	100.00%

Long-Term Debt (Revenue Bonds a

Long-Term Debt (Revenue Bonds and Bridge Loan Agreement) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 1997
Debt Instrument [Line Items]
Payments of Debt Issuance Costs		$ 35,773,000	$ 0	$ 1,186,000
Weighted average interest rate on all long-term debt		4.40%	5.50%
Waste Disposal Revenue Bonds Due 2027 [Member]
Debt Instrument [Line Items]
Senior notes, principal amount issued					$ 10,889,000
Effective interest rate		0.79%	0.07%
Axiall Corporation [Member]
Debt Instrument [Line Items]
Bridge Loan	$ 1,765,000,000
Payments of Debt Issuance Costs	$ 9,700,000

Stockholders' Equity (Details)

Stockholders' Equity (Details)	Feb. 14, 2014	Dec. 31, 2016USD ($)vote$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)	Nov. 20, 2015USD ($)	Mar. 31, 2015USD ($)shares	Nov. 30, 2014USD ($)	May 16, 2014$ / sharesshares	May 15, 2014shares	Aug. 31, 2011USD ($)
Class of Stock [Line Items]
Aggregated regular quarterly dividends on common stock		$ 96,560,000	$ 91,551,000	$ 77,656,000
Common stock, sinking fund		$ 0
Common stock, voting rights | vote		1
Common stock, redemption provision		$ 0
Stock split conversion ratio	2
Common Stock, shares authorized | shares		300,000,000	300,000,000					300,000,000	150,000,000
Common stock, par value per share (in dollars per share) | $ / shares		$ 0.01	$ 0.01					$ 0.01
Common stock, shares issued | shares		134,651,380	134,663,244
Ordinary Dividend [Member]
Class of Stock [Line Items]
Aggregated regular quarterly dividends on common stock		$ 96,560,000	$ 91,551,000	$ 77,656,000
2011 Program [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount										$ 100,000,000
Stock repurchase 2011 program, shares repurchased | shares						1,944,161
Aggregate purchase price of common stock repurchased						$ 100,000,000
2014 Program [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount					$ 150,000,000		$ 250,000,000
Stock repurchase 2014 program, shares repurchase | shares		1,511,109	2,682,489

Accumulated Other Comprehensi88

Accumulated Other Comprehensive Income (Loss) Changes in AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total equity, beginning balance	$ 3,561,931	$ 3,201,888	$ 2,418,603
Other comprehensive income (loss) before reclassifications	58,703	(49,384)
Amounts reclassified from accumulated other comprehensive loss	(50,717)	(475)
Net other comprehensive income (loss) for the year	7,986	(49,859)	(76,817)
Total equity, ending balance	3,892,045	3,561,931	3,201,888
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total equity, beginning balance	(129,292)	(79,433)
Total equity, ending balance	(121,306)	(129,292)	(79,433)
Benefits Liability, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total equity, beginning balance	(8,607)	(23,442)
Other comprehensive income (loss) before reclassifications	36,211	12,877
Amounts reclassified from accumulated other comprehensive loss	1,341	1,958
Net other comprehensive income (loss) for the year	37,552	14,835
Total equity, ending balance	28,945	(8,607)	(23,442)
Cumulative Foreign Currency Exchange
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total equity, beginning balance	(115,690)	(56,224)
Other comprehensive income (loss) before reclassifications	(34,512)	(59,466)
Amounts reclassified from accumulated other comprehensive loss	0	0
Net other comprehensive income (loss) for the year	(34,512)	(59,466)
Total equity, ending balance	(150,202)	(115,690)	(56,224)
Net Unrealized Holding Gains on Investments, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total equity, beginning balance	(4,995)	233
Other comprehensive income (loss) before reclassifications	57,004	(2,795)
Amounts reclassified from accumulated other comprehensive loss	(52,058)	(2,433)
Net other comprehensive income (loss) for the year	4,946	(5,228)
Total equity, ending balance	$ (49)	$ (4,995)	$ 233

Accumulated Other Comprehensi89

Accumulated Other Comprehensive Income (Loss) Reclassifications in AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense), net	$ 56,398	$ 38,270	$ (2,721)
Provision for income taxes, investments	(138,520)	(298,396)	(398,902)
Total reclassifications for the period	50,717	475
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	50,717	475	209
Accumulated Defined Benefit Plans Adjustment, Net Prior Service 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	(347)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) 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	(1,429)	(2,663)	(577)
Accumulated Defined Benefit Plan Adjustment, Curtailments 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	(364)	0	0
Accumulated Defined Benefit Plan Adjustment, Settlement Benefits 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	(371)	(355)	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	(1,341)	(1,958)
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	(2,164)	(3,018)	(924)
Provision for income taxes, defined benefit plan	823	1,060	356
Total reclassifications for the period	(1,341)	(1,958)	(568)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense), net	53,720	3,798	1,212
Provision for income taxes, investments	(1,662)	(1,365)	(435)
Income (Loss) from Continuing Operations, including portion attributable to noncontrolling interest	$ 52,058	$ 2,433	$ 777

Employee Benefits (Narrative De

Employee Benefits (Narrative Defined Contribution Plans) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)plan	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Non-U.S. Plans [Member]
Defined Contribution Plan [Line Items]
Defined contribution savings plan expense	$ 2,028	$ 1,912	$ 416
Defined Contribution Savings Plan [Member] | U. S. Plans [Member]
Defined Contribution Plan [Line Items]
Maximum employee contribution as a percentage of annual compensation	100.00%
Employer contributions to plans	$ 10,697	7,594	6,856
Defined Contribution Retirement Plan [Member] | U. S. Plans [Member]
Defined Contribution Plan [Line Items]
Employer contributions to plans	$ 16,766	$ 11,715	$ 8,309
Number of subsidiaries company provides a defined contribution plan | plan	1
Length of service required to be eligible for annual retirement contributions (in years)	1 year

Employee Benefits (Narrative 91

Employee Benefits (Narrative Defined Benefit Plans) (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2014plan	Dec. 31, 2016USD ($)subsidiary
Defined Benefit Plan Disclosure [Line Items]
Estimated prior service cost to be amortized from other comprehensive income into net periodic benefit cost during 2017		$ 0
Estimated net loss to be amortized from other comprehensive income into net periodic benefit cost during 2017		$ 1,761
Number of subsidiaries company provides post-retirement healthcare benefits to | subsidiary		2
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans amended | plan	1
Post-Retirement Healthcare Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated prior service cost to be amortized from other comprehensive income into net periodic benefit cost during 2017		$ 0
Estimated net loss to be amortized from other comprehensive income into net periodic benefit cost during 2017		56,446
Wage Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions		2,254
Salaried Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions		$ 900
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of pension plans		80.00%
Percentage of investments for long-term growth included in investment strategy		55.00%
Percentage of investments for short-term growth included in investment strategy		35.00%
Discretionary range for pension fund trustee included in investment policy		10.00%
Minimum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fixed income, target allocation percentage		55.00%
Minimum [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fixed income, target allocation percentage		35.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of pension plans		100.00%
Percentage of investments for long-term growth included in investment strategy		65.00%
Percentage of investments for short-term growth included in investment strategy		45.00%
Discretionary range for pension fund trustee included in investment policy		15.00%
Maximum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fixed income, target allocation percentage		65.00%
Maximum [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fixed income, target allocation percentage		45.00%

Employee Benefits (Schedule Of

Employee Benefits (Schedule Of Change In Benefit Obligation and Change In Plan Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U. S. Plans [Member]
Change in benefit obligation
Benefit obligation, beginning of year	$ 62,192	$ 67,010
Benefit obligation assumed with acquisition	818,602	0
Service cost	975	29
Interest cost	8,832	2,015	$ 2,322
Actuarial (gain) loss	(74,262)	(2,330)
Benefits paid	(17,081)	(4,532)
Other	0	0
Foreign exchange effects	0	0
Benefit obligation, end of year	799,258	62,192	67,010
Change in plan assets
Fair value of plan assets, beginning of year	50,763	53,415
Acquisition	575,865	0
Actual return	7,334	(268)
Employer contribution	456	2,148
Benefits paid	(17,081)	(4,532)
Experience gain	136	0
Administrative expenses paid	(3,204)	0
Foreign exchange effects	0	0
Fair value of plan assets, end of year	614,269	50,763	53,415
Funded status, end of year	(184,989)	(11,429)
Non-U. S. Plans [Member]
Change in benefit obligation
Benefit obligation, beginning of year	94,821	122,701
Benefit obligation assumed with acquisition	20,895	0
Service cost	1,459	1,661
Interest cost	2,441	2,110	1,366
Actuarial (gain) loss	12,705	(17,310)
Benefits paid	(2,571)	(2,139)
Other	(61)	0
Foreign exchange effects	(4,537)	(12,202)
Benefit obligation, end of year	125,152	94,821	122,701
Change in plan assets
Fair value of plan assets, beginning of year	0	0
Acquisition	16,298	0
Actual return	27	0
Employer contribution	2,609	2,139
Benefits paid	(2,571)	(2,139)
Experience gain	0	0
Administrative expenses paid	0	0
Foreign exchange effects	(371)	0
Fair value of plan assets, end of year	15,992	0	0
Funded status, end of year	(109,160)	(94,821)
U. S. Plans [Member]
Change in benefit obligation
Benefit obligation, beginning of year	17,815	20,177
Benefit obligation assumed with acquisition	69,650	0
Service cost	289	22
Interest cost	1,000	571	733
Actuarial (gain) loss	(6,151)	(1,848)
Benefits paid	(2,355)	(1,107)
Curtailment	(364)	0	0
Plan participants' contributions	35	0
Foreign exchange effects	0	0
Benefit obligation, end of year	79,919	17,815	20,177
Change in plan assets
Fair value of plan assets, beginning of year	0	0
Employer contribution	2,320	1,107
Benefits paid	(2,355)	(1,107)
Fair value of plan assets, end of year		0	$ 0
Funded status, end of year	(79,919)	(17,815)
Non-U.S. Plans [Member]
Change in benefit obligation
Benefit obligation, beginning of year	0
Benefit obligation assumed with acquisition	3,324
Service cost	5
Interest cost	12
Actuarial (gain) loss	91
Benefits paid	(9)
Curtailment	0
Plan participants' contributions	0
Foreign exchange effects	(82)
Benefit obligation, end of year	3,341	0
Change in plan assets
Fair value of plan assets, beginning of year	0
Employer contribution	9
Benefits paid	(9)
Fair value of plan assets, end of year		$ 0
Funded status, end of year	$ (3,341)

Employee Benefits (Schedule O93

Employee Benefits (Schedule Of Amounts Recognized In The Consolidated Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	$ (364,819)	$ (122,821)
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Current liabilities	(1,691)	0
Noncurrent liabilities	(183,298)	(11,429)
Net amount recognized	(184,989)	(11,429)
Non-U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	233	0
Current liabilities	(2,583)	0
Noncurrent liabilities	(106,810)	(94,821)
Net amount recognized	(109,160)	(94,821)
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(8,447)	(1,244)
Noncurrent liabilities	(71,472)	(16,571)
Net amount recognized	(79,919)	$ (17,815)
Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(102)
Noncurrent liabilities	(3,239)
Net amount recognized	$ (3,341)

Employee Benefits (Schedule O94

Employee Benefits (Schedule Of Amounts Recognized In Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income, benefits, net of tax	$ 30,287	$ 6,812
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (gain) loss	(53,302)	14,755
Foreign exchange effects	0	0
Total before tax	(53,302)	14,755
Non-U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (gain) loss	7,990	(4,919)
Foreign exchange effects	(15)	1,986
Total before tax	7,975	(2,933)
Post-Retirement Healthcare Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income, benefits, net of tax	(1,342)	1,795
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (gain) loss	(3,659)	2,978
Total before tax	(3,659)	$ 2,978
Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (gain) loss	91
Total before tax	$ 91

Employee Benefits (Schedule O95

Employee Benefits (Schedule Of Accumulated Benefit Obligations In Excess Of Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ (799,258)	$ (62,192)	$ (67,010)
Fair value of plan assets	614,269	50,763	53,415
U. S. Plans [Member] | Underfunded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	(799,258)	(62,192)
Accumulated benefit obligation	(799,258)	(62,192)
Fair value of plan assets	614,269	50,763
Non-U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	(125,152)	(94,821)	(122,701)
Fair value of plan assets	15,992	0	$ 0
Non-U. S. Plans [Member] | Underfunded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	(113,286)	(94,821)
Accumulated benefit obligation	(109,837)	(93,231)
Fair value of plan assets	$ 4,627	$ 0

Employee Benefits (Schedule O96

Employee Benefits (Schedule Of Net Benefit Costs And Amounts Recognized In Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Amortization of net loss	$ (1,429)	$ (2,663)	$ (924)
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,261	29	334
Administrative expenses	2,919	0	0
Interest cost	8,832	2,015	2,322
Expected return on plan assets	(15,354)	(2,960)	(3,140)
Net amortization	1,307	1,270	571
Settlement benefits	371	355	0
Net periodic benefit (gain) cost	(664)	709	87
Net (gain) loss emerging	(66,379)	898	9,352
Amortization of net loss	(1,307)	(1,270)	(274)
Amortization of prior service cost	0	0	(297)
Settlement benefits	(371)	(355)	0
Total recognized in OCI	(68,057)	(727)	8,781
Total net periodic benefit cost and OCI	(68,721)	(18)	8,868
Non-U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,459	1,661	602
Administrative expenses	0	0	0
Interest cost	2,441	2,110	1,366
Expected return on plan assets	(199)	0	0
Net amortization	0	1,048	0
Settlement benefits	0	0	0
Net periodic benefit (gain) cost	3,701	4,819	1,968
Net (gain) loss emerging	12,893	(17,310)	15,425
Amortization of net loss	0	(1,048)	0
Amortization of prior service cost	0	0	0
Settlement benefits	0	0	0
Total recognized in OCI	12,893	(18,358)	15,425
Total net periodic benefit cost and OCI	16,594	(13,539)	17,393
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	289	22	22
Interest cost	1,000	571	733
Net amortization	122	345	353
Net periodic benefit (gain) cost	1,411	938	1,108
Net (gain) loss emerging	(6,151)	(1,848)	989
Curtailment	(364)	0	0
Amortization of net loss	(122)	(345)	(303)
Amortization of prior service cost	0	0	(50)
Total recognized in OCI	(6,637)	(2,193)	636
Total net periodic benefit cost and OCI	(5,226)	$ (1,255)	$ 1,744
Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	5
Interest cost	12
Net amortization	0
Net periodic benefit (gain) cost	17
Net (gain) loss emerging	91
Curtailment	0
Amortization of net loss	0
Amortization of prior service cost	0
Total recognized in OCI	91
Total net periodic benefit cost and OCI	$ 108

Employee Benefits (Schedule O97

Employee Benefits (Schedule Of Weighted Average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.80%	4.00%	3.50%
Rate of compensation increase	0.00%	0.00%	0.00%
Discount rate for benefit obligations	3.20%	3.50%	4.50%
Discount rate for service cost	3.40%	0.00%	0.00%
Discount rate for interest cost	2.90%	0.00%	0.00%
Expected return on plan assets	6.80%	7.00%	7.00%
Rate of compensation increase	0.00%	0.00%	0.00%
Non-U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	1.80%	2.40%	1.90%
Rate of compensation increase	2.60%	2.50%	2.50%
Discount rate for benefit obligations	2.40%	1.90%	2.60%
Discount rate for service cost	2.40%	0.00%	0.00%
Discount rate for interest cost	2.40%	0.00%	0.00%
Expected return on plan assets	4.60%	0.00%	0.00%
Rate of compensation increase	2.60%	2.50%	2.50%
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.30%	3.50%	3.30%
Discount rate for benefit obligations	2.60%	3.30%	4.00%
Discount rate for service cost	3.10%	0.00%	0.00%
Discount rate for interest cost	2.80%	0.00%	0.00%
Health care cost trend rate - Initial rate	7.30%	0.00%	0.00%
Health care cost trend rate- Ultimate rate	4.50%	0.00%	0.00%
Health care cost trend rate- Years to ultimate (benefit obligations)	11 years
Health care cost trend rate- Initial rate (periodic benefit costs)	7.00%	0.00%	0.00%
Health care cost trend rate- Years to ultimate (periodic benefit costs)	12 years
Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.00%
Discount rate for benefit obligations	3.30%
Discount rate for service cost	3.30%
Discount rate for interest cost	3.30%
Health care cost trend rate - Initial rate	6.20%
Health care cost trend rate- Ultimate rate	4.50%
Health care cost trend rate- Years to ultimate (benefit obligations)	12 years
Health care cost trend rate- Initial rate (periodic benefit costs)	6.80%
Health care cost trend rate- Years to ultimate (periodic benefit costs)	13 years

Employee Benefits (Schedule O98

Employee Benefits (Schedule Of Fair Value Of Pension Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 614,269	$ 50,763	$ 53,415
U. S. Plans [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U. S. Plans [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,546	0
U. S. Plans [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	190,268
U. S. Plans [Member] | Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U. S. Plans [Member] | Level 1 [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,546
U. S. Plans [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	424,001	50,763
U. S. Plans [Member] | Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U. S. Plans [Member] | Level 2 [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Large-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	216,747	18,384
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Small-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31,786	4,069
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | International Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	107,051	8,181
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 1 [Member] | Large-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50,143
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 1 [Member] | Small-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,379
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 1 [Member] | International Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	53,422
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 2 [Member] | Large-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	166,604	18,384
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 2 [Member] | Small-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23,407	4,069
U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 2 [Member] | International Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	53,629	8,181
U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Bond Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	227,435	19,624
U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Short Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,704	505
U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 1 [Member] | Bond Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	61,778
U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 1 [Member] | Short Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 2 [Member] | Bond Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	165,657	19,624
U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 2 [Member] | Short Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,704	505
Non-U. S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,992	$ 0	$ 0
Non-U. S. Plans [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,627
Non-U. S. Plans [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,627
Non-U. S. Plans [Member] | Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,627
Non-U. S. Plans [Member] | Level 1 [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,365
Non-U. S. Plans [Member] | Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Level 2 [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Large-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,609
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Small-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | International Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,370
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 1 [Member] | Large-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 1 [Member] | Small-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 1 [Member] | International Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 2 [Member] | Large-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,609
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 2 [Member] | Small-Cap Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Equity Securities [Member] | Level 2 [Member] | International Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,370
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Bond Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,386
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Short Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 1 [Member] | Bond Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 1 [Member] | Short Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 2 [Member] | Bond Index Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,386
Non-U. S. Plans [Member] | Bank Collective Trust Funds - Fixed Income [Member] | Level 2 [Member] | Short Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0

Employee Benefits (Multiemploye

Employee Benefits (Multiemployer Plans) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)plan	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Number of multiemployer plans | plan	2
Contributions to multi-employer plans | $	$ 4,952	$ 4,489	$ 2,295

Employee Benefits (Schedule 100

Employee Benefits (Schedule Of Estimated Future Benefit Payments) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Year 1	$ 51,324
Year 2	49,626
Year 3	51,163
Year 4	51,554
Year 5	51,715
Years 6 to 10	267,024
Post-Retirement Healthcare Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Year 1	8,663
Year 2	8,460
Year 3	8,302
Year 4	8,185
Year 5	8,122
Years 6 to 10	$ 34,681

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	4 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Aug. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 14,193	$ 10,196	$ 9,261
Total intrinsic value of options exercised		3,630	1,145	14,534
Income tax benefit from the exercise of stock options		1,090	78	4,512
Transaction and integration-related costs		$ 103,672	0	9,614
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	$ 3,708	$ 3,708
Unrecognized compensation expense, weighted-average period of recognition (in years)		1 year 6 months
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense			0
Total fair value of shares of restricted stock that vested		$ 4,260	8,363	8,831
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	16,110	$ 16,110
Unrecognized compensation expense, weighted-average period of recognition (in years)		2 years 2 months 12 days
Total fair value of shares of restricted stock that vested		$ 4,031	$ 725	$ 371
Ratably On Annual Basis [Member] | Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		1 year
Ratably On Annual Basis [Member] | Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		4 years
Ratably On Annual Basis [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		3 years
Cliff Vest [Member] | Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		1 year
Cliff Vest [Member] | Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		6 years
First One Half Increment On Anniversary Of Award Date [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		5 years
Second One Half Increment On Anniversary Of Award Date [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		9 years 6 months
Second One Half Increment On Anniversary Of Award Date [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period		9 years 6 months
Axiall Corporation [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Transaction and integration-related costs		$ 103,672
Share price (in dollars per share)					$ 33
Axiall Corporation [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		38,031
Unrecognized compensation expense	$ 11,707	11,707
Unrecognized compensation expense, weighted-average period of recognition (in years)	1 year 2 months 12 days
Transaction and integration-related costs		$ 32,644
Total fair value of shares of restricted stock that vested	$ 2,870
Share price (in dollars per share)					$ 33

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule Of Option Activity And Changes) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Options
Options, Outstanding, beginning balance | shares	1,267,790
Options, Granted | shares	292,448
Options, Exercised | shares	(112,611)
Options, Cancelled | shares	(42,893)
Options, Outstanding, ending balance | shares	1,404,734
Options, Exercisable, ending balance | shares	940,314
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding, beginning balance (in dollars per share) | $ / shares	$ 30.07
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	44.42
Weighted Average Exercise Price, Exercised (in dollars per share) | $ / shares	19.33
Weighted Average Exercise Price, Cancelled (in dollars per share) | $ / shares	35.07
Weighted Average Exercise Price, Outstanding, ending balance (in dollars per share) | $ / shares	33.76
Weighted Average Exercise Price, Exercisable, ending balance (in dollars per share) | $ / shares	$ 24.29
Weighted Average Remaining Term (Years), Outstanding	5 years 3 months 18 days
Weighted Average Remaining Term (Years), Exercisable	3 years 8 months 12 days
Aggregate Intrinsic Value, Outstanding | $	$ 34,368
Aggregate Intrinsic Value, Exercisable | $	$ 31,009

Stock-Based Compensation (Sc103

Stock-Based Compensation (Schedule Of Range Of Exercise Prices For Outstanding Options) (Details)	12 Months Ended
	Dec. 31, 2016$ / sharesshares
$7.12 - $9.65 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise prices, minimum (in dollars per share)	$ 7.12
Range of exercise prices, maximum (in dollars per share)	$ 9.65
Options Outstanding | shares	304,200
Weighted Average Remaining Contractual Life (Years)	1 year 8 months 12 days
$10.26 - $18.05 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise prices, minimum (in dollars per share)	$ 10.26
Range of exercise prices, maximum (in dollars per share)	$ 18.05
Options Outstanding | shares	235,916
Weighted Average Remaining Contractual Life (Years)	2 years 3 months 18 days
$22.92 - $30.05 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise prices, minimum (in dollars per share)	$ 22.92
Range of exercise prices, maximum (in dollars per share)	$ 30.05
Options Outstanding | shares	174,082
Weighted Average Remaining Contractual Life (Years)	4 years 8 months 12 days
$40.38 - $52.35 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise prices, minimum (in dollars per share)	$ 40.38
Range of exercise prices, maximum (in dollars per share)	$ 52.35
Options Outstanding | shares	391,083
Weighted Average Remaining Contractual Life (Years)	8 years 4 months 24 days
$63.98 - $68.18 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise prices, minimum (in dollars per share)	$ 63.98
Range of exercise prices, maximum (in dollars per share)	$ 68.18
Options Outstanding | shares	299,453
Weighted Average Remaining Contractual Life (Years)	7 years 8 months 12 days

Stock-Based Compensation (Sc104

Stock-Based Compensation (Schedule Of Weighted Average Value And Assumptions For Fair Value Of Options) (Details) - $ / shares	4 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value (in dollars per share)		$ 11.67	$ 20.21	$ 20.49
Risk-free interest rate		1.40%	1.70%	1.60%
Expected life in years		5 years	5 years	5 years
Expected volatility		32.90%	34.20%	35.70%
Expected dividend yield		1.60%	0.90%	0.70%
Restricted Stock [Member] | Axiall Corporation [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average vesting period (in years)	1 year 2 months 12 days
Risk-free interest rate	0.90%
Expected volatility	28.20%
Expected dividend yield	1.40%

Stock-Based Compensation (Sc105

Stock-Based Compensation (Schedule Of Non-Vested Restricted Stock Award and RSU Activity and Changes) (Details) - $ / shares	4 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016
Restricted Stock [Member]
Number of Shares
Number of Shares, Non-vested, beginning balance		64,856
Number of Shares, Granted		28,142
Number of Shares, Vested		(81,134)
Number of Shares, Forfeited		(11,864)
Number of Shares, Non-vested, ending balance	0	0
Weighted Average Grant Date Fair Value
Weighted Average Grant Date Fair Value, Non-vested, beginning balance (in dollars per share)		$ 15.81
Weighted Average Grant Date Fair Value, Granted (in dollars per share)		51.53
Weighted Average Grant Date Fair Value, Vested (in dollars per share)		28.19
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share)		15.81
Weighted Average Grant Date Fair Value, Non-vested, ending balance (in dollars per share)	$ 0	$ 0
Restricted Stock [Member] | Axiall Corporation [Member]
Number of Shares
Number of Shares, Non-vested, beginning balance	340,413
Number of Shares, Vested	(54,266)
Number of Shares, Non-vested, ending balance	286,147	286,147
Weighted Average Grant Date Fair Value
Weighted Average Grant Date Fair Value, Non-vested, beginning balance (in dollars per share)	$ 51.82
Weighted Average Grant Date Fair Value, Vested (in dollars per share)	52.88
Weighted Average Grant Date Fair Value, Non-vested, ending balance (in dollars per share)	$ 60.77	$ 60.77
Restricted Stock Units (RSUs) [Member]
Number of Shares
Number of Shares, Non-vested, beginning balance		498,872
Number of Shares, Granted		204,642
Number of Shares, Vested		(88,877)
Number of Shares, Forfeited		(17,078)
Number of Shares, Non-vested, ending balance	597,559	597,559
Weighted Average Grant Date Fair Value
Weighted Average Grant Date Fair Value, Non-vested, beginning balance (in dollars per share)		$ 57.61
Weighted Average Grant Date Fair Value, Granted (in dollars per share)		48.64
Weighted Average Grant Date Fair Value, Vested (in dollars per share)		48.28
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share)		67.47
Weighted Average Grant Date Fair Value, Non-vested, ending balance (in dollars per share)	$ 55.64	$ 55.64

Derivative Commodity Instrum106

Derivative Commodity Instruments (Narrative) (Details) - Commodity Forward Contracts [Member] gal in Millions, MMBTU in Millions	12 Months Ended
	Dec. 31, 2016MMBTUinstrumentgal	Dec. 31, 2015MMBTUinstrumentgal	Dec. 31, 2014instrument
Designated As Fair Value Hedges [Member]
Derivative [Line Items]
Number of derivative instruments designated as fair value hedges | instrument	0	0	0
Derivatives Not Designated As Hedging Instrument [Member]
Derivative [Line Items]
Notional amount of derivative (in gallons) | gal	257	171
Notional amount of derivative (in btu's) | MMBTU	8.5	8

Derivative Commodity Instrum107

Derivative Commodity Instruments (Fair Values Of Derivative Instruments In Consolidated Balance Sheets) (Details) - Derivatives Not Designated As Hedging Instrument [Member] - Commodity Forward Contracts [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Total asset derivatives	$ 14,986	$ 5,553
Total liability derivatives	7,221	21,762
Accounts Receivable, Net [Member]
Derivative [Line Items]
Total asset derivatives	7,727	3,465
Deferred Charges and Other Assets, Net [Member]
Derivative [Line Items]
Total asset derivatives	7,259	2,088
Accrued Liabilities [Member]
Derivative [Line Items]
Total liability derivatives	1,487	9,325
Other Liabilities [Member]
Derivative [Line Items]
Total liability derivatives	$ 5,734	$ 12,437

Derivative Commodity Instrum108

Derivative Commodity Instruments (Impact Of Derivative Instruments Not Designated As Fair Value Hedges) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commodity Forward Contracts [Member] | Derivatives Not Designated As Hedging Instrument [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ 19,696	$ (11,395)	$ (9,678)

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Assets And Liabilities On A Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	$ 0	$ 568,225
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		568,225
Fair Value, Measurements, Recurring [Member] | Commodity Forward Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Risk management assets	14,986	5,553
Risk management liabilities	(7,221)	(21,762)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		48,081
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Commodity Forward Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Risk management assets	878	5,553
Risk management liabilities	(6,854)	(11,648)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities		520,144
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Commodity Forward Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Risk management assets	14,108	0
Risk management liabilities	$ (367)	$ (10,114)

Fair Value Measurements (Sch110

Fair Value Measurements (Schedule Of Carrying And Fair Values Of Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 07, 2016	Sep. 06, 2016	Dec. 31, 2015	Jul. 17, 2012	Dec. 02, 2010
Senior Notes [Member] | 4.625% Westlake Senior Notes 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	4.625%		4.625%
Senior Notes [Member] | 4.625 Subsidiary Senior Notes 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	4.625%		4.625%
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.60%			3.60%	3.60%
Senior Notes [Member] | 4.875% Westlake Senior 2023 Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	4.875%	4.875%
Senior Notes [Member] | 4.875% Subsidiary 2023 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	4.875%	4.875%
Senior Notes [Member] | 3.60% 2026 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.60%
Senior Notes [Member] | 6.5% Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 6.75% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	6.75%
Senior Notes [Member] | 6.5% 2035 GO Zone Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
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]
Stated interest rate (percent)	6.50%					6.50%
Senior Notes [Member] | 5.0% 2046 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	5.00%
Reported Value Measurement [Member] | Waste Disposal Revenue Bonds Due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	$ 10,889			$ 10,889
Reported Value Measurement [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving credit facility	325,000			0
Reported Value Measurement [Member] | Senior Notes [Member] | 4.625% Westlake Senior Notes 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	651,630			0
Reported Value Measurement [Member] | Senior Notes [Member] | 4.625 Subsidiary Senior Notes 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	66,069			0
Reported 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	248,109			247,768
Reported Value Measurement [Member] | Senior Notes [Member] | 4.875% Westlake Senior 2023 Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	447,224			0
Reported Value Measurement [Member] | Senior Notes [Member] | 4.875% Subsidiary 2023 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	16,747			0
Reported Value Measurement [Member] | Senior Notes [Member] | 3.60% 2026 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	739,243			0
Reported Value Measurement [Member] | Senior Notes [Member] | 6.5% Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	99,084			99,011
Reported Value Measurement [Member] | Senior Notes [Member] | 6.75% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	248,117			247,998
Reported Value Measurement [Member] | Senior Notes [Member] | 6.5% 2035 GO Zone Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	88,161			88,116
Reported 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	64,398			64,366
Reported Value Measurement [Member] | Senior Notes [Member] | 5.0% 2046 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	673,983			0
Estimate of Fair Value Measurement [Member] | Waste Disposal Revenue Bonds Due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	10,889			10,889
Estimate of Fair Value Measurement [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving credit facility	325,000			0
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 4.625% Westlake Senior Notes 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	650,847			0
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 4.625 Subsidiary Senior Notes 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	65,775			0
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	251,725			244,828
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 4.875% Westlake Senior 2023 Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	451,301			0
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 4.875% Subsidiary 2023 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	16,501			0
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 3.60% 2026 Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	722,055			0
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 6.5% Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	112,433			117,153
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 6.75% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	258,818			268,490
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | 6.5% 2035 GO Zone Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	100,323			106,491
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	73,270			76,741
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	$ 691,712			$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Tax Examination [Line Items]
Foreign and state net operating loss carryforwards	$ 564,896
Net operating loss carryforwards, change in valuation allowance	36,661
Undistributed earnings of foreign subsidiaries	209,791
Unremitted foreign earnings U.S. income tax expense	32,319
Deferred tax liability related to undistributed foreign earnings	2,218
Unrecognized tax benefits	7,188	$ 0
Unrecognized tax benefits that would impact effective tax rate	4,571
Income tax penalties and interest expense	328	$ 0
Income tax penalties and interest accrued	253
Foreign [Member]
Income Tax Examination [Line Items]
Deferred tax liability related to undistributed foreign earnings	1,448
U.S. [Member]
Income Tax Examination [Line Items]
Deferred tax liability related to undistributed foreign earnings	$ 770

Income Taxes (Components Of Inc

Income Taxes (Components Of Income (Loss) Before Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Domestic	$ 476,423	$ 880,044	$ 1,102,101
Foreign	81,956	83,397	(18,183)
Income before income taxes	$ 558,379	$ 963,441	$ 1,083,918

Income Taxes (Schedule Of The P

Income Taxes (Schedule Of The Provision For (Benefit From) Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
Federal	$ 8,156	$ 225,617	$ 300,610
State	8,967	23,966	37,351
Foreign	20,720	9,029	1,974
Total Current	37,843	258,612	339,935
Deferred
Federal	136,206	29,820	40,950
State	(33,681)	2,807	22,714
Foreign	(1,848)	7,157	(4,697)
Total Deferred	100,677	39,784	58,967
Provision for income taxes	$ 138,520	$ 298,396	$ 398,902

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Taxes Computed At The Statutory Rate To Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Provision for federal income tax, at statutory rate	$ 195,432	$ 337,204	$ 379,371
State income tax provision, net of federal income tax effect	1,408	17,403	40,012
Foreign income tax rate differential	(7,594)	(13,002)	3,640
Manufacturing deduction	(2,371)	(24,185)	(24,465)
Depletion	(2,298)	0	0
Contingent tax liability	2,172	0	(1,626)
Noncontrolling interests	(6,940)	(6,662)	(2,255)
Tax on previously held shares of Axiall Corporation and certain other acquisition related items	(12,924)	0	0
Changes in state apportionment and other state adjustments	(16,929)	0	0
Research and development expenditures and adjustments related to prior years’ tax returns	(8,344)
Other, net	(3,092)	(12,362)	4,225
Provision for income taxes	$ 138,520	$ 298,396	$ 398,902

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ 69,790	$ 17,679
Credit carryforward	23,932	746
Accruals	66,694	57,811
Pension	113,644	4,393
Allowance for doubtful accounts	12,039	4,617
Inventories	13,257	8,663
Other	36,624	7,747
Deferred taxes assets—total	335,980	101,656
Property, plant and equipment	(1,374,095)	(408,374)
Intangibles	(220,489)	(15,007)
Turnaround costs	(701)	(1,467)
Basis difference—consolidated partnerships	(308,361)	(200,627)
Other	(17,377)	0
Deferred tax liabilities—total	(1,921,023)	(625,475)
Valuation allowance	(53,006)	(16,345)
Total net deferred tax liabilities	(1,638,049)	(540,164)
Balance sheet classifications
Current deferred tax asset	0	35,439
Noncurrent deferred tax asset	12,526	0
Noncurrent deferred tax liability	$ (1,650,575)	$ (575,603)

Income Taxes (Schedule Of Chang

Income Taxes (Schedule Of Changes In Gross Unrecognized Tax Benefits) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 0
Amounts attributable to Axiall pre-acquisition	5,030
Additions during the year ended December 31, 2016	3,398
Reductions due to statutes of limitations expiring	(1,184)
Effects of changes in foreign exchange rates	(56)
Ending balance	$ 7,188

Earnings per Share (Narrative)

Earnings per Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Options excluded from computation of earnings per share, shares	318,259	301,969	126,091

Earnings per Share (Schedule Of

Earnings per Share (Schedule Of Net Income Attributable To Common Stockholders) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income attributable to Westlake Chemical Corporation	$ 98,945	$ 65,662	$ 111,124	$ 123,128	$ 110,969	$ 183,604	$ 205,095	$ 146,342	$ 398,859	$ 646,010	$ 678,523
Less: Net income attributable to participating securities									(1,784)	(2,825)	(1,502)
Net income attributable to common shareholders									$ 397,075	$ 643,185	$ 677,021

Earnings per Share (Reconciliat

Earnings per Share (Reconciliation Of Denominator For Basic And Diluted Earnings (Loss) Per Share) (Details) - $ / shares	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Weighted average common shares—basic									129,367,712	131,823,707	133,111,230
Plus incremental shares from: Assumed exercise of options									607,110	478,105	532,184
Weighted average common shares—diluted									129,974,822	132,301,812	133,643,414
Basic (in dollars per share)	$ 0.76	$ 0.51	$ 0.85	$ 0.94	$ 0.85	$ 1.39	$ 1.55	$ 1.10	$ 3.07	$ 4.88	$ 5.09
Diluted (in dollars per share)	$ 0.76	$ 0.51	$ 0.85	$ 0.94	$ 0.84	$ 1.39	$ 1.54	$ 1.10	$ 3.06	$ 4.86	$ 5.07

Supplemental Information (Detai

Supplemental Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities
Accrued liabilities	$ 537,483	$ 287,313
Accrued rebates	77,985	46,460
Other Income, Net
Interest income	8,421	6,034	$ 3,468
Dividend income	4,821	3,559	532
Acquisition-related financing costs	(12,453)	0	0
Foreign exchange currency gains (losses), net	122	1,828	(7,382)
Income from equity method investments	3,613	6,242	5,883
Impairment of equity method investments	0	(4,925)	(6,747)
Gain realized on previously held shares of Axiall common stock	49,080	0	0
Gain on acquisition and related expenses, net	0	20,430	0
Gain from sales of securities, net	4,640	3,798	1,212
Other	(1,846)	1,304	313
Other income (expense), net	56,398	38,270	(2,721)
Cash Flow Information
Interest paid, net of interest capitalized	45,534	31,946	35,336
Income taxes paid	$ 3,066	$ 314,186	$ 314,745

Related Party And Affiliate 121

Related Party And Affiliate Transactions (Details) $ in Thousands, T in Billions	Jun. 17, 2015USD ($)T	Dec. 31, 2016USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Aug. 31, 2016	Apr. 30, 2014
Related Party Transaction [Line Items]
Ownership percentage by parent		100.00%	100.00%
Dividends received from equity method investments			$ 5,116	$ 5,610	$ 5,459
Affiliates [Member]
Related Party Transaction [Line Items]
Incurred and paid lease payments			3,024	2,148	2,001
Accounts payable due to related parties		$ (236)	$ (236)	(196)
Cypress Interstate Pipeline L.L.C [Member] | Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Pipeline fees incurred for usage					14,206
InfraServ Knapsack GmbH & Co. KG [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership percentage by parent		15.00%	15.00%
InfraServ Gendorf GmbH & Co. KG [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Investments in joint ventures		$ 49,532	$ 49,532	51,333
Ownership percentage by parent		11.00%	11.00%
Shriram Axiall Private Limited [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)							50.00%
Investments in joint ventures		$ 1,974	$ 1,974
Sales to related parties		49
Related party receivable		80	80
RS Cogen LLC [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Investments in joint ventures		9,949	9,949
Sales to related parties		8,623
Related party receivable		$ 1,159	$ 1,159
RS Cogen LLC [Member] | Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)						50.00%
Vinyl Solutions, LLC [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%	50.00%
Investments in joint ventures		$ 500	$ 500
Sales to related parties		6,218
Related party receivable		4,855	4,855
LACC [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)	10.00%
Investments in joint ventures		59,405	$ 59,405
Accounts payable due to affiliate	$ 225,000
Related party receivable				820
Plant capacity (in T) | T	1
Optional ownership percentage	50.00%
Funding to related parties		$ 17,000
EPS Ethylene Pipeline Süd GmbH & Co. KG [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Ownership percentage by parent		10.00%	10.00%
American Air Liquide Holdings [Member] | American Air Liquide Holdings, Inc. [Member]
Related Party Transaction [Line Items]
Accounts payable due to related parties		$ (3,724)	$ (3,724)	(762)
Sales to related parties			3,988
Related party receivable		$ 664	664	0
Purchases and lease expense to related parties			$ 22,167	10,345	13,862
Cypress Interstate Pipeline L.L.C [Member] | Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Ownership interest (in percent)		50.00%	50.00%
Investments in joint ventures		$ 9,098	$ 9,098	9,208
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]
Pipeline fees incurred for usage			13,748	14,110
Accounts payable due to affiliate		1,018	1,018	991
Electricity And Technical Services [Member] | InfraServ Knapsack & Gendorf GmbH & Co. KG [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Accounts payable due to affiliate		24,708	24,708	22,931
Purchases from related parties			130,840	115,961	55,400
Pipeline Fees For Transport Of Ethylene Feedstocks [Member] | EPS Ethylene Pipeline Süd GmbH & Co. KG [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Accounts payable due to affiliate		$ 0	0
Purchases from related parties			$ 797	$ 1,022	$ 548

Insurance Recovery (Details)

Insurance Recovery (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Insurance Recovery [Abstract]
Insurance recoveries	$ 2,670	$ 7,809

Westlake Chemical Partners L123

Westlake Chemical Partners LP (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 04, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Net proceeds from WLKP LP common stock units		$ 0	$ 0	$ 286,088
Westlake Chemical Partners LP [Member] | IPO [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited partner interest (percent)	52.20%
Westlake Chemical Partners LP [Member] | IPO [Member] | Subsidiaries [Member]
Related Party Transaction [Line Items]
Percentage sold to public in IPO	47.80%
Westlake Chemical OpCo LP [Member] | IPO [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited partner interest (percent)	89.40%	86.70%
Westlake Chemical Partners LP [Member] | IPO [Member] | Subsidiaries [Member]
Related Party Transaction [Line Items]
Net proceeds distributed to the Company from the initial public offering	$ 230,669
Westlake Chemical Partners LP [Member] | IPO [Member] | Subsidiaries [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Number of units sold in public offering	12,937,500			12,937,500
Price per unit (in dollars per share)	$ 24
Net proceeds from WLKP LP common stock units	$ 286,088
Estimated offering expenses from sale of partnership units	(24,412)
Total proceeds from the initial public offering	$ 310,500
Westlake Chemical Partners LP [Member] | Over-Allotment Option [Member] | Subsidiaries [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Number of units sold in public offering	1,687,500
Subsidiary of Common Parent [Member] | Westlake Chemical OpCo LP [Member] | IPO [Member] | Subsidiaries [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Limited partner interest (percent)	10.60%	13.30%
Cash Reserve Turnaround [Member] | Westlake Chemical OpCo LP [Member] | IPO [Member] | Subsidiaries [Member]
Related Party Transaction [Line Items]
Amount used from proceeds	$ (55,419)
Preformation Capital Expenditure [Member] | Westlake Chemical OpCo LP [Member] | IPO [Member] | Subsidiaries [Member]
Related Party Transaction [Line Items]
Amount used from proceeds	151,729
Intercompany Debt [Member] | Westlake Chemical OpCo LP [Member] | IPO [Member] | Subsidiaries [Member]
Related Party Transaction [Line Items]
Amount used from proceeds	$ 78,940

Commitments And Contingencie124

Commitments And Contingencies (Narrative) (Details) $ in Thousands	Apr. 21, 2014USD ($)	May 31, 2013USD ($)	Dec. 31, 2016USD ($)settlement	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Loss Contingencies [Line Items]
Loss contingency accrual			$ 48,817	$ 5,368
Operating lease rental expense			87,323	69,455	$ 56,014
Minimum [Member]
Loss Contingencies [Line Items]
Reasonably possible additional loss			40,000
Maximum [Member]
Loss Contingencies [Line Items]
Reasonably possible additional loss			$ 80,000
Threatened Litigation [Member]
Loss Contingencies [Line Items]
Penalty amount		$ 449
Number of claims settled | settlement			2
Amount of settlement			$ (192)
Axiall Corporation [Member] | Threatened Litigation [Member]
Loss Contingencies [Line Items]
Amount of settlement				$ (900)
LDEQ [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Approximate value of damages sought			100
EPA [Member] | Pending Litigation [Member] | Plaquemine, Louisiana [Member]
Loss Contingencies [Line Items]
Approximate value of damages sought			$ 167
EPA [Member] | Pending Litigation [Member] | Culvert City, Kentucky and Lakes Charles, Louisiana [Member]
Loss Contingencies [Line Items]
Approximate value of damages sought	$ 100

Commitments And Contingencie125

Commitments And Contingencies (Future Minimum Lease Commitments) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Operating Leases
2,017	$ 86,910
2,018	78,941
2,019	60,885
2,020	48,395
2,021	39,626
Thereafter	603,621
Total minimum lease payments	918,378
Capital Leases
2,017	3,713
2,018	3,627
2,019	3,367
2,020	3,367
2,021	2,610
Thereafter	13,943
Total minimum lease payments	30,627
Less: Imputed interest costs	(10,681)
Present value of net minimum lease payments	$ 19,946

Commitments And Contingencie126

Commitments And Contingencies (Minimum Purchase Obligations) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Unconditional purchase obligations
2,017	$ 307,768
2,018	304,129
2,019	284,894
2,020	266,989
2,021	$ 188,372

Segment And Geographic Infor127

Segment And Geographic Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016plantSegmentcustomer	Dec. 31, 2015customer	Dec. 31, 2014customer
Segment Reporting Information [Line Items]
Number of segments | Segment	2
Number of plants | plant	26
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 Infor128

Segment And Geographic Information (Segment Reporting Information) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net external sales	$ 1,735,180	$ 1,279,028	$ 1,086,061	$ 975,187	$ 986,766	$ 1,188,037	$ 1,185,002	$ 1,103,531	$ 5,075,456	$ 4,463,336	$ 4,415,350
Intersegment sales									191,075	108,354	147,924
Income from operations	$ 152,677	$ 46,563	$ 179,938	$ 202,276	$ 181,145	$ 254,028	$ 295,374	$ 229,280	581,454	959,827	1,123,991
Depreciation and amortization									377,666	245,757	208,486
Other income (expense), net									56,398	38,270	(2,721)
Provision for (benefit from) income taxes									138,520	298,396	398,902
Capital expenditures									628,483	491,426	431,104
Olefins [Member]
Segment Reporting Information [Line Items]
Net external sales									1,893,634	2,260,113	2,723,690
Intersegment sales									165,266	106,861	146,539
Income from operations									557,806	747,436	1,013,825
Depreciation and amortization									136,500	110,684	106,244
Other income (expense), net									5,156	4,656	6,102
Provision for (benefit from) income taxes									175,394	242,516	354,159
Capital expenditures									323,590	304,873	188,729
Vinyls [Member]
Segment Reporting Information [Line Items]
Net external sales									3,181,822	2,203,223	1,691,660
Intersegment sales									25,809	1,493	1,385
Income from operations									174,141	254,452	142,740
Depreciation and amortization									237,588	134,546	101,666
Other income (expense), net									3,138	8,540	2,680
Provision for (benefit from) income taxes									24,695	64,456	52,249
Capital expenditures									302,208	176,582	237,992
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Income from operations									(150,493)	(42,061)	(32,574)
Depreciation and amortization									3,578	527	576
Other income (expense), net									48,104	25,074	(11,503)
Provision for (benefit from) income taxes									(61,569)	(8,576)	(7,506)
Capital expenditures									2,685	9,971	4,383
Polyethylene [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net external sales									1,462,407	1,650,964	1,922,535
Styrene, Feedstock and Other [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net external sales									431,227	609,149	801,155
PVC, Caustic Soda And Other [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net external sales									2,492,562	1,718,359	1,203,332
Building Products [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net external sales									$ 689,260	$ 484,864	$ 488,328

Segment And Geographic Infor129

Segment And Geographic Information (Capital Expenditures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Capital expenditures	$ 628,483	$ 491,426	$ 431,104
Olefins [Member]
Segment Reporting Information [Line Items]
Capital expenditures	323,590	304,873	188,729
Vinyls [Member]
Segment Reporting Information [Line Items]
Capital expenditures	302,208	176,582	237,992
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Capital expenditures	$ 2,685	$ 9,971	$ 4,383

Segment And Geographic Infor130

Segment And Geographic Information (Total Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total assets	$ 10,890,253	$ 5,569,285
Olefins [Member]
Segment Reporting Information [Line Items]
Total assets	2,092,617	1,869,888
Vinyls [Member]
Segment Reporting Information [Line Items]
Total assets	8,287,204	2,638,833
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Total assets	$ 510,432	$ 1,060,564

Segment And Geographic Infor131

Segment And Geographic Information (Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting [Abstract]
Income from operations for reportable segments	$ 152,677	$ 46,563	$ 179,938	$ 202,276	$ 181,145	$ 254,028	$ 295,374	$ 229,280	$ 581,454	$ 959,827	$ 1,123,991
Interest expense									(79,473)	(34,656)	(37,352)
Other income (expense), net									56,398	38,270	(2,721)
Income before income taxes									$ 558,379	$ 963,441	$ 1,083,918

Segment And Geographic Infor132

Segment And Geographic Information (Geographic Information for Sales to External Customers and Long-lived Assets) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales	$ 1,735,180	$ 1,279,028	$ 1,086,061	$ 975,187	$ 986,766	$ 1,188,037	$ 1,185,002	$ 1,103,531	$ 5,075,456	$ 4,463,336	$ 4,415,350
Long-lived assets	6,420,062				3,004,067				6,420,062	3,004,067
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									3,525,492	3,133,395	3,596,091
Long-lived assets	5,782,796				2,588,366				5,782,796	2,588,366
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									401,950	394,459	198,921
Long-lived assets	401,572				379,262				401,572	379,262
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									317,083	195,790	217,567
Switzerland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									101,320	106,750	89,214
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									87,118	46,451	6,515
Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									84,359	90,237	36,823
Belgium [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									50,662	41,542	24,082
France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									50,371	58,727	27,521
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net external sales									457,101	395,985	$ 218,616
Long-lived assets	$ 235,694				$ 36,439				$ 235,694	$ 36,439

Guarantor Disclosures (Narrativ

Guarantor Disclosures (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Jul. 17, 2012
Condensed Financial Statements, Captions [Line Items]
Ownership percentage by parent	100.00%
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (percent)	3.60%	3.60%	3.60%
Senior notes, minimum debt amount guaranteed by subsidiaries		$ 5,000	$ 5,000

Guarantor Disclosures (Condense

Guarantor Disclosures (Condensed Consolidating Financial Information Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 459,453	$ 662,525	$ 880,601	$ 461,301
Marketable securities	0	520,144
Accounts receivable, net	938,743	508,532
Inventories	801,100	434,060
Prepaid expenses and other current assets	48,493	14,489
Restricted cash	160,527
Deferred income taxes	0	35,439
Total current assets	2,408,316	2,175,189
Property, plant and equipment, net	6,420,062	3,004,067
Other assets, net	2,061,875	390,029
Total assets	10,890,253	5,569,285
Accounts and notes payable	496,259	235,329
Accrued liabilities	537,483	287,313
Term loan	149,341	0
Total current liabilities	1,183,083	522,642
Long-term debt	3,678,654	758,148
Deferred income taxes	1,650,575	575,603
Pension and other liabilities	485,896	150,961
Total liabilities	6,998,208	2,007,354
Total Westlake Chemical Corporation stockholders' equity	3,523,629	3,265,878
Noncontrolling interests	368,416	296,053
Total equity	3,892,045	3,561,931	3,201,888	2,418,603
Total liabilities and equity	10,890,253	5,569,285
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Marketable securities		0
Accounts receivable, net	(4,832,599)	(2,167,758)
Inventories	0	0
Prepaid expenses and other current assets	(36,504)	(2,879)
Restricted cash	0
Deferred income taxes		0
Total current assets	(4,869,103)	(2,170,637)
Property, plant and equipment, net	0	0
Other assets, net	(10,857,635)	(6,970,326)
Total assets	(15,726,738)	(9,140,963)
Accounts and notes payable	(4,807,780)	(2,143,033)
Accrued liabilities	(61,323)	(27,604)
Term loan	0
Total current liabilities	(4,869,103)	(2,170,637)
Long-term debt	(3,997,070)	(733,516)
Deferred income taxes	(22,494)	(6,567)
Pension and other liabilities	0	0
Total liabilities	(8,888,667)	(2,910,720)
Total Westlake Chemical Corporation stockholders' equity	(6,838,071)	(6,230,243)
Noncontrolling interests	0	0
Total equity	(6,838,071)	(6,230,243)
Total liabilities and equity	(15,726,738)	(9,140,963)
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	146,990	303,131	655,947	420,948
Marketable securities		520,144
Accounts receivable, net	2,117,540	10,943
Inventories	0	0
Prepaid expenses and other current assets	30,748	2,201
Restricted cash	0
Deferred income taxes		702
Total current assets	2,295,278	837,121
Property, plant and equipment, net	0	0
Other assets, net	9,170,042	5,003,096
Total assets	11,465,320	5,840,217
Accounts and notes payable	4,330,375	1,817,963
Accrued liabilities	26,367	9,117
Term loan	0
Total current liabilities	4,356,742	1,827,080
Long-term debt	3,584,949	747,259
Deferred income taxes	0	0
Pension and other liabilities	0	0
Total liabilities	7,941,691	2,574,339
Total Westlake Chemical Corporation stockholders' equity	3,523,629	3,265,878
Noncontrolling interests	0	0
Total equity	3,523,629	3,265,878
Total liabilities and equity	11,465,320	5,840,217
100% Owned Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	53,006	6,818	3,047	6,213
Marketable securities		0
Accounts receivable, net	3,329,871	2,474,963
Inventories	597,819	287,114
Prepaid expenses and other current assets	41,755	10,186
Restricted cash	0
Deferred income taxes		28,325
Total current assets	4,022,451	2,807,406
Property, plant and equipment, net	4,475,943	1,476,642
Other assets, net	2,264,597	914,823
Total assets	10,762,991	5,198,871
Accounts and notes payable	748,364	374,468
Accrued liabilities	389,216	163,167
Term loan	0
Total current liabilities	1,137,580	537,635
Long-term debt	4,090,775	744,405
Deferred income taxes	1,581,260	513,692
Pension and other liabilities	360,622	49,202
Total liabilities	7,170,237	1,844,934
Total Westlake Chemical Corporation stockholders' equity	3,592,754	3,353,937
Noncontrolling interests	0	0
Total equity	3,592,754	3,353,937
Total liabilities and equity	10,762,991	5,198,871
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	259,457	352,576	$ 221,607	$ 34,140
Marketable securities		0
Accounts receivable, net	323,931	190,384
Inventories	203,281	146,946
Prepaid expenses and other current assets	12,494	4,981
Restricted cash	160,527
Deferred income taxes		6,412
Total current assets	959,690	701,299
Property, plant and equipment, net	1,944,119	1,527,425
Other assets, net	1,484,871	1,442,436
Total assets	4,388,680	3,671,160
Accounts and notes payable	225,300	185,931
Accrued liabilities	183,223	142,633
Term loan	149,341
Total current liabilities	557,864	328,564
Long-term debt	0	0
Deferred income taxes	91,809	68,478
Pension and other liabilities	125,274	101,759
Total liabilities	774,947	498,801
Total Westlake Chemical Corporation stockholders' equity	3,245,317	2,876,306
Noncontrolling interests	368,416	296,053
Total equity	3,613,733	3,172,359
Total liabilities and equity	$ 4,388,680	$ 3,671,160

Guarantor Disclosures (Conde135

Guarantor Disclosures (Condensed Consolidating Financial Information Statement Of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,735,180	$ 1,279,028	$ 1,086,061	$ 975,187	$ 986,766	$ 1,188,037	$ 1,185,002	$ 1,103,531	$ 5,075,456	$ 4,463,336	$ 4,415,350
Cost of sales									4,094,894	3,278,145	3,098,000
Gross profit	281,478	202,133	241,366	255,585	236,188	311,276	353,181	284,546	980,562	1,185,191	1,317,350
Selling, general and administrative expenses									295,436	225,364	183,745
Transaction and integration-related costs									103,672	0	9,614
Income from operations	152,677	46,563	179,938	202,276	181,145	254,028	295,374	229,280	581,454	959,827	1,123,991
Interest expense									(79,473)	(34,656)	(37,352)
Other income (expense), net									56,398	38,270	(2,721)
Income before income taxes									558,379	963,441	1,083,918
Provision for (benefit from) income taxes									138,520	298,396	398,902
Equity in net income of subsidiaries									0	0	0
Net income	105,289	70,014	115,620	128,936	116,157	188,420	210,061	150,407	419,859	665,045	685,016
Net income attributable to noncontrolling interests									21,000	19,035	6,493
Net income attributable to Westlake Chemical Corporation	$ 98,945	$ 65,662	$ 111,124	$ 123,128	$ 110,969	$ 183,604	$ 205,095	$ 146,342	398,859	646,010	678,523
Comprehensive income (loss) attributable to Westlake Chemical Corporation									406,845	596,151	601,706
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									(1,379,313)	(1,380,877)	(1,694,376)
Cost of sales									(1,357,342)	(1,361,055)	(1,673,074)
Gross profit									(21,971)	(19,822)	(21,302)
Selling, general and administrative expenses									(21,971)	(19,822)	(21,302)
Transaction and integration-related costs									0		0
Income from operations									0	0	0
Interest expense									81,920	42,208	28,629
Other income (expense), net									(81,920)	(42,208)	(28,629)
Income before income taxes									0	0	0
Provision for (benefit from) income taxes									0	0	0
Equity in net income of subsidiaries									(400,057)	(663,834)	(699,615)
Net income									(400,057)	(663,834)	(699,615)
Net income attributable to noncontrolling interests									0	0	0
Net income attributable to Westlake Chemical Corporation									(400,057)	(663,834)	(699,615)
Comprehensive income (loss) attributable to Westlake Chemical Corporation									(407,377)	(595,839)	(622,741)
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0	0
Cost of sales									0	0	0
Gross profit									0	0	0
Selling, general and administrative expenses									3,488	2,478	2,082
Transaction and integration-related costs									0		0
Income from operations									(3,488)	(2,478)	(2,082)
Interest expense									(82,908)	(42,197)	(39,763)
Other income (expense), net									77,151	19,614	21,001
Income before income taxes									(9,245)	(25,061)	(20,844)
Provision for (benefit from) income taxes									(8,047)	(7,237)	248
Equity in net income of subsidiaries									400,057	663,834	699,615
Net income									398,859	646,010	678,523
Net income attributable to noncontrolling interests									0	0	0
Net income attributable to Westlake Chemical Corporation									398,859	646,010	678,523
Comprehensive income (loss) attributable to Westlake Chemical Corporation									406,845	596,151	601,706
100% Owned Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									4,009,891	3,557,806	3,617,627
Cost of sales									3,532,638	2,842,466	3,056,659
Gross profit									477,253	715,340	560,968
Selling, general and administrative expenses									204,353	150,968	121,182
Transaction and integration-related costs									103,226		7,411
Income from operations									169,674	564,372	432,375
Interest expense									(75,907)	(34,667)	(26,218)
Other income (expense), net									(14,247)	5,576	(4,278)
Income before income taxes									79,520	535,281	401,879
Provision for (benefit from) income taxes									115,457	275,687	192,659
Equity in net income of subsidiaries									0	0	0
Net income									(35,937)	259,594	209,220
Net income attributable to noncontrolling interests									0	0	0
Net income attributable to Westlake Chemical Corporation									(35,937)	259,594	209,220
Comprehensive income (loss) attributable to Westlake Chemical Corporation									11,695	261,392	203,428
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									2,444,878	2,286,407	2,492,099
Cost of sales									1,919,598	1,796,734	1,714,415
Gross profit									525,280	489,673	777,684
Selling, general and administrative expenses									109,566	91,740	81,783
Transaction and integration-related costs									446		2,203
Income from operations									415,268	397,933	693,698
Interest expense									(2,578)	0	0
Other income (expense), net									75,414	55,288	9,185
Income before income taxes									488,104	453,221	702,883
Provision for (benefit from) income taxes									31,110	29,946	205,995
Equity in net income of subsidiaries									0	0	0
Net income									456,994	423,275	496,888
Net income attributable to noncontrolling interests									21,000	19,035	6,493
Net income attributable to Westlake Chemical Corporation									435,994	404,240	490,395
Comprehensive income (loss) attributable to Westlake Chemical Corporation									$ 395,682	$ 334,447	$ 419,313

Guarantor Disclosures (Conde136

Guarantor Disclosures (Condensed Consolidating Financial Information Statement Of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ 105,289	$ 70,014	$ 115,620	$ 128,936	$ 116,157	$ 188,420	$ 210,061	$ 150,407	$ 419,859	$ 665,045	$ 685,016
Depreciation and amortization									377,666	245,757	208,486
Deferred income taxes									100,677	39,784	58,967
Net changes in working capital and other									(64,350)	128,250	79,907
Net cash provided by operating activities									833,852	1,078,836	1,032,376
Acquisition of business, net of cash acquired									(2,437,829)	15,782	(611,087)
Additions to cost method investments									(17,000)	0	0
Additions to property, plant and equipment									(628,483)	(491,426)	(431,104)
Proceeds from disposition of assets									1,207	49	181
Proceeds from disposition of equity method investment									0	27,865	0
Proceeds from repayment of loan to affiliate									0	0	45,923
Proceeds from sales and maturities of securities									662,938	48,900	342,045
Purchase of securities									(138,422)	(605,098)	(117,332)
Settlements of derivative instruments									(5,211)	(2,248)	(1,831)
Net cash used for investing activities									(2,562,800)	(1,006,176)	(773,205)
Intercompany financing									0	0	0
Net distributions prior to Westlake Partners initial public offering											0
Capitalized debt issuance costs									(35,773)	0	(1,186)
Dividends paid									(96,560)	(91,551)	(77,656)
Distributions paid									(16,637)	(14,856)	(2,204)
Proceeds from senior notes issuance									1,428,512	0	0
Net proceeds from issuance of Westlake Partners common units									0	0	286,088
Proceeds from exercise of stock options									2,179	1,063	5,524
Proceeds from issuance of notes payable									8,324	52,960	0
Proceeds from term loan and drawdown of revolver									600,000	0	0
Restricted cash associated with term loan									(154,000)	0	0
Repayment of notes payable									(13,046)	(73,615)	0
Repayment of revolver									(125,000)	0	0
Repurchase of common stock for treasury									(67,406)	(162,459)	(52,630)
Windfall tax benefits from share-based payment arrangements									2,624	1,646	6,704
Net cash provided (used for) by financing activities									1,533,217	(286,812)	164,640
Effect of exchange rate changes on cash and cash equivalents									(7,341)	(3,924)	(4,511)
Net (decrease) increase in cash and cash equivalents									(203,072)	(218,076)	419,300
Cash and cash equivalents at beginning of the year				662,525				880,601	662,525	880,601	461,301
Cash and cash equivalents at end of the year	459,453				662,525				459,453	662,525	880,601
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									(400,057)	(663,834)	(699,615)
Depreciation and amortization									0	0	0
Deferred income taxes									0	0	0
Net changes in working capital and other									400,057	663,834	699,615
Net cash provided by operating activities									0	0	0
Acquisition of business, net of cash acquired									0	0	0
Additions to cost method investments									0
Additions to property, plant and equipment									0	0	0
Proceeds from disposition of assets									0	0	0
Proceeds from disposition of equity method investment										0
Proceeds from repayment of loan to affiliate											0
Proceeds from sales and maturities of securities									0	0	0
Purchase of securities									0	0	0
Settlements of derivative instruments									0	0	0
Net cash used for investing activities									0	0	0
Intercompany financing									0	0	0
Net distributions prior to Westlake Partners initial public offering											0
Capitalized debt issuance costs									0		0
Dividends paid									0	0	0
Distributions paid									0	0	0
Proceeds from senior notes issuance									0
Net proceeds from issuance of Westlake Partners common units											0
Proceeds from exercise of stock options									0	0	0
Proceeds from issuance of notes payable									0	0
Proceeds from term loan and drawdown of revolver									0
Restricted cash associated with term loan									0
Repayment of notes payable									0	0
Repayment of revolver									0
Repurchase of common stock for treasury									0	0	0
Windfall tax benefits from share-based payment arrangements									0	0	0
Net cash provided (used for) by financing activities									0	0	0
Effect of exchange rate changes on cash and cash equivalents									0	0	0
Net (decrease) increase in cash and cash equivalents									0	0	0
Cash and cash equivalents at beginning of the year				0				0	0	0	0
Cash and cash equivalents at end of the year	0				0				0	0	0
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									398,859	646,010	678,523
Depreciation and amortization									0	0	0
Deferred income taxes									1,214	(285)	(288)
Net changes in working capital and other									(437,148)	(658,773)	(704,370)
Net cash provided by operating activities									(37,075)	(13,048)	(26,135)
Acquisition of business, net of cash acquired									0	0	0
Additions to cost method investments									0
Additions to property, plant and equipment									0	0	0
Proceeds from disposition of assets									0	0	0
Proceeds from disposition of equity method investment										0
Proceeds from repayment of loan to affiliate											0
Proceeds from sales and maturities of securities									658,338	48,900	342,045
Purchase of securities									(138,422)	(556,211)	(117,332)
Settlements of derivative instruments									0	0	0
Net cash used for investing activities									519,916	(507,311)	224,713
Intercompany financing									(2,199,148)	418,844	155,665
Net distributions prior to Westlake Partners initial public offering											0
Capitalized debt issuance costs									(34,183)		(1,186)
Dividends paid									(96,560)	(91,551)	(77,656)
Distributions paid									0	0	0
Proceeds from senior notes issuance									1,428,512
Net proceeds from issuance of Westlake Partners common units											0
Proceeds from exercise of stock options									2,179	1,063	5,524
Proceeds from issuance of notes payable									0	0
Proceeds from term loan and drawdown of revolver									450,000
Restricted cash associated with term loan									0
Repayment of notes payable									0	0
Repayment of revolver									(125,000)
Repurchase of common stock for treasury									(67,406)	(162,459)	(52,630)
Windfall tax benefits from share-based payment arrangements									2,624	1,646	6,704
Net cash provided (used for) by financing activities									(638,982)	167,543	36,421
Effect of exchange rate changes on cash and cash equivalents									0	0	0
Net (decrease) increase in cash and cash equivalents									(156,141)	(352,816)	234,999
Cash and cash equivalents at beginning of the year				303,131				655,947	303,131	655,947	420,948
Cash and cash equivalents at end of the year	146,990				303,131				146,990	303,131	655,947
100% Owned Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									(35,937)	259,594	209,220
Depreciation and amortization									216,374	113,575	101,779
Deferred income taxes									103,315	38,680	47,692
Net changes in working capital and other									90,183	93,633	(560,996)
Net cash provided by operating activities									373,935	505,482	(202,305)
Acquisition of business, net of cash acquired									(2,502,018)	0	0
Additions to cost method investments									(17,000)
Additions to property, plant and equipment									(274,564)	(215,405)	(209,111)
Proceeds from disposition of assets									1,037	18	180
Proceeds from disposition of equity method investment										27,865
Proceeds from repayment of loan to affiliate											0
Proceeds from sales and maturities of securities									0	0	0
Purchase of securities									0	(48,887)	0
Settlements of derivative instruments									(5,211)	(2,248)	(1,698)
Net cash used for investing activities									(2,797,756)	(238,657)	(210,629)
Intercompany financing									2,207,119	(590,114)	(244,122)
Net distributions prior to Westlake Partners initial public offering											448,101
Capitalized debt issuance costs									0		0
Dividends paid									0	0	151,729
Distributions paid									262,890	327,060	54,060
Proceeds from senior notes issuance									0
Net proceeds from issuance of Westlake Partners common units											0
Proceeds from exercise of stock options									0	0	0
Proceeds from issuance of notes payable									0	0
Proceeds from term loan and drawdown of revolver									0
Restricted cash associated with term loan									0
Repayment of notes payable									0	0
Repayment of revolver									0
Repurchase of common stock for treasury									0	0	0
Windfall tax benefits from share-based payment arrangements									0	0	0
Net cash provided (used for) by financing activities									2,470,009	(263,054)	409,768
Effect of exchange rate changes on cash and cash equivalents									0	0	0
Net (decrease) increase in cash and cash equivalents									46,188	3,771	(3,166)
Cash and cash equivalents at beginning of the year				6,818				3,047	6,818	3,047	6,213
Cash and cash equivalents at end of the year	53,006				6,818				53,006	6,818	3,047
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									456,994	423,275	496,888
Depreciation and amortization									161,292	132,182	106,707
Deferred income taxes									(3,852)	1,389	11,563
Net changes in working capital and other									(117,442)	29,556	645,658
Net cash provided by operating activities									496,992	586,402	1,260,816
Acquisition of business, net of cash acquired									64,189	15,782	(611,087)
Additions to cost method investments									0
Additions to property, plant and equipment									(353,919)	(276,021)	(221,993)
Proceeds from disposition of assets									170	31	1
Proceeds from disposition of equity method investment										0
Proceeds from repayment of loan to affiliate											45,923
Proceeds from sales and maturities of securities									4,600	0	0
Purchase of securities									0	0	0
Settlements of derivative instruments									0	0	(133)
Net cash used for investing activities									(284,960)	(260,208)	(787,289)
Intercompany financing									(7,971)	171,270	88,457
Net distributions prior to Westlake Partners initial public offering											(448,101)
Capitalized debt issuance costs									(1,590)		0
Dividends paid									0	0	(151,729)
Distributions paid									(279,527)	(341,916)	(56,264)
Proceeds from senior notes issuance
Net proceeds from issuance of Westlake Partners common units											286,088
Proceeds from exercise of stock options									0	0	0
Proceeds from issuance of notes payable									8,324	52,960
Proceeds from term loan and drawdown of revolver									150,000
Restricted cash associated with term loan									(154,000)
Repayment of notes payable									(13,046)	(73,615)
Repayment of revolver									0
Repurchase of common stock for treasury									0	0	0
Windfall tax benefits from share-based payment arrangements									0	0	0
Net cash provided (used for) by financing activities									(297,810)	(191,301)	(281,549)
Effect of exchange rate changes on cash and cash equivalents									(7,341)	(3,924)	(4,511)
Net (decrease) increase in cash and cash equivalents									(93,119)	130,969	187,467
Cash and cash equivalents at beginning of the year				$ 352,576				$ 221,607	352,576	221,607	34,140
Cash and cash equivalents at end of the year	$ 259,457				$ 352,576				$ 259,457	$ 352,576	$ 221,607

Quarterly Financial Informat137

Quarterly Financial Information (Summary Of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 1,735,180	$ 1,279,028	$ 1,086,061	$ 975,187	$ 986,766	$ 1,188,037	$ 1,185,002	$ 1,103,531	$ 5,075,456	$ 4,463,336	$ 4,415,350
Gross profit	281,478	202,133	241,366	255,585	236,188	311,276	353,181	284,546	980,562	1,185,191	1,317,350
Income from operations	152,677	46,563	179,938	202,276	181,145	254,028	295,374	229,280	581,454	959,827	1,123,991
Net income	105,289	70,014	115,620	128,936	116,157	188,420	210,061	150,407	419,859	665,045	685,016
Net income attributable to Westlake Chemical Corporation	$ 98,945	$ 65,662	$ 111,124	$ 123,128	$ 110,969	$ 183,604	$ 205,095	$ 146,342	$ 398,859	$ 646,010	$ 678,523
Basic (in dollars per share)	$ 0.76	$ 0.51	$ 0.85	$ 0.94	$ 0.85	$ 1.39	$ 1.55	$ 1.10	$ 3.07	$ 4.88	$ 5.09
Diluted (in dollars per share)	$ 0.76	$ 0.51	$ 0.85	$ 0.94	$ 0.84	$ 1.39	$ 1.54	$ 1.10	$ 3.06	$ 4.86	$ 5.07