Westlake (WLK) 10-Q 3 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 26, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	WLK
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 Common Stock, Shares Outstanding		129,047,052

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 372,591	$ 459,453
Accounts receivable, net	1,003,966	938,743
Inventories	821,708	801,100
Prepaid expenses and other current assets	43,695	48,493
Restricted cash	9,328	160,527
Total current assets	2,251,288	2,408,316
Property, plant and equipment, net	6,392,745	6,420,062
Other assets, net
Goodwill	950,681	946,553
Customer relationships, net	596,641	611,615
Other intangible assets, net	172,697	175,839
Deferred charges and other assets, net	360,778	327,868
Total other assets, net	2,080,797	2,061,875
Total assets	10,724,830	10,890,253
Current liabilities
Accounts payable	543,121	496,259
Accrued liabilities	400,310	537,483
Term loan	0	149,341
Total current liabilities	943,431	1,183,083
Long-term debt, net	3,601,642	3,678,654
Deferred income taxes	1,649,120	1,650,575
Pension and other post-retirement benefits	362,608	364,819
Other liabilities	135,197	121,077
Total liabilities	6,691,998	6,998,208
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; 134,651,312 and 134,651,380 shares issued at March 31, 2017 and December 31, 2016, respectively	1,347	1,347
Common stock, held in treasury, at cost; 5,608,312 and 5,726,377 shares at March 31, 2017 and December 31, 2016, respectively	(316,396)	(319,339)
Additional paid-in capital	552,061	550,641
Retained earnings	3,525,820	3,412,286
Accumulated other comprehensive loss	(103,636)	(121,306)
Total Westlake Chemical Corporation stockholders' equity	3,659,196	3,523,629
Noncontrolling interests	373,636	368,416
Total equity	4,032,832	3,892,045
Total liabilities and equity	$ 10,724,830	$ 10,890,253

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
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, in dollars per share	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	134,651,312	134,651,380
Common stock, held in treasury	5,608,312	5,726,377

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Net sales	$ 1,942,616	$ 975,187
Cost of sales	1,575,473	719,602
Gross profit	367,143	255,585
Selling, general and administrative expenses	123,651	53,309
Transaction and integration-related costs	8,194	0
Income from operations	235,298	202,276
Other income (expense)
Interest expense	(39,776)	(6,685)
Other income, net	5,071	2,645
Income before income taxes	200,593	198,236
Provision for income taxes	55,883	69,300
Net income	144,710	128,936
Net income attributable to noncontrolling interests	6,520	5,808
Net income attributable to Westlake Chemical Corporation	$ 138,190	$ 123,128
Earnings per common share attributable to Westlake Chemical Corporation:
Basic (usd per share)	$ 1.07	$ 0.94
Diluted (usd per share)	$ 1.06	$ 0.94
Weighted average common shares outstanding:
Basic (in shares)	128,979,357	130,189,964
Diluted (in shares)	129,692,015	130,600,514
Dividends per common share (usd per share)	$ 0.1906	$ 0.1815

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 144,710	$ 128,936
Pension and other post-retirement benefits liability
Amortization of benefits liability	572	334
Income tax provision on pension and other post-retirement benefits liability	(171)	(128)
Foreign currency translation	19,126	22,805
Income tax provision on foreign currency translation	(1,782)	0
Net unrealized holding gains (losses) on investments
Unrealized holding gains on investments	0	24,428
Reclassification of net realized gains to net income	0	(52)
Income tax provision on available-for-sale investments	0	(8,758)
Other	(75)	0
Other comprehensive income, net of income taxes	17,670	38,629
Comprehensive income	162,380	167,565
Comprehensive income attributable to noncontrolling interests, net of tax of $813 and $0 for March 31, 2017 and 2016, respectively.	6,520	5,808
Comprehensive income attributable to Westlake Chemical Corporation	$ 155,860	$ 161,757

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest	$ 813	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities
Net income	$ 144,710	$ 128,936
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	150,269	65,714
Provision for doubtful accounts	978	148
Amortization of debt issuance costs	535	220
Stock-based compensation expense	6,303	2,303
Loss from disposition of property, plant and equipment	2,899	309
Gains realized from sales of securities	0	(52)
Write-off of debt issuance costs	659	0
Deferred income taxes	(6,273)	58,637
Windfall tax benefits from share-based payment arrangements	0	(266)
Loss (income) from equity method investments, net of dividends	511	(223)
Gain on involuntary conversion of assets	(1,555)	0
Other losses (gains), net	(835)	661
Changes in operating assets and liabilities, net of effect of business acquisitions
Accounts receivable	(64,676)	(36,324)
Inventories	(19,244)	(40,878)
Prepaid expenses and other current assets	5,572	(10,791)
Accounts payable	49,377	23,752
Accrued liabilities	(121,851)	(54,257)
Other, net	10,015	(8,954)
Net cash provided by operating activities	157,394	128,935
Cash flows from investing activities
Additions to property, plant and equipment	(134,285)	(136,328)
Additions to cost method investment	(15,000)	0
Proceeds from disposition of assets	66	104
Proceeds from involuntary conversion of assets	1,555	0
Proceeds from sales and maturities of securities	0	26,859
Purchase of securities	0	(36,637)
Settlements of derivative instruments	(355)	(1,219)
Net cash used for investing activities	(148,019)	(147,221)
Cash flows from financing activities
Debt issuance costs	(319)	0
Dividends paid	(24,656)	(23,700)
Distributions to noncontrolling interests	(4,463)	(3,985)
Proceeds from issuance of notes payable	1,874	2,050
Proceeds from drawdown of revolver	50,000	0
Restricted cash associated with term loan	154,000	0
Repayment of term loan	(150,000)	0
Repayment of notes payable	(2,469)	(7,095)
Repayment of revolver	(125,000)	0
Repurchase of common stock for treasury	0	(679)
Other	1,354	288
Net cash used for financing activities	(99,679)	(33,121)
Effect of exchange rate changes on cash and cash equivalents	3,442	3,858
Net decrease in cash and cash equivalents	(86,862)	(47,549)
Cash and cash equivalents at beginning of period	459,453	662,525
Cash and cash equivalents at end of period	$ 372,591	$ 614,976

Basis of Financial Statements

Basis of Financial Statements	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial Statements	Basis of Financial Statements The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the December 31, 2016 financial statements and notes thereto of Westlake Chemical Corporation (the "Company") included in the annual report on Form 10-K for the fiscal year ended December 31, 2016 (the " 2016 Form 10-K"), filed with the SEC on February 22, 2017 . These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Company for the fiscal year ended December 31, 2016 . In the opinion of the Company's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Company's financial position as of March 31, 2017 , its results of operations for the three months ended March 31, 2017 and 2016 and the changes in its cash position for the three months ended March 31, 2017 and 2016 . Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2017 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. Recent Accounting 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 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. 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. Cash Flows (ASU No. 2016-18) In November 2016, the FASB issued an accounting standards update to clarify certain existing principles in Accounting Standards Codification ("ASC") 230, Cash flows, 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 after December 15, 2017 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 standards 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 the ASC 606, Revenue from contracts with customers. 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 standards update to simplify the subsequent measurement of goodwill. The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The accounting standard will be effective for reporting periods beginning after December 15, 2019. 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. Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (ASU No. 2017-05) In February 2017, the FASB issued an accounting standards update to clarify the scope of guidance related to other income — gains and losses from the derecognition of nonfinancial assets, and to add guidance for partial sales of nonfinancial assets. The new guidance clarifies that an in substance nonfinancial asset is an asset or group of assets for which substantially all of the fair value consists of nonfinancial assets and the group or subsidiary is not a business. The guidance also outlines that when an entity transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling interest, it will measure the retained interest at fair value resulting in full gain or loss recognition upon sale of the controlling interest. 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. Compensation - Retirement Benefits (ASU No. 2017-07) In March 2017, the FASB issued an accounting standards update to improve the presentation of net periodic pension cost and net periodic postretirement benefit cost. The new guidance requires employers to disaggregate the service cost component from the other components of net periodic benefit cost and report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The amendments also allow only the service cost component to be eligible for capitalization when applicable. 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. Recently Adopted Accounting Standards 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 will be effective for reporting periods beginning after December 15, 2016. The Company adopted this accounting standard effective January 1, 2017 and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. 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 became effective for reporting periods beginning after December 15, 2016. The Company adopted this accounting standard effective January 1, 2017 and the adoption did not have a material impact on the Company's 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 became effective for annual periods beginning after December 15, 2016. The Company adopted this accounting standard, to be applied prospectively, effective January 1, 2017, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows.

Acquisition

Acquisition	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Acquisition	Acquisition 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 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 in 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) Transaction 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 in the consolidated balance sheet. The Company recognized a $49,080 gain for the investment in other income, net in the consolidated statements 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, assumed 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 3,134,741 Customer relationships (weighted average lives of 10.7 years) 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.

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Financial Instruments	Financial Instruments Restricted Cash The Company had restricted cash and cash equivalents of $32,231 at March 31, 2017 , which was primarily related to balances that are restricted for payment of distributions to certain of the Company's current and former employees. The Company had restricted cash and cash equivalents of $186,216 at December 31, 2016 , which was primarily related to balances deposited with and held as security by the lender under the Company's term loan facility and for distributions to certain of the Company's current and former employees. The current portion of restricted cash and cash equivalents was $9,328 and $160,527 at March 31, 2017 and December 31, 2016 , respectively. The noncurrent portion of restricted cash and cash equivalents was $22,903 and $25,689 at March 31, 2017 and December 31, 2016 , respectively, and is reflected in deferred charges and other assets, net in the consolidated balance sheets. Available-for-Sale Marketable Securities The Company had no available-for-sale securities at March 31, 2017 or at December 31, 2016 . There were no sales or maturities of available-for-sale securities during the three months ended March 31, 2017 . The proceeds from sales and maturities of available-for-sale securities included in the consolidated statement of cash flows and the gross realized gains and losses included in the consolidated statement of operations for the three months ended March 31, 2016 are reflected in the table below. The cost of securities sold was determined using the specific identification method. Three Months Ended March 31, 2016 Proceeds from sales and maturities of securities $ 26,859 Gross realized gains 61 Gross realized losses (9 )

Accounts Receivable

Accounts Receivable	3 Months Ended
	Mar. 31, 2017
Accounts Receivable, Net [Abstract]
Accounts Receivable	Accounts Receivable Accounts receivable consist of the following: March 31, December 31, Trade customers $ 951,555 $ 819,739 Affiliates 9,965 7,982 Allowance for doubtful accounts (18,856 ) (17,991 ) 942,664 809,730 Federal and state taxes 32,901 90,414 Other 28,401 38,599 Accounts receivable, net $ 1,003,966 $ 938,743

Inventories

Inventories	3 Months Ended
	Mar. 31, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consist of the following: March 31, December 31, Finished products $ 491,849 $ 500,861 Feedstock, additives and chemicals 202,065 216,877 Materials and supplies 127,794 83,362 Inventories $ 821,708 $ 801,100

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment As of March 31, 2017 , the Company had property, plant and equipment, net totaling $6,392,745 . The Company assesses these assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable, including when negative conditions such as significant current or projected operating losses exist. Other factors considered by the Company when determining if an impairment assessment is necessary include, but are not limited to, significant changes or projected changes in supply and demand fundamentals (which would have a negative impact on operating rates or margins), new technological developments, new competitors with significant raw material or other cost advantages, adverse changes associated with the U.S. and world economies and uncertainties associated with governmental actions. 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. Depreciation expense on property, plant and equipment of $114,091 and $56,041 is primarily included in cost of sales in the consolidated statements of operations for the three months ended March 31, 2017 and 2016 , respectively.

Other Assets

Other Assets	3 Months Ended
	Mar. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Other Assets Amortization expense on intangible and other assets of $36,330 is primarily included in selling, general and administrative expenses for the three months ended March 31, 2017 . Amortization expense on intangible and other assets of $9,770 is primarily included in cost of sales for the three months ended March 31, 2016 . Goodwill The gross carrying amounts of goodwill and the changes in the carrying amount of goodwill for the three months ended March 31, 2017 were as follows: Olefins Segment Vinyls Segment Total Balance at December 31, 2016 $ 29,990 $ 916,563 $ 946,553 Goodwill acquired during the period — — — Effects of changes in foreign exchange rates — 4,128 4,128 Balance at March 31, 2017 $ 29,990 $ 920,691 $ 950,681

Accounts and Notes Payable

Accounts and Notes Payable	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Accounts and Notes Payable	Accounts Payable Accounts payable consist of the following: March 31, December 31, Accounts payable—third parties $ 529,388 $ 474,017 Accounts payable to affiliates 12,544 20,726 Notes payable to banks 1,189 1,516 Accounts payable $ 543,121 $ 496,259

Term Loan

Term Loan	3 Months Ended
	Mar. 31, 2017
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 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	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consists of the following: March 31, 2017 December 31, 2016 Principal Unamortized Discount Net Principal Unamortized Net Revolving credit facility $ 250,000 $ — $ 250,000 $ 325,000 $ — $ 325,000 4.625% senior notes due 2021 (the "4.625% Westlake 2021 Senior Notes") 624,793 25,123 649,916 624,793 26,837 651,630 4.625% senior notes due 2021 (the "4.625% Subsidiary 2021 Senior Notes") 63,207 2,690 65,897 63,207 2,862 66,069 3.60% senior notes due 2022 250,000 (1,806 ) 248,194 250,000 (1,891 ) 248,109 4.875% senior notes due 2023 (the "4.875% Westlake 2023 Senior Notes") 433,793 12,840 446,633 433,793 13,431 447,224 4.875% senior notes due 2023 (the "4.875% Subsidiary 2023 Senior Notes") 16,207 519 16,726 16,207 540 16,747 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750,000 (10,564 ) 739,436 750,000 (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 (898 ) 99,102 100,000 (916 ) 99,084 6 ¾% senior notes due 2032 250,000 (1,853 ) 248,147 250,000 (1,883 ) 248,117 6 ½% senior notes due 2035 (the "6 ½% 2035 GO Zone Senior Notes") 89,000 (828 ) 88,172 89,000 (839 ) 88,161 6 ½% senior notes due 2035 (the "6 ½% 2035 IKE Zone Senior Notes") 65,000 (594 ) 64,406 65,000 (602 ) 64,398 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700,000 (25,876 ) 674,124 700,000 (26,017 ) 673,983 Long-term debt, net $ 3,602,889 $ (1,247 ) $ 3,601,642 $ 3,677,889 $ 765 $ 3,678,654 Credit Agreement At March 31, 2017 , the Company had $250,000 of borrowings outstanding under the Credit Agreement. The interest rate on the borrowings outstanding under the revolving credit facility was 2.34% at March 31, 2017 . The Credit Agreement matures on August 23, 2021. As of March 31, 2017 , the Company had outstanding letters of credit totaling $76,493 and borrowing availability of $673,507 under the Credit Agreement. As of March 31, 2017 , the Company was in compliance with the total leverage ratio financial maintenance covenant. 3.60% Senior Notes due 2026 and 5.0% Senior Notes due 2046 In August 2016, the Company issued $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. In connection with the private offering and issuance of the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes, the Company entered into a registration rights agreement pursuant to which, among other things, the Company agreed to file with the SEC a registration statement relating to an offer to exchange the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes for new SEC-registered notes (the “2026 and 2046 Exchange Notes”) containing terms substantially identical to the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes (except that the transfer restrictions on the 2026 and 2046 Exchange Notes will be modified or eliminated and there will be no registration rights). 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. On March 27, 2017, the Company commenced registered exchange offers to exchange the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes for new notes that are identical in all material respects to the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes, except that the offer and issuance of the new SEC-registered notes have been registered under the Securities Act of 1933, as amended (the “Securities Act”). The exchange offers expired on April 24, 2017, and approximately 99.97% of the 3.60% 2026 Senior Notes and 100.00% of the 5.0% 2046 Senior Notes were exchanged. The 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes that were not exchanged pursuant to the exchange offers have not been registered under the Securities Act or any state securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements or a transaction not subject to the registration requirements of the Securities Act or any state securities law. 4.625% Senior Notes due 2021 and 4.875% Senior Notes due 2023 In September 2016, the Company issued $624,793 aggregate principal amount of 4.625% senior notes due 2021 (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 ”) upon the closing of the Company’s 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 issued by Eagle Spinco Inc., a wholly-owned subsidiary of Axiall (“Eagle Spinco”), and the $450,000 aggregate principal amount of the outstanding 4.875% senior notes due 2023 issued by Axiall. In the Axiall Exchange Offers, $624,793 aggregate principal amount of 4.625% Westlake 2021 Senior Notes and $433,793 aggregate principal amount of 4.875% Westlake 2023 Senior Notes were issued by the Company, leaving outstanding $63,207 aggregate principal amount of the 4.625% 2021 senior notes (the " 4.625% Subsidiary 2021 Senior Notes ") and $16,207 aggregate principal amount of the 4.875% 2023 senior notes (the " 4.875% Subsidiary 2023 Senior Notes "). The Subsidiary 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. In connection with the private offering and issuance of the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes, the Company entered into a registration rights agreement pursuant to which, among other things, the Company agreed to file with the SEC a registration statement relating to an offer to exchange the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes for new SEC-registered notes (the “2021 and 2023 Exchange Notes”) containing terms substantially identical to the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes (except that the transfer restrictions on the 2021 and 2023 Exchange Notes will be modified or eliminated and there will be no registration rights). 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. On March 27, 2017, the Company commenced registered exchange offers to exchange the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes for new SEC-registered notes that are identical in all material respects to the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes , except that the offer and issuance of the new notes have been registered under the Securities Act. The exchange offers expired on April 24, 2017, and approximately 99.97% of the 4.625% Westlake 2021 Senior Notes and 100.00% of the 4.875% Westlake 2023 Senior Notes were exchanged. The 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes that were not exchanged pursuant to the exchange offers have not been registered under the Securities Act or any state securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements or a transaction not subject to the registration requirements of the Securities Act or any state securities law. As of March 31, 2017, 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, 6 ½% senior notes due 2029, the 6 ¾% senior notes due 2032, the 6 ½% 2035 GO Zone Senior Notes, the 6 ½% 2035 IKE Zone Senior Notes and the waste disposal revenue bonds. Unamortized debt issuance costs on Long-term debt were $23,767 and $24,113 at March 31, 2017 and December 31, 2016 , respectively.

Pension and Post-Retirement Ben

Pension and Post-Retirement Benefits	3 Months Ended
	Mar. 31, 2017
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Pension and Post-Retirement Benefits	Pension and Post-Retirement Benefits In connection with the Merger, the Company assumed certain U.S. and non-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. See Note 2 for the fair value of pension and other post-retirement obligations assumed in the Merger. Defined Benefit Plans Components of net periodic benefit cost (income) for the Company's pension plans are as follows: Three Months Ended March 31, 2017 2016 U.S. Non-U.S. U.S. Non-U.S. Service cost $ 1,336 $ 554 $ — $ 323 Interest cost 6,198 561 567 568 Expected return on plan assets (9,976 ) (114 ) (802 ) — Amortization of net loss 297 151 303 — Net periodic benefit cost (income) $ (2,145 ) $ 1,152 $ 68 $ 891 The Company made $2,258 of contributions to its U.S. pension plans and $390 of contributions to its non-U.S. pension plans during the first three months of 2017 . The Company made no contributions to its U.S. and non-U.S. pension plans during the three months ended March 31, 2016 . 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 $6,774 to its U.S. pension plans and contributions of approximately $459 to its non-U.S. pension plans during the remainder of the fiscal year ending December 31, 2017 . Other Post-retirement Benefits Components of net periodic benefit cost for the Company's other post-retirement benefits are as follows: Three Months Ended March 31, Three Months Ended March 31, 2017 2016 U.S. Non-U.S. U.S. Service cost $ 163 $ 5 $ 5 Interest cost 500 14 145 Amortization of net loss 15 — 31 Net periodic benefit cost $ 678 $ 19 $ 181

Stockholders Equity

Stockholders Equity	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Changes in stockholders' equity for the three months ended March 31, 2017 and 2016 were as follows: Common Stock Common Stock, Held in Treasury Additional Paid-in Capital Retained Earnings Accumulated Other Comprehensive Income (Loss) Noncontrolling Interests Total Balances at December 31, 2016 $ 1,347 $ (319,339 ) $ 550,641 $ 3,412,286 $ (121,306 ) $ 368,416 $ 3,892,045 Net income — — — 138,190 — 6,520 144,710 Other comprehensive income (loss), net of income taxes: Pension and other post- retirement benefits liability — — — — 401 (44 ) 357 Foreign currency translation adjustments — — — — 17,344 3,207 20,551 Other — — — — (75 ) — (75 ) Shares issued—stock- based compensation — 2,943 (1,589 ) — — — 1,354 Stock-based compensation, net of tax on stock options exercised — — 3,009 — — — 3,009 Dividends declared — — — (24,656 ) — — (24,656 ) Distributions to noncontrolling interests — — — — — (4,463 ) (4,463 ) Balances at March 31, 2017 $ 1,347 $ (316,396 ) $ 552,061 $ 3,525,820 $ (103,636 ) $ 373,636 $ 4,032,832 Common Stock Common Stock, Held in Treasury Additional Paid-in Capital Retained Earnings Accumulated Other Comprehensive Income (Loss) Noncontrolling Interests Total Balances at December 31, 2015 $ 1,347 $ (258,312 ) $ 542,148 $ 3,109,987 $ (129,292 ) $ 296,053 $ 3,561,931 Net income — — — 123,128 — 5,808 128,936 Other comprehensive income (loss), net of income taxes Pension and other post- retirement benefits liability — — — — 206 — 206 Foreign currency translation adjustments — — — — 22,805 — 22,805 Net unrealized holding gains on investments — — — — 15,618 — 15,618 Shares issued—stock- based compensation — 1,853 (1,831 ) — — — 22 Stock-based compensation, net of tax on stock options exercised — — 2,569 — — — 2,569 Dividends declared — — — (23,700 ) — — (23,700 ) Distributions to noncontrolling interests — — — — — (3,985 ) (3,985 ) Balances at March 31, 2016 $ 1,347 $ (256,459 ) $ 542,886 $ 3,209,415 $ (90,663 ) $ 297,876 $ 3,704,402 Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) by component for the three months ended March 31, 2017 and 2016 were as follows: Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Net Unrealized Holding Gains (Losses) on Investments, Net of Tax Total Balances at December 31, 2016 $ 28,945 $ (150,202 ) $ (49 ) $ (121,306 ) Other comprehensive income (loss) before reclassifications 101 17,344 (75 ) 17,370 Amounts reclassified from accumulated other comprehensive loss 300 — — 300 Net other comprehensive income (loss) for the period 401 17,344 (75 ) 17,670 Balances at March 31, 2017 $ 29,346 $ (132,858 ) $ (124 ) $ (103,636 ) Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Net Unrealized Holding Gains (Losses) on Investments, Net of Tax Total Balances at December 31, 2015 $ (8,607 ) $ (115,690 ) $ (4,995 ) $ (129,292 ) Other comprehensive income before reclassifications — 22,805 15,651 38,456 Amounts reclassified from accumulated other comprehensive loss (income) 206 — (33 ) 173 Net other comprehensive income for the period 206 22,805 15,618 38,629 Balances at March 31, 2016 $ (8,401 ) $ (92,885 ) $ 10,623 $ (90,663 ) 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 for the three months ended March 31, 2017 and 2016 : Details about Accumulated Other Comprehensive Income (Loss) Components Location of Reclassification (Income (Expense)) in Consolidated Statements of Operations Three Months Ended March 31, 2017 2016 Amortization of pension and other post-retirement items Net loss (1) $ (463 ) $ (334 ) Benefit from income taxes 163 128 (300 ) (206 ) Net unrealized gains on available-for-sale investments Realized gain on available-for-sale investments Other income, net — 52 Provision for income taxes — (19 ) — 33 Total reclassifications for the period $ (300 ) $ (173 ) _____________ (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, please read Note 13 (Employee Benefits) to the financial statements included in the 2016 Form 10-K.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [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). Total stock-based compensation expense related to the 2013 Plan was $6,303 and $2,303 for the three months ended March 31, 2017 and 2016 , respectively. 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 financial accounting purposes and are re-measured at each reporting date until they vest.

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments Commodity Risk Management The Company uses derivative instruments to reduce price volatility risk on commodities, primarily ethane and natural gas. 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 three months ended March 31, 2017 and 2016 . Gains and losses from changes in the fair value of derivative instruments that are not designated as hedging instruments are included in cost of sales in the consolidated statements of operations for the three months ended March 31, 2017 and 2016 . 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 221,800,000 gallons and 8,800,000 MMBtu as of March 31, 2017 and for approximately 257,000,000 gallons and 8,500,000 MMBtu as of December 31, 2016 . The fair values of derivative instruments reflected in the Company's consolidated balance sheets were as follows: Asset Derivatives Balance Sheet Location Fair Value as of March 31, December 31, Not designated as hedging instruments Commodity forward contracts Accounts receivable, net $ 3,124 $ 7,589 Commodity forward contracts Deferred charges and other assets, net 2,246 5,249 Total asset derivatives $ 5,370 $ 12,838 Liability Derivatives Balance Sheet Location Fair Value as of March 31, December 31, Not designated as hedging instruments Commodity forward contracts Accrued liabilities $ 1,048 $ 1,349 Commodity forward contracts Other liabilities 5,115 3,724 Total liability derivatives $ 6,163 $ 5,073 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 Three Months Ended March 31, 2017 2016 Commodity forward contracts Cost of sales $ (9,167 ) $ 4,057 See Note 15 for the fair value of the Company's derivative instruments. Disclosure about Offsetting Asset and Liability Derivatives Certain of the Company's derivative instruments are executed under an International Swaps and Derivatives Association ("ISDA") Master Agreement, which permits the Company and a counterparty to aggregate the amounts owed by each party under multiple transactions and replace them with a single net amount payable by one party to the other. The following tables present the Company's derivative assets and derivative liabilities reported in the consolidated balance sheets and derivative assets and derivative liabilities subject to enforceable master netting arrangements. March 31, 2017 Net Presentation Gross Presentation Net Assets (Liabilities) Presented in the Consolidated Balance Sheets Risk management assets—Commodity forward contracts Risk management liabilities—Commodity forward contracts Accounts receivable, net Derivative positions subject to enforceable master netting arrangements $ 520 $ 1,049 $ (529 ) Derivative positions not subject to enforceable master netting arrangements 2,604 2,604 — 3,124 3,653 (529 ) Deferred charges and other assets, net Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting 2,246 2,246 — 2,246 2,246 — Accrued liabilities Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting (1,048 ) — (1,048 ) (1,048 ) — (1,048 ) Other liabilities Derivative positions subject to enforceable master netting (1,629 ) 978 (2,607 ) Derivative positions not subject to enforceable master netting (3,486 ) — (3,486 ) (5,115 ) 978 (6,093 ) Risk management assets (liabilities)—Commodity forward contracts $ 6,877 $ (7,670 ) December 31, 2016 Net Presentation Gross Presentation Net Assets (Liabilities) Presented in the Consolidated Balance Sheets Risk management assets—Commodity forward contracts Risk management liabilities—Commodity forward contracts Accounts receivable, net Derivative positions subject to enforceable master netting $ 1,498 $ 1,636 $ (138 ) Derivative positions not subject to enforceable master netting 6,091 6,091 — 7,589 7,727 (138 ) Deferred charges and other assets, net Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting 5,249 5,249 — 5,249 5,249 — Accrued liabilities Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting (1,349 ) — (1,349 ) (1,349 ) — (1,349 ) Other liabilities Derivative positions subject to enforceable master netting (436 ) 2,010 (2,446 ) Derivative positions not subject to enforceable master netting (3,288 ) — (3,288 ) (3,724 ) 2,010 (5,734 ) Risk management assets (liabilities)—Commodity forward contracts $ 14,986 $ (7,221 )

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
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). 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 following tables summarize, by level within the fair value hierarchy, the Company's assets and liabilities that were accounted for at fair value on a recurring basis: March 31, 2017 Level 1 Level 2 Total Derivative instruments Risk management assets—Commodity forward contracts $ 406 $ 6,471 $ 6,877 Risk management liabilities—Commodity forward contracts (6,710 ) (960 ) (7,670 ) December 31, 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 ) The Level 2 measurements for the Company's commodity contracts are derived using forward curves supplied by industry-recognized and unrelated third-party services. There were no transfers in or out of Levels 1 and 2 of the fair value hierarchy for the three months ended March 31, 2017 and 2016 . In addition to the financial 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 current 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, accounts payable and current term loan approximate their fair values due to the short maturities of these instruments. The carrying and fair values of the Company's long-term debt are summarized in the table below. The fair value of the Company's long-term debt instruments is determined using a market approach, based upon quotes from financial reporting services. 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. March 31, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value Revolving credit facility $ 250,000 $ 250,000 $ 325,000 $ 325,000 4.625% Westlake 2021 Senior Notes 624,793 649,354 651,630 650,847 4.625% Subsidiary 2021 Senior Notes 63,207 65,639 66,069 65,775 3.60% senior notes due 2022 250,000 254,443 248,109 251,725 4.875% Westlake 2023 Senior Notes 433,793 451,761 447,224 451,301 4.875% Subsidiary 2023 Senior Notes 16,207 16,873 16,747 16,501 3.60% 2026 Senior Notes 750,000 735,870 739,243 722,055 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 100,000 110,000 99,084 112,433 6 ¾% senior notes due 2032 250,000 258,760 248,117 258,818 6 ½% 2035 GO Zone Senior Notes 89,000 101,760 88,161 100,323 6 ½% 2035 IKE Zone Senior Notes 65,000 74,298 64,398 73,270 5.0% 2046 Senior Notes 700,000 717,864 673,983 691,712

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective income tax rate was 27.9% for the first quarter of 2017 . The effective income tax rate for the first quarter of 2017 was below the U.S. federal statutory rate of 35.0% primarily due to certain discrete adjustments, a higher domestic manufacturing deduction, depletion deductions, income attributable to noncontrolling interests, research and development credits and the foreign earnings rate differential, partially offset by state income taxes. The effective income tax rate for the first quarter of 2016 was at the U.S. federal statutory rate of 35.0% primarily due to the benefit of state tax credits, the domestic manufacturing deduction, income attributable to noncontrolling interests and the foreign earnings rate differential, offset by state income taxes.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2017
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. Three Months Ended March 31, 2017 2016 Net income attributable to Westlake Chemical Corporation $ 138,190 $ 123,128 Less: Net income attributable to participating securities (694 ) (549 ) Net income attributable to common shareholders $ 137,496 $ 122,579 The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Three Months Ended March 31, 2017 2016 Weighted average common shares—basic 128,979,357 130,189,964 Plus incremental shares from: Assumed exercise of options 712,658 410,550 Weighted average common shares—diluted 129,692,015 130,600,514 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 1.07 $ 0.94 Diluted $ 1.06 $ 0.94 Excluded from the computation of diluted earnings per share are options to purchase 437,787 and 555,948 shares of common stock for the three months ended March 31, 2017 and 2016 , 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	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Information	Supplemental Information Accrued Liabilities Accrued liabilities were $400,310 and $537,483 at March 31, 2017 and December 31, 2016 , respectively. Accrued rebates, which are a component of accrued liabilities, were $47,933 and $77,985 at March 31, 2017 and December 31, 2016 , respectively. No other component of accrued liabilities was more than five percent of total current liabilities. Non-cash Investing Activity The change in capital expenditure accrual increasing additions to property, plant and equipment was $8,241 for the three months ended March 31, 2017. The change in capital expenditure accrual reducing additions to property, plant and equipment was $14,690 for the three months ended March 31, 2016.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2017
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 March 31, 2017 and December 31, 2016 , the Company had reserves for environmental contingencies totaling approximately $48,217 and $48,817 , 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 are on-going per a December 2016 agreement to extend the compliance date under the amended consent order. • 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 subsequently engaged in negotiations to resolve alleged violations. A Consent Agreement and Final Order (“CAFO”) was filed in October 2016, pursuant to which the Company paid civil penalties in the amount 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 has reached an agreement with the LDEQ to settle certain of the NOVs along with other alleged violations not made the subject of any specific NOV in two separate settlement agreements 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 penalty payment of $878 . • 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 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 resolutions 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 .

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Segment 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. Three Months Ended March 31, 2017 2016 Net external sales Olefins Polyethylene $ 385,942 $ 346,032 Styrene, feedstock and other 157,053 84,988 Total Olefins 542,995 431,020 Vinyls PVC, caustic soda and other 1,131,129 430,902 Building products 268,492 113,265 Total Vinyls 1,399,621 544,167 $ 1,942,616 $ 975,187 Intersegment sales Olefins $ 85,944 $ 27,949 Vinyls 292 364 $ 86,236 $ 28,313 Three Months Ended March 31, 2017 2016 Income (loss) from operations Olefins $ 179,817 $ 149,235 Vinyls 71,441 62,116 Corporate and other (15,960 ) (9,075 ) $ 235,298 $ 202,276 Depreciation and amortization Olefins $ 41,040 $ 28,697 Vinyls 107,273 36,287 Corporate and other 1,956 730 $ 150,269 $ 65,714 Other income (expense), net Olefins $ 1,370 $ 1,513 Vinyls 3,878 (1,519 ) Corporate and other (177 ) 2,651 $ 5,071 $ 2,645 Provision for (benefit from) income taxes Olefins $ 57,811 $ 52,533 Vinyls 14,958 17,270 Corporate and other (16,886 ) (503 ) $ 55,883 $ 69,300 Capital expenditures Olefins $ 25,350 $ 95,152 Vinyls 108,081 40,256 Corporate and other 854 920 $ 134,285 $ 136,328 A reconciliation of total segment income from operations to consolidated income before income taxes is as follows: Three Months Ended March 31, 2017 2016 Income from operations $ 235,298 $ 202,276 Interest expense (39,776 ) (6,685 ) Other income, net 5,071 2,645 Income before income taxes $ 200,593 $ 198,236 March 31, December 31, Total assets Olefins $ 2,120,429 $ 2,092,617 Vinyls 8,214,203 8,287,204 Corporate and other 390,198 510,432 $ 10,724,830 $ 10,890,253

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2017
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	3 Months Ended
	Mar. 31, 2017
Guarantees [Abstract]
Guarantor Disclosures	Guarantor Disclosures The Company's payment obligations under the 3.60% senior notes due 2022 , the 3.60% 2026 Senior Notes, the 5.0% 2046 Senior Notes, 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes 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 those notes in excess of $5,000 (the "Guarantor Subsidiaries"). Each Guarantor Subsidiary is 100% owned by Westlake Chemical Corporation (the " 100% Owned 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. These guarantees are the joint and several obligations of the Guarantor Subsidiaries. The following unaudited 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 , the 3.60% 2026 Senior Notes, the 5.0% 2046 Senior Notes, 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes (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. Condensed Consolidating Financial Information as of March 31, 2017 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Balance Sheet Current assets Cash and cash equivalents $ 54,966 $ 5,647 $ 311,978 $ — $ 372,591 Accounts receivable, net 2,446,732 3,521,181 330,311 (5,294,258 ) 1,003,966 Inventories — 605,775 215,933 — 821,708 Prepaid expenses and other current assets 53,239 38,066 11,463 (59,073 ) 43,695 Restricted cash — 2,681 6,647 — 9,328 Total current assets 2,554,937 4,173,350 876,332 (5,353,331 ) 2,251,288 Property, plant and equipment, net — 4,438,292 1,954,453 — 6,392,745 Other assets, net Goodwill — 791,706 158,975 — 950,681 Customer relationships, net — 453,985 142,656 — 596,641 Other intangible assets, net — 102,339 70,358 — 172,697 Deferred charges and other assets, net 9,335,542 846,041 1,131,172 (10,951,977 ) 360,778 Total other assets, net 9,335,542 2,194,071 1,503,161 (10,951,977 ) 2,080,797 Total assets $ 11,890,479 $ 10,805,713 $ 4,333,946 $ (16,305,308 ) $ 10,724,830 Current liabilities Accounts payable $ 4,705,704 $ 761,986 $ 273,714 $ (5,198,283 ) $ 543,121 Accrued liabilities 17,449 357,968 179,941 (155,048 ) 400,310 Total current liabilities 4,723,153 1,119,954 453,655 (5,353,331 ) 943,431 Long-term debt, net 3,508,130 2,999,225 — (2,905,713 ) 3,601,642 Deferred income taxes — 1,581,202 91,303 (23,385 ) 1,649,120 Pension and other liabilities — 1,479,584 133,658 (1,115,437 ) 497,805 Total liabilities 8,231,283 7,179,965 678,616 (9,397,866 ) 6,691,998 Total Westlake Chemical Corporation stockholders' equity 3,659,196 3,625,748 3,281,694 (6,907,442 ) 3,659,196 Noncontrolling interests — — 373,636 — 373,636 Total equity 3,659,196 3,625,748 3,655,330 (6,907,442 ) 4,032,832 Total liabilities and equity $ 11,890,479 $ 10,805,713 $ 4,333,946 $ (16,305,308 ) $ 10,724,830 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 Goodwill — 791,706 154,847 — 946,553 Customer relationships, net — 468,645 142,970 — 611,615 Other intangible assets, net — 130,243 71,177 (25,581 ) 175,839 Deferred charges and other assets, net 9,170,042 874,003 1,115,877 (10,832,054 ) 327,868 Total 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 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, net 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 for the Three Months Ended March 31, 2017 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 1,579,725 $ 736,085 $ (373,194 ) $ 1,942,616 Cost of sales — 1,359,275 582,660 (366,462 ) 1,575,473 Gross profit — 220,450 153,425 (6,732 ) 367,143 Selling, general and administrative expenses 778 92,260 37,345 (6,732 ) 123,651 Transaction and integration-related costs — 8,132 62 — 8,194 Income (loss) from operations (778 ) 120,058 116,018 — 235,298 Other income (expense) Interest expense (38,185 ) (45,677 ) (806 ) 44,892 (39,776 ) Other income (expense), net 37,157 (255 ) 13,061 (44,892 ) 5,071 Income (loss) before income taxes (1,806 ) 74,126 128,273 — 200,593 Provision for (benefit from) income taxes (5,467 ) 53,372 7,978 — 55,883 Equity in net income of subsidiaries 134,529 — — (134,529 ) — Net income 138,190 20,754 120,295 (134,529 ) 144,710 Net income attributable to noncontrolling interests — — 6,520 — 6,520 Net income attributable to Westlake Chemical Corporation $ 138,190 $ 20,754 $ 113,775 $ (134,529 ) $ 138,190 Comprehensive income attributable to Westlake Chemical Corporation $ 155,860 $ 4,635 $ 122,243 $ (126,878 ) $ 155,860 Condensed Consolidating Financial Information for the Three Months Ended March 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 761,736 $ 569,824 $ (356,373 ) $ 975,187 Cost of sales — 642,730 427,777 (350,905 ) 719,602 Gross profit — 119,006 142,047 (5,468 ) 255,585 Selling, general and administrative expenses 607 36,996 21,174 (5,468 ) 53,309 Income (loss) from operations (607 ) 82,010 120,873 — 202,276 Other income (expense) Interest expense (10,411 ) (4,851 ) — 8,577 (6,685 ) Other income (expense), net 1,815 (825 ) 10,232 (8,577 ) 2,645 Income (loss) before income taxes (9,203 ) 76,334 131,105 — 198,236 Provision for (benefit from) income taxes (3,219 ) 62,199 10,320 — 69,300 Equity in net income of subsidiaries 129,112 — — (129,112 ) — Net income 123,128 14,135 120,785 (129,112 ) 128,936 Net income attributable to noncontrolling interests — — 5,808 — 5,808 Net income attributable to Westlake Chemical Corporation $ 123,128 $ 14,135 $ 114,977 $ (129,112 ) $ 123,128 Comprehensive income attributable to Westlake Chemical Corporation $ 161,757 $ 14,341 $ 149,462 $ (163,803 ) $ 161,757 Condensed Consolidating Financial Information for the Three Months Ended March 31, 2017 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income $ 138,190 $ 20,754 $ 120,295 $ (134,529 ) $ 144,710 Adjustments to reconcile net income to net cash provided by (used for) operating activities Depreciation and amortization — 98,578 51,691 — 150,269 Deferred income taxes (585 ) (2,905 ) (2,783 ) — (6,273 ) Net changes in working capital and other (213,242 ) (28,009 ) (24,590 ) 134,529 (131,312 ) Net cash provided by (used for) operating activities (75,637 ) 88,418 144,613 — 157,394 Cash flows from investing activities Additions to property, plant and equipment — (120,719 ) (13,566 ) — (134,285 ) Additions to cost method investment — (15,000 ) — — (15,000 ) Proceeds from disposition of assets — 66 — — 66 Proceeds from involuntary conversion of assets — 1,555 — — 1,555 Settlements of derivative instruments — (355 ) — — (355 ) Net cash used for investing activities — (134,453 ) (13,566 ) — (148,019 ) Cash flows from financing activities Intercompany financing 78,234 (95,698 ) 17,464 — — Debt issuance costs (319 ) — — — (319 ) Dividends paid (24,656 ) — — — (24,656 ) Distributions to noncontrolling interests — 94,631 (99,094 ) — (4,463 ) Proceeds from issuance of notes payable — — 1,874 — 1,874 Proceeds from drawdown of revolver 50,000 — — — 50,000 Restricted cash associated with term loan 154,000 — — — 154,000 Repayment of term loan (150,000 ) — — — (150,000 ) Repayment of notes payable — (257 ) (2,212 ) — (2,469 ) Repayment of revolver (125,000 ) — — — (125,000 ) Other 1,354 — — — 1,354 Net cash used for financing activities (16,387 ) (1,324 ) (81,968 ) — (99,679 ) Effect of exchange rate changes on cash and cash equivalents — — 3,442 — 3,442 Net increase (decrease) in cash and cash equivalents (92,024 ) (47,359 ) 52,521 — (86,862 ) Cash and cash equivalents at beginning of period 146,990 53,006 259,457 — 459,453 Cash and cash equivalents at end of period $ 54,966 $ 5,647 $ 311,978 $ — $ 372,591 Condensed Consolidating Financial Information for the Three Months Ended March 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 $ 123,128 $ 14,135 $ 120,785 $ (129,112 ) $ 128,936 Adjustments to reconcile net income to net cash provided by operating activities Depreciation and amortization — 32,687 33,027 — 65,714 Deferred income taxes (2,724 ) 55,473 5,888 — 58,637 Net changes in working capital and other (120,345 ) (94,115 ) (39,004 ) 129,112 (124,352 ) Net cash provided by operating activities 59 8,180 120,696 — 128,935 Cash flows from investing activities Additions to property, plant and equipment — (50,568 ) (85,760 ) — (136,328 ) Proceeds from disposition of assets — 6 98 — 104 Proceeds from sales and maturities of securities 26,859 — — — 26,859 Purchase of securities (29,045 ) — (7,592 ) — (36,637 ) Settlements of derivative instruments — (1,219 ) — — (1,219 ) Net cash used for investing activities (2,186 ) (51,781 ) (93,254 ) — (147,221 ) Cash flows from financing activities Intercompany financing (13,763 ) (42,072 ) 55,835 — — Dividends paid (23,700 ) — — — (23,700 ) Distributions to noncontrolling interests — 79,999 (83,984 ) — (3,985 ) Proceeds from issuance of notes payable — — 2,050 — 2,050 Repayment of notes payable — — (7,095 ) — (7,095 ) Repurchase of common stock for treasury (679 ) — — — (679 ) Other 288 — — — 288 Net cash provided by (used for) financing activities (37,854 ) 37,927 (33,194 ) — (33,121 ) Effect of exchange rate changes on cash and cash equivalents — — 3,858 — 3,858 Net decrease in cash and cash equivalents (39,981 ) (5,674 ) (1,894 ) — (47,549 ) Cash and cash equivalents at beginning of period 303,131 6,828 352,566 — 662,525 Cash and cash equivalents at end of period $ 263,150 $ 1,154 $ 350,672 $ — $ 614,976

Basis of Financial Statements (

Basis of Financial Statements (Policies)	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial Statements	Basis of Financial Statements The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the December 31, 2016 financial statements and notes thereto of Westlake Chemical Corporation (the "Company") included in the annual report on Form 10-K for the fiscal year ended December 31, 2016 (the " 2016 Form 10-K"), filed with the SEC on February 22, 2017 . These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Company for the fiscal year ended December 31, 2016 . In the opinion of the Company's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Company's financial position as of March 31, 2017 , its results of operations for the three months ended March 31, 2017 and 2016 and the changes in its cash position for the three months ended March 31, 2017 and 2016 . Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2017 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.
Recent Accounting 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 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. 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. Cash Flows (ASU No. 2016-18) In November 2016, the FASB issued an accounting standards update to clarify certain existing principles in Accounting Standards Codification ("ASC") 230, Cash flows, 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 after December 15, 2017 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 standards 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 the ASC 606, Revenue from contracts with customers. 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 standards update to simplify the subsequent measurement of goodwill. The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The accounting standard will be effective for reporting periods beginning after December 15, 2019. 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. Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (ASU No. 2017-05) In February 2017, the FASB issued an accounting standards update to clarify the scope of guidance related to other income — gains and losses from the derecognition of nonfinancial assets, and to add guidance for partial sales of nonfinancial assets. The new guidance clarifies that an in substance nonfinancial asset is an asset or group of assets for which substantially all of the fair value consists of nonfinancial assets and the group or subsidiary is not a business. The guidance also outlines that when an entity transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling interest, it will measure the retained interest at fair value resulting in full gain or loss recognition upon sale of the controlling interest. 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. Compensation - Retirement Benefits (ASU No. 2017-07) In March 2017, the FASB issued an accounting standards update to improve the presentation of net periodic pension cost and net periodic postretirement benefit cost. The new guidance requires employers to disaggregate the service cost component from the other components of net periodic benefit cost and report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The amendments also allow only the service cost component to be eligible for capitalization when applicable. 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. Recently Adopted Accounting Standards 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 will be effective for reporting periods beginning after December 15, 2016. The Company adopted this accounting standard effective January 1, 2017 and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows. 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 became effective for reporting periods beginning after December 15, 2016. The Company adopted this accounting standard effective January 1, 2017 and the adoption did not have a material impact on the Company's 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 became effective for annual periods beginning after December 15, 2016. The Company adopted this accounting standard, to be applied prospectively, effective January 1, 2017, and the adoption did not have a material impact on the Company's consolidated financial position, results of operations and cash flows.

Acquisition (Tables)

Acquisition (Tables)	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Schedule of Business Acquisitions	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 in 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) Transaction 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 in the consolidated balance sheet. The Company recognized a $49,080 gain for the investment in other income, net in the consolidated statements 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 3,134,741 Customer relationships (weighted average lives of 10.7 years) 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

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Realized Gain (Loss)	The cost of securities sold was determined using the specific identification method. Three Months Ended March 31, 2016 Proceeds from sales and maturities of securities $ 26,859 Gross realized gains 61 Gross realized losses (9 )

Accounts Receivable (Tables)

Accounts Receivable (Tables)	3 Months Ended
	Mar. 31, 2017
Accounts Receivable, Net [Abstract]
Schedule Of Accounts Receivable	Accounts receivable consist of the following: March 31, December 31, Trade customers $ 951,555 $ 819,739 Affiliates 9,965 7,982 Allowance for doubtful accounts (18,856 ) (17,991 ) 942,664 809,730 Federal and state taxes 32,901 90,414 Other 28,401 38,599 Accounts receivable, net $ 1,003,966 $ 938,743

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2017
Inventory Disclosure [Abstract]
Schedule Of Inventory	Inventories consist of the following: March 31, December 31, Finished products $ 491,849 $ 500,861 Feedstock, additives and chemicals 202,065 216,877 Materials and supplies 127,794 83,362 Inventories $ 821,708 $ 801,100

Other Assets (Tables)

Other Assets (Tables)	3 Months Ended
	Mar. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	The gross carrying amounts of goodwill and the changes in the carrying amount of goodwill for the three months ended March 31, 2017 were as follows: Olefins Segment Vinyls Segment Total Balance at December 31, 2016 $ 29,990 $ 916,563 $ 946,553 Goodwill acquired during the period — — — Effects of changes in foreign exchange rates — 4,128 4,128 Balance at March 31, 2017 $ 29,990 $ 920,691 $ 950,681

Accounts and Notes Payable (Tab

Accounts and Notes Payable (Tables)	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable consist of the following: March 31, December 31, Accounts payable—third parties $ 529,388 $ 474,017 Accounts payable to affiliates 12,544 20,726 Notes payable to banks 1,189 1,516 Accounts payable $ 543,121 $ 496,259

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Schedule Of Long-Term Debt	Long-term debt consists of the following: March 31, 2017 December 31, 2016 Principal Unamortized Discount Net Principal Unamortized Net Revolving credit facility $ 250,000 $ — $ 250,000 $ 325,000 $ — $ 325,000 4.625% senior notes due 2021 (the "4.625% Westlake 2021 Senior Notes") 624,793 25,123 649,916 624,793 26,837 651,630 4.625% senior notes due 2021 (the "4.625% Subsidiary 2021 Senior Notes") 63,207 2,690 65,897 63,207 2,862 66,069 3.60% senior notes due 2022 250,000 (1,806 ) 248,194 250,000 (1,891 ) 248,109 4.875% senior notes due 2023 (the "4.875% Westlake 2023 Senior Notes") 433,793 12,840 446,633 433,793 13,431 447,224 4.875% senior notes due 2023 (the "4.875% Subsidiary 2023 Senior Notes") 16,207 519 16,726 16,207 540 16,747 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") 750,000 (10,564 ) 739,436 750,000 (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 (898 ) 99,102 100,000 (916 ) 99,084 6 ¾% senior notes due 2032 250,000 (1,853 ) 248,147 250,000 (1,883 ) 248,117 6 ½% senior notes due 2035 (the "6 ½% 2035 GO Zone Senior Notes") 89,000 (828 ) 88,172 89,000 (839 ) 88,161 6 ½% senior notes due 2035 (the "6 ½% 2035 IKE Zone Senior Notes") 65,000 (594 ) 64,406 65,000 (602 ) 64,398 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes") 700,000 (25,876 ) 674,124 700,000 (26,017 ) 673,983 Long-term debt, net $ 3,602,889 $ (1,247 ) $ 3,601,642 $ 3,677,889 $ 765 $ 3,678,654

Pension and Post-Retirement B38

Pension and Post-Retirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2017
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Components of Net Periodic Benefit Cost	Components of net periodic benefit cost for the Company's other post-retirement benefits are as follows: Three Months Ended March 31, Three Months Ended March 31, 2017 2016 U.S. Non-U.S. U.S. Service cost $ 163 $ 5 $ 5 Interest cost 500 14 145 Amortization of net loss 15 — 31 Net periodic benefit cost $ 678 $ 19 $ 181 Components of net periodic benefit cost (income) for the Company's pension plans are as follows: Three Months Ended March 31, 2017 2016 U.S. Non-U.S. U.S. Non-U.S. Service cost $ 1,336 $ 554 $ — $ 323 Interest cost 6,198 561 567 568 Expected return on plan assets (9,976 ) (114 ) (802 ) — Amortization of net loss 297 151 303 — Net periodic benefit cost (income) $ (2,145 ) $ 1,152 $ 68 $ 891

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Schedule of Stockholders Equity	Changes in stockholders' equity for the three months ended March 31, 2017 and 2016 were as follows: Common Stock Common Stock, Held in Treasury Additional Paid-in Capital Retained Earnings Accumulated Other Comprehensive Income (Loss) Noncontrolling Interests Total Balances at December 31, 2016 $ 1,347 $ (319,339 ) $ 550,641 $ 3,412,286 $ (121,306 ) $ 368,416 $ 3,892,045 Net income — — — 138,190 — 6,520 144,710 Other comprehensive income (loss), net of income taxes: Pension and other post- retirement benefits liability — — — — 401 (44 ) 357 Foreign currency translation adjustments — — — — 17,344 3,207 20,551 Other — — — — (75 ) — (75 ) Shares issued—stock- based compensation — 2,943 (1,589 ) — — — 1,354 Stock-based compensation, net of tax on stock options exercised — — 3,009 — — — 3,009 Dividends declared — — — (24,656 ) — — (24,656 ) Distributions to noncontrolling interests — — — — — (4,463 ) (4,463 ) Balances at March 31, 2017 $ 1,347 $ (316,396 ) $ 552,061 $ 3,525,820 $ (103,636 ) $ 373,636 $ 4,032,832 Common Stock Common Stock, Held in Treasury Additional Paid-in Capital Retained Earnings Accumulated Other Comprehensive Income (Loss) Noncontrolling Interests Total Balances at December 31, 2015 $ 1,347 $ (258,312 ) $ 542,148 $ 3,109,987 $ (129,292 ) $ 296,053 $ 3,561,931 Net income — — — 123,128 — 5,808 128,936 Other comprehensive income (loss), net of income taxes Pension and other post- retirement benefits liability — — — — 206 — 206 Foreign currency translation adjustments — — — — 22,805 — 22,805 Net unrealized holding gains on investments — — — — 15,618 — 15,618 Shares issued—stock- based compensation — 1,853 (1,831 ) — — — 22 Stock-based compensation, net of tax on stock options exercised — — 2,569 — — — 2,569 Dividends declared — — — (23,700 ) — — (23,700 ) Distributions to noncontrolling interests — — — — — (3,985 ) (3,985 ) Balances at March 31, 2016 $ 1,347 $ (256,459 ) $ 542,886 $ 3,209,415 $ (90,663 ) $ 297,876 $ 3,704,402
Schedule of Accumulated Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive income (loss) by component for the three months ended March 31, 2017 and 2016 were as follows: Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Net Unrealized Holding Gains (Losses) on Investments, Net of Tax Total Balances at December 31, 2016 $ 28,945 $ (150,202 ) $ (49 ) $ (121,306 ) Other comprehensive income (loss) before reclassifications 101 17,344 (75 ) 17,370 Amounts reclassified from accumulated other comprehensive loss 300 — — 300 Net other comprehensive income (loss) for the period 401 17,344 (75 ) 17,670 Balances at March 31, 2017 $ 29,346 $ (132,858 ) $ (124 ) $ (103,636 ) Benefits Liability, Net of Tax Cumulative Foreign Currency Exchange, Net of Tax Net Unrealized Holding Gains (Losses) on Investments, Net of Tax Total Balances at December 31, 2015 $ (8,607 ) $ (115,690 ) $ (4,995 ) $ (129,292 ) Other comprehensive income before reclassifications — 22,805 15,651 38,456 Amounts reclassified from accumulated other comprehensive loss (income) 206 — (33 ) 173 Net other comprehensive income for the period 206 22,805 15,618 38,629 Balances at March 31, 2016 $ (8,401 ) $ (92,885 ) $ 10,623 $ (90,663 )
Reclassification out of Accumulated Other Comprehensive Income (Loss)	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 for the three months ended March 31, 2017 and 2016 : Details about Accumulated Other Comprehensive Income (Loss) Components Location of Reclassification (Income (Expense)) in Consolidated Statements of Operations Three Months Ended March 31, 2017 2016 Amortization of pension and other post-retirement items Net loss (1) $ (463 ) $ (334 ) Benefit from income taxes 163 128 (300 ) (206 ) Net unrealized gains on available-for-sale investments Realized gain on available-for-sale investments Other income, net — 52 Provision for income taxes — (19 ) — 33 Total reclassifications for the period $ (300 ) $ (173 ) _____________ (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, please read Note 13 (Employee Benefits) to the financial statements included in the 2016 Form 10-K.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values of Derivatives Instruments in Consolidated Balance Sheets	The fair values of derivative instruments reflected in the Company's consolidated balance sheets were as follows: Asset Derivatives Balance Sheet Location Fair Value as of March 31, December 31, Not designated as hedging instruments Commodity forward contracts Accounts receivable, net $ 3,124 $ 7,589 Commodity forward contracts Deferred charges and other assets, net 2,246 5,249 Total asset derivatives $ 5,370 $ 12,838 Liability Derivatives Balance Sheet Location Fair Value as of March 31, December 31, Not designated as hedging instruments Commodity forward contracts Accrued liabilities $ 1,048 $ 1,349 Commodity forward contracts Other liabilities 5,115 3,724 Total liability derivatives $ 6,163 $ 5,073
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 Three Months Ended March 31, 2017 2016 Commodity forward contracts Cost of sales $ (9,167 ) $ 4,057
ImpactofDerivativesNetInConsolidatedBalanceSheet [Table Text Block]	March 31, 2017 Net Presentation Gross Presentation Net Assets (Liabilities) Presented in the Consolidated Balance Sheets Risk management assets—Commodity forward contracts Risk management liabilities—Commodity forward contracts Accounts receivable, net Derivative positions subject to enforceable master netting arrangements $ 520 $ 1,049 $ (529 ) Derivative positions not subject to enforceable master netting arrangements 2,604 2,604 — 3,124 3,653 (529 ) Deferred charges and other assets, net Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting 2,246 2,246 — 2,246 2,246 — Accrued liabilities Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting (1,048 ) — (1,048 ) (1,048 ) — (1,048 ) Other liabilities Derivative positions subject to enforceable master netting (1,629 ) 978 (2,607 ) Derivative positions not subject to enforceable master netting (3,486 ) — (3,486 ) (5,115 ) 978 (6,093 ) Risk management assets (liabilities)—Commodity forward contracts $ 6,877 $ (7,670 ) December 31, 2016 Net Presentation Gross Presentation Net Assets (Liabilities) Presented in the Consolidated Balance Sheets Risk management assets—Commodity forward contracts Risk management liabilities—Commodity forward contracts Accounts receivable, net Derivative positions subject to enforceable master netting $ 1,498 $ 1,636 $ (138 ) Derivative positions not subject to enforceable master netting 6,091 6,091 — 7,589 7,727 (138 ) Deferred charges and other assets, net Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting 5,249 5,249 — 5,249 5,249 — Accrued liabilities Derivative positions subject to enforceable master netting — — — Derivative positions not subject to enforceable master netting (1,349 ) — (1,349 ) (1,349 ) — (1,349 ) Other liabilities Derivative positions subject to enforceable master netting (436 ) 2,010 (2,446 ) Derivative positions not subject to enforceable master netting (3,288 ) — (3,288 ) (3,724 ) 2,010 (5,734 ) Risk management assets (liabilities)—Commodity forward contracts $ 14,986 $ (7,221 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Summary Of Assets And Liabilities Accounted At Fair Value On A Recurring Basis	The following tables summarize, by level within the fair value hierarchy, the Company's assets and liabilities that were accounted for at fair value on a recurring basis: March 31, 2017 Level 1 Level 2 Total Derivative instruments Risk management assets—Commodity forward contracts $ 406 $ 6,471 $ 6,877 Risk management liabilities—Commodity forward contracts (6,710 ) (960 ) (7,670 ) December 31, 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 )
Summary Of Carrying And Fair Values Of Long-Term Debt	The carrying and fair values of the Company's long-term debt are summarized in the table below. The fair value of the Company's long-term debt instruments is determined using a market approach, based upon quotes from financial reporting services. 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. March 31, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value Revolving credit facility $ 250,000 $ 250,000 $ 325,000 $ 325,000 4.625% Westlake 2021 Senior Notes 624,793 649,354 651,630 650,847 4.625% Subsidiary 2021 Senior Notes 63,207 65,639 66,069 65,775 3.60% senior notes due 2022 250,000 254,443 248,109 251,725 4.875% Westlake 2023 Senior Notes 433,793 451,761 447,224 451,301 4.875% Subsidiary 2023 Senior Notes 16,207 16,873 16,747 16,501 3.60% 2026 Senior Notes 750,000 735,870 739,243 722,055 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 100,000 110,000 99,084 112,433 6 ¾% senior notes due 2032 250,000 258,760 248,117 258,818 6 ½% 2035 GO Zone Senior Notes 89,000 101,760 88,161 100,323 6 ½% 2035 IKE Zone Senior Notes 65,000 74,298 64,398 73,270 5.0% 2046 Senior Notes 700,000 717,864 673,983 691,712

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Schedule Of Net Income Attributable To Common Stockholders	Diluted earnings per share include the effect of certain stock options. Three Months Ended March 31, 2017 2016 Net income attributable to Westlake Chemical Corporation $ 138,190 $ 123,128 Less: Net income attributable to participating securities (694 ) (549 ) Net income attributable to common shareholders $ 137,496 $ 122,579
Reconciliation Of Denominator For Basic And Diluted Earnings Per Share	The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations: Three Months Ended March 31, 2017 2016 Weighted average common shares—basic 128,979,357 130,189,964 Plus incremental shares from: Assumed exercise of options 712,658 410,550 Weighted average common shares—diluted 129,692,015 130,600,514 Earnings per common share attributable to Westlake Chemical Corporation: Basic $ 1.07 $ 0.94 Diluted $ 1.06 $ 0.94

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Segment Reporting Information	Three Months Ended March 31, 2017 2016 Net external sales Olefins Polyethylene $ 385,942 $ 346,032 Styrene, feedstock and other 157,053 84,988 Total Olefins 542,995 431,020 Vinyls PVC, caustic soda and other 1,131,129 430,902 Building products 268,492 113,265 Total Vinyls 1,399,621 544,167 $ 1,942,616 $ 975,187 Intersegment sales Olefins $ 85,944 $ 27,949 Vinyls 292 364 $ 86,236 $ 28,313 Three Months Ended March 31, 2017 2016 Income (loss) from operations Olefins $ 179,817 $ 149,235 Vinyls 71,441 62,116 Corporate and other (15,960 ) (9,075 ) $ 235,298 $ 202,276 Depreciation and amortization Olefins $ 41,040 $ 28,697 Vinyls 107,273 36,287 Corporate and other 1,956 730 $ 150,269 $ 65,714 Other income (expense), net Olefins $ 1,370 $ 1,513 Vinyls 3,878 (1,519 ) Corporate and other (177 ) 2,651 $ 5,071 $ 2,645 Provision for (benefit from) income taxes Olefins $ 57,811 $ 52,533 Vinyls 14,958 17,270 Corporate and other (16,886 ) (503 ) $ 55,883 $ 69,300 Capital expenditures Olefins $ 25,350 $ 95,152 Vinyls 108,081 40,256 Corporate and other 854 920 $ 134,285 $ 136,328
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: Three Months Ended March 31, 2017 2016 Income from operations $ 235,298 $ 202,276 Interest expense (39,776 ) (6,685 ) Other income, net 5,071 2,645 Income before income taxes $ 200,593 $ 198,236
Total Assets	March 31, December 31, Total assets Olefins $ 2,120,429 $ 2,092,617 Vinyls 8,214,203 8,287,204 Corporate and other 390,198 510,432 $ 10,724,830 $ 10,890,253

Guarantor Disclosures (Tables)

Guarantor Disclosures (Tables)	3 Months Ended
	Mar. 31, 2017
Guarantees [Abstract]
Condensed Consolidating Financial Information Balance Sheet	Condensed Consolidating Financial Information as of March 31, 2017 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Balance Sheet Current assets Cash and cash equivalents $ 54,966 $ 5,647 $ 311,978 $ — $ 372,591 Accounts receivable, net 2,446,732 3,521,181 330,311 (5,294,258 ) 1,003,966 Inventories — 605,775 215,933 — 821,708 Prepaid expenses and other current assets 53,239 38,066 11,463 (59,073 ) 43,695 Restricted cash — 2,681 6,647 — 9,328 Total current assets 2,554,937 4,173,350 876,332 (5,353,331 ) 2,251,288 Property, plant and equipment, net — 4,438,292 1,954,453 — 6,392,745 Other assets, net Goodwill — 791,706 158,975 — 950,681 Customer relationships, net — 453,985 142,656 — 596,641 Other intangible assets, net — 102,339 70,358 — 172,697 Deferred charges and other assets, net 9,335,542 846,041 1,131,172 (10,951,977 ) 360,778 Total other assets, net 9,335,542 2,194,071 1,503,161 (10,951,977 ) 2,080,797 Total assets $ 11,890,479 $ 10,805,713 $ 4,333,946 $ (16,305,308 ) $ 10,724,830 Current liabilities Accounts payable $ 4,705,704 $ 761,986 $ 273,714 $ (5,198,283 ) $ 543,121 Accrued liabilities 17,449 357,968 179,941 (155,048 ) 400,310 Total current liabilities 4,723,153 1,119,954 453,655 (5,353,331 ) 943,431 Long-term debt, net 3,508,130 2,999,225 — (2,905,713 ) 3,601,642 Deferred income taxes — 1,581,202 91,303 (23,385 ) 1,649,120 Pension and other liabilities — 1,479,584 133,658 (1,115,437 ) 497,805 Total liabilities 8,231,283 7,179,965 678,616 (9,397,866 ) 6,691,998 Total Westlake Chemical Corporation stockholders' equity 3,659,196 3,625,748 3,281,694 (6,907,442 ) 3,659,196 Noncontrolling interests — — 373,636 — 373,636 Total equity 3,659,196 3,625,748 3,655,330 (6,907,442 ) 4,032,832 Total liabilities and equity $ 11,890,479 $ 10,805,713 $ 4,333,946 $ (16,305,308 ) $ 10,724,830 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 Goodwill — 791,706 154,847 — 946,553 Customer relationships, net — 468,645 142,970 — 611,615 Other intangible assets, net — 130,243 71,177 (25,581 ) 175,839 Deferred charges and other assets, net 9,170,042 874,003 1,115,877 (10,832,054 ) 327,868 Total 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 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, net 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 Statement Of Operations	Condensed Consolidating Financial Information for the Three Months Ended March 31, 2017 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 1,579,725 $ 736,085 $ (373,194 ) $ 1,942,616 Cost of sales — 1,359,275 582,660 (366,462 ) 1,575,473 Gross profit — 220,450 153,425 (6,732 ) 367,143 Selling, general and administrative expenses 778 92,260 37,345 (6,732 ) 123,651 Transaction and integration-related costs — 8,132 62 — 8,194 Income (loss) from operations (778 ) 120,058 116,018 — 235,298 Other income (expense) Interest expense (38,185 ) (45,677 ) (806 ) 44,892 (39,776 ) Other income (expense), net 37,157 (255 ) 13,061 (44,892 ) 5,071 Income (loss) before income taxes (1,806 ) 74,126 128,273 — 200,593 Provision for (benefit from) income taxes (5,467 ) 53,372 7,978 — 55,883 Equity in net income of subsidiaries 134,529 — — (134,529 ) — Net income 138,190 20,754 120,295 (134,529 ) 144,710 Net income attributable to noncontrolling interests — — 6,520 — 6,520 Net income attributable to Westlake Chemical Corporation $ 138,190 $ 20,754 $ 113,775 $ (134,529 ) $ 138,190 Comprehensive income attributable to Westlake Chemical Corporation $ 155,860 $ 4,635 $ 122,243 $ (126,878 ) $ 155,860 Condensed Consolidating Financial Information for the Three Months Ended March 31, 2016 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Statement of Operations Net sales $ — $ 761,736 $ 569,824 $ (356,373 ) $ 975,187 Cost of sales — 642,730 427,777 (350,905 ) 719,602 Gross profit — 119,006 142,047 (5,468 ) 255,585 Selling, general and administrative expenses 607 36,996 21,174 (5,468 ) 53,309 Income (loss) from operations (607 ) 82,010 120,873 — 202,276 Other income (expense) Interest expense (10,411 ) (4,851 ) — 8,577 (6,685 ) Other income (expense), net 1,815 (825 ) 10,232 (8,577 ) 2,645 Income (loss) before income taxes (9,203 ) 76,334 131,105 — 198,236 Provision for (benefit from) income taxes (3,219 ) 62,199 10,320 — 69,300 Equity in net income of subsidiaries 129,112 — — (129,112 ) — Net income 123,128 14,135 120,785 (129,112 ) 128,936 Net income attributable to noncontrolling interests — — 5,808 — 5,808 Net income attributable to Westlake Chemical Corporation $ 123,128 $ 14,135 $ 114,977 $ (129,112 ) $ 123,128 Comprehensive income attributable to Westlake Chemical Corporation $ 161,757 $ 14,341 $ 149,462 $ (163,803 ) $ 161,757
Condensed Consolidating Financial Information Statement Of Cash Flows	Condensed Consolidating Financial Information for the Three Months Ended March 31, 2017 Westlake Chemical Corporation 100% Owned Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated Statement of Cash Flows Cash flows from operating activities Net income $ 138,190 $ 20,754 $ 120,295 $ (134,529 ) $ 144,710 Adjustments to reconcile net income to net cash provided by (used for) operating activities Depreciation and amortization — 98,578 51,691 — 150,269 Deferred income taxes (585 ) (2,905 ) (2,783 ) — (6,273 ) Net changes in working capital and other (213,242 ) (28,009 ) (24,590 ) 134,529 (131,312 ) Net cash provided by (used for) operating activities (75,637 ) 88,418 144,613 — 157,394 Cash flows from investing activities Additions to property, plant and equipment — (120,719 ) (13,566 ) — (134,285 ) Additions to cost method investment — (15,000 ) — — (15,000 ) Proceeds from disposition of assets — 66 — — 66 Proceeds from involuntary conversion of assets — 1,555 — — 1,555 Settlements of derivative instruments — (355 ) — — (355 ) Net cash used for investing activities — (134,453 ) (13,566 ) — (148,019 ) Cash flows from financing activities Intercompany financing 78,234 (95,698 ) 17,464 — — Debt issuance costs (319 ) — — — (319 ) Dividends paid (24,656 ) — — — (24,656 ) Distributions to noncontrolling interests — 94,631 (99,094 ) — (4,463 ) Proceeds from issuance of notes payable — — 1,874 — 1,874 Proceeds from drawdown of revolver 50,000 — — — 50,000 Restricted cash associated with term loan 154,000 — — — 154,000 Repayment of term loan (150,000 ) — — — (150,000 ) Repayment of notes payable — (257 ) (2,212 ) — (2,469 ) Repayment of revolver (125,000 ) — — — (125,000 ) Other 1,354 — — — 1,354 Net cash used for financing activities (16,387 ) (1,324 ) (81,968 ) — (99,679 ) Effect of exchange rate changes on cash and cash equivalents — — 3,442 — 3,442 Net increase (decrease) in cash and cash equivalents (92,024 ) (47,359 ) 52,521 — (86,862 ) Cash and cash equivalents at beginning of period 146,990 53,006 259,457 — 459,453 Cash and cash equivalents at end of period $ 54,966 $ 5,647 $ 311,978 $ — $ 372,591 Condensed Consolidating Financial Information for the Three Months Ended March 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 $ 123,128 $ 14,135 $ 120,785 $ (129,112 ) $ 128,936 Adjustments to reconcile net income to net cash provided by operating activities Depreciation and amortization — 32,687 33,027 — 65,714 Deferred income taxes (2,724 ) 55,473 5,888 — 58,637 Net changes in working capital and other (120,345 ) (94,115 ) (39,004 ) 129,112 (124,352 ) Net cash provided by operating activities 59 8,180 120,696 — 128,935 Cash flows from investing activities Additions to property, plant and equipment — (50,568 ) (85,760 ) — (136,328 ) Proceeds from disposition of assets — 6 98 — 104 Proceeds from sales and maturities of securities 26,859 — — — 26,859 Purchase of securities (29,045 ) — (7,592 ) — (36,637 ) Settlements of derivative instruments — (1,219 ) — — (1,219 ) Net cash used for investing activities (2,186 ) (51,781 ) (93,254 ) — (147,221 ) Cash flows from financing activities Intercompany financing (13,763 ) (42,072 ) 55,835 — — Dividends paid (23,700 ) — — — (23,700 ) Distributions to noncontrolling interests — 79,999 (83,984 ) — (3,985 ) Proceeds from issuance of notes payable — — 2,050 — 2,050 Repayment of notes payable — — (7,095 ) — (7,095 ) Repurchase of common stock for treasury (679 ) — — — (679 ) Other 288 — — — 288 Net cash provided by (used for) financing activities (37,854 ) 37,927 (33,194 ) — (33,121 ) Effect of exchange rate changes on cash and cash equivalents — — 3,858 — 3,858 Net decrease in cash and cash equivalents (39,981 ) (5,674 ) (1,894 ) — (47,549 ) Cash and cash equivalents at beginning of period 303,131 6,828 352,566 — 662,525 Cash and cash equivalents at end of period $ 263,150 $ 1,154 $ 350,672 $ — $ 614,976

Acquisition (Narrative) (Detail

Acquisition (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	Aug. 31, 2016	Aug. 30, 2016	Mar. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill			$ 950,681	$ 946,553
Axiall Corporation [Member]
Business Acquisition [Line Items]
Equity interest in acquiree held prior to combination, shares		3.1
Offer per share	$ 33
Purchase consideration	$ 2,539,360
Goodwill	$ 887,491

Acquisition (Allocation of Purc

Acquisition (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 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
Step acquisition, equity interest in acquiree, remeasurement gain (loss), net	$ 49,080

Acquisition (Purchase Price All

Acquisition (Purchase Price Allocation) (Details) - USD ($) $ in Thousands	Aug. 31, 2016	Mar. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 950,681	$ 946,553
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]
Business Combination, Acquired Receivables, Fair Value	$ 422,459
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	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 fair value allocated to net assets acquired	2,641,660
Business Combination, Acquired Receivables, Gross Contractual Amount	434,834
Business Combination, Acquired Receivables, Estimated Uncollectible	12,375
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) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Restricted cash	$ 32,231	$ 186,216
Current	9,328	160,527
Noncurrent	$ 22,903	$ 25,689

Financial Instruments (Availabl

Financial Instruments (Available-for-Sale Marketable Securities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Gain (Loss) on Investments [Line Items]
Available-for-sale Securities, Gross Realized Gains		$ 61
Available-for-sale Securities, Gross Realized Losses		(9)
Available-for-sale Securities	$ 0		$ 0
Proceeds from Sale and Maturity of Available-for-sale Securities	$ 0	$ 26,859

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accounts Receivable, Net [Abstract]
Trade customers	$ 951,555	$ 819,739
Affiliates	9,965	7,982
Allowance for doubtful accounts	(18,856)	(17,991)
Accounts receivable from trade customers, net	942,664	809,730
Federal and state taxes	32,901	90,414
Other	28,401	38,599
Accounts receivable, net	$ 1,003,966	$ 938,743

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Finished products	$ 491,849	$ 500,861
Feedstock, additives and chemicals	202,065	216,877
Materials and supplies	127,794	83,362
Inventories	$ 821,708	$ 801,100

Property, Plant and Equipment (

Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	$ 6,392,745		$ 6,420,062
Depreciation expense on property, plant and equipment	$ 114,091	$ 56,041

Other Assets (Narrative) (Detai

Other Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other assets, net [Member]
Other Assets [Line Items]
Amortization expense	$ 36,330	$ 9,770

Other Assets (Changes in Goodwi

Other Assets (Changes in Goodwill) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 946,553
Goodwill acquired during the period	0
Effects of changes in foreign exchange rates	4,128
Ending Balance	950,681
Olefins [Member]
Goodwill [Roll Forward]
Beginning Balance	29,990
Goodwill acquired during the period	0
Effects of changes in foreign exchange rates	0
Ending Balance	29,990
Vinyls [Member]
Goodwill [Roll Forward]
Beginning Balance	916,563
Goodwill acquired during the period	0
Effects of changes in foreign exchange rates	4,128
Ending Balance	$ 920,691

Accounts and Notes Payable (Det

Accounts and Notes Payable (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accounts payable—third parties	$ 529,388	$ 474,017
Accounts payable to affiliates	12,544	20,726
Notes payable to banks	1,189	1,516
Accounts payable	$ 543,121	$ 496,259

Term Loan (Narrative) (Details)

Term Loan (Narrative) (Details) - USD ($)	Aug. 10, 2016	Mar. 31, 2017	Dec. 31, 2016	Sep. 10, 2016	Sep. 09, 2016
Line of Credit Facility [Line Items]
Restricted cash		$ 32,231,000	$ 186,216,000
Line of Credit [Member] | Term Loan Facility Maturing March 31, 2017 [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 150,000,000
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%
Line of Credit [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%
Line of Credit [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	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Debt Instrument [Line Items]
Principal Amount	$ 3,602,889	$ 3,677,889
Unamortized Premium, Discount and Debt Issuance Costs,	(1,247)	765
Net, Long-term Debt	3,601,642	3,678,654
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal Amount	250,000	325,000
Unamortized Premium, Discount and Debt Issuance Costs,	0	0
Net, Long-term Debt	$ 250,000	325,000
Senior Notes [Member] | 4.625% Senior Notes Due 2021 (New Westlake 2021 Notes) [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,021
Stated interest rate (percent)	4.625%		4.625%
Principal Amount	$ 624,793	624,793
Unamortized Premium, Discount and Debt Issuance Costs,	25,123	26,837
Net, Long-term Debt	$ 649,916	651,630
Senior Notes [Member] | 4.625% Senior Notes Due 2021 (Existing Axiall 2021 Notes) [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,021
Stated interest rate (percent)	4.625%		4.625%
Principal Amount	$ 63,207	63,207	$ 688,000
Unamortized Premium, Discount and Debt Issuance Costs,	2,690	2,862
Net, Long-term Debt	$ 65,897	66,069
Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,022
Stated interest rate (percent)	3.60%
Principal Amount	$ 250,000	250,000
Unamortized Premium, Discount and Debt Issuance Costs,	(1,806)	(1,891)
Net, Long-term Debt	$ 248,194	248,109
Senior Notes [Member] | 4.875% Senior Notes Due 2023 (New Westlake 2023 Notes) [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,023
Stated interest rate (percent)	4.875%		4.875%
Principal Amount	$ 433,793	433,793
Unamortized Premium, Discount and Debt Issuance Costs,	12,840	13,431
Net, Long-term Debt	$ 446,633	447,224
Senior Notes [Member] | 4.875% Senior Notes Due 2023 (Existing Axiall 2023 Notes) [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,023
Stated interest rate (percent)	4.875%		4.875%
Principal Amount	$ 16,207	16,207	$ 450,000
Unamortized Premium, Discount and Debt Issuance Costs,	519	540
Net, Long-term Debt	$ 16,726	16,747
Senior Notes [Member] | 3.6% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,026
Stated interest rate (percent)	3.60%
Principal Amount	$ 750,000	750,000
Unamortized Premium, Discount and Debt Issuance Costs,	(10,564)	(10,757)
Net, Long-term Debt	$ 739,436	739,243
Senior Notes [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,027
Principal Amount	$ 10,889	10,889
Unamortized Premium, Discount and Debt Issuance Costs,	0	0
Net, Long-term Debt	$ 10,889	10,889
Senior Notes [Member] | 6 1/2% Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,029
Stated interest rate (percent)	6.50%
Principal Amount	$ 100,000	100,000
Unamortized Premium, Discount and Debt Issuance Costs,	(898)	(916)
Net, Long-term Debt	$ 99,102	99,084
Senior Notes [Member] | 6 3/4% Senior Notes Due 2032 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,032
Stated interest rate (percent)	6.75%
Principal Amount	$ 250,000	250,000
Unamortized Premium, Discount and Debt Issuance Costs,	(1,853)	(1,883)
Net, Long-term Debt	$ 248,147	248,117
Senior Notes [Member] | 2035 GO Zone 6 1/2% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,035
Stated interest rate (percent)	6.50%
Principal Amount	$ 89,000	89,000
Unamortized Premium, Discount and Debt Issuance Costs,	(828)	(839)
Net, Long-term Debt	$ 88,172	88,161
Senior Notes [Member] | 2035 IKE Zone 6 1/2% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,035
Stated interest rate (percent)	6.50%
Principal Amount	$ 65,000	65,000
Unamortized Premium, Discount and Debt Issuance Costs,	(594)	(602)
Net, Long-term Debt	$ 64,406	64,398
Senior Notes [Member] | 5% Senior Notes Due 2046 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity	2,046
Stated interest rate (percent)	5.00%
Principal Amount	$ 700,000	700,000
Unamortized Premium, Discount and Debt Issuance Costs,	(25,876)	(26,017)
Net, Long-term Debt	$ 674,124	$ 673,983

Long-Term Debt (Revolving Credi

Long-Term Debt (Revolving Credit Facility) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Principal amount	$ 3,602,889	$ 3,677,889
Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Principal amount	$ 250,000	$ 325,000
Line of Credit Facility, Interest Rate at Period End	2.34%
Letters of credit outstanding	$ 76,493
Remaining borrowing capacity	$ 673,507

Long-Term Debt (Senior Notes) (

Long-Term Debt (Senior Notes) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Aug. 10, 2016
Debt Instrument [Line Items]
Principal amount	$ 3,602,889	$ 3,677,889
Unamortized Debt Issuance Expense	$ 23,767	$ 24,113
Senior Notes [Member] | 3.60% Percentage Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Principal amount			$ 750,000
Stated interest rate (percent)			3.60%
Senior Notes [Member] | 5.0% Percentage Senior Notes Due 2046 [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	Mar. 27, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Aug. 10, 2016
Debt Instrument [Line Items]
Principal amount		$ 3,602,889	$ 3,677,889
Senior Notes [Member] | 3.60% Percentage Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Principal amount					$ 750,000
Stated interest rate (percent)					3.60%
Exchange Offer Percentage	99.9667%
Senior Notes [Member] | 5.0% Percentage Senior Notes Due 2046 [Member]
Debt Instrument [Line Items]
Principal amount					$ 700,000
Stated interest rate (percent)					5.00%
Exchange Offer Percentage	100.00%
Senior Notes [Member] | 4.625% Senior Notes Due 2021 (New Westlake 2021 Notes) [Member]
Debt Instrument [Line Items]
Principal amount		$ 624,793	624,793
Stated interest rate (percent)		4.625%		4.625%
Senior Notes [Member] | 4.875% Senior Notes Due 2023 (New Westlake 2023 Notes) [Member]
Debt Instrument [Line Items]
Principal amount		$ 433,793	433,793
Stated interest rate (percent)		4.875%		4.875%
Senior Notes [Member] | 4.625% Senior Notes Due 2021 (Existing Axiall 2021 Notes) [Member]
Debt Instrument [Line Items]
Principal amount		$ 63,207	63,207	$ 688,000
Stated interest rate (percent)		4.625%		4.625%
Exchange Offer Percentage	99.9717%
Senior Notes [Member] | 4.875% Senior Notes Due 2023 (Existing Axiall 2023 Notes) [Member]
Debt Instrument [Line Items]
Principal amount		$ 16,207	$ 16,207	$ 450,000
Stated interest rate (percent)		4.875%		4.875%
Exchange Offer Percentage	100.00%

Pension and Post-Retirement B61

Pension and Post-Retirement Benefits (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,336	$ 0
Interest cost	6,198	567
Expected return on plan assets	(9,976)	(802)
Amortization of net loss	297	303
Net periodic benefit cost (income)	(2,145)	68
Non-US Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	554	323
Interest cost	561	568
Expected return on plan assets	(114)	0
Amortization of net loss	151	0
Net periodic benefit cost (income)	1,152	891
United States Postretirement Benefit Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	163
Interest cost	500
Amortization of net loss	15
Net periodic benefit cost (income)	678
Non-U.S. Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	5
Interest cost	14	145
Amortization of net loss	0	31
Net periodic benefit cost (income)	$ 19	$ 181

Pension and Post-Retirement B62

Pension and Post-Retirement Benefits (Additional Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contribution	$ 2,258	$ 0
Estimated future employer contributions in current fiscal year	6,774
Non-US Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contribution	390	$ 0
Estimated future employer contributions in current fiscal year	$ 459

Stockholders' Equity (Changes i

Stockholders' Equity (Changes in Stockholders' Equity) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount, beginning balance	$ 3,892,045	$ 3,561,931
Net income	144,710	128,936
Pension and other post- retirement benefits liability	357	206
Foreign currency translation adjustments	20,551	22,805
Other	(75)	15,618
Shares issued—stock- based compensation	1,354	22
Stock-based compensation, net of tax on stock options exercised	3,009	2,569
Dividends declared	(24,656)	(23,700)
Distributions to noncontrolling interests	(4,463)	(3,985)
Amount, ending balance	4,032,832	3,704,402
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount, beginning balance	1,347	1,347
Shares issued—stock- based compensation	0	0
Amount, ending balance	1,347	1,347
Common Stock, Held in Treasury [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount, beginning balance	(319,339)	(258,312)
Shares issued—stock- based compensation	2,943	1,853
Amount, ending balance	(316,396)	(256,459)
Additional Paid-in Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount, beginning balance	550,641	542,148
Shares issued—stock- based compensation	(1,589)	(1,831)
Stock-based compensation, net of tax on stock options exercised	3,009	2,569
Amount, ending balance	552,061	542,886
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount, beginning balance	3,412,286	3,109,987
Net income	138,190	123,128
Dividends declared	(24,656)	(23,700)
Amount, ending balance	3,525,820	3,209,415
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount, beginning balance	(121,306)	(129,292)
Pension and other post- retirement benefits liability	401	206
Foreign currency translation adjustments	17,344	22,805
Other	(75)	15,618
Amount, ending balance	(103,636)	(90,663)
Noncontrolling Interests [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount, beginning balance	368,416	296,053
Net income	6,520	5,808
Pension and other post- retirement benefits liability	(44)
Foreign currency translation adjustments	3,207
Distributions to noncontrolling interests	(4,463)	(3,985)
Amount, ending balance	$ 373,636	$ 297,876

Stockholders' Equity (Changes64

Stockholders' Equity (Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss	$ (103,636)		$ (121,306)
Other comprehensive income, net of income taxes	17,670	$ 38,629
Amount, ending balance	4,032,832	3,704,402
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss			(121,306)	$ (129,292)
Other comprehensive income (loss) before reclassifications	17,370	38,456
Amounts reclassified from accumulated other comprehensive loss (income)	300	173
Other comprehensive income, net of income taxes	17,670	38,629
Amount, ending balance	(103,636)	(90,663)
Benefits Liability, Net of Tax [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss			28,945	(8,607)
Other comprehensive income (loss) before reclassifications	101	0
Amounts reclassified from accumulated other comprehensive loss (income)	300	206
Other comprehensive income, net of income taxes	401	206
Amount, ending balance	29,346	(8,401)
Cumulative Foreign Currency Exchange, Net of Tax [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss			(150,202)	(115,690)
Other comprehensive income (loss) before reclassifications	17,344	22,805
Amounts reclassified from accumulated other comprehensive loss (income)	0	0
Other comprehensive income, net of income taxes	17,344	22,805
Amount, ending balance	(132,858)	(92,885)
Net Unrealized Holdings Gains (Losses) on Investments, Net of Tax [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss			$ (49)	$ (4,995)
Other comprehensive income (loss) before reclassifications	(75)	15,651
Amounts reclassified from accumulated other comprehensive loss (income)	0	(33)
Other comprehensive income, net of income taxes	(75)	15,618
Amount, ending balance	$ (124)	$ 10,623

Stockholders' Equity (Reclassif

Stockholders' Equity (Reclassifications in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision for income taxes, investments	$ (55,883)	$ (69,300)
Benefits Liability, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	(463)	(334)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	163	128
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	(300)	(206)
Total reclassifications for the period	(300)	(206)
Net Unrealized Holdings Gains on Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	0	33
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	(300)	(173)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Unrealized Holdings Gains on Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income, net	0	52
Provision for income taxes, investments	0	(19)
Income (loss), including portion attributable to noncontrolling interest	$ 0	$ 33

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Aug. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6,303	$ 2,303
Axiall Corporation [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in usd per share)			$ 33

Derivative Instruments (Fair Va

Derivative Instruments (Fair Values of Derivative Instruments in Consolidated Balance Sheets) (Details) - Not Designated as Hedging Instrument [Member] - Commodity Forward Contracts [Member]	3 Months Ended	12 Months Ended
	Mar. 31, 2017MMBTUgal	Dec. 31, 2016MMBTUgal
Derivatives, Fair Value [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | gal	221,800,000	257,000,000
Derivative, Nonmonetary Notional Amount, Energy Measure | MMBTU	8,800,000	8,500,000

Derivative Instruments (Impact

Derivative Instruments (Impact of Derivative Instruments on Consolidated Balance Sheet) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Commodity Forward Contracts [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 6,877	$ 14,986
Derivative Liability, Fair Value, Gross Liability	(7,670)	(7,221)
Accounts receivable, net [Member]
Derivative [Line Items]
Derivative Asset, Current	3,124	7,589
Derivative Asset, Fair Value, Gross Asset	3,653	7,727
Derivative Liability, Fair Value, Gross Liability	(529)	(138)
Accounts receivable, net [Member] | Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Asset, Current	520	1,498
Derivative Asset, Fair Value, Gross Asset	1,049	1,636
Derivative Liability, Fair Value, Gross Liability	(529)	(138)
Accounts receivable, net [Member] | Not Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Asset, Current	2,604	6,091
Derivative Asset, Fair Value, Gross Asset	2,604	6,091
Derivative Liability, Fair Value, Gross Liability	0	0
Deferred Charges and other assets, net [Member]
Derivative [Line Items]
Derivative Asset, Noncurrent	2,246	5,249
Derivative Asset, Fair Value, Gross Asset	2,246	5,249
Derivative Liability, Fair Value, Gross Liability	0	0
Deferred Charges and other assets, net [Member] | Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Asset, Noncurrent	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Deferred Charges and other assets, net [Member] | Not Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Asset, Noncurrent	2,246	5,249
Derivative Asset, Fair Value, Gross Asset	2,246	5,249
Derivative Liability, Fair Value, Gross Liability	0	0
Accrued Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Current	(1,048)	(1,349)
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(1,048)	(1,349)
Accrued Liabilities [Member] | Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Liability, Current	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Accrued Liabilities [Member] | Not Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Liability, Current	(1,048)	(1,349)
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(1,048)	(1,349)
Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Noncurrent	(5,115)	(3,724)
Derivative Asset, Fair Value, Gross Asset	978	2,010
Derivative Liability, Fair Value, Gross Liability	(6,093)	(5,734)
Other Liabilities [Member] | Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Liability, Noncurrent	(1,629)	(436)
Derivative Asset, Fair Value, Gross Asset	978	2,010
Derivative Liability, Fair Value, Gross Liability	(2,607)	(2,446)
Other Liabilities [Member] | Not Subject to Master Netting [Member]
Derivative [Line Items]
Derivative Liability, Noncurrent	(3,486)	(3,288)
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	$ (3,486)	$ (3,288)

Derivative Instruments (Impac69

Derivative Instruments (Impact of Derivative Instruments Not Designated as Fair Value Hedges) (Details) - Not Designated as Hedging Instrument [Member] - Commodity Forward Contracts [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	$ 5,370		$ 12,838
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	6,163		5,073
Cost of Sales [Member]
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(9,167)	$ 4,057
Accounts receivable, net [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	3,124		7,589
Deferred Charges and other assets, net [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	2,246		5,249
Accrued Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	1,048		1,349
Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	$ 5,115		$ 3,724

Fair Value Measurements (Summar

Fair Value Measurements (Summary of Assets and Liabilities Accounted at Fair Value on Recurring Basis) (Details) - Commodity Forward Contracts [Member] - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk management assets - Commodity forward contracts	$ 6,877	$ 14,986
Risk management liabilities - Commodity forward contracts	7,670	7,221
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk management assets - Commodity forward contracts	6,877	14,986
Risk management liabilities - Commodity forward contracts	(7,670)	(7,221)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk management assets - Commodity forward contracts	406	878
Risk management liabilities - Commodity forward contracts	(6,710)	(6,854)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk management assets - Commodity forward contracts	6,471	14,108
Risk management liabilities - Commodity forward contracts	$ (960)	$ (367)

Fair Value Measurements (Summ71

Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Senior Notes [Member] | 4.625% Senior Notes Due 2021 (New Westlake 2021 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,021
Stated interest rate (percent)	4.625%		4.625%
Senior Notes [Member] | 4.625% Senior Notes Due 2021 (Existing Axiall 2021 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,021
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]
Debt Instrument Maturity	2,022
Stated interest rate (percent)	3.60%
Senior Notes [Member] | 4.875% Senior Notes Due 2023 (New Westlake 2023 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,023
Stated interest rate (percent)	4.875%		4.875%
Senior Notes [Member] | 4.875% Senior Notes Due 2023 (Existing Axiall 2023 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,023
Stated interest rate (percent)	4.875%		4.875%
Senior Notes [Member] | 3.6% Senior Notes Due 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,026
Stated interest rate (percent)	3.60%
Senior Notes [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,027
Senior Notes [Member] | 6 1/2% Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,029
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 6 3/4% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,032
Stated interest rate (percent)	6.75%
Senior Notes [Member] | 2035 GO Zone 6 1/2% Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,035
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 2035 IKE Zone 6 1/2% Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,035
Stated interest rate (percent)	6.50%
Senior Notes [Member] | 5% Senior Notes Due 2046 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Maturity	2,046
Stated interest rate (percent)	5.00%
Carrying Value [Member] | Line of Credit [Member] | Unsecured Revolving Credit Facility [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving credit facility	$ 250,000	$ 325,000
Carrying Value [Member] | Senior Notes [Member] | 4.625% Senior Notes Due 2021 (New Westlake 2021 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	624,793	651,630
Carrying Value [Member] | Senior Notes [Member] | 4.625% Senior Notes Due 2021 (Existing Axiall 2021 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	63,207	66,069
Carrying Value [Member] | Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	250,000	248,109
Carrying Value [Member] | Senior Notes [Member] | 4.875% Senior Notes Due 2023 (New Westlake 2023 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	433,793	447,224
Carrying Value [Member] | Senior Notes [Member] | 4.875% Senior Notes Due 2023 (Existing Axiall 2023 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	16,207	16,747
Carrying Value [Member] | Senior Notes [Member] | 3.6% Senior Notes Due 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	750,000	739,243
Carrying Value [Member] | Senior Notes [Member] | 6 1/2% Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	100,000	99,084
Carrying Value [Member] | Senior Notes [Member] | 6 3/4% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	250,000	248,117
Carrying Value [Member] | Senior Notes [Member] | 2035 GO Zone 6 1/2% Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	89,000	88,161
Carrying Value [Member] | Senior Notes [Member] | 2035 IKE Zone 6 1/2% Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	65,000	64,398
Carrying Value [Member] | Senior Notes [Member] | 5% Senior Notes Due 2046 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	700,000	673,983
Carrying Value [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	10,889	10,889
Fair Value [Member] | Line of Credit [Member] | Unsecured Revolving Credit Facility [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving credit facility	250,000	325,000
Fair Value [Member] | Senior Notes [Member] | 4.625% Senior Notes Due 2021 (New Westlake 2021 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	649,354	650,847
Fair Value [Member] | Senior Notes [Member] | 4.625% Senior Notes Due 2021 (Existing Axiall 2021 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	65,639	65,775
Fair Value [Member] | Senior Notes [Member] | 3.60% Senior Notes Due 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	254,443	251,725
Fair Value [Member] | Senior Notes [Member] | 4.875% Senior Notes Due 2023 (New Westlake 2023 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	451,761	451,301
Fair Value [Member] | Senior Notes [Member] | 4.875% Senior Notes Due 2023 (Existing Axiall 2023 Notes) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	16,873	16,501
Fair Value [Member] | Senior Notes [Member] | 3.6% Senior Notes Due 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	735,870	722,055
Fair Value [Member] | Senior Notes [Member] | 6 1/2% Senior Notes Due 2029 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	110,000	112,433
Fair Value [Member] | Senior Notes [Member] | 6 3/4% Senior Notes Due 2032 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	258,760	258,818
Fair Value [Member] | Senior Notes [Member] | 2035 GO Zone 6 1/2% Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	101,760	100,323
Fair Value [Member] | Senior Notes [Member] | 2035 IKE Zone 6 1/2% Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	74,298	73,270
Fair Value [Member] | Senior Notes [Member] | 5% Senior Notes Due 2046 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	717,864	691,712
Fair Value [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member] | Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	$ 10,889	$ 10,889

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Detail)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Effective income tax rate	27.90%
U.S. federal statutory income tax rate	35.00%	35.00%

Earnings per Share (Schedule of

Earnings per Share (Schedule of Net Income Attributable to Common Stockholders) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net income attributable to Westlake Chemical Corporation	$ 138,190	$ 123,128
Net income attributable to participating securities	(694)	(549)
Net income attributable to common shareholders	$ 137,496	$ 122,579

Earnings per Share (Reconciliat

Earnings per Share (Reconciliation of Denominator for Basic and Diluted Earnings Per Share) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Weighted average common shares—basic	128,979,357	130,189,964
Incremental Shares From Assumed exercise of options	712,658	410,550
Weighted average common shares-diluted	129,692,015	130,600,514
Earnings per share attributable to Westlake Chemical Corporation: Basic	$ 1.07	$ 0.94
Earnings per share attributable to Westlake Chemical Corporation: Diluted	$ 1.06	$ 0.94

Earnings per Share (Additional

Earnings per Share (Additional Information) (Detail) - shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Number of options excluded from computation of diluted earnings per share	437,787	555,948

Supplemental Information (Detai

Supplemental Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Accrued Liabilities [Abstract]
Accrued liabilities	$ 400,310		$ 537,483
Accrued rebates	47,933		$ 77,985
Increase (Decrease) in Capital Expenditure Accrual	$ 8,241	$ 14,690

Commitments and Contingencies (

Commitments and Contingencies (Additional Information) (Detail) $ in Thousands	Apr. 21, 2014USD ($)	Oct. 31, 2016USD ($)	Mar. 31, 2017USD ($)settlement	Dec. 31, 2015USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2016USD ($)
Environmental Loss Contingencies [Line Items]
Environmental Loss contingency accrual			$ 48,217			$ 48,817
Pending Litigation [Member]
Environmental Loss Contingencies [Line Items]
Maximum Expected Damages		$ 167
LDEQ [Member] | Settled Litigation [Member]
Environmental Loss Contingencies [Line Items]
Number of claims settled | settlement			2
Amount of settlement for compliance violations			$ 192
LDEQ [Member] | Pending Litigation [Member]
Environmental Loss Contingencies [Line Items]
Maximum Expected Damages			100
Natrium [Member] | Axiall Corporation [Member] | Settled Litigation [Member]
Environmental Loss Contingencies [Line Items]
Payments for environmental loss contingencies					$ 449
Lake Charles, Louisiana [Member] | Axiall Corporation [Member] | Environmental Protection Agency [Member] | Settled Litigation [Member]
Environmental Loss Contingencies [Line Items]
Amount of settlement for compliance violations				$ 878
Culvert City, Kentucky and Lakes Charles, Louisiana [Member] | Environmental Protection Agency [Member] | Pending Litigation [Member]
Environmental Loss Contingencies [Line Items]
Maximum Expected Damages	$ 100
Maximum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss			80
Minimum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss			$ 40

Segment Information (Additional

Segment Information (Additional Information) (Detail)	3 Months Ended
	Mar. 31, 2017Segment
Segment Reporting [Abstract]
Number of segments	2

Segment Information (Sales) (De

Segment Information (Sales) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Net external sales	$ 1,942,616	$ 975,187
Income (loss) from operations	235,298	202,276
Depreciation and amortization	150,269	65,714
Other income (expense), net	5,071	2,645
Provision for (benefit from) income taxes	55,883	69,300
Capital expenditures	134,285	136,328
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net external sales	1,942,616	975,187
Operating Segments [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net external sales	542,995	431,020
Income (loss) from operations	179,817	149,235
Depreciation and amortization	41,040	28,697
Other income (expense), net	1,370	1,513
Provision for (benefit from) income taxes	57,811	52,533
Capital expenditures	25,350	95,152
Operating Segments [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net external sales	1,399,621	544,167
Income (loss) from operations	71,441	62,116
Depreciation and amortization	107,273	36,287
Other income (expense), net	3,878	(1,519)
Provision for (benefit from) income taxes	14,958	17,270
Capital expenditures	108,081	40,256
Operating Segments [Member] | Polyethylene [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net external sales	385,942	346,032
Operating Segments [Member] | Styrene, Feedstock And Other [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net external sales	157,053	84,988
Operating Segments [Member] | PVC, Caustic Soda And Other [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net external sales	1,131,129	430,902
Operating Segments [Member] | Building Products [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net external sales	268,492	113,265
Corporate and other [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	(15,960)	(9,075)
Depreciation and amortization	1,956	730
Other income (expense), net	(177)	2,651
Provision for (benefit from) income taxes	(16,886)	(503)
Capital expenditures	854	920
Intersegment sales [Member]
Segment Reporting Information [Line Items]
Net external sales	86,236	28,313
Intersegment sales [Member] | Olefins [Member]
Segment Reporting Information [Line Items]
Net external sales	85,944	27,949
Intersegment sales [Member] | Vinyls [Member]
Segment Reporting Information [Line Items]
Net external sales	$ 292	$ 364

Segment Information (Reconcilia

Segment Information (Reconciliation of Total Segment Income from Operations to Consolidated Income before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting [Abstract]
Income from operations	$ 235,298	$ 202,276
Interest expense	(39,776)	(6,685)
Other income, net	5,071	2,645
Income before income taxes	$ 200,593	$ 198,236

Segment Information (Total Asse

Segment Information (Total Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 10,724,830	$ 10,890,253
Operating Segments [Member] | Olefins [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,120,429	2,092,617
Operating Segments [Member] | Vinyls [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	8,214,203	8,287,204
Corporate and other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 390,198	$ 510,432

Guarantor Disclosures (Addition

Guarantor Disclosures (Additional Information) (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)
Condensed Financial Statements, Captions [Line Items]
Equity Method Investment, Ownership Percentage	100.00%
3.60%, 5.0%, 4.625%, 4.875% Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Minimum debt amount guaranteed by subsidiaries	$ 5,000
3.60% Senior Notes Due 2022 [Member] | Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument Maturity	2,022
3.6% Senior Notes Due 2026 [Member] | Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument Maturity	2,026
5% Senior Notes Due 2046 [Member] | Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument Maturity	2,046
4.625% Senior Notes Due 2021 (New Westlake 2021 Notes) [Member] | Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument Maturity	2,021
4.875% Senior Notes Due 2023 (New Westlake 2023 Notes) [Member] | Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument Maturity	2,023

Guarantor Disclosures (Condense

Guarantor Disclosures (Condensed Consolidating Financial Information Balance Sheets) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 372,591	$ 459,453	$ 614,976	$ 662,525
Accounts receivable, net	1,003,966	938,743
Inventories	821,708	801,100
Prepaid expenses and other current assets	43,695	48,493
Restricted cash	9,328	160,527
Total current assets	2,251,288	2,408,316
Property, plant and equipment, net	6,392,745	6,420,062
Goodwill	950,681	946,553
Customer relationships, net	596,641	611,615
Other intangible assets, net	172,697	175,839
Deferred charges and other assets, net	360,778	327,868
Total other assets, net	2,080,797	2,061,875
Total assets	10,724,830	10,890,253
Accounts payable	543,121	496,259
Accrued liabilities	400,310	537,483
Term loan	0	149,341
Total current liabilities	943,431	1,183,083
Long-term debt, net	3,601,642	3,678,654
Deferred income taxes	1,649,120	1,650,575
Pension and other liabilities	497,805	485,896
Total liabilities	6,691,998	6,998,208
Total Westlake Chemical Corporation stockholders' equity	3,659,196	3,523,629
Noncontrolling interests	373,636	368,416
Total equity	4,032,832	3,892,045	3,704,402	3,561,931
Total liabilities and equity	10,724,830	10,890,253
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	(5,294,258)	(4,832,599)
Inventories	0	0
Prepaid expenses and other current assets	(59,073)	(36,504)
Restricted cash	0	0
Total current assets	(5,353,331)	(4,869,103)
Property, plant and equipment, net	0	0
Goodwill	0	0
Customer relationships, net	0	0
Other intangible assets, net	0	(25,581)
Deferred charges and other assets, net	(10,951,977)	(10,832,054)
Total other assets, net	(10,951,977)	(10,857,635)
Total assets	(16,305,308)	(15,726,738)
Accounts payable	(5,198,283)	(4,807,780)
Accrued liabilities	(155,048)	(61,323)
Term loan		0
Total current liabilities	(5,353,331)	(4,869,103)
Long-term debt, net	(2,905,713)	(3,997,070)
Deferred income taxes	(23,385)	(22,494)
Pension and other liabilities	(1,115,437)	0
Total liabilities	(9,397,866)	(8,888,667)
Total Westlake Chemical Corporation stockholders' equity	(6,907,442)	(6,838,071)
Noncontrolling interests	0	0
Total equity	(6,907,442)	(6,838,071)
Total liabilities and equity	(16,305,308)	(15,726,738)
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	54,966	146,990	263,150	303,131
Accounts receivable, net	2,446,732	2,117,540
Inventories	0	0
Prepaid expenses and other current assets	53,239	30,748
Restricted cash	0	0
Total current assets	2,554,937	2,295,278
Property, plant and equipment, net	0	0
Goodwill	0	0
Customer relationships, net	0	0
Other intangible assets, net	0	0
Deferred charges and other assets, net	9,335,542	9,170,042
Total other assets, net	9,335,542	9,170,042
Total assets	11,890,479	11,465,320
Accounts payable	4,705,704	4,330,375
Accrued liabilities	17,449	26,367
Term loan		0
Total current liabilities	4,723,153	4,356,742
Long-term debt, net	3,508,130	3,584,949
Deferred income taxes	0	0
Pension and other liabilities	0	0
Total liabilities	8,231,283	7,941,691
Total Westlake Chemical Corporation stockholders' equity	3,659,196	3,523,629
Noncontrolling interests	0	0
Total equity	3,659,196	3,523,629
Total liabilities and equity	11,890,479	11,465,320
100% Owned Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	5,647	53,006	1,154	6,828
Accounts receivable, net	3,521,181	3,329,871
Inventories	605,775	597,819
Prepaid expenses and other current assets	38,066	41,755
Restricted cash	2,681	0
Total current assets	4,173,350	4,022,451
Property, plant and equipment, net	4,438,292	4,475,943
Goodwill	791,706	791,706
Customer relationships, net	453,985	468,645
Other intangible assets, net	102,339	130,243
Deferred charges and other assets, net	846,041	874,003
Total other assets, net	2,194,071	2,264,597
Total assets	10,805,713	10,762,991
Accounts payable	761,986	748,364
Accrued liabilities	357,968	389,216
Term loan		0
Total current liabilities	1,119,954	1,137,580
Long-term debt, net	2,999,225	4,090,775
Deferred income taxes	1,581,202	1,581,260
Pension and other liabilities	1,479,584	360,622
Total liabilities	7,179,965	7,170,237
Total Westlake Chemical Corporation stockholders' equity	3,625,748	3,592,754
Noncontrolling interests	0	0
Total equity	3,625,748	3,592,754
Total liabilities and equity	10,805,713	10,762,991
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	311,978	259,457	$ 350,672	$ 352,566
Accounts receivable, net	330,311	323,931
Inventories	215,933	203,281
Prepaid expenses and other current assets	11,463	12,494
Restricted cash	6,647	160,527
Total current assets	876,332	959,690
Property, plant and equipment, net	1,954,453	1,944,119
Goodwill	158,975	154,847
Customer relationships, net	142,656	142,970
Other intangible assets, net	70,358	71,177
Deferred charges and other assets, net	1,131,172	1,115,877
Total other assets, net	1,503,161	1,484,871
Total assets	4,333,946	4,388,680
Accounts payable	273,714	225,300
Accrued liabilities	179,941	183,223
Term loan		149,341
Total current liabilities	453,655	557,864
Long-term debt, net	0	0
Deferred income taxes	91,303	91,809
Pension and other liabilities	133,658	125,274
Total liabilities	678,616	774,947
Total Westlake Chemical Corporation stockholders' equity	3,281,694	3,245,317
Noncontrolling interests	373,636	368,416
Total equity	3,655,330	3,613,733
Total liabilities and equity	$ 4,333,946	$ 4,388,680

Guarantor Disclosures (Conden84

Guarantor Disclosures (Condensed Consolidating Financial Information Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,942,616	$ 975,187
Cost of sales	1,575,473	719,602
Gross profit	367,143	255,585
Selling, general and administrative expenses	123,651	53,309
Transaction and integration-related costs	8,194	0
Income (loss) from operations	235,298	202,276
Interest expense	(39,776)	(6,685)
Other income (expense), net	5,071	2,645
Income (loss) before income taxes	(200,593)	(198,236)
Provision for (benefit from) income taxes	55,883	69,300
Equity in net income of subsidiaries	0	0
Net income	144,710	128,936
Net income attributable to noncontrolling interests	6,520	5,808
Net income attributable to Westlake Chemical Corporation	138,190	123,128
Comprehensive income attributable to Westlake Chemical Corporation	155,860	161,757
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	0	0
Cost of sales	0	0
Gross profit	0	0
Selling, general and administrative expenses	778	607
Transaction and integration-related costs	0
Income (loss) from operations	(778)	(607)
Interest expense	(38,185)	(10,411)
Other income (expense), net	37,157	1,815
Income (loss) before income taxes	1,806	9,203
Provision for (benefit from) income taxes	(5,467)	(3,219)
Equity in net income of subsidiaries	134,529	129,112
Net income	138,190	123,128
Net income attributable to noncontrolling interests	0	0
Net income attributable to Westlake Chemical Corporation	138,190	123,128
Comprehensive income attributable to Westlake Chemical Corporation	155,860	161,757
100% Owned Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	1,579,725	761,736
Cost of sales	1,359,275	642,730
Gross profit	220,450	119,006
Selling, general and administrative expenses	92,260	36,996
Transaction and integration-related costs	8,132
Income (loss) from operations	120,058	82,010
Interest expense	(45,677)	(4,851)
Other income (expense), net	(255)	(825)
Income (loss) before income taxes	(74,126)	(76,334)
Provision for (benefit from) income taxes	53,372	62,199
Equity in net income of subsidiaries	0	0
Net income	20,754	14,135
Net income attributable to noncontrolling interests	0	0
Net income attributable to Westlake Chemical Corporation	20,754	14,135
Comprehensive income attributable to Westlake Chemical Corporation	4,635	14,341
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	736,085	569,824
Cost of sales	582,660	427,777
Gross profit	153,425	142,047
Selling, general and administrative expenses	37,345	21,174
Transaction and integration-related costs	62
Income (loss) from operations	116,018	120,873
Interest expense	(806)	0
Other income (expense), net	13,061	10,232
Income (loss) before income taxes	(128,273)	(131,105)
Provision for (benefit from) income taxes	7,978	10,320
Equity in net income of subsidiaries	0	0
Net income	120,295	120,785
Net income attributable to noncontrolling interests	6,520	5,808
Net income attributable to Westlake Chemical Corporation	113,775	114,977
Comprehensive income attributable to Westlake Chemical Corporation	122,243	149,462
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	(373,194)	(356,373)
Cost of sales	(366,462)	(350,905)
Gross profit	(6,732)	(5,468)
Selling, general and administrative expenses	(6,732)	(5,468)
Transaction and integration-related costs	0
Income (loss) from operations	0	0
Interest expense	44,892	8,577
Other income (expense), net	(44,892)	(8,577)
Income (loss) before income taxes	0	0
Provision for (benefit from) income taxes	0	0
Equity in net income of subsidiaries	(134,529)	(129,112)
Net income	(134,529)	(129,112)
Net income attributable to noncontrolling interests	0	0
Net income attributable to Westlake Chemical Corporation	(134,529)	(129,112)
Comprehensive income attributable to Westlake Chemical Corporation	$ (126,878)	$ (163,803)

Guarantor Disclosures (Conden85

Guarantor Disclosures (Condensed Consolidating Financial Information Statement of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net income	$ 144,710	$ 128,936
Depreciation and amortization	150,269	65,714
Deferred income taxes	(6,273)	58,637
Net changes in working capital and other	(131,312)	(124,352)
Net cash provided by (used for) operating activities	(157,394)	(128,935)
Additions to property, plant and equipment	(134,285)	(136,328)
Additions to cost method investment	(15,000)	0
Proceeds from disposition of assets	66	104
Proceeds from involuntary conversion of assets	1,555	0
Proceeds from sales and maturities of securities	0	26,859
Purchase of securities	0	(36,637)
Settlements of derivative instruments	(355)	(1,219)
Net cash used for investing activities	(148,019)	(147,221)
Intercompany financing	0	0
Debt issuance costs	(319)	0
Dividends paid	(24,656)	(23,700)
Distributions to noncontrolling interests	(4,463)	(3,985)
Proceeds from issuance of notes payable	1,874	2,050
Proceeds from drawdown of revolver	50,000	0
Restricted cash associated with term loan	154,000	0
Repayment of term loan	(150,000)	0
Repayment of notes payable	(2,469)	(7,095)
Repayment of revolver	(125,000)	0
Other	1,354	288
Repurchase of common stock for treasury	0	(679)
Net cash provided by (used for) financing activities	99,679	33,121
Effect of exchange rate changes on cash and cash equivalents	3,442	3,858
Net increase (decrease) in cash and cash equivalents	86,862	47,549
Cash and cash equivalents at beginning of period	459,453	662,525
Cash and cash equivalents at end of period	372,591	614,976
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	(134,529)	(129,112)
Depreciation and amortization	0	0
Deferred income taxes	0	0
Net changes in working capital and other	134,529	129,112
Net cash provided by (used for) operating activities	0	0
Additions to property, plant and equipment	0	0
Additions to cost method investment	0
Proceeds from disposition of assets	0	0
Proceeds from involuntary conversion of assets	0
Proceeds from sales and maturities of securities		0
Purchase of securities		0
Settlements of derivative instruments	0	0
Net cash used for investing activities	0	0
Intercompany financing	0	0
Debt issuance costs	0
Dividends paid	0	0
Distributions to noncontrolling interests	0	0
Proceeds from issuance of notes payable	0	0
Proceeds from drawdown of revolver	0
Restricted cash associated with term loan	0
Repayment of term loan	0
Repayment of notes payable	0	0
Repayment of revolver	0
Other	0	0
Repurchase of common stock for treasury		0
Net cash provided by (used for) financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	138,190	123,128
Depreciation and amortization	0	0
Deferred income taxes	(585)	(2,724)
Net changes in working capital and other	(213,242)	(120,345)
Net cash provided by (used for) operating activities	75,637	(59)
Additions to property, plant and equipment	0	0
Additions to cost method investment	0
Proceeds from disposition of assets	0	0
Proceeds from involuntary conversion of assets	0
Proceeds from sales and maturities of securities		26,859
Purchase of securities		(29,045)
Settlements of derivative instruments	0	0
Net cash used for investing activities	0	(2,186)
Intercompany financing	78,234	(13,763)
Debt issuance costs	(319)
Dividends paid	(24,656)	(23,700)
Distributions to noncontrolling interests	0	0
Proceeds from issuance of notes payable	0	0
Proceeds from drawdown of revolver	50,000
Restricted cash associated with term loan	154,000
Repayment of term loan	(150,000)
Repayment of notes payable	0	0
Repayment of revolver	(125,000)
Other	1,354	288
Repurchase of common stock for treasury		(679)
Net cash provided by (used for) financing activities	16,387	37,854
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	92,024	39,981
Cash and cash equivalents at beginning of period	146,990	303,131
Cash and cash equivalents at end of period	54,966	263,150
100% Owned Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	20,754	14,135
Depreciation and amortization	98,578	32,687
Deferred income taxes	(2,905)	55,473
Net changes in working capital and other	(28,009)	(94,115)
Net cash provided by (used for) operating activities	(88,418)	(8,180)
Additions to property, plant and equipment	(120,719)	(50,568)
Additions to cost method investment	(15,000)
Proceeds from disposition of assets	66	6
Proceeds from involuntary conversion of assets	1,555
Proceeds from sales and maturities of securities		0
Purchase of securities		0
Settlements of derivative instruments	(355)	(1,219)
Net cash used for investing activities	(134,453)	(51,781)
Intercompany financing	(95,698)	(42,072)
Debt issuance costs	0
Dividends paid	0	0
Distributions to noncontrolling interests	94,631	79,999
Proceeds from issuance of notes payable	0	0
Proceeds from drawdown of revolver	0
Restricted cash associated with term loan	0
Repayment of term loan	0
Repayment of notes payable	(257)	0
Repayment of revolver	0
Other	0	0
Repurchase of common stock for treasury		0
Net cash provided by (used for) financing activities	1,324	(37,927)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	47,359	5,674
Cash and cash equivalents at beginning of period	53,006	6,828
Cash and cash equivalents at end of period	5,647	1,154
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	120,295	120,785
Depreciation and amortization	51,691	33,027
Deferred income taxes	(2,783)	5,888
Net changes in working capital and other	(24,590)	(39,004)
Net cash provided by (used for) operating activities	(144,613)	(120,696)
Additions to property, plant and equipment	(13,566)	(85,760)
Additions to cost method investment	0
Proceeds from disposition of assets	0	98
Proceeds from involuntary conversion of assets	0
Proceeds from sales and maturities of securities		0
Purchase of securities		(7,592)
Settlements of derivative instruments	0	0
Net cash used for investing activities	(13,566)	(93,254)
Intercompany financing	17,464	55,835
Debt issuance costs	0
Dividends paid	0	0
Distributions to noncontrolling interests	(99,094)	(83,984)
Proceeds from issuance of notes payable	1,874	2,050
Proceeds from drawdown of revolver	0
Restricted cash associated with term loan	0
Repayment of term loan	0
Repayment of notes payable	(2,212)	(7,095)
Repayment of revolver	0
Other	0	0
Repurchase of common stock for treasury		0
Net cash provided by (used for) financing activities	81,968	33,194
Effect of exchange rate changes on cash and cash equivalents	3,442	3,858
Net increase (decrease) in cash and cash equivalents	(52,521)	1,894
Cash and cash equivalents at beginning of period	259,457	352,566
Cash and cash equivalents at end of period	$ 311,978	$ 350,672