10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q

x	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the quarterly period ended September 30, 2014

or

¨	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the Transition Period from                    to

Commission File No. 001-32260

Westlake Chemical Corporation

(Exact name of Registrant as specified in its charter)

Delaware	76-0346924
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification Number)

2801 Post Oak Boulevard, Suite 600

Houston, Texas 77056

(Address of principal executive offices, including zip code)

(713) 960-9111

(Registrant's telephone number, including area code)

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     YesxNo¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).     YesxNo¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a smaller reporting company. See definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act (Check one):

Large accelerated filer	x	Accelerated filer	¨
Non-accelerated filer	¨  (Do not check if a smaller reporting company)	Smaller reporting company	¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act)     Yes¨Nox

The number of shares outstanding of the registrant's sole class of common stock as of October 31, 2014 was 133,082,630 (on a post-split basis).

INDEX

Item	Page
PART I. FINANCIAL INFORMATION
1) Financial Statements	1
2) Management's Discussion and Analysis of Financial Condition and Results of Operations	31
3) Quantitative and Qualitative Disclosures about Market Risk	41
4) Controls and Procedures	42
PART II. OTHER INFORMATION
1) Legal Proceedings	43
1A) Risk Factors	43
2) Unregistered Sales of Equity Securities and Use of Proceeds	43
6) Exhibits	44

PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

WESTLAKE CHEMICAL CORPORATION

CONSOLIDATED BALANCE SHEETS

(Unaudited)

	September 30, 2014			December 31, 2013
	(in thousands of dollars, except par values and share amounts)
ASSETS
Current assets
Cash and cash equivalents	$	813,468		$	461,301
Marketable securities	—			239,388
Accounts receivable, net	592,964			428,457
Inventories	500,552			471,879
Prepaid expenses and other current assets	18,884			13,888
Deferred income taxes	26,080			34,169
Total current assets	1,951,948			1,649,082
Property, plant and equipment, net	2,710,475			2,088,014
Equity investments	70,828			66,875
Other assets, net
Intangible assets, net	222,728			159,046
Deferred charges and other assets, net	170,304			97,892
Total other assets, net	393,032			256,938
Total assets	$	5,126,283		$	4,060,909
LIABILITIES AND EQUITY
Current liabilities
Accounts payable	$	263,365		$	249,613
Accrued liabilities	309,671			155,245
Total current liabilities	573,036			404,858
Long-term debt	763,968			763,879
Deferred income taxes	513,773			437,976
Other liabilities	153,158			35,593
Total liabilities	2,003,935			1,642,306
Commitments and contingencies (Notes 7 and 15)
Stockholders' equity
Preferred stock, $0.01 par value, 50,000,000 shares authorized;    no shares issued and outstanding	—			—
Common stock, $0.01 par value, 300,000,000 shares authorized;    134,680,164 and 134,580,208 shares issued at September 30, 2014    and December 31, 2013, respectively (Note 1)	1,347			1,346
Common stock, held in treasury, at cost; 1,220,544 and 1,252,922 shares    at September 30, 2014 and December 31, 2013, respectively (Note 1)	(53,248		)	(46,220		)
Additional paid-in capital	527,992			511,432
Retained earnings	2,394,203			1,954,661
Accumulated other comprehensive loss	(36,433		)	(2,616		)
Total Westlake Chemical Corporation stockholders' equity	2,833,861			2,418,603
Noncontrolling interests	288,487			—
Total equity	3,122,348			2,418,603
Total liabilities and equity	$	5,126,283		$	4,060,909

The accompanying notes are an integral part of these consolidated financial statements.

1

WESTLAKE CHEMICAL CORPORATION

CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
	(in thousands of dollars, except per share data and share amounts)
Net sales	$	1,253,227		$	1,004,165		$	3,279,479		$	2,807,859
Cost of sales	891,707			699,694			2,324,978			2,002,092
Gross profit	361,520			304,471			954,501			805,767
Selling, general and administrative expenses	54,759			37,869			132,897			109,883
Income from operations	306,761			266,602			821,604			695,884
Other income (expense)
Interest expense	(9,486		)	(3,297		)	(28,182		)	(14,921		)
Other (expense) income, net	(2,670		)	(287		)	4,440			3,137
Income before income taxes	294,605			263,018			797,862			684,100
Provision for income taxes	124,449			92,728			300,231			244,647
Net income	170,156			170,290			497,631			439,453
Net income attributable to noncontrolling    interests	2,399			—			2,399			—
Net income attributable to Westlake Chemical    Corporation	$	167,757		$	170,290		$	495,232		$	439,453
Earnings per common share attributable to    Westlake Chemical Corporation (Note 1):
Basic	$	1.26		$	1.28		$	3.71		$	3.29
Diluted	$	1.25		$	1.27		$	3.69		$	3.27
Weighted average common shares outstanding (Note 1):
Basic	133,299,458			133,257,494			133,199,304			133,256,054
Diluted	133,846,059			133,811,108			133,743,145			133,806,758
Dividends per common share (Note 1)	$	0.1650		$	0.1125		$	0.4170		$	0.3000

The accompanying notes are an integral part of these consolidated financial statements.

2

WESTLAKE CHEMICAL CORPORATION

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

(Unaudited)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
	(in thousands of dollars)
Net income	$	170,156		$	170,290		$	497,631		$	439,453
Other comprehensive income (loss), net of income taxes
Pension and other post-retirement benefits liability
Pension and other post-retirement reserves    adjustment (excluding amortization)	(31		)	(489		)	(62		)	(978		)
Amortization of benefits liability	240			695			685			2,004
Income tax provision on pension and other    post-retirement benefits liability	(81		)	(78		)	(240		)	(394		)
Foreign currency translation adjustments	(37,792		)	546			(37,882		)	(844		)
Available-for-sale investments
Unrealized holding gains on investments	2,129			205			6,960			205
Reclassification of net realized gains to    net income	—			—			(1,212		)	—
Income tax provision on available-for-sale    investments	(766		)	(74		)	(2,066		)	(74		)
Other comprehensive (loss) income	(36,301		)	805			(33,817		)	(81		)
Comprehensive income	133,855			171,095			463,814			439,372
Comprehensive income attributable to    noncontrolling interests, net of tax	2,399			—			2,399			—
Comprehensive income attributable to    Westlake Chemical Corporation	$	131,456		$	171,095		$	461,415		$	439,372

The accompanying notes are an integral part of these consolidated financial statements.

3

WESTLAKE CHEMICAL CORPORATION

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY

(Unaudited)

	Common Stock				Common Stock, Held in Treasury										Accumulated Other Comprehensive  Income (Loss)
	Number of Shares		Amount		Number of Shares		At Cost			Additional Paid-in Capital		Retained Earnings			Benefits Liability,  Net of Tax			Cumulative Foreign Currency Exchange			Net Unrealized Holding Gains on Investments, Net of Tax		Noncontrolling Interests		Total
	(in thousands of dollars, except share amounts)
Balances at December 31, 2012	134,374,448		$	1,345	568,986		$	(13,302	)	$	495,581	$	1,399,472		$	(16,351	)	$	5,511		$	—	$	—	$	1,872,256
Net income	—		—		—		—			—		610,425			—			—			—		—		610,425
Other comprehensive    (loss) income	—		—		—		—			—		—			9,655			(1,607		)	176		—		8,224
Common stock    repurchased	—		—		683,936		(32,918		)	—		—			—			—			—		—		(32,918		)
Shares issued - stock-    based compensation	225,924		1		—		—			3,436		—			—			—			—		—		3,437
Stock-based    compensation, net of    tax on stock options    exercised	(20,164	)	—		—		—			12,415		—			—			—			—		—		12,415
Dividends paid	—		—		—		—			—		(55,236		)	—			—			—		—		(55,236		)
Balances at December 31, 2013	134,580,208		1,346		1,252,922		(46,220		)	511,432		1,954,661			(6,696		)	3,904			176		—		2,418,603
Net income	—		—		—		—			—		495,232			—			—			—		2,399		497,631
Other comprehensive    income (loss)	—		—		—		—			—		—			383			(37,882		)	3,682		—		(33,817		)
Common stock    repurchased	—		—		104,163		(9,495		)	—		—			—			—			—		—		(9,495		)
Shares issued - stock-    based compensation	124,566		1		(136,541	)	2,467			3,034		—			—			—			—		—		5,502
Stock-based    compensation, net of    tax on stock options    exercised	(24,610	)	—		—		—			13,526		—			—			—			—		—		13,526
Dividends paid	—		—		—		—					(55,690		)	—			—			—		—		(55,690		)
Issuance of Westlake    Chemical Partners LP    common units	—		—		—		—					—			—			—			—		286,088		286,088
Balances at September 30, 2014	134,680,164		$	1,347	1,220,544		$	(53,248	)	$	527,992	$	2,394,203		$	(6,313	)	$	(33,978	)	$	3,858	$	288,487	$	3,122,348

The accompanying notes are an integral part of these consolidated financial statements.

4

WESTLAKE CHEMICAL CORPORATION

CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited)

	Nine Months Ended September 30,
	2014			2013
	(in thousands of dollars)
Cash flows from operating activities
Net income	$	497,631		$	439,453
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	148,394			116,294
Provision for doubtful accounts	295			3,600
Amortization of debt issuance costs	1,172			1,093
Stock-based compensation expense	6,856			4,804
Loss from disposition of fixed assets	2,635			4,679
Deferred income taxes	34,459			83,443
Windfall tax benefits from share-based payment arrangements	(6,670		)	(5,056		)
(Income) loss from equity method investments, net of dividends	(3,199		)	1,586
Other gains, net	(495		)	—
Changes in operating assets and liabilities
Accounts receivable	6,055			(18,874		)
Inventories	80,492			(26,325		)
Prepaid expenses and other current assets	458			(5,038		)
Accounts payable	(98,769		)	19,518
Accrued liabilities	111,965			(15,755		)
Other, net	(5,155		)	(55,922		)
Net cash provided by operating activities	776,124			547,500
Cash flows from investing activities
Acquisition of business, net of cash acquired	(611,087		)	(178,309		)
Additions to equity investments	—			(23,338		)
Additions to property, plant and equipment	(311,183		)	(498,290		)
Construction of assets pending sale-leaseback	—			(136		)
Proceeds from disposition of assets	145			78
Proceeds from repayment of loan acquired	45,923			—
Proceeds from repayment of loan to affiliate	—			167
Proceeds from sales and maturities of securities	342,045			239,764
Purchase of securities	(117,332		)	(232,286		)
Settlements of derivative instruments	(689		)	(2,297		)
Net cash used for investing activities	(652,178		)	(694,647		)
Cash flows from financing activities
Capitalized debt issuance costs	(1,167		)	—
Dividends paid	(55,690		)	(40,204		)
Net proceeds from issuance of Westlake Chemical Partners LP common units	286,088			—
Proceeds from exercise of stock options	5,502			3,182
Repurchase of common stock for treasury	(9,495		)	(19,409		)
Windfall tax benefits from share-based payment arrangements	6,670			5,056
Net cash provided by (used for) financing activities	231,908			(51,375		)
Effect of exchange rate changes on cash and cash equivalents	(3,687		)	—
Net increase (decrease) in cash and cash equivalents	352,167			(198,522		)
Cash and cash equivalents at beginning of period	461,301			790,078
Cash and cash equivalents at end of period	$	813,468		$	591,556

The accompanying notes are an integral part of these consolidated financial statements.

5

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

1. 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, 2013 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, 2013 (the "2013 Form 10-K"), filed with the SEC on February 21, 2014. 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, 2013.

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 September 30, 2014, its results of operations for the three and nine months ended September 30, 2014 and 2013 and the changes in its cash position for the nine months ended September 30, 2014 and 2013.

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, 2014 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.

On February 14, 2014, the Company's Board of Directors authorized a two-for-one split of the Company's common stock. Stockholders of record as of February 28, 2014 were entitled to one additional share for every share outstanding, which was distributed on March 18, 2014. The total number of authorized common stock shares and associated par value were unchanged by this stock split. All share amounts and per share data included in the accompanying consolidated financial statements and related notes have been restated to reflect the effect of the stock split.

In March 2014, the Company formed Westlake Chemical Partners LP ("WLKP") to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, WLKP closed its initial public offering of 12,937,500 common units. See Note 19 for additional information. The Company consolidates WLKP and records a noncontrolling interest for the interest in WLKP not owned by the Company.

Recent Accounting Pronouncements

Revenue from Contracts with Customers

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. The accounting standard will be effective for reporting periods beginning after December 15, 2016. The Company is in the process of evaluating the impact that the new accounting guidance will have on its consolidated financial position, results of operations and cash flows.

Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern

In August 2014, the FASB issued an accounting standards update on management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern. The new accounting guidance requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if "conditions or events raise substantial doubt about the entity's ability to continue as a going concern." The accounting standard will be effective for reporting periods

6

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

ending after December 15, 2016 and is not expected to have an impact on the Company's consolidated financial position, results of operations and cash flows.

2. Financial Instruments

Cash Equivalents

The Company had $747,008 and $263,967 of held-to-maturity securities with original maturities of three months or less, primarily consisting of corporate debt securities, classified as cash equivalents at September 30, 2014 and December 31, 2013, respectively. The Company's investments in held-to-maturity securities are held at amortized cost, which approximates fair value.

Available-for-Sale Marketable Securities

Investments in available-for-sale securities were classified as follows:

	September 30, 2014		December 31, 2013
Current	$	—	$	239,388
Non-current	21,066		—
Total available-for-sale securities	$	21,066	$	239,388

The cost, gross unrealized gains, gross unrealized losses and fair value of the Company’s available-for-sale securities were as follows:

	September 30, 2014
	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Equity securities	$	15,044	$	6,022	$	—	$	21,066
Total available-for-sale securities	$	15,044	$	6,022	$	—	$	21,066

	December 31, 2013
	Cost		Gross Unrealized Gains		Gross Unrealized Losses (1)			Fair Value
Debt securities
Corporate bonds	$	108,300	$	340	$	(69	)	$	108,571
U.S. government debt (2)	106,335		60		(79		)	106,316
Asset-backed securities	24,478		34		(11		)	24,501
Total available-for-sale securities	$	239,113	$	434	$	(159	)	$	239,388

_____________

(1) All unrealized loss positions were held at a loss for less than 12 months.

(2) U.S. Treasury obligations, U.S. government agency obligations and U.S government agency mortgage-backed securities.

As of September 30, 2014 and December 31, 2013, net unrealized gains on the Company's available-for-sale securities of $3,858 and $176, respectively, net of income tax expense of $2,164 and $99, respectively, were recorded in accumulated other comprehensive income. See Note 10 for the fair value hierarchy of the Company’s available-for-sale securities.

7

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

The proceeds from sales and maturities of available-for-sale securities and the gross realized gains and losses included in the consolidated statement of operations are reflected in the table below. The cost of securities sold was determined using the specific identification method. There were no sales or maturities of available-for-sale securities during the three and nine months ended September 30, 2013.

	Nine Months Ended September 30,
	2014
Proceeds from sales and maturities of securities	$	342,045
Gross realized gains	$	1,311
Gross realized losses	$	(99	)

3. Accounts Receivable

Accounts receivable consist of the following:

	September 30, 2014			December 31, 2013
Trade customers	$	576,735		$	410,302
Affiliates	631			315
Allowance for doubtful accounts	(13,772		)	(11,741		)
	563,594			398,876
Federal and state taxes	5,374			20,820
Other	23,996			8,761
Accounts receivable, net	$	592,964		$	428,457

4. Inventories

Inventories consist of the following:

	September 30, 2014		December 31, 2013
Finished products	$	268,969	$	232,658
Feedstock, additives and chemicals	166,268		180,646
Materials and supplies	65,315		58,575
Inventories	$	500,552	$	471,879

5. Property, Plant and Equipment

As of September 30, 2014, the Company had property, plant and equipment, net totaling $2,710,475. 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 $45,080 and $32,460 is included in cost of sales in the consolidated statements of operations for the three months ended September 30, 2014 and 2013, respectively. Depreciation expense on property, plant and equipment of $123,000 and $95,995 is included in cost of sales in the consolidated statements of operations for the nine months ended September 30, 2014 and 2013, respectively.

8

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

6. Other Assets

Amortization expense on intangible and other assets of $9,283 and $8,634 is included in the consolidated statements of operations for the three months ended September 30, 2014 and 2013, respectively. Amortization expense on intangible and other assets of $26,566 and $21,392 is included in the consolidated statements of operations for the nine months ended September 30, 2014 and 2013, respectively.

Goodwill

Goodwill for the Olefins segment was $29,990 at September 30, 2014 and December 31, 2013. Goodwill for the Vinyls segment was $32,026 at September 30, 2014 and December 31, 2013. There were no changes in the carrying amount of goodwill by operating segments for the nine months ended September 30, 2014.

7. Long-Term Debt

Long-term debt consists of the following:

	September 30, 2014		December 31, 2013
3.60% senior notes due 2022	$	249,079	$	248,990
6 ½% senior notes due 2029	100,000		100,000
6 ¾% senior notes due 2032	250,000		250,000
6 ½% senior notes due 2035 (the "6 ½% GO Zone Senior Notes Due 2035")	89,000		89,000
6 ½% senior notes due 2035 (the "6 ½% IKE Zone Senior Notes Due 2035")	65,000		65,000
Loan related to tax-exempt waste disposal revenue bonds due 2027	10,889		10,889
Long-term debt, net	$	763,968	$	763,879

Revolving Credit Facility

The Company has a $400,000 senior secured revolving credit facility. In July 2014, the Company entered into a third amendment and restatement to the revolving credit facility. The amendment and restatement extended the scheduled maturity date of the facility from September 16, 2016 to July 17, 2019, reduced the interest rate and facility fee payable under the facility and amended the covenants restricting the Company’s ability to make distributions and acquisitions and make investments, among other things. The facility includes a provision permitting the Company to increase the size of the facility, up to four times, in increments of at least $25,000 each (up to a maximum of $200,000) under certain circumstances if lenders agree to commit to such an increase.

At September 30, 2014, the Company had no borrowings outstanding under the revolving credit facility. Any borrowings under the facility will bear interest at either LIBOR plus a spread ranging from 1.75% to 1.25%, provided that so long as the Company is rated investment grade, the margin for LIBOR loans will not exceed 1.50%, or a base rate plus a spread ranging from 0.50% to 0.00%. The revolving credit facility also requires an unused commitment fee of 0.25% per annum. All interest rates under the facility are subject to monthly grid pricing adjustments based on prior month average daily loan availability. The revolving credit facility matures on July 17, 2019. As of September 30, 2014, the Company had outstanding letters of credit totaling $32,399 and borrowing availability of $367,601 under the revolving credit facility.

The Company's revolving credit facility generally restricts the Company's ability to make distributions unless, on a pro forma basis after giving effect to the distribution, the borrowing availability under the facility equals or exceeds the greater of (1) 20% of the commitments under the facility and (2) $80,000; or the borrowing availability under the facility equals or exceeds the greater of (1) 15% of the commitments under the facility and (2) $60,000, and the Company's fixed charge coverage ratio is at least 1.0:1. However, the Company may make specified distributions up to an aggregate of $75,000, to be increased by 5% in 2015, and in each fiscal year thereafter, on an aggregate basis, for each fiscal year.

In order to make acquisitions or investments, the Company's revolving credit facility generally provides that (1) the Company must maintain a minimum borrowing availability of at least the greater of $60,000 or 15% of the total bank commitments under its revolving credit facility or (2) the Company must maintain a minimum borrowing availability of at least the greater of $50,000 or 12.5% of the total bank commitments under its revolving credit facility and meet a minimum fixed charge coverage ratio of 1.0:1 under its revolving credit facility. Notwithstanding the foregoing, the Company may make investments in the aggregate up to the greater of $50,000 and 1.25% of tangible assets and acquisitions in the aggregate up to

9

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

the greater of $100,000 and 2.5% of tangible assets, if, on a pro forma basis after giving effect to the acquisition or investment, either (X) the borrowing availability under the facility equals or exceeds the greater of (A) 12.5% of the total bank commitments under the facility and (B) $50,000, but is less than the greater of (A) 15% of the total bank commitments and (B) $60,000, or (Y) the Company's fixed charge coverage ratio is at least 1.0:1.

The revolving credit facility contains other customary covenants and events of default that impose significant operating and financial restrictions on the Company. These restrictions, among other things, limit the occurrence of additional indebtedness and the Company's ability to create liens, to engage in certain affiliate transactions and to engage in sale-leaseback transactions.

8. Stock-Based Compensation

Under the Westlake Chemical Corporation 2013 Omnibus Incentive Plan (as amended and restated, the "2013 Plan"), all employees and nonemployee 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 nonemployee 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 $2,346 and $1,680 for the three months ended September 30, 2014 and 2013, respectively, and $6,856 and $4,804 for the nine months ended September 30, 2014 and 2013, respectively.

9. Derivative Instruments

Commodity Risk Management

The Company uses derivative instruments to reduce price volatility risk on raw materials and products as a substantial portion of its raw materials and products are commodities whose prices fluctuate as market supply and demand fundamentals change. Business strategies to protect against such instability include ethylene product feedstock flexibility and moving downstream into the olefins and vinyls products where pricing is more stable. The Company does not use derivative instruments to engage in speculative activities.

For derivative instruments that are designated and qualify as fair value hedges, the gains or losses on the derivative instruments, as well as the offsetting losses or gains on the hedged items attributable to the hedged risk, were included in cost of sales in the consolidated statements of operations for the three and nine months ended September 30, 2013. The Company had no derivative instruments that were designated as fair value hedges for the three and nine months ended September 30, 2014.

Gains and losses from changes in the fair value of derivative instruments that are not designated as hedging instruments were included in gross profit in the consolidated statements of operations for the three and nine months ended September 30, 2014 and 2013.

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).

Disclosures related to the Company's derivative assets and derivative liabilities subject to enforceable master netting arrangements have not been presented as they are not material to the Company's consolidated balance sheets at September 30, 2014 and December 31, 2013.

10

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

The fair values of derivative instruments in the Company's consolidated balance sheets were as follows:

	Derivative Assets
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
Not designated as hedging instruments
Commodity forward contracts	Accounts receivable, net	$	451	$	296
Total derivative assets		$	451	$	296

	Derivative Liabilities
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
Not designated as hedging instruments
Commodity forward contracts	Accrued liabilities	$	6,477	$	176
Total derivative liabilities		$	6,477	$	176

The following tables reflect the impact of derivative instruments designated as fair value hedges and the related hedged item on the Company's consolidated statements of operations. For the three and nine months ended September 30, 2013, there was no material ineffectiveness with regard to the Company's qualifying fair value hedges.

Derivatives in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Derivative	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
Commodity forward contracts	Cost of sales	$	—	$	(232	)	$	—	$	(342	)
Hedged Items in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Hedged Items	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
Firm commitment designated    as the hedged item	Cost of sales	$	—	$	236		$	—	$	15

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 September 30,					Nine Months Ended September 30,
		2014			2013		2014			2013
Commodity forward contracts	Gross profit	$	(6,937	)	$	4,854	$	(7,308	)	$	9,897

See Note 10 for the fair value of the Company's derivative instruments.

10. 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.

11

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share 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:

	September 30, 2014
	Level 1			Level 2			Total
Derivative instruments
Risk management assets - Commodity forward contracts	$	428		$	23		$	451
Risk management liabilities - Commodity forward contracts	(119		)	(6,358		)	(6,477		)
Available-for-sale marketable securities	21,066			—			21,066
	December 31, 2013
	Level 1			Level 2			Total
Derivative instruments
Risk management assets - Commodity forward contracts	$	48		$	248		$	296
Risk management liabilities - Commodity forward contracts	—			(176		)	(176		)
Available-for-sale marketable securities	91,595			147,793			239,388

The Level 2 measurements for the Company's commodity contracts are derived using forward curves supplied by industry-recognized and unrelated third-party services. The Level 2 measurements for the Company's available-for-sale securities are derived using market-based pricing provided by unrelated third-party services.

There were no transfers in or out of Levels 1 and 2 of the fair value hierarchy for the nine months ended September 30, 2014 and 2013.

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 long-term debt, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Company's long-term debt are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy.

	September 30, 2014				December 31, 2013
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.60% senior notes due 2022	$	249,079	$	247,633	$	248,990	$	236,905
6 ½% senior notes due 2029	100,000		114,624		100,000		109,490
6 ¾% senior notes due 2032	250,000		275,313		250,000		265,148
6 ½% GO Zone Senior Notes Due 2035	89,000		101,855		89,000		94,606
6 ½% IKE Zone Senior Notes Due 2035	65,000		74,389		65,000		69,094
Loan related to tax-exempt waste disposal revenue    bonds due 2027	10,889		10,889		10,889		10,889

11. Income Taxes

The effective income tax rate was 37.6% for the nine months ended September 30, 2014. The effective income tax rate for the 2014 period was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, partially offset by the domestic manufacturing deduction. The effective income tax rate was 35.8% for the nine months ended September 30, 2013. The effective income tax rate for the 2013 period was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, partially offset by the domestic manufacturing deduction.

There was no material change to the total gross unrecognized tax benefits for the nine months ended September 30, 2014. Management anticipates that all of the gross unrecognized tax benefits of $2,501 will be recognized within the next twelve

12

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

months due to expiring statutes of limitations. The impact from the recognition of these tax benefits on the Company's effective tax rate is expected to be immaterial.

The Company recognizes penalties and interest accrued related to unrecognized tax benefits in income tax expense. As of September 30, 2014, the Company had no material accrued interest and penalties related to uncertain tax positions.

The Company files income tax returns in the U.S. federal jurisdiction, various states and foreign jurisdictions. The Company is no longer subject to examinations by tax authorities before the year 2007.

12. 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 September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Net income attributable to Westlake Chemical    Corporation	$	167,757		$	170,290		$	495,232		$	439,453
Less:
Net income attributable to participating securities	(353		)	(587		)	(1,099		)	(1,691		)
Net income attributable to common shareholders	$	167,404		$	169,703		$	494,133		$	437,762

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 September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
Weighted average common shares—basic (1)	133,299,458		133,257,494		133,199,304		133,256,054
Plus incremental shares from:
Assumed exercise of options (1)	546,601		553,614		543,841		550,704
Weighted average common shares—diluted (1)	133,846,059		133,811,108		133,743,145		133,806,758
Earnings per common share attributable to    Westlake Chemical Corporation : (1)
Basic	$	1.26	$	1.28	$	3.71	$	3.29
Diluted	$	1.25	$	1.27	$	3.69	$	3.27

_____________

(1) Share amounts and per share data for the three and nine months ended September 30, 2013 have been restated to reflect the effect of a two-for-one stock split on March 18, 2014. See Note 1 for additional information.

There were no options excluded from the computation of diluted earnings per share for the three and nine months ended September 30, 2014. Excluded from the computation of diluted earnings per share for the three and nine months ended September 30, 2013 are options to purchase 137,324 and 115,518 shares of common stock, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive.

13

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

13. Pension and Post-Retirement Benefit Costs

Components of net periodic benefit cost are as follows:

	Three Months Ended September 30,										Nine Months Ended September 30,
	Pension						Post-retirement Healthcare				Pension						Post-retirement Healthcare
	2014			2013			2014		2013		2014			2013			2014		2013
Service cost	$	331		$	275		$	6	$	2	$	498		$	815		$	16	$	7
Interest cost	1,138			515			185		147		2,309			1,531			548		442
Expected return on    plan assets	(777		)	(713		)	—		—		(2,363		)	(2,140		)	—		—
Amortization of prior    service cost	74			74			13		21		223			223			38		63
Amortization of net loss	71			510			82		90		204			1,449			220		269
Net periodic benefit cost	$	837		$	661		$	286	$	260	$	871		$	1,878		$	822	$	781

The Company contributed $2,447 and $776 to the Salaried pension plan in the first nine months of 2014 and 2013, respectively, and contributed $916 and $640 to the Wage pension plan in the first nine months of 2014 and 2013, respectively. The Company expects to make additional contributions of $330 to the Salaried pension plan and $290 to the Wage pension plan during the fiscal year ending December 31, 2014.

14. Accumulated Other Comprehensive Loss

Changes in accumulated other comprehensive income (loss) by component for the nine months ended September 30, 2014 and 2013 were as follows:

	Benefits Liability, Net of Tax			Cumulative Foreign Currency Exchange			Net Unrealized Holding Gains on Investments, Net of Tax			Total
Balances at December 31, 2013	$	(6,696	)	$	3,904		$	176		$	(2,616	)
Other comprehensive (loss) income before    reclassifications	(39		)	(37,882		)	4,459			(33,462		)
Amounts reclassified from accumulated other    comprehensive loss	422			—			(777		)	(355		)
Net other comprehensive income (loss) for the period	383			(37,882		)	3,682			(33,817		)
Balances at September 30, 2014	$	(6,313	)	$	(33,978	)	$	3,858		$	(36,433	)

	Benefits Liability, Net of Tax			Cumulative Foreign Currency Exchange			Net Unrealized Holding Gains on Investments, Net of Tax		Total
Balances at December 31, 2012	$	(16,351	)	$	5,511		$	—	$	(10,840	)
Other comprehensive (loss) income before    reclassifications	(601		)	(844		)	131		(1,314		)
Amounts reclassified from accumulated other    comprehensive loss	1,233			—			—		1,233
Net other comprehensive income (loss) for the period	632			(844		)	131		(81		)
Balances at September 30, 2013	$	(15,719	)	$	4,667		$	131	$	(10,921	)

14

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

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 and nine months ended September 30, 2014 and 2013:

Details about Accumulated Other Comprehensive    Income (Loss) Components	Location of Reclassification (Income (Expense)) in Consolidated Statements of Operations	Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
Amortization of pension and    other post-retirement items
Prior service costs	(1)	$	(87	)	$	(95	)	$	(261	)	$	(286	)
Net loss	(1)	(153		)	(600		)	(424		)	(1,718		)
		(240		)	(695		)	(685		)	(2,004		)
	Provision for income    taxes	92			267			263			771
		(148		)	(428		)	(422		)	(1,233		)
Net unrealized gains on    available-for-sale    investments
Realized gain on    available-for-sale    investments	Other income, net	—			—			1,212			—
	Provision for income    taxes	—			—			(435		)	—
		—			—			$	777		$	—
Total reclassifications for    the period		$	(148	)	$	(428	)	$	355		$	(1,233	)

_____________

(1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, please read Note 10 (Employee Benefits) to the financial statements included in the 2013 Form 10-K.

15. Commitments and Contingencies

The Company is subject to environmental laws and regulations that can impose civil and criminal sanctions and that may require it to mitigate the effects of contamination caused by the release or disposal of hazardous substances into the environment. Under one law, the U.S. Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), an owner or operator of property may be held strictly liable for remediating contamination without regard to whether that person caused the contamination, and without regard to whether the practices that resulted in the contamination were legal at the time they occurred. Because several of the Company's production sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on the Company.

Contract Disputes with Goodrich and PolyOne. In connection with the 1990 and 1997 acquisitions of the Goodrich Corporation ("Goodrich") chemical manufacturing complex in Calvert City, Kentucky, Goodrich agreed to indemnify the Company for any liabilities related to preexisting contamination at the complex. For its part, the Company agreed to indemnify Goodrich for post-closing contamination caused by the Company's operations. The soil and groundwater at the complex, which does not include the Company's nearby polyvinyl chloride ("PVC") facility, had been extensively contaminated under Goodrich's operations. In 1993, Goodrich spun off the predecessor of PolyOne Corporation ("PolyOne"), and that predecessor assumed Goodrich's indemnification obligations relating to preexisting contamination.

In 2003, litigation arose among the Company, Goodrich and PolyOne with respect to the allocation of the cost of remediating contamination at the site. The parties settled this litigation in December 2007 and the case was dismissed. In the settlement the parties agreed that, among other things: (1) PolyOne would pay 100% of the costs (with specified exceptions), net of recoveries or credits from third parties, incurred with respect to environmental issues at the Calvert City site from August 1, 2007 forward; (2) either the Company or PolyOne might, from time to time in the future (but not more than once every five years), institute an arbitration proceeding to adjust that percentage; and (3) the Company and PolyOne would negotiate a new environmental remediation utilities and services agreement to cover the Company's provision to, or on behalf of, PolyOne of certain environmental remediation services at the site. The current environmental remediation activities at the

15

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Calvert City complex do not have a specified termination date but are expected to last for the foreseeable future. The costs incurred by the Company that have been invoiced to PolyOne to provide the environmental remediation services were $3,284 in 2013. By letter dated March 16, 2010, PolyOne notified the Company that it was initiating an arbitration proceeding under the settlement agreement. In this proceeding, PolyOne seeks to readjust the percentage allocation of costs and to recover approximately $1,400 from the Company in reimbursement of previously paid remediation costs. The arbitration is currently stayed.

State Administrative Proceedings. There are several administrative proceedings in Kentucky involving the Company, Goodrich and PolyOne related to the same manufacturing complex in Calvert City. In 2003, the Kentucky Environmental and Public Protection Cabinet (the "Cabinet") re-issued Goodrich's Resource Conservation and Recovery Act ("RCRA") permit which requires Goodrich to remediate contamination at the Calvert City manufacturing complex. Both Goodrich and PolyOne challenged various terms of the permit in an attempt to shift Goodrich's clean-up obligations under the permit to the Company. The Company intervened in the proceedings. The Cabinet has suspended all corrective action under the RCRA permit in deference to a remedial investigation and feasibility study ("RIFS") being conducted, under the auspices of the U.S. Environmental Protection Agency ("EPA"), pursuant to an Administrative Settlement Agreement ("AOC"), which became effective on December 9, 2009. See "Federal Administrative Proceedings" below. The proceedings have been postponed. Periodic status conferences will be held to evaluate whether additional proceedings will be required.

Federal Administrative Proceedings. In May 2009, the Cabinet sent a letter to the EPA requesting the EPA's assistance in addressing contamination at the Calvert City site under CERCLA. In its response to the Cabinet also in May 2009, the EPA stated that it concurred with the Cabinet's request and would incorporate work previously conducted under the Cabinet's RCRA authority into the EPA's cleanup efforts under CERCLA. Since 1983, the EPA has been addressing contamination at an abandoned landfill adjacent to the Company's plant which had been operated by Goodrich and which was being remediated pursuant to CERCLA. During the past three years, the EPA has directed Goodrich and PolyOne to conduct additional investigation activities at the landfill and at the Company's plant. In June 2009, the EPA notified the Company that the Company may have potential liability under section 107(a) of CERCLA at its plant site. Liability under section 107(a) of CERCLA is strict and joint and several. The EPA also identified Goodrich and PolyOne, among others, as potentially responsible parties at the plant site. The Company negotiated, in conjunction with the other potentially responsible parties, the AOC and an order to conduct the RIFS. On July 12, 2013, the parties submitted separate draft RIFS reports to the EPA. The EPA has hired a contractor to complete the remedial investigation report.

Monetary Relief. Except as noted above with respect to the settlement of the contract litigation among the Company, Goodrich and PolyOne, none of the court, the Cabinet nor the EPA has established any allocation of the costs of remediation among the various parties that are involved in the judicial and administrative proceedings discussed above. At this time, the Company is not able to estimate the loss or reasonable possible loss, if any, on the Company's financial statements that could result from the resolution of these proceedings. Any cash expenditures that the Company might incur in the future with respect to the remediation of contamination at the complex would likely be spread out over an extended period. As a result, the Company believes it is unlikely that any remediation costs allocable to it will be material in terms of expenditures made in any individual reporting period.

In addition to the matters described above, the Company is involved in various routine legal proceedings incidental to the conduct of its business. The Company does not believe that any of these routine legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows.

16. Share Capital

Common Stock

On May 16, 2014, the stockholders of the Company approved an amendment to the Company's Amended and Restated Certificate of Incorporation to increase the Company's authorized shares of common stock from 150,000,000 shares to 300,000,000 shares, par value $0.01 per share. The Company is now authorized to issue 300,000,000 shares of common stock, par value $0.01 per share, of which 134,680,164 and 134,580,208 shares (on a post-split basis) were issued as of September 30, 2014 and December 31, 2013, respectively. Each share of common stock entitles the holder to one vote on all matters on which holders are permitted to vote, including the election of directors.

16

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Stock Repurchase Program

In August 2011, the Company's Board of Directors authorized a stock repurchase program of the Company’s common stock totaling $100,000 (the "2011 Program"). Purchases under the 2011 Program began in September 2011. As of September 30, 2014 and December 31, 2013, the Company had repurchased 1,357,085 and 1,252,922 shares, respectively, of its common stock (on a post-split basis) under this program. Shares repurchased under the 2011 Program are held by the Company as treasury stock and may be used for general corporate purposes, including for the 2013 Omnibus Incentive Plan. Beginning in May 2014, the Company began issuing treasury shares to employees and nonemployee directors for options exercised and for the settlement of restricted stock units. The cost of treasury shares issued was determined using the specific identification method.

17. Supplemental Information

Other Liabilities

Other liabilities were $153,158 and $35,593 at September 30, 2014 and December 31, 2013, respectively. Non-current pension obligation, which is a component of other liabilities, was $117,293 and $8,710 at September 30, 2014 and December 31, 2013, respectively. No other component of other liabilities was more than five percent of total liabilities.

18. 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 September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Net external sales
Olefins
Polyethylene	$	498,450		$	460,105		$	1,461,097		$	1,294,566
Styrene, feedstock and other	204,647			219,234			663,851			590,959
Total Olefins	703,097			679,339			2,124,948			1,885,525
Vinyls
PVC, caustic soda and other	416,771			212,041			776,060			612,391
Building products	133,359			112,785			378,471			309,943
Total Vinyls	550,130			324,826			1,154,531			922,334
	$	1,253,227		$	1,004,165		$	3,279,479		$	2,807,859
Intersegment sales
Olefins	$	26,518		$	85,454		$	118,153		$	230,607
Vinyls	355			403			1,029			1,111
	$	26,873		$	85,857		$	119,182		$	231,718
Income (loss) from operations
Olefins	$	259,277		$	237,239		$	770,267		$	585,958
Vinyls	59,445			39,554			76,460			136,123
Corporate and other	(11,961		)	(10,191		)	(25,123		)	(26,197		)
	$	306,761		$	266,602		$	821,604		$	695,884
Depreciation and amortization
Olefins	$	26,443		$	26,515		$	79,811		$	76,415
Vinyls	27,336			14,089			68,127			39,507
Corporate and other	141			124			456			372
	$	53,920		$	40,728		$	148,394		$	116,294
Other income (expense), net
Olefins	$	1,609		$	728		$	4,262		$	5,889
Vinyls	1,189			(742		)	942			(1,687		)
Corporate and other	(5,468		)	(273		)	(764		)	(1,065		)
	$	(2,670	)	$	(287	)	$	4,440		$	3,137
Provision for (benefit from) income taxes
Olefins	$	105,030		$	82,553		$	282,082		$	208,170
Vinyls	21,761			10,710			22,121			44,120
Corporate and other	(2,342		)	(535		)	(3,972		)	(7,643		)
	$	124,449		$	92,728		$	300,231		$	244,647
Capital expenditures
Olefins	$	48,519		$	27,577		$	121,041		$	105,656
Vinyls	44,067			172,565			187,449			391,864
Corporate and other	1,685			276			2,693			770
	$	94,271		$	200,418		$	311,183		$	498,290

A reconciliation of total segment income from operations to consolidated income before income taxes is as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Income from operations	$	306,761		$	266,602		$	821,604		$	695,884
Interest expense	(9,486		)	(3,297		)	(28,182		)	(14,921		)
Other (expense) income, net	(2,670		)	(287		)	4,440			3,137
Income before income taxes	$	294,605		$	263,018		$	797,862		$	684,100

	September 30, 2014		December 31, 2013
Total assets
Olefins	$	1,740,878	$	1,557,510
Vinyls	2,898,250		1,740,595
Corporate and other	487,155		762,804
	$	5,126,283	$	4,060,909

19. Westlake Chemical Partners LP

Westlake Chemical Partners LP ("WLKP") is a publicly traded master limited partnership that was formed by the Company to operate, acquire and develop ethylene production facilities and related assets.

Initial Public Offering of WLKP

On August 4, 2014, WLKP completed its initial public offering of 12,937,500 common units at a price of $24.00 per unit, which included 1,687,500 units purchased by the underwriters pursuant to the exercise in full of their over-allotment option. Net proceeds to WLKP from the sale of the units was approximately $286,088, net of underwriting discounts, structuring fees and offering expenses (the "Offering Costs") of approximately $24,412. At the consummation of the offering, WLKP's assets consist of a 10.6% limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in

17

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

OpCo. The Company retained an 89.4% limited partner interest in OpCo and a significant interest in WLKP. The Company consolidates WLKP for financial reporting purposes as the Company has a controlling financial interest. The initial public offering represented the sale of 47.8% of the common and subordinated units in WLKP. OpCo used the net proceeds from the purchase of its limited partner interest to establish a cash reserve of approximately $55,419 for turnaround expenditures, to reimburse approximately $151,729 for capital expenditures incurred by the Company with respect to certain of the assets contributed to OpCo and to repay intercompany debt to the Company of approximately $78,940.

The following table is a reconciliation of proceeds from the initial public offering:

Total proceeds from the initial public offering	$	310,500
Less: Offering Costs	(24,412		)
Net proceeds from the initial public offering	286,088
Less: Cash retained by OpCo	(55,419		)
Net proceeds distributed to the Company from the initial public offering	$	230,669

20. Acquisition

On July 31, 2014, the Company acquired all the equity interests in German-based Vinnolit Holdings GmbH and its subsidiary companies ("Vinnolit") from several entities associated with Advent International Corporation (the "Sellers"). Vinnolit is headquartered in Ismaning, Germany and is an integrated global leader in specialty PVC resins, with a combined annual capacity of 1.7 billion pounds of PVC, including specialty paste and suspension grades, 1.5 billion pounds of vinyl chloride monomer ("VCM") and 1.0 billion pounds of caustic soda. The Vinnolit acquisition comprised six production facilities located in Burghausen, Gendorf, Cologne, Knapsack and Schkopau in Germany and Hillhouse in the United Kingdom. The Company also acquired Vinnolit's technical centers, including a research and development facility in Gendorf and an applications laboratory in Burghausen. The Company’s management believes that this strategic acquisition will enhance its strategy of integration and expansion into new markets and specialty products, in addition to growing the Company's global presence with a footprint in Europe and surrounding markets.

The purchase price of $736,224 was paid with available cash on hand. The acquisition is being accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed and the results of operations of this acquired business are included in the Vinyls segment.

The acquired business contributed net sales and net loss of $195,477 and $2,992, respectively, to the Company for the period from July 31, 2014 to September 30, 2014. The following unaudited consolidated pro forma information presents consolidated information as if the acquisition had occurred on January 1, 2013:

	Pro Forma Nine Months Ended September 30,
	2014		2013
Net sales	$	4,016,935	$	3,747,619
Net income	$	550,667	$	480,964
Net income attributable to noncontrolling interests	2,399		—
Net income attributable to Westlake Chemical Corporation	$	548,268	$	480,964
Earnings per common share attributable to Westlake Chemical Corporation:
Basic	$	4.11	$	3.59
Diluted	$	4.09	$	3.58

The pro forma amounts above have been calculated after applying the Company’s accounting policies and adjusting the Vinnolit results to reflect (1) the additional depreciation and amortization that would have been charged assuming the fair value adjustments to property, plant and equipment and intangible assets had been applied from January 1, 2013; (2) the elimination of interest expense assuming the long-term debt paid off on behalf of the Sellers as of the acquisition date had been retired as of January 1, 2013; (3) the elimination of transaction-related costs; and (4) an adjustment to tax-effect the aforementioned pro forma adjustments using an estimated aggregate statutory income tax rate of the jurisdictions to which the above adjustments

18

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

relate. The pro forma amounts do not include any potential synergies, cost savings or other expected benefits of the Vinnolit acquisition, are presented for illustrative purposes only and are not necessarily indicative of results that would have been achieved if the acquisition had occurred as of January 1, 2013 or of future operating performance.

For the nine months ended September 30, 2014, the Company recognized $11,235 of transaction-related costs. These costs are included in general and administrative expenses and other income, net in the consolidated statement of operations for the nine months ended September 30, 2014. The transaction-related costs included in other income, net pertained to losses incurred on forward foreign exchange contracts for the purchase consideration of Vinnolit.

The following table summarizes the purchase consideration transferred and the estimated fair value of identified assets acquired and liabilities assumed at the date of acquisition. The preliminary allocation of the purchase consideration is based on management’s 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 the fair value of the net assets acquired equals consideration paid. Therefore, no goodwill was recorded. The final allocation of purchase consideration could include changes in the estimated fair value of (1) inventories; (2) property, plant and equipment; (3) equity investments; (4) trademark and trade name, developed technologies and customer relationships; (5) power purchase agreement liability; and (6) deferred income taxes.

Fair value of consideration transferred:
Cash paid to Sellers	$	309,619
Cash deposited in escrow (1)	13,390
Retirement of long-term debt as of July 31, 2014, on behalf of the Sellers (2)	413,215
Total purchase consideration	$	736,224
Preliminary allocation of consideration transferred to net assets acquired:
Cash	$	125,137
Working capital, excluding inventory and cash (3)	23,072
Inventories (4)	114,961
Property, plant and equipment	471,123
Investments	51,552
Other assets (5)	65,366
Intangible assets:
Trademarks and trade name (weighted average life of 20 years)	40,170
Developed technologies (weighted average life of 20 years)	31,600
Other intangibles (weighted average life of 9.4 years)	1,422
Deferred income tax asset - current	8,697
Deferred income tax asset - non-current	27,387
Pension obligation	(117,970		)
Other long-term liabilities	(10,723		)
Power purchase agreement liability (6)	(10,826		)
Deferred income tax liability - current	(6,845		)
Deferred income tax liability - non-current	(77,899		)
Total identifiable net assets	736,224
Goodwill (7)	—
Consideration transferred	$	736,224

_____________

(1) None of the cash held in escrow is considered contingent consideration as it is expected to be released to the Sellers pending the Sellers’ satisfaction of general representations and warranties made in connection with the execution of the purchase agreement.

19

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

(2) Vinnolit’s long-term debt paid on behalf of the Sellers was not legally assumed by Westlake in the acquisition and was a condition of the consummation of the purchase agreement. Therefore, the retirement has been included in the total purchase consideration.

(3) The fair value of accounts receivable acquired is $181,826, with the gross contractual amount being $183,769. The Company expects $1,943 to be uncollectible.

(4) An adjustment of approximately $16,900 was recorded to reflect Vinnolit's inventories at fair value and increased cost of sales by the same amount for the three months ended September 30, 2014.

(5) Included in other assets was a loan acquired that was repaid prior to September 30, 2014.

(6) A liability arising from unfavorable forward purchase contracts for the purchase of power was recognized at fair value. This liability will be amortized over a period of approximately 3.0 years, being the weighted-average life of the forward purchase contracts.

(7) Management estimated that the fair value of the net assets acquired equals consideration paid. Therefore, no goodwill was recorded.

21. Related Party and Affiliate Transactions

InfraServ Knapsack GmbH & Co. KG, an on-site chemical complex provider in which the Company owns a 15% equity stake, provides electricity and technical services to the Company's Knapsack, Germany production facility. For the period from July 31, 2014 to September 30, 2014, the Company incurred charges aggregating approximately $11,581.

InfraServ Gendorf GmbH & Co. KG, an on-site chemical complex provider in which the Company owns an 11% equity stake, provides electricity and technical services to the Company's Gendorf, Germany production facility. For the period from July 31, 2014 to September 30, 2014, the Company incurred charges aggregating approximately $10,489.

22. Subsequent Events

Subsequent events were evaluated through the date on which the financial statements were issued.

23. Guarantor Disclosures

The Company's payment obligations under the 3.60% senior notes due 2022 are fully and unconditionally guaranteed by each of its current and future domestic subsidiaries that guarantee other debt of the Company or of another guarantor of the 3.60% senior notes due 2022 in excess of $5,000 (the "Guarantor Subsidiaries"). Except for OpCo, which is less than 100% owned, each Guarantor Subsidiary is 100% owned by Westlake Chemical Corporation (the "100% Owned Guarantor Subsidiaries"). See Note 19 regarding WLKP’s 10.6% limited partnership interest in OpCo. The initial public offering of WLKP resulted in OpCo ceasing to be a 100% owned subsidiary of the Company. OpCo has been presented as a less than 100% owned guarantor subsidiary in each of the tables below, including for periods prior to the initial public offering of WLKP. 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, OpCo and the remaining subsidiaries that do not guarantee the 3.60% senior notes due 2022 (the "Non-Guarantor Subsidiaries"), together with consolidating eliminations necessary to present the Company's results on a consolidated basis.

20

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information as of September 30, 2014

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries		OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries		Eliminations			Consolidated
Balance Sheet
Current assets
Cash and cash equivalents	$	652,709	$	1,644	$	89,144	$	69,971	$	—		$	813,468
Accounts receivable, net	15,064		1,377,250		58,106		170,833		(1,028,289		)	592,964
Inventories	—		385,826		5,551		109,175		—			500,552
Prepaid expenses and other current assets	137		14,737		303		3,707		—			18,884
Deferred income taxes	342		25,446		—		292		—			26,080
Total current assets	668,252		1,804,903		153,104		353,978		(1,028,289		)	1,951,948
Property, plant and equipment, net	—		1,451,807		806,648		452,020		—			2,710,475
Equity investments	3,878,703		1,207,569		—		356,286		(5,371,730		)	70,828
Other assets, net	34,847		351,271		61,679		137,990		(192,755		)	393,032
Total assets	$	4,581,802	$	4,815,550	$	1,021,431	$	1,300,274	$	(6,592,774	)	$	5,126,283
Current liabilities
Accounts payable	$	979,414	$	157,562	$	29,856	$	100,129	$	(1,003,596	)	$	263,365
Accrued liabilities	15,448		238,225		3,412		77,279		(24,693		)	309,671
Total current liabilities	994,862		395,787		33,268		177,408		(1,028,289		)	573,036
Long-term debt	753,079		10,889		188,523		—		(188,523		)	763,968
Deferred income taxes	—		473,343		1,507		43,155		(4,232		)	513,773
Other liabilities	—		31,616		—		121,542		—			153,158
Total liabilities	1,747,941		911,635		223,298		342,105		(1,221,044		)	2,003,935
Total Westlake Chemical Corporation stockholders' equity	2,833,861		3,903,915		798,133		669,682		(5,371,730		)	2,833,861
Noncontrolling interests	—		—		—		288,487		—			288,487
Total equity	2,833,861		3,903,915		798,133		958,169		(5,371,730		)	3,122,348
Total liabilities and equity	$	4,581,802	$	4,815,550	$	1,021,431	$	1,300,274	$	(6,592,774	)	$	5,126,283

21

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information as of December 31, 2013

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries		OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non-Guarantor Subsidiaries		Eliminations			Consolidated
Balance Sheet
Current assets
Cash and cash equivalents	$	420,948	$	6,227	$	—	$	34,126	$	—		$	461,301
Marketable securities	239,388		—		—		—		—			239,388
Accounts receivable, net	3,879		666,344		71,812		2,755		(316,333		)	428,457
Inventories	—		339,929		116,377		15,573		—			471,879
Prepaid expenses and other current assets	778		11,055		257		1,798		—			13,888
Deferred income taxes	441		28,974		4,448		306		—			34,169
Total current assets	665,434		1,052,529		192,894		54,558		(316,333		)	1,649,082
Property, plant and equipment, net	—		1,318,119		762,972		6,923		—			2,088,014
Equity investments	2,815,752		636,461		10,411		31,518		(3,427,267		)	66,875
Other assets, net	15,393		423,901		75,197		1,199		(258,752		)	256,938
Total assets	$	3,496,579	$	3,431,010	$	1,041,474	$	94,198	$	(4,002,352	)	$	4,060,909
Current liabilities
Accounts payable	$	316,652	$	100,570	$	122,564	$	10,649	$	(300,822	)	$	249,613
Accrued liabilities	8,334		134,452		26,688		1,282		(15,511		)	155,245
Total current liabilities	324,986		235,022		149,252		11,931		(316,333		)	404,858
Long-term debt	752,990		10,889		252,973		—		(252,973		)	763,879
Deferred income taxes	—		260,171		182,855		729		(5,779		)	437,976
Other liabilities	—		34,571		962		60		—			35,593
Total equity	2,418,603		2,890,357		455,432		81,478		(3,427,267		)	2,418,603
Total liabilities and equity	$	3,496,579	$	3,431,010	$	1,041,474	$	94,198	$	(4,002,352	)	$	4,060,909

22

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information for the Three Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	1,026,282		$	392,008		$	208,313		$	(373,376	)	$	1,253,227
Cost of sales	—			831,675			227,015			202,110			(369,093		)	891,707
Gross profit	—			194,607			164,993			6,203			(4,283		)	361,520
Selling, general and administrative expenses	399			36,445			8,014			14,184			(4,283		)	54,759
(Loss) income from operations	(399		)	158,162			156,979			(7,981		)	—			306,761
Interest expense	(10,343		)	(2		)	(2,137		)	(39		)	3,035			(9,486		)
Other income (expense), net	2,138			(2,942		)	486			683			(3,035		)	(2,670		)
(Loss) income before income taxes	(8,604		)	155,218			155,328			(7,337		)	—			294,605
(Benefit from) provision for income taxes	(3,088		)	93,366			36,309			(2,138		)	—			124,449
Equity in net income of subsidiaries	173,273			113,157			—			5,862			(292,292		)	—
Net income (loss)	167,757			175,009			119,019			663			(292,292		)	170,156
Net income attributable to noncontrolling interests	—			—			—			2,399			—			2,399
Net income (loss) attributable to Westlake Chemical Corporation	$	167,757		$	175,009		$	119,019		$	(1,736	)	$	(292,292	)	$	167,757
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	131,456		$	175,137		$	119,019		$	(39,528	)	$	(254,628	)	$	131,456

23

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information for the Three Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	844,081		$	540,133		$	13,337		$	(393,386	)	$	1,004,165
Cost of sales	—			754,037			327,152			11,891			(393,386		)	699,694
Gross profit	—			90,044			212,981			1,446			—			304,471
Selling, general and administrative expenses	514			29,323			6,391			1,641			—			37,869
(Loss) income from operations	(514		)	60,721			206,590			(195		)	—			266,602
Interest expense	(3,292		)	(5		)	(2,295		)	—			2,295			(3,297		)
Other income (expense), net	3,585			(2,688		)	1,162			(51		)	(2,295		)	(287		)
(Loss) income before income taxes	(221		)	58,028			205,457			(246		)	—			263,018
(Benefit from) provision for income taxes	(70		)	19,973			72,876			(51		)	—			92,728
Equity in net income of subsidiaries	170,441			132,581			—			—			(303,022		)	—
Net income (loss) attributable to Westlake Chemical Corporation	$	170,290		$	170,636		$	132,581		$	(195	)	$	(303,022	)	$	170,290
Comprehensive income attributable to Westlake Chemical    Corporation	$	171,095		$	170,764		$	132,581		$	351		$	(303,696	)	$	171,095

24

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	2,809,844		$	1,476,157		$	229,183		$	(1,235,705	)	$	3,279,479
Cost of sales	—			2,476,608			832,304			221,233			(1,205,167		)	2,324,978
Gross profit	—			333,236			643,853			7,950			(30,538		)	954,501
Selling, general and administrative expenses	1,474			123,050			21,957			16,954			(30,538		)	132,897
(Loss) income from operations	(1,474		)	210,186			621,896			(9,004		)	—			821,604
Interest expense	(29,032		)	(8		)	(9,833		)	(39		)	10,730			(28,182		)
Other income (expense), net	14,488			(1,729		)	3,135			(724		)	(10,730		)	4,440
(Loss) income before income taxes	(16,018		)	208,449			615,198			(9,767		)	—			797,862
(Benefit from) provision for income taxes	(5,686		)	109,920			198,461			(2,464		)	—			300,231
Equity in net income of subsidiaries	505,564			410,875			—			5,862			(922,301		)	—
Net income (loss)	495,232			509,404			416,737			(1,441		)	(922,301		)	497,631
Net income attributable to noncontrolling interests	—			—			—			2,399			—			2,399
Net income (loss) attributable to Westlake Chemical Corporation	$	495,232		$	509,404		$	416,737		$	(3,840	)	$	(922,301	)	$	495,232
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	461,415		$	509,787		$	416,737		$	(41,722	)	$	(884,802	)	$	461,415

25

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	2,407,341		$	1,565,809		$	37,561		$	(1,202,852	)	$	2,807,859
Cost of sales	—			2,247,338			924,663			32,943			(1,202,852		)	2,002,092
Gross profit	—			160,003			641,146			4,618			—			805,767
Selling, general and administrative expenses	1,576			84,152			19,326			4,829			—			109,883
(Loss) income from operations	(1,576		)	75,851			621,820			(211		)	—			695,884
Interest expense	(14,882		)	(39		)	(4,893		)	—			4,893			(14,921		)
Other income (expense), net	7,490			(4,002		)	6,422			(1,880		)	(4,893		)	3,137
(Loss) income before income taxes	(8,968		)	71,810			623,349			(2,091		)	—			684,100
(Benefit from) provision for income taxes	(3,202		)	27,292			221,009			(452		)	—			244,647
Equity in net income of subsidiaries	445,219			402,340			—			—			(847,559		)	—
Net income (loss) attributable to Westlake Chemical Corporation	$	439,453		$	446,858		$	402,340		$	(1,639	)	$	(847,559	)	$	439,453
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	439,372		$	447,490		$	402,340		$	(2,483	)	$	(847,347	)	$	439,372

26

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Cash Flows
Cash flows from operating activities
Net income (loss)	$	495,232		$	509,404		$	416,737		$	(1,441	)	$	(922,301	)	$	497,631
Adjustments to reconcile net income (loss) to net cash (used for)    provided by operating activities
Depreciation and amortization	1,172			82,597			58,501			7,296			—			149,566
Deferred income taxes	(418		)	26,991			8,267			(381		)	—			34,459
Net changes in working capital and other	(509,862		)	(919,521		)	1,641			599,909			922,301			94,468
Net cash (used for) provided by operating activities	(13,876		)	(300,529		)	485,146			605,383			—			776,124
Cash flows from investing activities
Acquisition of business, net of cash acquired	—			—			—			(611,087		)	—			(611,087		)
Additions to property, plant and equipment	—			(160,147		)	(144,348		)	(6,688		)	—			(311,183		)
Proceeds from disposition of assets	—			144			—			1			—			145
Proceeds from repayment of loan acquired	—			—			—			45,923			—			45,923
Proceeds from sales and maturities of securities	342,045			—			—			—			—			342,045
Purchase of securities	(117,332		)	—			—			—			—			(117,332		)
Settlements of derivative instruments	—			(556		)	(133		)	—			—			(689		)
Net cash provided by (used for) investing activities	224,713			(160,559		)	(144,481		)	(571,851		)	—			(652,178		)
Cash flows from financing activities
Intercompany financing	75,104			(143,325		)	62,221			6,000			—			—
Net distributions prior to WLKP initial public offering	—			448,101			(448,101		)	—			—			—
Capitalized debt issuance costs	(1,167		)	—			—			—			—			(1,167		)
Dividends paid	(55,690		)	151,729			(151,729		)	—			—			(55,690		)
Net proceeds from issuance of WLKP common units	—			—			—			286,088			—			286,088
Purchase of limited partner interests	—			—			286,088			(286,088		)	—			—
Proceeds from exercise of stock options	5,502			—			—			—			—			5,502
Repurchase of common stock for treasury	(9,495		)	—			—			—			—			(9,495		)
Windfall tax benefits from share-based payment arrangements	6,670			—			—			—			—			6,670
Net cash provided by (used for) financing activities	20,924			456,505			(251,521		)	6,000			—			231,908

27

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries			Eliminations		Consolidated
Effect of exchange rate changes on cash and cash equivalents	—		—			—		(3,687		)	—		(3,687		)
Net increase (decrease) in cash and cash equivalents	231,761		(4,583		)	89,144		35,845			—		352,167
Cash and cash equivalents at beginning of period	420,948		6,227			—		34,126			—		461,301
Cash and cash equivalents at end of period	$	652,709	$	1,644		$	89,144	$	69,971		$	—	$	813,468

28

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Cash Flows
Cash flows from operating activities
Net income (loss)	$	439,453		$	446,858		$	402,340		$	(1,639	)	$	(847,559	)	$	439,453
Adjustments to reconcile net income (loss) to net cash (used for)    provided by operating activities
Depreciation and amortization	1,094			59,893			54,539			1,861			—			117,387
Deferred income taxes	(1,102		)	57,279			27,253			13			—			83,443
Net changes in working capital and other	(458,336		)	(421,066		)	(68,604		)	7,664			847,559			(92,783		)
Net cash (used for) provided by operating activities	(18,891		)	142,964			415,528			7,899			—			547,500
Cash flows from investing activities
Acquisition of business	—			(178,309		)	—			—			—			(178,309		)
Additions to equity investments	—			(23,338		)	—			—			—			(23,338		)
Additions to property, plant and equipment	—			(337,158		)	(158,869		)	(2,263		)	—			(498,290		)
Construction of assets pending sale-leaseback	—			(136		)	—			—			—			(136		)
Proceeds from disposition of assets	—			6			—			72			—			78
Proceeds from repayment of loan to affiliate	—			—			—			167			—			167
Proceeds from sales and maturities of securities	239,764			—			—			—			—			239,764
Purchase of securities	(232,286		)	—			—			—			—			(232,286		)
Settlements of derivative instruments	—			—			(2,297		)	—			—			(2,297		)
Net cash provided by (used for) investing activities	7,478			(538,935		)	(161,166		)	(2,024		)	—			(694,647		)
Cash flows from financing activities
Intercompany financing	(130,832		)	(28,499		)	167,629			(8,298		)	—			—
Net distributions prior to WLKP initial public offering	—			421,991			(421,991		)	—			—			—
Dividends paid	(40,204		)	—			—			—			—			(40,204		)
Proceeds from exercise of stock options	3,182			—			—			—			—			3,182
Repurchase of common stock for treasury	(19,409		)	—			—			—			—			(19,409		)
Windfall tax benefits from share-based payment arrangements	5,056			—			—			—			—			5,056
Net cash (used for) provided by financing activities	(182,207		)	393,492			(254,362		)	(8,298		)	—			(51,375		)

29

WESTLAKE CHEMICAL CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars, except share amounts and per share data)

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries			Eliminations		Consolidated
Net decrease in cash and cash equivalents	(193,620		)	(2,479		)	—		(2,423		)	—		(198,522		)
Cash and cash equivalents at beginning of period	753,881			6,973			—		29,224			—		790,078
Cash and cash equivalents at end of period	$	560,261		$	4,494		$	—	$	26,801		$	—	$	591,556

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Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations

This discussion and analysis should be read in conjunction with information contained in the accompanying unaudited consolidated interim financial statements of Westlake Chemical Corporation and the notes thereto and the consolidated financial statements and notes thereto of Westlake Chemical Corporation included in Westlake Chemical Corporation's Annual Report on Form 10-K for the fiscal year ended December 31, 2013 (the "2013 Form 10-K"). The following discussion contains forward-looking statements. Please read "Forward-Looking Statements" for a discussion of limitations inherent in such statements.

We are a vertically integrated manufacturer and marketer of basic chemicals, vinyls, polymers and fabricated building products. Our two principal operating segments are Olefins and Vinyls. We use the majority of our internally-produced basic chemicals to produce higher value-added chemicals and building products.

Since 2009 and continuing through the third quarter of 2014, a cost advantage for ethane-based ethylene producers over naphtha-based ethylene producers has allowed a strong export market for ethylene derivatives and higher margins for North American chemical producers, including Westlake. Increased global demand for polyethylene in recent years in particular has resulted in improved operating margins and cash flow for our Olefins segment. Crude oil prices have fallen toward the end of the third quarter of 2014, narrowing such cost advantage.

Continued slow recovery in the U.S. construction markets and budgetary constraints in municipal spending have contributed to lower domestic demand for our vinyls products. However, since late 2010, the polyvinyl chloride ("PVC") industry has experienced an increase in PVC resin export demand, driven largely by more competitive feedstock and energy cost positions in North America. As a consequence, domestic PVC resin industry operating rates have improved since 2010, largely due to higher PVC resin export shipments. In the fourth quarter of 2013, we started up our new world scale Geismar, Louisiana chlor-alkali plant. In April 2014, we completed the ethane feedstock conversion and ethylene expansion project at our Calvert City, Kentucky ethylene plant. In July 2014, we closed the acquisition of German-based Vinnolit Holdings GmbH and its subsidiary companies ("Vinnolit") (see further discussion in "Recent Developments" below). The completion of these two projects, as well as the acquisition of Vinnolit, is expected to improve the profitability of our Vinyls segment.

The U.S. and global economic environment appears to be slowly improving, but depending on the performance of the global economy in the remainder of 2014 and beyond, could still have an impact on our financial condition, results of operations or cash flows.

Recent Developments

In March 2014, we formed Westlake Chemical Partners LP ("WLKP") to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, WLKP closed its initial public offering of 12,937,500 common units at a price of $24.00 per unit, which included 1,687,500 units purchased by the underwriters through an over-allotment option. Net proceeds to WLKP from the sale of the units was approximately $286.1 million, net of underwriting discounts, structuring fees and estimated offering expenses of approximately $24.4 million. At the consummation of this offering, WLKP's assets consist of a 10.6% limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in OpCo. We retained an 89.4% limited partner interest in OpCo and a significant interest in WLKP. OpCo used the net proceeds from the purchase of its limited partner interest to establish a cash reserve of approximately $55.4 million for turnaround expenditures, to reimburse us approximately $151.7 million for capital expenditures incurred with respect to certain of the assets contributed to OpCo and to repay intercompany debt of approximately $78.9 million. The initial public offering represented the sale of 47.8% of the common and subordinated units in WLKP.

On July 31, 2014, we acquired Vinnolit from several entities associated with Advent International Corporation. Vinnolit is headquartered in Ismaning, Germany and is an integrated global leader in specialty PVC resins, with a combined annual capacity of 1.7 billion pounds of PVC, including specialty paste and suspension grades, 1.5 billion pounds of vinyl chloride monomer ("VCM") and 1.0 billion pounds of caustic soda.

31

Results of Operations

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
	(dollars in thousands, except per share data)
Net external sales
Olefins
Polyethylene	$	498,450		$	460,105		$	1,461,097		$	1,294,566
Styrene, feedstock and other	204,647			219,234			663,851			590,959
Total Olefins	703,097			679,339			2,124,948			1,885,525
Vinyls
PVC, caustic soda and other	416,771			212,041			776,060			612,391
Building products	133,359			112,785			378,471			309,943
Total Vinyls	550,130			324,826			1,154,531			922,334
Total	$	1,253,227		$	1,004,165		$	3,279,479		$	2,807,859
Income (loss) from operations
Olefins	$	259,277		$	237,239		$	770,267		$	585,958
Vinyls	59,445			39,554			76,460			136,123
Corporate and other	(11,961		)	(10,191		)	(25,123		)	(26,197		)
Total income from operations	306,761			266,602			821,604			695,884
Interest expense	(9,486		)	(3,297		)	(28,182		)	(14,921		)
Other (expense) income, net	(2,670		)	(287		)	4,440			3,137
Provision for income taxes	124,449			92,728			300,231			244,647
Net income	170,156			170,290			497,631			439,453
Net income attributable to noncontrolling    interests	2,399			—			2,399			—
Net income attributable to Westlake Chemical    Corporation	$	167,757		$	170,290		$	495,232		$	439,453
Diluted earnings per share (1)	$	1.25		$	1.27		$	3.69		$	3.27
_____________
(1) Per share data for the three and nine months ended September 30, 2013 have been restated to reflect the effect of           a two-for-one stock split on March 18, 2014. See Note 1 to the unaudited consolidated financial statements within           this Quarterly Report on Form 10-Q for additional information.
	Three Months Ended September 30, 2014						Nine Months Ended September 30, 2014
	Average Sales Price			Volume			Average Sales Price			Volume
Product sales price and volume percentage change    from prior year period
Olefins	+10.7		%	-7.2		%	+9.8		%	+2.9		%
Vinyls	+1.6		%	+67.8		%	-0.2		%	+25.3		%
Company average	+7.8		%	+17.1		%	+6.6		%	+10.2		%

32

	Three Months Ended September 30,		Nine Months Ended September 30,
	2014	2013	2014	2013
Average industry prices (1)
Ethane (cents/lb)	7.9	8.4	9.7	8.7
Propane (cents/lb)	24.6	24.4	26.9	22.2
Ethylene (cents/lb) (2)	66.6	54.3	59.1	58.7
Polyethylene (cents/lb) (3)	110.0	101.7	108.9	99.7
Styrene (cents/lb) (4)	85.8	83.2	85.0	83.6
Caustic soda ($/short ton) (5)	588.3	605.8	587.5	611.4
Chlorine ($/short ton) (6)	232.5	248.3	233.9	252.8
PVC (cents/lb) (7)	70.2	61.5	68.7	60.9

_____________

(1) Industry pricing data was obtained from IHS Chemical. We have not independently verified the data.

(2) Represents average North American spot prices of ethylene over the period as reported by IHS Chemical.

(3) Represents average North American contract prices of polyethylene low density film over the period as reported by IHS Chemical.

(4) Represents average North American contract prices of styrene over the period as reported by IHS Chemical.

(5) Represents average North American undiscounted contract prices of caustic soda over the period as reported by IHS Chemical.

(6) Represents average North American contract prices of chlorine (into chemicals) over the period as reported by IHS Chemical.

(7) Represents average North American contract prices of PVC over the period as reported by IHS Chemical.

Summary

For the quarter ended September 30, 2014, net income attributable to Westlake Chemical Corporation was $167.8 million, or $1.25 per diluted share, on net sales of $1,253.2 million. This represents a decrease in net income attributable to Westlake Chemical Corporation of $2.5 million, or $0.02 per diluted share, compared to the quarter ended September 30, 2013 net income attributable to Westlake Chemical Corporation of $170.3 million, or $1.27 per diluted share, on net sales of $1,004.2 million. Net income for the third quarter of 2014 was negatively impacted by (1) WLKP formation and initial public offering costs and Vinnolit acquisition and associated costs of approximately $21.6 million, after tax; (2) a third quarter 2014 elevated effective tax rate of 42.2% as a result of the recognition of the tax impact of current changes in state tax rates and other discrete tax items, which reduced net income by $16.2 million; and (3) unplanned outages at our Calvert City and Geismar facilities in the third quarter of 2014, which resulted in maintenance and other costs of $7.1 million, after tax. The increase in the effective tax rate was primarily attributable to discrete items totaling $16.2 million which increased the third quarter of 2014 tax provision, comprising $13.7 million related to state apportionment rate changes, $2.1 million related to goodwill on a pipeline contributed to WLKP and $0.4 million related to other miscellaneous items. We estimate the 2014 annual tax rate on ordinary income will be approximately 35.6%. Net sales for the third quarter of 2014 increased by $249.0 million compared to net sales for the third quarter of 2013, mainly attributable to sales contributed by Vinnolit, which we acquired in July 2014, higher sales prices for our major Olefins products and PVC resin and higher sales volumes for PVC resin, caustic soda and ethylene. The increase in net sales was partially offset by lower sales volumes for styrene and ethylene co-products. Income from operations was $306.8 million for the third quarter of 2014 as compared to $266.6 million for the third quarter of 2013. Income from operations for the third quarter of 2014 benefited primarily from improved olefins and vinyls integrated product margins, predominantly due to higher sales prices for most of our major products and lower overall feedstock costs as compared to the prior year period. Income from operations for the third quarter of 2014 was negatively impacted by lost sales, lower production rates, unabsorbed fixed manufacturing costs and other costs associated with the unplanned outages at our Calvert City and Geismar complexes, as well as the negative impact of WLKP formation and initial public offering costs and the Vinnolit acquisition-related costs, including the effect of selling higher cost inventory recorded at fair value.

For the nine months ended September 30, 2014, net income attributable to Westlake Chemical Corporation was $495.2 million, or $3.69 per diluted share, on net sales of $3,279.5 million. This represents an increase in net income attributable to Westlake Chemical Corporation of $55.7 million, or $0.42 per diluted share, from the nine months ended September 30, 2013 net income attributable to Westlake Chemical Corporation of $439.5 million, or $3.27 per diluted share, on net sales of $2,807.9 million. Net income for the nine months ended September 30, 2014 was negatively impacted by WLKP formation and initial public offering costs and Vinnolit acquisition and associated costs of approximately $24.5 million, after tax, and the

33

discrete tax items which increased the third quarter tax provision by approximately $16.2 million. Net sales for the nine months ended September 30, 2014 increased by $471.6 million compared to the prior year period primarily due to sales contributed by Vinnolit and our specialty PVC pipe business, which we acquired in July 2014 and May 2013, respectively, higher sales prices and sales volumes for most of our major Olefins products and higher PVC resin sales prices, partially offset by lower ethylene co-products and styrene sales volumes. Income from operations was $821.6 million for the nine months ended September 30, 2014 as compared to $695.9 million for the nine months ended September 30, 2013, an increase mainly attributable to improved olefins integrated product margins, primarily as a result of the increased ethylene production at our Lake Charles, Louisiana complex after the first quarter 2013 completion of the Petro 2 ethylene unit expansion and its conversion to 100% ethane feedstock capability. The increase in income from operations for the nine months ended September 30, 2014 was partially offset by lost sales, lower production rates, unabsorbed fixed manufacturing costs and other costs associated with several planned and unplanned outages at our chemical complexes.

RESULTS OF OPERATIONS

Third Quarter 2014 Compared with Third Quarter 2013

Net Sales. Net sales increased by $249.0 million, or 24.8%, to $1,253.2 million in the third quarter of 2014 from $1,004.2 million in the third quarter of 2013, primarily attributable to sales contributed by Vinnolit, higher sales prices for our major Olefins products and PVC resin and higher sales volumes for PVC resin, caustic soda and ethylene, partially offset by lower sales volumes for styrene and ethylene co-products. Ethylene co-products sales volumes were lower for the third quarter of 2014 primarily due to the change to ethane feedstock currently utilized at our Calvert City ethylene plant following the completion of the feedstock conversion and ethylene expansion project. Average sales prices for the third quarter of 2014 increased by 7.8% as compared to the third quarter of 2013. Overall sales volumes increased by 17.1% as compared to the third quarter of 2013.

Gross Profit. Gross profit margin percentage decreased to 28.8% for the third quarter of 2014 from 30.3% for the third quarter of 2013. Our raw material cost in both segments normally tracks industry prices, which experienced a decrease of 6.0% for ethane as compared to the third quarter of 2013. In addition, our overall feedstock costs were also lower in the third quarter of 2014 due to the cost-advantaged ethane feedstock currently utilized at our Calvert City ethylene plant, as compared to the propane feedstock utilized during the prior year period. Sales prices increased an average of 7.8% for the third quarter of 2014 as compared to the third quarter of 2013. These benefits to gross profit margin for the third quarter of 2014 were more than offset by the negative impact of lost sales, lower production rates, unabsorbed fixed manufacturing costs and other costs associated with the unplanned outages at our Calvert City and Geismar complexes, the negative impact of selling higher cost Vinnolit inventory recorded at fair value and higher energy costs.

Selling, General and Administrative Expenses. Selling, general and administrative expenses for the third quarter of 2014 of $54.8 million increased by $16.9 million as compared to the third quarter of 2013, mainly due to general and administrative costs incurred by Vinnolit for the period from July 31, 2014 to September 30, 2014 and an increase in consulting and professional fees related to the formation and initial public offering of WLKP and the acquisition of Vinnolit.

Interest Expense. Interest expense increased by $6.2 million to $9.5 million in the third quarter of 2014 from $3.3 million in the third quarter of 2013 largely as a result of decreased capitalized interest on major capital projects as compared to the prior year period. Debt balances remained relatively unchanged from the prior year period.

Other Expense, Net. Other expense, net increased by $2.4 million to $2.7 million in the third quarter of 2014 from $0.3 million in the third quarter of 2013 mainly due to higher losses on foreign exchange, partially offset by higher income from our equity method investments.

Income Taxes. The effective income tax rate was 42.2% for the third quarter of 2014. The effective income tax rate for the third quarter of 2014 was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, partially offset by the domestic manufacturing deduction. The effective income tax rate was 35.3% for the third quarter of 2013. The effective income tax rate for the third quarter of 2013 was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, mostly offset by the domestic manufacturing deduction.

Olefins Segment

Net Sales. Net sales increased by $23.8 million, or 3.5%, to $703.1 million in the third quarter of 2014 from $679.3 million in the third quarter of 2013, primarily due to higher sales prices for our major products and higher sales volumes for ethylene, partially offset by lower sales volumes for styrene, as compared to the prior year period. Average sales prices for the Olefins segment increased by 10.7% in the third quarter of 2014 as compared to the third quarter of 2013. Average sales volumes for the Olefins segment decreased by 7.2% in the third quarter of 2014 as compared to the third quarter of 2013.

34

Income from Operations. Income from operations increased by $22.1 million, or 9.3%, to $259.3 million in the third quarter of 2014 from $237.2 million in the third quarter of 2013. This increase was mainly attributable to higher olefins integrated product margins in the third quarter of 2014 as compared to the prior year period, primarily as a result of higher sales prices and lower ethane costs. Trading activity in the third quarter of 2014 resulted in a loss of $6.9 million as compared to a gain of $4.9 million in the third quarter of 2013.

Vinyls Segment

Net Sales. Net sales increased by $225.3 million, or 69.4%, to $550.1 million in the third quarter of 2014 from $324.8 million in the third quarter of 2013. This increase was mainly attributable to sales contributed by Vinnolit, higher sales prices for PVC resin and higher sales volumes for PVC resin and caustic soda. The increase in net sales in the third quarter of 2014 was partially offset by the lower ethylene co-products volumes produced, and consequently sold, as a result of the change in feedstock utilized at our Calvert City ethylene plant from propane to ethane, following the completion of the feedstock conversion project. Average sales prices for the Vinyls segment increased by 1.6% in the third quarter of 2014 as compared to the third quarter of 2013. Average sales volumes for the Vinyls segment increased by 67.8% in the third quarter of 2014 as compared to the third quarter of 2013.

Income from Operations. Income from operations increased by $19.8 million, or 50.0%, to $59.4 million in the third quarter of 2014 from $39.6 million in the third quarter of 2013. This increase was mainly driven by higher vinyls integrated product margins in the third quarter of 2014 primarily as a result of the cost-advantaged ethane feedstock currently utilized at our Calvert City ethylene plant, as compared to the propane feedstock utilized during the prior year period. The third quarter 2014 income from operations was negatively impacted by lost sales, lower production rates, unabsorbed fixed manufacturing costs and other costs associated with the unplanned outages at our Calvert City and Geismar complexes and the effect of selling higher cost Vinnolit inventory recorded at fair value.

Nine Months Ended September 30, 2014 Compared with Nine Months Ended September 30, 2013

Net Sales. Net sales increased by $471.6 million, or 16.8%, to $3,279.5 million for the nine months ended September 30, 2014 from $2,807.9 million for the nine months ended September 30, 2013, primarily attributable to sales contributed by Vinnolit and our specialty PVC pipe business, higher sales prices and sales volumes for most of our major Olefins products and higher PVC resin sales prices, partially offset by lower ethylene co-products and styrene sales volumes. Ethylene co-products sales volumes were lower for the nine months ended September 30, 2014, as compared to the nine months ended September 30, 2013, primarily due to the planned shut-down of our Calvert City ethylene plant as a result of the feedstock conversion and ethylene expansion project, and the change to ethane feedstock currently utilized at our Calvert City ethylene plant following the completion of such project. Average sales prices for the nine months ended September 30, 2014 increased by 6.6% as compared to the nine months ended September 30, 2013. Overall sales volumes for the nine months ended September 30, 2014 increased by 10.2% as compared to the nine months ended September 30, 2013.

Gross Profit. Gross profit margin percentage of 29.1% for the nine months ended September 30, 2014 increased from the 28.7% gross profit margin percentage for the nine months ended September 30, 2013. The improvement in gross profit margin percentage was mainly due to the improved olefins integrated product margins, primarily as a result of the increased ethylene production at our Lake Charles complex after the first quarter 2013 completion of the Petro 2 ethylene unit expansion and its conversion to 100% ethane feedstock capability. In addition, olefins integrated product margins for the nine months ended September 30, 2014 benefited from an increase in sales prices that outpaced increases in feedstock and energy costs as compared to the prior year period. Our raw material cost in both segments normally tracks industry prices, which experienced an increase of 11.5% for ethane and an increase of 21.2% for propane as compared to the nine months ended September 30, 2013. Sales prices increased an average of 6.6% for the nine months ended September 30, 2014 as compared to the prior year period. The gross profit margin for the nine months ended September 30, 2014 was negatively impacted by lost sales, lower production rates, unabsorbed fixed manufacturing costs and other costs associated with several planned and unplanned outages at our chemical complexes.

Selling, General and Administrative Expenses. Selling, general and administrative expenses for the nine months ended September 30, 2014 increased by $23.0 million as compared to the nine months ended September 30, 2013, mainly attributable to general and administrative costs incurred by Vinnolit for the period from July 31, 2014 to September 30, 2014, an increase in payroll and related labor costs, including incentive compensation, and an increase in consulting and professional fees, partially offset by a decrease in the provision for doubtful accounts.

Interest Expense. Interest expense increased by $13.3 million to $28.2 million for the nine months ended September 30, 2014, largely as a result of decreased capitalized interest on major capital projects as compared to the prior year period. Debt balances remained relatively unchanged from the prior year period.

35

Other Income, Net. Other income, net increased by $1.3 million to $4.4 million for the nine months ended September 30, 2014 from $3.1 million for the nine months ended September 30, 2013. The increase from prior year period was principally due to higher income from our equity method investments and higher gain from sales of securities, partially offset by higher losses on foreign exchange.

Income Taxes. The effective income tax rate was 37.6% for the nine months ended September 30, 2014. The effective income tax rate for the 2014 period was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, partially offset by the domestic manufacturing deduction. The effective income tax rate was 35.8% for the nine months ended September 30, 2013. The effective income tax rate for the 2013 period was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, partially offset by the domestic manufacturing deduction.

Olefins Segment

Net Sales. Net sales increased by $239.4 million, or 12.7%, to $2,124.9 million for the nine months ended September 30, 2014 from $1,885.5 million for the nine months ended September 30, 2013, mainly driven by higher sales prices and sales volumes for most of our major products, partially offset by lower styrene sales volumes. Average sales prices for the Olefins segment increased by 9.8% for the nine months ended September 30, 2014 as compared to the nine months ended September 30, 2013. Average sales volumes for the Olefins segment increased by 2.9% for the nine months ended September 30, 2014 as compared to the nine months ended September 30, 2013.

Income from Operations. Income from operations increased by $184.3 million, or 31.5%, to $770.3 million for the nine months ended September 30, 2014 from $586.0 million for the nine months ended September 30, 2013. This increase was mainly attributable to improved olefins integrated product margins, primarily as a result of the increased ethylene production at our Lake Charles complex after the first quarter 2013 completion of the Petro 2 ethylene unit expansion and its conversion to 100% ethane feedstock capability. In addition, olefins integrated product margins for the nine months ended September 30, 2014 benefited from an increase in sales prices that outpaced increases in feedstock and energy costs as compared to the prior year period. Trading activity for the nine months ended September 30, 2014 resulted in a loss of $7.3 million as compared to a gain of $9.9 million for the prior year period. Income from operations for the nine months ended September 30, 2013 was negatively impacted by the lost production, unabsorbed fixed manufacturing costs and other costs associated with the turnaround and expansion of the Lake Charles Petro 2 ethylene unit.

Vinyls Segment

Net Sales. Net sales increased by $232.2 million, or 25.2%, to $1,154.5 million for the nine months ended September 30, 2014 from $922.3 million for the nine months ended September 30, 2013. This increase was primarily attributable to sales contributed by Vinnolit and our specialty PVC pipe business and higher PVC resin sales prices, partially offset by lower ethylene co-products sales volumes. Ethylene co-products sales volumes were lower for the nine months ended September 30, 2014, as compared to the nine months ended September 30, 2013, primarily due to the planned shut down of our Calvert City ethylene plant as a result of the feedstock conversion and ethylene expansion project and the ethane feedstock currently utilized at our Calvert City ethylene plant following the completion of such project. Average sales prices for the Vinyls segment decreased marginally by 0.2% for the nine months ended September 30, 2014 as compared to the nine months ended September 30, 2013, while average sales volumes increased by 25.3% for the nine months ended September 30, 2014 as compared to the nine months ended September 30, 2013.

Income from Operations. Income from operations decreased by $59.6 million to $76.5 million for the nine months ended September 30, 2014 from $136.1 million for the nine months ended September 30, 2013. This decrease was primarily driven by lost sales, lower production rates and the expensing of $29.5 million related to unabsorbed fixed manufacturing costs and other costs associated with the maintenance turnaround at our Calvert City complex, our Calvert City ethylene plant’s feedstock conversion and expansion project and the unplanned outages at our Calvert City and Geismar complexes. In addition, income from operations for the nine months ended September 30, 2014 was negatively impacted by lower caustic sales prices, the severe winter weather experienced in early 2014 and prior to the completion of the Calvert City ethylene plant’s feedstock conversion and ethylene expansion project, lower vinyls integrated product margins attributable to significantly higher propane costs, as average industry prices for propane increased by 50.2% in the first quarter of 2014 as compared to the prior year period.

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CASH FLOW DISCUSSION FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2014 AND 2013

Cash Flows

Operating Activities

Operating activities provided cash of $776.1 million in the first nine months of 2014 compared to cash provided of $547.5 million in the first nine months of 2013. The $228.6 million increase in cash flows from operating activities was mainly due to an increase in income from operations and a decrease in the use of cash for working capital purposes. Income from operations increased by $125.7 million in the first nine months of 2014 primarily as a result of higher olefins integrated product margins as compared to the prior year period, partially offset by lost sales, lower production rates, unabsorbed fixed manufacturing costs and other costs associated with several planned and unplanned outages at our chemical complexes. Cash flows from operating activities for the first nine months of 2014 was also negatively impacted by WLKP formation and initial public offering costs and costs associated with the Vinnolit acquisition, including the effect of selling higher cost inventory recorded at fair value. Cash flows from operating activities for the first nine months of 2013 were negatively impacted by deferred turnaround costs from the turnaround of one of our Lake Charles ethylene units. Changes in components of working capital, which we define for purposes of this cash flow discussion as accounts receivable, net, inventories, prepaid expenses and other current assets, less accounts payable and accrued liabilities, provided cash of $100.3 million in the first nine months of 2014, compared to $46.5 million of cash used in the first nine months of 2013, a favorable change of $146.8 million. The change was mainly due to a decrease in inventory during the 2014 period as compared to the prior year period, primarily due to less higher-cost propane held in inventory at the end of the current year period, as raw materials or in finished goods, and lower styrene inventory on hand as of September 30, 2014. In addition, Vinnolit's inventory decreased during the period from July 31, 2014 to September 30, 2014 as higher cost inventory recorded at fair value were sold.

Investing Activities

Net cash used for investing activities during the first nine months of 2014 was $652.2 million as compared to net cash used for investing activities of $694.6 million in the first nine months of 2013. Capital expenditures were $311.2 million in the first nine months of 2014 compared to $498.3 million in the first nine months of 2013, a decrease mainly attributable to the completion of the new chlor-alkali plant at our Geismar facility in December 2013. Capital expenditures in the first nine months of 2014 were mainly incurred on the feedstock conversion and ethylene expansion project and PVC plant expansion project at our Calvert City complex and the planned upgrade and expansion of the second ethylene unit at our Lake Charles complex. Capital expenditures in the first nine months of 2013 were mainly incurred on the construction of the new Geismar chlor-alkali plant, the expansion of the first ethylene unit at our Lake Charles complex and the feedstock conversion and ethylene furnaces modernization projects at our Calvert City complex. The remaining capital expenditures in the first nine months of 2014 and 2013 primarily related to projects to improve production capacity or reduce costs, maintenance and safety projects and environmental projects at our various facilities. We used $611.1 million, net of cash acquired, for the acquisition of Vinnolit. Purchases of securities in the first nine months of 2014 totaled $117.3 million and were comprised of corporate and U.S. government debt securities and equity securities. We also received aggregate proceeds of $342.0 million from the sales and maturities of our investments in the first nine months of 2014. The activity during the first nine months of 2013 was primarily related to the acquisition of our specialty PVC pipe business and the purchases of, and the receipt of proceeds from the maturities of, short-term commercial paper.

Financing Activities

Net cash provided by financing activities during the first nine months of 2014 was $231.9 million as compared to net cash used of $51.4 million in the first nine months of 2013. Net proceeds from the issuance of WLKP common units was $286.1 million. The initial public offering represented the sale of 47.8% of common and subordinated units in WLKP. See Note 19 to the unaudited consolidated financial statements within this Quarterly Report on Form 10-Q for further discussion of WLKP and its initial public offering. The remaining activity during the first nine months of 2014 was primarily related to the $55.7 million payment of cash dividends, the $9.5 million of cash used for the repurchases of shares of our common stock and fees incurred in connection with the amendment and restatement of our revolving credit facility in July 2014, partially offset by proceeds of $5.5 million from the exercise of stock options. The activity during the first nine months of 2013 was mainly related to the $40.2 million payment of cash dividends and the $19.4 million of cash used for the repurchases of shares of our common stock, partially offset by proceeds from the exercise of stock options.

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LIQUIDITY AND CAPITAL RESOURCES

Liquidity and Financing Arrangements

Our principal sources of liquidity are from cash and cash equivalents, cash from operations, short-term borrowings under our revolving credit facility and our long-term financing.

In April 2011, we announced an expansion program to increase the ethane-based ethylene capacity of both of the ethylene units at our Lake Charles complex. We completed the expansion of the first ethylene unit in the first quarter of 2013. We currently plan to upgrade and expand the capacity of the other ethylene unit at our Lake Charles complex in the late 2015 to early 2016 time frame. This project is currently estimated to cost in the range of $250.0 million to $310.0 million and will add approximately 250 million pounds of ethylene capacity. The additional capacity from this expansion is expected to provide ethylene for existing internal uses and may also be sold in the merchant market. This capital project is expected to be funded with cash on hand, cash flow from operations, and, if necessary, borrowings under our revolving credit facility and other external financing. As of September 30, 2014, we had incurred a total cost of approximately $40.4 million on this capital project.

In August 2011, our Board of Directors authorized a stock repurchase program totaling $100.0 million. As of September 30, 2014, we had repurchased 1,357,085 shares of our common stock (on a post-split basis) for an aggregate purchase price of approximately $55.7 million under this program. During the three months ended September 30, 2014, we repurchased 104,163 shares of our common stock for an aggregate purchase price of approximately $9.5 million under this program. Purchases under this program may be made either through the open market or in privately negotiated transactions. Decisions regarding the amount and the timing of purchases under the program will be influenced by our cash on hand, our cash flow from operations, general market conditions and other factors. The program may be discontinued by our Board of Directors at any time.

We believe that our sources of liquidity as described above will be adequate to fund our normal operations and ongoing capital expenditures. Funding of any potential large expansions or any potential acquisitions may depend on our ability to obtain additional financing in the future. We may not be able to access additional liquidity at cost effective interest rates due to the volatility of the commercial credit markets.

Cash and Cash Equivalents

As of September 30, 2014, our cash and cash equivalents totaled $813.5 million. In addition, we have a revolving credit facility available to supplement cash if needed, as described under "Debt" below.

Debt

As of September 30, 2014, our long-term debt, including current maturities, totaled $764.0 million, consisting of $250.0 million principal amount of 3.60% senior notes due 2022 (less the unamortized discount of $0.9 million), $100.0 million of 6 ½% senior notes due 2029, $250.0 million of 6 ¾% senior notes due 2032, $89.0 million of 6 ½% senior notes due 2035 (the "6 ½% GO Zone Senior Notes Due 2035"), $65.0 million of 6 ½% senior notes due 2035 (the "6 ½% IKE Zone Senior Notes Due 2035") (collectively, but excluding the 3.60% senior notes due 2022, the "Senior Notes") and a $10.9 million loan from the proceeds of tax-exempt waste disposal revenue bonds (supported by an $11.3 million letter of credit). The 6 ½% senior notes due 2029, the 6 ¾% senior notes due 2032, the 6 ½% GO Zone Senior Notes Due 2035 and the 6 ½% IKE Zone Senior Notes Due 2035 evidence and secure our obligations to the Louisiana Local Government Environmental Facility and Development Authority (the "Authority"), a political subdivision of the State of Louisiana, under four loan agreements relating to the issuance of $100.0 million, $250.0 million, $89.0 million and $65.0 million aggregate principal amount of the Authority's tax-exempt revenue bonds, respectively. As of September 30, 2014, debt outstanding under the tax-exempt waste disposal revenue bonds bore interest at a variable rate. As of September 30, 2014, we were in compliance with all of the covenants with respect to the 3.60% senior notes due 2022, the Senior Notes, our waste disposal revenue bonds and our revolving credit facility.

Our ability to make payments on our indebtedness and to fund planned capital expenditures will depend on our ability to generate cash in the future, which is subject to general economic, financial, competitive, legislative, regulatory and other factors that are beyond our control. Based on our current level of operations, we believe our cash flow from operations, available cash and available borrowings under our revolving credit facility will be adequate to meet our normal operating needs for the foreseeable future.

Revolving Credit Facility

We have a $400.0 million senior secured revolving credit facility. At September 30, 2014, we had no borrowings outstanding under the revolving credit facility.

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In July 2014, we entered into a third amendment and restatement to the revolving credit facility. The third amendment and restatement extended the scheduled maturity date of the facility from September 16, 2016 to July 17, 2019, reduced the interest rate and facility fee payable under the facility and amended the covenants restricting our ability to make distributions and acquisitions and make investments, among other things.

The facility includes a provision permitting us to increase the size of the facility, up to four times, in increments of at least $25.0 million each (up to a maximum of $200.0 million) under certain circumstances if certain lenders agree to commit to such an increase.

Any borrowings under the facility will bear interest at either LIBOR plus a spread ranging from 1.75% to 1.25%, provided that so long as we are rated investment grade, the margin for LIBOR loans will not exceed 1.50%, or a base rate plus a spread ranging from 0.50% to 0.00%. The revolving credit facility also requires an unused commitment fee of 0.25% per annum. All interest rates under the facility are subject to monthly grid pricing adjustments based on prior month average daily loan availability. The revolving credit facility matures on July 17, 2019. As of September 30, 2014, we had outstanding letters of credit totaling $32.4 million and borrowing availability of $367.6 million under the revolving credit facility.

Our revolving credit facility generally restricts our ability to make distributions unless, on a pro forma basis after giving effect to the distribution, the borrowing availability under the facility equals or exceeds the greater of (1) 20% of the commitments under the facility and (2) $80.0 million; or the borrowing availability under the facility equals or exceeds the greater of (1) 15% of the commitments under the facility and (2) $60.0 million, and our fixed charge coverage ratio is at least 1.0:1. However, we may make specified distributions up to an aggregate of $75.0 million, to be increased by 5% in 2015, and in each fiscal year thereafter, on an aggregate basis, for each fiscal year.

In order to make acquisitions or investments, our revolving credit facility generally provides that (1) we must maintain a minimum borrowing availability of at least the greater of $60.0 million or 15% of the total bank commitments under our revolving credit facility or (2) we must maintain a minimum borrowing availability of at least the greater of $50.0 million or 12.5% of the total bank commitments under our revolving credit facility and meet a minimum fixed charge coverage ratio of 1.0:1 under our revolving credit facility. Notwithstanding the foregoing, we may make investments in the aggregate up to the greater of $50.0 million and 1.25% of tangible assets and acquisitions in the aggregate up to the greater of $100.0 million and 2.5% of tangible assets, if, on a pro forma basis after giving effect to the acquisition or investment, either (X) the borrowing availability under the facility equals or exceeds the greater of (A) 12.5% of the total bank commitments under the facility and (B) $50.0 million, but is less than the greater of (A) 15% of the total bank commitments and (B) $60.0 million, or (Y) our fixed charge coverage ratio is at least 1.0:1.

The revolving credit facility contains other customary covenants and events of default that impose significant operating and financial restrictions on us. These restrictions, among other things, provide limitations on the occurrence of additional indebtedness and our ability to create liens, to engage in certain affiliate transactions and to engage in sale-leaseback transactions. See our Current Report on Form 8-K filed with the SEC on July 17, 2014 for more information on the third amendment and restatement of our revolving credit facility.

GO Zone and IKE Zone Bonds

As of September 30, 2014, we had drawn all the proceeds from the issuance of the 6 ½% senior notes due 2029, 6 ¾% senior notes due 2032, 6 ½% GO Zone Senior Notes Due 2035 and 6 ½% IKE Zone Senior Notes Due 2035. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Debt" in the 2013 Form 10-K for more information on the 6 ½% senior notes due 2029, the 6 ¾% senior notes due 2032, the 6 ½% GO Zone Senior Notes Due 2035 and the 6 ½% IKE Zone Senior Notes Due 2035. All domestic restricted subsidiaries that guarantee other debt of ours or of another guarantor of the Senior Notes in excess of $5.0 million are guarantors of these notes.

The indentures governing the Senior Notes contain customary covenants and events of default. Accordingly, these agreements generally impose significant operating and financial restrictions on us. These restrictions, among other things, provide limitations on incurrence of additional indebtedness, the payment of dividends, certain investments and acquisitions and sales of assets. However, the effectiveness of certain of these restrictions is currently suspended because the Senior Notes are currently rated investment grade by at least two nationally recognized credit rating agencies. The most significant of these provisions, if it were currently effective, would restrict us from incurring additional debt, except specified permitted debt (including borrowings under our credit facility), when our fixed charge coverage ratio is below 2.0:1. These limitations are subject to a number of important qualifications and exceptions, including, without limitation, an exception for the payment of our regular quarterly dividend of up to $0.10 per share. If the restrictions were currently effective, distributions in excess of $100.0 million would not be allowed unless, after giving pro forma effect to the distribution, our fixed charge coverage ratio is at least 2.0:1 and such payment, together with the aggregate amount of all other distributions after January 13, 2006, is less than

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the sum of 50% of our consolidated net income for the period from October 1, 2003 to the end of the most recent quarter for which financial statements have been filed, plus 100% of net cash proceeds received after October 1, 2003 as a contribution to our common equity capital or from the issuance or sale of certain securities, plus several other adjustments.

3.60% Senior Notes due 2022

The 3.60% senior notes due 2022 are unsecured and were issued with an original issue discount of $1.2 million. There is no sinking fund and no scheduled amortization of the 3.60% senior notes due 2022 prior to maturity. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Debt" in the 2013 Form 10-K for more information on the 3.60% senior notes due 2022. All of our domestic subsidiaries that guarantee other indebtedness of ours or of another guarantor of the 3.60% senior notes due 2022 in excess of $5.0 million are guarantors of the 3.60% senior notes due 2022.

The indenture governing the 3.60% senior notes due 2022 contains customary events of default and covenants that will restrict our and certain of our 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 our assets.

Revenue Bonds

In December 1997, we entered into a loan agreement with a public trust established for public purposes for the benefit of the Parish of Calcasieu, Louisiana. The public trust issued $10.9 million principal amount of tax-exempt waste disposal revenue bonds in order to finance our construction of waste disposal facilities for an ethylene plant. The waste disposal revenue bonds expire in December 2027 and are subject to redemption and mandatory tender for purchase prior to maturity under certain conditions. Interest on the waste disposal revenue bonds accrues at a rate determined by a remarketing agent and is payable quarterly.

Off-Balance Sheet Arrangements

None.

FORWARD-LOOKING STATEMENTS

The Private Securities Litigation Reform Act of 1995 provides safe harbor provisions for forward-looking information. Certain of the statements contained in this report are forward-looking statements. All statements, other than statements of historical facts, included in this report that address activities, events or developments that we expect, project, believe or anticipate will or may occur in the future are forward-looking statements. Forward-looking statements can be identified by the use of words such as "believes," "intends," "may," "should," "could," "anticipates," "expected" or comparable terminology, or by discussions of strategies or trends. Although we believe that the expectations reflected in such forward-looking statements are reasonable, we cannot give any assurances that these expectations will prove to be correct. Forward-looking statements relate to matters such as:

• future operating rates, margins, cash flow and demand for our products;

• industry market outlook, including the price of crude oil;

• production capacities;

• our ability to borrow additional funds under our credit facility;

• our ability to meet our liquidity needs;

• our intended quarterly dividends;

• future capacity additions and expansions in the industry;

• timing, funding and results of the expansion program at our Lake Charles complex;

• results of the new chlor-alkali plant in Geismar;

• results of the feedstock conversion program at our Calvert City ethylene plant;

• results of the Vinnolit acquisition;

• estimated annual tax rate for the year 2014;

• pension plan funding requirements and investment policies;

• compliance with present and future environmental regulations and costs associated with environmentally related penalties, capital expenditures, remedial actions and proceedings, including any new laws, regulations or treaties

40

that may come into force to limit or control carbon dioxide and other greenhouse gases emissions or to address other issues of climate change;

• effects of pending legal proceedings; and

• timing of and amount of capital expenditures.

We have based these statements on assumptions and analyses in light of our experience and perception of historical trends, current conditions, expected future developments and other factors we believe were appropriate in the circumstances when the statements were made. Forward-looking statements by their nature involve substantial risks and uncertainties that could significantly impact expected results, and actual future results could differ materially from those described in such statements. These statements are subject to a number of assumptions, risks and uncertainties, including those described in "Risk Factors" in the 2013 Form 10-K and the following:

• general economic and business conditions;

• the cyclical nature of the chemical industry;

• the availability, cost and volatility of raw materials and energy;

• uncertainties associated with the United States and worldwide economies, including those due to political tensions in the Middle East and elsewhere;

• current and potential governmental regulatory actions in the United States and regulatory actions and political unrest in other countries;

• industry production capacity and operating rates;

• the supply/demand balance for our products;

• competitive products and pricing pressures;

• instability in the credit and financial markets;

• access to capital markets;

• terrorist acts;

• operating interruptions (including leaks, explosions, fires, weather-related incidents, mechanical failure, unscheduled downtime, labor difficulties, transportation interruptions, spills and releases and other environmental risks);

• changes in laws or regulations;

• technological developments;

• our ability to integrate acquired businesses;

• foreign currency exchange risks;

• our ability to implement our business strategies; and

• creditworthiness of our customers.

Many of these factors are beyond our ability to control or predict. Any of the factors, or a combination of these factors, could materially affect our future results of operations and the ultimate accuracy of the forward-looking statements. These forward-looking statements are not guarantees of our future performance, and our actual results and future developments may differ materially from those projected in the forward-looking statements. Management cautions against putting undue reliance on forward-looking statements or projecting any future results based on such statements or present or prior earnings levels. Every forward-looking statement speaks only as of the date of the particular statement, and we undertake no obligation to publicly update or revise any forward-looking statements.

Item 3. Quantitative and Qualitative Disclosures about Market Risk

Commodity Price Risk

A substantial portion of our products and raw materials are commodities whose prices fluctuate as market supply and demand fundamentals change. Accordingly, product margins and the level of our profitability tend to fluctuate with changes in the business cycle. We try to protect against such instability through various business strategies. Our strategies include ethylene feedstock flexibility and moving downstream into the olefins and vinyls products where pricing is more stable. We use derivative instruments in certain instances to reduce price volatility risk on feedstocks and products. Based on our open derivative positions at September 30, 2014, a hypothetical $0.10 increase in the price of a gallon of ethane would have

41

increased our income before taxes by $8.4 million and a hypothetical $0.10 increase in the price of a pound of ethylene would have decreased our income before taxes by $3.0 million. Additional information concerning derivative commodity instruments appears in Notes 9 and 10 to the unaudited consolidated financial statements within this Quarterly Report on Form 10-Q.

Interest Rate Risk

We are exposed to interest rate risk with respect to fixed and variable rate debt. At September 30, 2014, we had variable rate debt of $10.9 million outstanding. All of the debt outstanding under our revolving credit facility (none was outstanding at September 30, 2014) and our loan relating to the tax-exempt waste disposal revenue bonds are at variable rates. We do not currently hedge our variable interest rate debt, but we may do so in the future. The average variable interest rate for our variable rate debt of $10.9 million as of September 30, 2014 was 0.06%. A hypothetical 100 basis point increase in the average interest rate on our variable rate debt would increase our annual interest expense by approximately $0.1 million. Also, at September 30, 2014, we had $754.0 million aggregate principal amount of fixed rate debt. We are subject to the risk of higher interest cost if and when this debt is refinanced. If interest rates are 1% higher at the time of refinancing, our annual interest expense would increase by approximately $7.5 million.

Foreign Currency Exchange Rate Risk

We are exposed to foreign currency exchange rate risk associated with our international operations. However, the effect of fluctuations in foreign currency exchange rates caused by our international operations has not had a material impact on our overall operating results. We may engage in activities to mitigate our exposure to foreign currency exchange risk in certain instances through the use of currency exchange derivative instruments, including forward exchange contracts, or spot purchases. A forward exchange contract obligates us to exchange predetermined amounts of specified currencies at a stated exchange rate on a stated date.

Item 4. Controls and Procedures

We carried out an evaluation, under the supervision and with the participation of our management, including our President and Chief Executive Officer and our Senior Vice President, Chief Financial Officer and Treasurer, of the effectiveness of our disclosure controls and procedures pursuant to Rules 13a-15 or 15d-15 under the Securities Exchange Act of 1934 as of the end of the period covered by this report. Based upon that evaluation, our President and Chief Executive Officer and our Senior Vice President, Chief Financial Officer and Treasurer concluded that our disclosure controls and procedures are effective with respect to (i) the accumulation and communication to our management, including our Chief Executive Officer and our Chief Financial Officer, of information required to be disclosed by us in the reports that we submit under the Exchange Act, and (ii) the recording, processing, summarizing and reporting of such information within the time periods specified in the SEC's rules and forms.

There were no changes in our internal control over financial reporting that occurred during the three months ended September 30, 2014 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

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PART II. OTHER INFORMATION

Item 1. Legal Proceedings

The 2013 Form 10-K, filed on February 21, 2014, contained a description of various legal proceedings in which we are involved, including environmental proceedings at our facilities in Calvert City. See Note 15 to the unaudited consolidated financial statements within this Quarterly Report on Form 10-Q for a description of certain of those proceedings, which information is incorporated by reference herein.

Item 1A. Risk Factors

For a discussion of risk factors, please read Item 1A, "Risk Factors" in the 2013 Form 10-K and in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2014. There have been no material changes from those risk factors.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

The following table provides information on our purchase of equity securities during the quarter ended September 30, 2014, on a post-split basis.

Period	Total Number of Shares Purchased (1)	Average Price Paid Per Share		Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs (1)	Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs (1)
July 2014	—	$	—	—	$	53,780,000
August 2014	—	$	—	—	$	53,780,000
September 2014	104,163	$	91.16	104,163	$	44,285,000
	104,163	$	91.16	104,163

_____________

(1) On August 22, 2011, we announced the authorization by our Board of Directors of a $100.0 million stock repurchase program. As of September 30, 2014, 1,357,085 shares of common stock (on a post-split basis) had been acquired at an aggregate purchase price of $55.7 million. Decisions regarding the amount and the timing of purchases under the program will be influenced by our cash on hand, our cash flow from operations, general market conditions and other factors. The program may be discontinued by our Board of Directors at any time.

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Item 6. Exhibits

Exhibit No.
4.1	Supplemental Indenture dated as of July 17, 2014 among Westlake Chemical OpCo LP, Westlake Chemical Corporation, the other Subsidiary Guarantors (as defined therein) and The Bank of New York Mellon Trust Company, N.A., as trustee (incorporated by reference to Westlake Chemical Corporation’s Quarterly Report on Form 10-Q, filed on August 6, 2014, File No. 001-32260).
10.1	Third Amended and Restated Credit Agreement dated as of July 17, 2014 by and among the financial institutions party thereto, as lenders, Bank of America, N.A., as agent, and Westlake Chemical Corporation and certain of its domestic subsidiaries, as borrowers, relating to a $400.0 million senior secured revolving credit facility (incorporated by reference to Westlake Chemical Corporation’s Current Report on Form 8-K, filed on July 17, 2014, File No. 001-32260).
31.1	Rule 13a – 14(a) / 15d – 14(a) Certification (Principal Executive Officer)
31.2	Rule 13a – 14(a) / 15d – 14(a) Certification (Principal Financial Officer)
32.1	Section 1350 Certification (Principal Executive Officer and Principal Financial Officer)
99.1	Unaudited Financial Statements of Non Wholly-Owned Subsidiary Guarantor (Westlake Chemical OpCo LP)
101.INS	XBRL Instance Document
101.SCH	XBRL Taxonomy Extension Schema Document
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB	XBRL Taxonomy Extension Label Linkbase Document
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

		WESTLAKE CHEMICAL CORPORATION
Date:	November 7, 2014	By:	/S/    ALBERT CHAO
			Albert Chao
			President and Chief Executive Officer (Principal Executive Officer)
Date:	November 7, 2014	By:	/S/    M. STEVEN BENDER
			M. Steven Bender
			Senior Vice President, Chief Financial Officer and Treasurer (Principal Financial Officer)

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EXHIBIT INDEX

Exhibit No.	Exhibit
4.1	Supplemental Indenture dated as of July 17, 2014 among Westlake Chemical OpCo LP, Westlake Chemical Corporation, the other Subsidiary Guarantors (as defined therein) and The Bank of New York Mellon Trust Company, N.A., as trustee (incorporated by reference to Westlake Chemical Corporation’s Quarterly Report on Form 10-Q, filed on August 6, 2014, File No. 001-32260).
10.1	Third Amended and Restated Credit Agreement dated as of July 17, 2014 by and among the financial institutions party thereto, as lenders, Bank of America, N.A., as agent, and Westlake Chemical Corporation and certain of its domestic subsidiaries, as borrowers, relating to a $400.0 million senior secured revolving credit facility (incorporated by reference to Westlake Chemical Corporation’s Current Report on Form 8-K, filed on July 17, 2014, File No. 001-32260).
31.1	Rule 13a – 14(a) / 15d – 14(a) Certification (Principal Executive Officer)
31.2	Rule 13a – 14(a) / 15d – 14(a) Certification (Principal Financial Officer)
32.1	Section 1350 Certification (Principal Executive Officer and Principal Financial Officer)
99.1	Unaudited Financial Statements of Non Wholly-Owned Subsidiary Guarantor (Westlake Chemical OpCo LP)
101.INS	XBRL Instance Document
101.SCH	XBRL Taxonomy Extension Schema Document
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB	XBRL Taxonomy Extension Label Linkbase Document
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document

46

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, Albert Chao, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Westlake Chemical Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:	November 7, 2014	/S/    ALBERT CHAO
		Albert Chao
		President and Chief Executive Officer (Principal Executive Officer)

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, M. Steven Bender, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Westlake Chemical Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:	November 7, 2014	/S/ M. STEVEN BENDER
		M. Steven Bender
		Senior Vice President, Chief Financial Officer and Treasurer (Principal Financial Officer)

EX-32.1

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Westlake Chemical Corporation (the "Company") on Form 10-Q for the fiscal quarter ended September 30, 2014 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Albert Chao, President and Chief Executive Officer of the Company, and I, M. Steven Bender, Senior Vice President, Chief Financial Officer and Treasurer of the Company, certify, to the best of our knowledge, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material aspects, the financial condition and results of operations of the Company.

Date:	November 7, 2014	/S/    ALBERT CHAO
		Albert Chao
		President and Chief Executive Officer (Principal Executive Officer)
Date:	November 7, 2014	/S/    M. STEVEN BENDER
		M. Steven Bender
		Senior Vice President, Chief Financial Officer and Treasurer (Principal Financial Officer)

EX-99.1

Exhibit 99.1

Westlake Chemical OpCo LP

Combined Financial Statements for the quarterly period ended September 30, 2014

WESTLAKE CHEMICAL OPCO LP

COMBINED BALANCE SHEETS

(Unaudited)

	September 30, 2014		December 31, 2013
			Predecessor
	(in thousands of dollars)
ASSETS
Current assets
Cash and cash equivalents	$	89,144	$	—
Accounts receivable, net—Westlake	28,500		—
Accounts receivable, net—third parties	29,606		71,812
Inventories	5,551		116,377
Prepaid expenses and other current assets	303		257
Deferred income taxes	—		4,448
Total current assets	153,104		192,894
Property, plant and equipment, net	806,648		762,972
Equity investment	—		10,411
Other assets, net
Goodwill and intangible assets, net	5,814		5,873
Deferred charges and other assets, net	55,865		69,324
Total other assets, net	61,679		75,197
Total assets	$	1,021,431	$	1,041,474
LIABILITIES
Current liabilities
Accounts payable—Westlake	$	17,029	$	—
Accounts payable—third parties	12,827		122,564
Accrued liabilities	3,412		26,688
Total current liabilities	33,268		149,252
Long-term debt payable to Westlake	188,523		252,973
Deferred income taxes	1,507		182,855
Other liabilities	—		962
Total liabilities	223,298		586,042
Commitments and contingencies (Notes 9 and 15)
EQUITY
Net investment	—		455,432
Limited partners interest—Westlake	471,142		—
Limited partner interest—Westlake Chemical Partners LP	326,991		—
Total equity	798,133		455,432
Total liabilities and equity	$	1,021,431	$	1,041,474

The accompanying notes are an integral part of the combined financial statements.

1

WESTLAKE CHEMICAL OPCO LP

COMBINED STATEMENTS OF OPERATIONS

(Unaudited)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
				Predecessor						Predecessor
	(in thousands of dollars)
Revenue
Net sales—Westlake	$	289,601		$	391,801		$	1,088,561		$	1,195,870
Net co-product, ethylene and feedstock    sales—third parties	102,407			148,332			387,596			369,939
Total net sales	392,008			540,133			1,476,157			1,565,809
Cost of sales	227,015			327,152			832,304			924,663
Gross profit	164,993			212,981			643,853			641,146
Selling, general and administrative expenses	8,014			6,391			21,957			19,326
Income from operations	156,979			206,590			621,896			621,820
Other income (expense)
Interest expense—Westlake	(2,137		)	(2,295		)	(9,833		)	(4,893		)
Other income, net	486			1,162			3,135			6,422
Income before income taxes	155,328			205,457			615,198			623,349
Provision for income taxes	36,309			72,876			198,461			221,009
Net income	$	119,019		$	132,581		$	416,737		$	402,340
Less: Predecessor net income prior to initial public    offering on August 4, 2014	63,616						361,334
Net income subsequent to initial public offering	$	55,403					$	55,403

The accompanying notes are an integral part of the combined financial statements.

2

WESTLAKE CHEMICAL OPCO LP

COMBINED STATEMENTS OF CHANGES IN EQUITY

(Unaudited)

	Predecessor			Westlake Chemical OpCo LP
	Net Investment			Limited Partners Interest - Westlake			Limited Partner Interest - Westlake Chemical Partners LP		Total
	(in thousands of dollars)
Balance as of December 31, 2012	$	273,812		$	—		$	—	$	273,812
Contribution of debt payable to parent into net    investment	238,600			—			—		238,600
Net income from January 1, 2013 through    September 30, 2013	402,340			—			—		402,340
Net distributions to Westlake	(421,991		)	—			—		(421,991		)
Balance as of September 30, 2013	$	492,761		$	—		$	—	$	492,761
Balance as of December 31, 2013	$	455,432		$	—		$	—	$	455,432
Net income from January 1, 2014 through    August 3, 2014	361,334			—			—		361,334
Net distributions to Westlake prior to initial public    offering	(448,101		)	—			—		(448,101		)
Predecessor net liabilities not assumed by OpCo	239,706			—			—		239,706
Balance as of August 4, 2014 (prior to initial public offering)	608,371			—			—		608,371
Allocation of net investment to partners' capital	(608,371		)	573,329			35,042		—
Capital contribution from Westlake Chemical Partners LP	—			—			286,088		286,088
Proceeds from capital contribution from Westlake    Chemical Partners LP distributed to Westlake	—			(151,729		)	—		(151,729		)
Net income from August 4, 2014 through    September 30, 2014	—			49,542			5,861		55,403
Balance as of September 30, 2014	$	—		$	471,142		$	326,991	$	798,133

The accompanying notes are an integral part of the combined financial statements.

3

WESTLAKE CHEMICAL OPCO LP

COMBINED STATEMENTS OF CASH FLOWS

(Unaudited)

	Nine Months Ended September 30,
	2014			2013
				Predecessor
	(in thousands of dollars)
Cash flows from operating activities
Net income	$	416,737		$	402,340
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	58,501			54,539
Provision for (recovery of) doubtful accounts	65			(66		)
Loss from disposition of fixed assets	1,244			1,892
Deferred income taxes	8,267			27,253
Equity in income of joint venture, net of dividends	1,073			84
Changes in operating assets and liabilities
Accounts receivable	(23,637		)	22,745
Net accounts receivable—Westlake	(11,471		)	—
Inventories	25,769			(22,216		)
Prepaid expenses and other current assets	(715		)	(346		)
Accounts payable	(8,226		)	7,595
Accrued and other liabilities	7,041			(23,730		)
Other, net	10,498			(54,562		)
Net cash provided by operating activities	485,146			415,528
Cash flows from investing activities
Additions to property, plant and equipment	(144,348		)	(158,869		)
Settlements of derivative instruments	(133		)	(2,297		)
Net cash used for investing activities	(144,481		)	(161,166		)
Cash flows from financing activities
Proceeds from debt payable to Westlake	141,161			167,629
Repayment of debt payable to Westlake with proceeds from    the capital contribution from Westlake Chemical Partners LP	(78,940		)	—
Capital contribution from Westlake Chemical Partners LP	286,088			—
Proceeds from capital contribution from Westlake Chemical Partners LP    distributed to Westlake	(151,729		)	—
Net distributions to Westlake prior to initial public offering	(448,101		)	(421,991		)
Net cash used for financing activities	(251,521		)	(254,362		)
Net change in cash	89,144			—
Cash at beginning of period	—			—
Cash at end of period	$	89,144		$	—

The accompanying notes are an integral part of the combined financial statements.

4

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS

(Unaudited)

(in thousands of dollars)

1. Business and Basis of Presentation

Description of Business

Westlake Chemical OpCo LP ("OpCo") was formed on May 6, 2014 by Westlake. On August 4, 2014, Westlake Chemical Partners LP (the "Partnership" or "WLKP"), a Delaware limited partnership formed in March 2014, completed its initial public offering ("IPO") of 12,937,500 common units representing limited partner interests in the Partnership. In connection with the IPO, the Partnership acquired a 10.6% limited partner interest in OpCo and a 100% interest in Westlake Chemical OpCo GP LLC ("OpCo GP"), which is the general partner of OpCo. OpCo owns three ethylene production facilities and a common carrier ethylene pipeline (collectively, the "Contributed Assets").

Unless the context otherwise requires, references in this report to the "Predecessor" refer to Westlake Chemical Partners LP Predecessor, the Partnership's and OpCo's predecessor for accounting purposes and refer to the time periods prior to the IPO. References in this report to OpCo used in the present tense or prospectively refer to the periods subsequent to the IPO. References to "Westlake" refer collectively to Westlake Chemical Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP.

Prior to the IPO, the Predecessor generated revenue predominantly by selling ethylene and ethylene co-products to Westlake and external customers. The Predecessor typically shipped ethylene, propylene and hydrogen via pipeline systems that connected its ethylene plants to Westlake and numerous third-party customers. The Predecessor transported its butadiene and pyrolysis gasoline by rail or truck.

At the closing of the IPO, OpCo and Westlake entered into an ethylene sales agreement (the "Ethylene Sales Agreement") pursuant to which OpCo generates a substantial majority of its revenue. The Ethylene Sales Agreement has a 12-year initial term and a minimum commitment provision under which Westlake has agreed to purchase 95% of OpCo’s planned ethylene production each year, subject to a maximum of 3.8 billion pounds per year. This agreement represents a long-term minimum purchase commitment by Westlake with variable pricing equal to OpCo’s actual feedstock and natural gas costs and estimated other costs of producing ethylene, plus a fixed margin of $0.10 per pound, less revenue from associated co-product sales. Currently, OpCo expects to sell 95% of its ethylene production to Westlake.

OpCo sells ethylene production in excess of volumes sold to Westlake, as well as all of the co-products resulting from the ethylene production, including propylene, crude butadiene, pyrolysis gasoline and hydrogen, directly to third parties on either a spot or contract basis. Co-products sold to third parties continue to be transported by rail or truck. Net proceeds (after transportation and other costs) from the sales of associated co-products that result from the production of ethylene purchased by Westlake are netted against the ethylene price charged to Westlake under the Ethylene Sales Agreement thereby substantially reducing OpCo's exposure to fluctuations in the market prices of these co-products. OpCo’s operations consist of one reportable segment: ethylene production.

The Predecessor’s operations consisted of the entire ethylene business of Westlake, including the activities of the Contributed Assets, as well as activities which were retained by Westlake. Ethylene business activities retained by Westlake include, but are not limited to, procuring feedstock, managing inventory and commodity risk and transporting ethylene from manufacturing facilities. OpCo’s operations consist of activities of only the Contributed Assets.

Basis of Presentation

Financial information presented for the periods prior to the IPO on August 4, 2014 consists of the Predecessor's combined financial position as of December 31, 2013, its results of operations for the three and nine months periods ended September 30, 2013 and cash flows for the nine months ended September 30, 2013. Financial information of the Predecessor is derived from the financial statements and accounting records of Westlake. Subsequent to the IPO, OpCo's financial position, results of operations and cash flows consist of the activities and balances of OpCo.

For the three and nine months ended September 30, 2014, the results of operations and changes in cash position include OpCo's results subsequent to the IPO and the Predecessor’s combined results prior to the IPO. For these periods, the results of operations and changes in cash flows are referred to as OpCo's results and changes in cash flows.

5

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

The accompanying unaudited interim combined 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 combined financial statements should be read in conjunction with the combined carve-out financial statements and notes thereto of the Predecessor for the fiscal year ended December 31, 2013 included in the WLKP's prospectus dated July 29, 2014 (File No. 333-195551) (the "WLKP Prospectus"), as filed with the SEC on July 31, 2014. These combined financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the combined financial statements of the Predecessor for the fiscal year ended December 31, 2013.

All financial information presented for the periods after the IPO represents the results of operations, financial position and cash flows of OpCo. Financial information for the periods prior to the IPO represent the combined results of operations, financial position and cash flows of the Predecessor. The combined financial statements were prepared as follows:

• The statement of operations for the three months ended September 30, 2014 consists of the results of OpCo for the period from August 4, 2014 through September 30, 2014 and the combined results of the Predecessor for the period from July 1, 2014 through August 3, 2014. The statement of operations for the nine months ended September 30, 2014 consists of the results of OpCo for the period from August 4, 2014 through September 30, 2014 and the combined results of the Predecessor for the period from January 1, 2014 through August 3, 2014. The statements of operations for the three and nine months ended September 30, 2013 consist entirely of the combined results of the Predecessor.

• The balance sheet as of September 30, 2014 consists of the balances of OpCo, while the combined balance sheet as of December 31, 2013 consists of the combined balances of the Predecessor.

• The statement of cash flows for the nine months ended September 30, 2014 consists of the results of OpCo for the period from August 4, 2014 through September 30, 2014 and the combined results of the Predecessor for the period from January 1, 2014 through August 3, 2014. The combined statement of cash flows for the nine months ended September 30, 2013 consists entirely of the combined results of the Predecessor.

• The statement of changes in equity for the nine months ended September 30, 2014 consists of the combined activity for the Predecessor prior to August 4, 2014, and the activity for OpCo during and subsequent to the IPO on August 4, 2014. The combined statement of changes in equity for the nine months ended September 30, 2013 consists entirely of the combined activity of the Predecessor.

In the opinion of management, the accompanying unaudited combined financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Predecessor's combined financial statements as of and for the periods ended September 30, 2013 and OpCo’s financial statements as of and for the periods ended September 30, 2014.

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, 2014 or any other 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 materially from those estimates.

The combined statements of operations for the periods before August 4, 2014 include expense allocations for certain functions historically performed by Westlake and allocated to the ethylene business, including allocations of general corporate expenses related to finance, legal, information technology, human resources, communications, ethics and compliance, shared services, employee benefits and incentives and stock-based compensation. These allocations were based primarily on the basis of direct usage when identifiable, with the remainder allocated on the basis of fixed assets, headcount or other measure. Management believes the assumptions underlying the combined financial statements, including the assumptions regarding the allocation of expenses from Westlake, are reasonable and reflect all costs related to the operations of the Predecessor, including those incurred by Westlake on behalf of the Predecessor. Nevertheless, the combined financial statements may not include all of the expenses that would have been incurred had the Predecessor been a stand-alone company during the periods presented and may not reflect its results of operations, financial position and cash flows had the Predecessor been a stand-alone company during the periods presented.

With respect to the Predecessor, Westlake used a centralized approach to the cash management and financing of its operations. The cash generated by the Predecessor’s operations was transferred to Westlake daily, and Westlake funded the Predecessor’s operating and investing activities as needed. Accordingly, the cash and cash equivalents generated by the

6

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

Predecessor’s operations that were held by Westlake were not presented in its combined financial statements for any of the periods presented. The Predecessor reflected transfers of cash to and from Westlake's cash management system as a component of "Net investment" on its combined balance sheet, and as part of "Net distributions to Westlake" on its combined statements of cash flows.

2. WLKP's Initial Public Offering

Contributed Assets

In connection with the IPO, the Partnership acquired a 10.6% limited partner interest in OpCo and a 100% interest in OpCo GP. OpCo owns the Contributed Assets, as described in more detail in the WLKP Prospectus.

Other assets contributed to OpCo in conjunction with the IPO include the deferred turnaround costs associated with Lake Charles Olefins and Calvert City Olefins, co-product inventories, goodwill and other assets. Additionally, OpCo assumed $246,056 of promissory notes payable to Westlake.

The Predecessor's combined financial statements reflect certain assets, liabilities and business activities that were retained by Westlake, and therefore are not reflected in OpCo's financial statements. Assets and liabilities which are reflected in the Predecessor's combined financial statements but which were retained by Westlake include working capital accounts, ethylene and other inventories, an equity interest in a pipeline joint venture, deferred federal income taxes, certain long-term debt payable to Westlake and other long-term liabilities. Ethylene business activities retained by Westlake include, but are not limited to, procuring feedstock, managing inventory and commodity risk and transporting ethylene from manufacturing facilities. See Note 13 for details of the Predecessor's net liabilities retained by Westlake.

Initial Public Offering

On July 30, 2014, WLKP’s common units began trading on the New York Stock Exchange under the ticker symbol "WLKP." On August 4, 2014, the Partnership closed its IPO of 12,937,500 common units at a price to the public of $24.00 per unit ($22.53 per unit net of underwriting discount), including the 1,687,500 common units that were issued pursuant to the exercise in full of the underwriters' over-allotment option as described in the WLKP Prospectus.

In connection with the closing of the IPO, in exchange for Westlake’s contribution of a 5.8% limited partner interest in OpCo and OpCo's general partner interest to the Partnership, Westlake received:

• 1,436,115 common units and 12,686,115 subordinated units, representing an aggregate 52.2% limited partner interest in the Partnership; and

• the Partnership's general partner interest and its incentive distribution rights.

The Partnership received net proceeds of $286,088 from the IPO, net of underwriting discounts, structuring fees and offering expenses of approximately $24,412. The Partnership used the net proceeds from the IPO to purchase an additional 4.8% limited partner interest in OpCo, resulting in the Partnership owning a 10.6% limited partner interest in OpCo.

From the period beginning August 4, 2012 to July 31, 2013, Westlake incurred approximately $151,729 in capital expenditures (the "Pre-August 2013 Capex") with respect to the assets contributed to OpCo. The portion of these capital expenditures incurred before January 1, 2013 was accounted for as an adjustment to Net investment, as it was funded through equity. The portion of the capital expenditures incurred from January 1, 2013 through July 31, 2013 was accounted for as a liability and is reflected as such on the Predecessor’s combined financial statements and the associated liability was retained by Westlake in connection with the closing of the IPO. During the period from August 1, 2013 through August 3, 2014, Westlake funded capital expenditures of $246,056 related to the Contributed Assets under the terms of the intercompany notes that OpCo assumed in connection with the IPO (the "August 2013 Promissory Notes"). At the close of the IPO, the outstanding balance of the August 2013 Promissory Notes was $246,056.

OpCo used the $286,088 it received from the Partnership in exchange for a 4.8% limited partner interest in OpCo to (i) establish a $55,419 turnaround reserve, (ii) reimburse $151,729 to Westlake for the Pre-August 2013 Capex, and (iii) repay $78,940 of the August 2013 Promissory Notes it assumed. Immediately after the repayment, the outstanding indebtedness payable to Westlake under the August 2013 Promissory Notes was $167,116.

7

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

Agreements with Westlake and Related Parties

The agreements described below became effective on August 4, 2014, concurrent with the closing of the IPO.

Ethylene Sales Agreement

OpCo entered into a 12-year ethylene sales agreement with Westlake (the "Ethylene Sales Agreement"). The Ethylene Sales Agreement requires Westlake to purchase a minimum volume of ethylene each year equal to 95% of OpCo’s planned ethylene production per year (the "Minimum Commitment"), subject to certain exceptions and a maximum commitment of 3.8 billion pounds per year. So long as Westlake is not in default under the Ethylene Sales Agreement, if OpCo’s actual production exceeds planned production, Westlake has the option to purchase up to 95% of the excess production (the "Excess Production Option").

The fee for each pound of ethylene purchased by Westlake from OpCo up to the Minimum Commitment in any calendar year will equal:

• the actual price OpCo pays Westlake to purchase ethane (or other feedstock, such as propane, if applicable) to produce each pound of ethylene, subject to a specified cap and a floor on the amount of feedstock that should be needed to produce each pound of ethylene; plus

• the actual price OpCo pays Westlake to purchase natural gas to produce each pound of ethylene, subject to a specified cap and a floor on the amount of natural gas that should be needed to produce each pound of ethylene; plus

• OpCo’s estimated operating costs (including selling, general and administrative expenses), divided by OpCo’s planned ethylene production for the year (in pounds); plus

• a five-year average of OpCo’s expected future maintenance capital expenditures and other turnaround expenditures, divided by OpCo’s planned ethylene production capacity for the year (in pounds); less

• the proceeds (on a per pound of ethylene basis) received by OpCo from the sale of co-products (including, but not limited to, propylene, crude butadiene, pyrolysis gasoline and hydrogen) associated with producing the ethylene purchased by Westlake; plus

• a $0.10 per pound margin.

The fee for the Excess Production Option, if exercised, equals OpCo’s estimated variable operating costs of producing the incremental ethylene, net of revenues from co-product sales plus a $0.10 per pound margin.

The estimated operating costs and expected future maintenance capital expenditures and other turnaround expenditures will be adjusted at the end of each year, to be applicable for the fee for the next calendar year, to reflect certain changes in forecasted costs.

The result of the fee structure is that OpCo should recover the portion of its total operating costs and maintenance capital expenditures and other turnaround expenditures corresponding to the portion of OpCo’s aggregate production that is purchased by Westlake. The Ethylene Sales Agreement has an initial term extending until December 31, 2026 and automatically renews thereafter for successive 12-month terms unless terminated.

Feedstock Supply Agreement

OpCo entered into a feedstock supply agreement with Westlake, pursuant to which Westlake agrees to sell to OpCo ethane and other feedstock in amounts sufficient for OpCo to produce the ethylene to be sold under the Ethylene Sales Agreement (the "Feedstock Supply Agreement"). The Feedstock Supply Agreement provides that OpCo obtains feedstock from Westlake, based on Westlake’s total cost of purchasing and delivering the feedstock, including applicable transportation, storage and other costs. Title and risk of loss for all feedstock purchased by OpCo through the Feedstock Supply Agreement passes to OpCo upon delivery to one of three delivery points described in the Feedstock Supply Agreement.

The Feedstock Supply Agreement has an initial term extending until December 31, 2026 and automatically renews thereafter for successive 12-month terms unless terminated by either party; provided, however, that such agreement can only be renewed in the event the Ethylene Sales Agreement is renewed simultaneously. The Feedstock Supply Agreement may, in certain circumstances, terminate concurrently with the termination of the Ethylene Sales Agreement.

8

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

Services and Secondment Agreement

OpCo entered into a services and secondment agreement with Westlake, pursuant to which OpCo provides Westlake with certain services required for the operation of Westlake’s facilities; and Westlake provides OpCo with comprehensive operating services for OpCo’s facilities, ranging from services relating to the maintenance and operations of the common facilities necessary for the operation of OpCo’s units, to making available certain shared utilities such as electricity and natural gas that are necessary for the operation of OpCo’s units. Westlake also seconded employees to OpCo to allow OpCo to operate OpCo’s facilities in an efficient and compliant manner. Such seconded employees will be under the control of OpCo while they work on OpCo’s facilities.

The services and secondment agreement has an initial 12-year term. The services and secondment agreement may be renewed thereafter upon agreement of the parties and shall automatically terminate if the Ethylene Sales Agreement terminates under certain circumstances. Westlake and OpCo each can terminate the services and secondment agreement under certain circumstances, including if the other party materially defaults on the performance of its obligations and such default continues for a 30-day period.

Site Lease Agreements

OpCo entered into two site lease agreements with Westlake pursuant to which Westlake leases to OpCo the real property underlying Lake Charles Olefins and Calvert City Olefins, respectively, and grants OpCo rights to access and use certain other portions of Westlake’s ethylene production facilities that are necessary to operate OpCo’s units at such ethylene production facilities. OpCo owes Westlake one dollar per site per year. The site lease agreements each have a term of 50 years. Each of the site lease agreements may be renewed if agreed by the parties.

Omnibus Agreement

The Partnership entered into an omnibus agreement with Westlake that addresses Westlake’s indemnification of the Partnership for certain matters, including environmental and tax matters, as well as the provision by Westlake of certain management and other general and administrative services to the Partnership and its general partner and the Partnership’s reimbursement to Westlake for such services. The omnibus agreement also addresses Westlake’s right of first refusal on any proposed transfer of the ethylene production facilities that serve Westlake’s other facilities and Westlake’s right of first refusal on any proposed transfer of the Partnership's equity interests in OpCo.

3. Recent Accounting Pronouncements

Revenue from Contracts with Customers

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. The accounting standard will be effective for reporting periods beginning after December 15, 2016. OpCo is in the process of evaluating the impact that the new accounting guidance will have on its financial position, results of operations and cash flows.

Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern

In August 2014, the FASB issued an accounting standards update on management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern. The new accounting guidance requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if "conditions or events raise substantial doubt about the entity's ability to continue as a going concern." The accounting standard will be effective for reporting periods

9

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

ending after December 15, 2016 and is not expected to have an impact on the OpCo's financial position, results of operations and cash flows.

4. Accounts Receivable

Accounts receivable consist of the following:

	September 30, 2014		December 31, 2013
			Predecessor
Trade customers	$	29,606	$	73,594
Allowance for doubtful accounts	—		(2,105		)
	29,606		71,489
Other	—		323
Accounts receivable, net—third parties	$	29,606	$	71,812

5. Inventories

Inventories consist of the following:

	September 30, 2014		December 31, 2013
			Predecessor
Finished products	$	5,551	$	21,330
Feedstock, additives and chemicals	—		80,407
Materials and supplies	—		14,640
Inventories	$	5,551	$	116,377

6. Property, Plant and Equipment

As of September 30, 2014, OpCo had property, plant and equipment, net totaling $806,648. OpCo 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 OpCo 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 $14,900 and $14,579 is included in cost of sales in the combined statements of operations for the three months ended September 30, 2014 and 2013, respectively. Depreciation expense on property, plant and equipment of $45,104 and $42,930 is included in cost of sales in the combined statements of operations for the nine months ended September 30, 2014 and 2013, respectively.

7. Other Assets

Amortization expense on other assets of $4,319 and $4,600 is included in the combined statements of operations for the three months ended September 30, 2014 and 2013, respectively. Amortization expense on other assets of $13,397 and $11,609 is included in the combined statements of operations for the nine months ended September 30, 2014 and 2013, respectively.

10

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

8.Related Party Transactions

OpCo regularly enters into related party transactions with Westlake. See below for a description of transactions with related parties.

Sales to Related Parties

OpCo sells ethylene to Westlake under the Ethylene Sales Agreement described in Note 2. Additionally, OpCo from time to time provides other services or products for which it charges Westlake a fee. Prior to the IPO, the Predecessor sold the majority of its ethylene to Westlake for use in Westlake's downstream operations.

Sales to related parties were as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
			Predecessor				Predecessor
Net sales—Westlake	$	289,601	$	391,801	$	1,088,561	$	1,195,870

Cost of Sales from Related Parties

Charges for goods and services purchased by OpCo from Westlake and included in cost of sales relate primarily to feedstock purchased under the Feedstock Supply Agreement and services provided under the services and secondment agreement described in Note 2. Prior to the IPO, services provided by Westlake and included in cost of sales related primarily to services provided by employees of Westlake Management Services, Inc., a subsidiary of Westlake. The cost of services provided by employees of Westlake Management Services, Inc. were allocated to the Predecessor's operations primarily on the basis of direct usage.

Charges from related parties in cost of sales were as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
			Predecessor				Predecessor
Feedstock purchased from Westlake and included in    cost of sales	$	63,108	$	—	$	63,108	$	—
Other charges from Westlake and included in cost    of sales	13,879		15,484		47,000		46,273
Total	$	76,987	$	15,484	$	110,108	$	46,273

Services from Related Parties Included in Selling, General and Administrative Expenses

Charges for services purchased by OpCo from Westlake and included in general and administrative expenses primarily relate to services Westlake performs on behalf of OpCo under the omnibus agreement, including the OpCo's finance, legal, information technology, human resources, communication, ethics and compliance, and other administrative functions. Prior to the IPO, the Predecessor was allocated costs incurred by Westlake on its behalf for similar functions. These allocations were based primarily on the basis of direct usage when identifiable, with the remainder allocated on the basis of fixed assets, headcount or other measure. Management believes the allocation of expenses incurred by Westlake on the Predecessor's behalf are reasonable and reflect all costs related to the operations of the Predecessor. Nevertheless, the financial information of the Predecessor may not have included all of the expenses that would have been incurred had the Predecessor been a stand-alone company during the periods prior to the IPO.

Charges from related parties included within selling, general and administrative expenses were as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
			Predecessor				Predecessor
Services received from Westlake and included in    selling, general and administrative expenses	$	3,955	$	4,845	$	30,210	$	29,906

11

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

Goods and Services from Related Parties that have been Capitalized

Charges for goods and services purchased by OpCo from Westlake which were capitalized as assets relate primarily to the services of Westlake employees under the services and secondment agreement. Prior to the IPO, salaries and benefits of Westlake Management Services, Inc. were allocated to the Predecessor primarily on the basis of direct usage.

Charges from related parties for goods and services capitalized as assets were as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
			Predecessor				Predecessor
Goods and services purchased from Westlake and    capitalized as assets	$	830	$	624	$	2,074	$	15,256

Accounts Receivable from and Accounts Payable to Related Parties

OpCo’s accounts receivable from Westlake result primarily from ethylene sales to Westlake under the Ethylene Sales Agreement. OpCo’s accounts payable to Westlake result primarily from feedstock purchases under the Feedstock Supply Agreement and services provided under the services and secondment agreement and the omnibus agreement. Prior to the IPO, ethylene sales and other transactions between the Predecessor and Westlake were settled immediately through net investment, and therefore, the Predecessor did not have related party accounts receivable or related party accounts payable balances.

The related party accounts receivable and accounts payable balances were as follows:

	September 30, 2014			December 31, 2013
				Predecessor
Accounts receivable, net—Westlake	$	28,500		$	—
Accounts payable—Westlake	(17,029		)	—

Debt Payable to Related Parties

OpCo assumed promissory notes payable to Westlake and entered into a revolving credit facility with Westlake in connection with the closing of the IPO. Prior to the IPO, the Predecessor funded capital expenditures through promissory notes payable to Westlake, a portion of which were assumed by OpCo in connection with the IPO. See Note 9 for a description of related party debt payable balances.

Debt payable to related parties was as follows:

	September 30, 2014		December 31, 2013
Long-term debt payable to Westlake	$	188,523	$	252,973

General

OpCo, together with other subsidiaries of Westlake not included in these combined financial statements, are guarantors under Westlake's revolving credit facility and the indentures governing its senior notes. As of September 30, 2014, Westlake had outstanding letters of credit totaling $32,399 under its revolving credit facility and $754,000 outstanding under its senior notes (less the unamortized discount of $921).

The indentures governing Westlake’s senior notes prevent OpCo from making distributions to the Partnership if any default or event of default (as defined in the indentures) exists. However, Westlake’s credit facility does not prevent OpCo from making distributions to the Partnership.

12

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

9. Long-term Debt Payable to Westlake

Long-term debt payable to Westlake consists of the following:

	September 30, 2014		December 31, 2013
			Predecessor
2006 Pipeline Note (variable interest rate of prime plus 0.25%,    original scheduled maturity of November 30, 2016)	$	—	$	14,400
2013 Promissory Notes (variable interest rate of prime plus 1.5%,    original scheduled maturity of August 1, 2023)	168,376		238,573
Senior unsecured revolving credit facility (variable interest rate of LIBOR    plus 3.0%, original scheduled maturity of August 4, 2019)	20,147		—
	$	188,523	$	252,973

In 2013, three intercompany promissory notes were issued for capital expenditures incurred by Westlake on behalf of the Predecessor’s operations (together, the "2013 Promissory Notes"). For additional information on the 2013 Promissory Notes, please read Note 9 (Promissory Notes Payable to Westlake) to the audited combined carve-out financial statements for the fiscal year ended December 31, 2013 included in the WLKP Prospectus. Proceeds drawn under the 2013 Promissory Notes during the nine months ended September 30, 2014 were used to fund capital expenditures at the Predecessor’s ethylene plants. In connection with the IPO, OpCo assumed a portion of the 2013 Promissory Notes and used proceeds from the capital contribution from WLKP to repay a portion of the balance it assumed. See Note 2 for a description of the promissory notes assumed and proceeds used to repay balances of promissory notes assumed in connection with the IPO.

In connection with the IPO on August 4, 2014, OpCo entered into a senior unsecured revolving credit facility agreement with Westlake. The credit facility accrues interest quarterly at a rate of LIBOR plus 3.0%, which may be paid-in-kind as an addition to the principal at OpCo's option.

10. Derivative Instruments

Commodity Risk Management

The Predecessor used derivative instruments to reduce price volatility risk on raw materials and products as a substantial portion of its raw materials and products were commodities whose prices fluctuate as market supply and demand fundamentals change. The Predecessor employed strategies to protect against such instability, including ethylene product feedstock flexibility. The Predecessor did not use derivative instruments to engage in speculative activities. The Contributed Assets do not include the entity engaged in commodity risk management activities or any of its open derivative positions. OpCo has not engaged in any hedging activity and did not use derivative instruments in the period subsequent to the IPO. Therefore, there are no derivative assets or liabilities reflected in the balance sheet of OpCo as of September 30, 2014.

For derivative instruments that were designated and qualify as fair value hedges, the gains or losses on the derivative instruments, as well as the offsetting losses or gains on the hedged items attributable to the hedged risk, were included in cost of sales in the combined statements of operations for the three and nine months ended September 30, 2013. OpCo had no derivative instruments that were designated as fair value hedges for the three and nine months ended September 30, 2014.

Gains and losses from changes in the fair value of derivative instruments that are not designated as hedging instruments were included in gross profit in the combined statements of operations for the three and nine months ended September 30, 2014 and 2013.

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, OpCo would lose the benefit of the derivative differential on the volume of the commodities covered. In any event, OpCo would continue to receive the market price on the actual volume hedged. OpCo 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).

13

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

Disclosures related to the Predecessor's derivative assets and derivative liabilities subject to enforceable master netting arrangements have not been presented as they are not material to the Predecessor's combined balance sheet at December 31, 2013. There were no open derivative positions at September 30, 2014.

The fair values of derivative instruments in the combined balance sheets were as follows:

	Derivative Assets
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
				Predecessor
Not designated as hedging instruments
Commodity forward contracts	Accounts receivable, net	$	—	$	296
Total derivative assets		$	—	$	296

	Derivative Liabilities
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
				Predecessor
Not designated as hedging instruments
Commodity forward contracts	Accrued liabilities	$	—	$	176
Total derivative liabilities		$	—	$	176

The following tables reflect the impact of derivative instruments designated as fair value hedges and the related hedged items on the combined statements of operations. For the three and nine months ended September 30, 2013, there was no material ineffectiveness with regard to the Predecessor's qualifying fair value hedges.

Derivatives in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Derivative	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
				Predecessor					Predecessor
Commodity forward contracts	Cost of sales	$	—	$	(232	)	$	—	$	(342	)
Hedged Items in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Hedged Items	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
				Predecessor					Predecessor
Firm commitment designated    as the hedged item	Cost of sales	$	—	$	236		$	—	$	15

The impact of derivative instruments that have not been designated as hedges in the combined statements of operations were as follows:

Derivatives Not Designated as    Hedging Instruments	Location of Gain (Loss) Recognized in  Income on Derivative	Three Months Ended September 30,					Nine Months Ended September 30,
		2014			2013		2014			2013
					Predecessor					Predecessor
Commodity forward contracts	Gross profit	$	(8,873	)	$	4,854	$	(9,244	)	$	9,897

See Note 11 for the fair value of derivative instruments.

14

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

11. Fair Value Measurements

OpCo 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.

There were no assets or liabilities accounted for at fair value on a recurring basis as of September 30, 2014. The following table summarizes, by level within the fair value hierarchy, assets and liabilities that were accounted for at fair value on a recurring basis:

	December 31, 2013
	Level 1		Level 2			Total
	Predecessor
Derivative instruments
Risk management assets—Commodity forward contracts	$	48	$	248		$	296
Risk management liabilities—Commodity forward contracts	—		(176		)	(176		)

The Level 2 measurements for the Predecessor's commodity contracts were 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 nine months ended September 30, 2014 and 2013.

In addition to the financial assets and liabilities above, OpCo has other financial assets and liabilities subject to fair value measures. These financial assets and liabilities include accounts receivable, net, accounts payable and long-term debt payable to Westlake, all of which are recorded at carrying value. The amounts reported in the combined balance sheets for accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of OpCo's or the Predecessor's long-term debt at September 30, 2014 and December 31, 2013 are summarized in the table below. OpCo’s long-term debt includes related party promissory notes issued to Westlake and a credit facility entered with Westlake in connection with the IPO. The fair value of debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because OpCo’s valuation methodology used for long-term debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of OpCo’s long-term debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of OpCo's long-term debt include the selection of an appropriate discount rate.

	September 30, 2014				December 31, 2013
	Carrying Value		Fair Value		Carrying Value		Fair Value
					Predecessor
2006 Pipeline Note	$	—	$	—	$	14,400	$	13,922
2013 Promissory Notes	168,376		168,376		238,573		238,573
Senior unsecured revolving credit facility	20,147		20,147		—		—

12. Income Taxes

OpCo is a limited partnership and is treated as a partnership for U.S. federal income tax purposes and, therefore, is not liable for entity-level federal income taxes. The Predecessor’s operating results were included in Westlake’s consolidated U.S. federal and state income tax returns. Amounts presented in the combined financial statements prior to the IPO relate to income taxes that have been determined on a separate tax return basis, and the Predecessor’s contribution to Westlake Chemical Corporation’s net operating losses and tax credits have been included in the Predecessor’s financial statements.

The effective income tax rate of the Predecessor was 35.4% for the period from January 1, 2014 through August 3, 2014. The effective income tax rate for the 2014 period prior to the IPO was above the U.S. federal statutory rate of 35.0% primarily

15

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

due to state income taxes, mostly offset by the domestic manufacturing deduction and state income tax credits. The effective income tax rate of the Predecessor was 35.5% for the nine months ended September 30, 2013. The effective income tax rate for the nine months ended September 30, 2013 was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, mostly offset by the domestic manufacturing deduction and state income tax credits. OpCo’s effective tax rate was less than one percent for the period subsequent to the IPO.

13.Supplemental Information

Net Liabilities Retained by Westlake

Net liabilities of the Predecessor that were not assumed by OpCo in connection with the IPO are composed of the following:

Accounts receivable, net—third parties	$	64,650
Inventories	85,057
Prepaid expenses and other current assets	669
Deferred income taxes	4,448
Property, plant and equipment, net	62,886
Equity investments	9,338
Accounts payable—third parties	(101,671		)
Accrued liabilities	(37,451		)
Deferred income taxes	(189,615		)
Long-term debt payable to Westlake	(137,103		)
Other liabilities	(914		)
Total	$	(239,706	)

Non-cash Operating Activity

OpCo or the Predecessor settled $2,089 and $2,168 of its total interest expense incurred on long-term debt payable to Westlake as an addition to principal on debt outstanding for the three months ended September 30, 2014 and 2013, respectively. OpCo or the Predecessor settled $9,530 and $4,498 of its total interest expense incurred on long-term debt payable to Westlake as an addition to principal on long-term debt payable to Westlake for the nine months ended September 30, 2014 and 2013, respectively. Interest incurred on long-term debt payable to Westlake discussed in Note 9 may be settled through additions to principal outstanding, at OpCo's option. For additional information on the 2013 Promissory Notes, please read Note 9 (Promissory Notes Payables to Westlake) to the audited combined carve-out financial statements for the fiscal year ended December 31, 2013 included in the WLKP Prospectus.

Non-cash Investing Activity

The change in capital expenditure accrual reducing additions to property, plant and equipment was $8,564 for the nine months ended September 30, 2014. The change in capital expenditure accrual reducing additions to property, plant and equipment was $9,512 for the nine months ended September 30, 2013.

Non-cash Financing Activity

Related party notes payable to Westlake of $238,600 were deemed settled through net investment in 2013. The non-cash settlement was recorded as an increase in Westlake’s net investment in the Predecessor. No cash was transferred in connection with the deemed settlement of these notes. See Note 9 (Promissory Notes Payable to Westlake) to the audited combined carve-out financial statements for the fiscal year ended December 31, 2013 included in the WLKP Prospectus, for a description of the intercompany debt settled in 2013 between the Predecessor and Westlake.

14. Major Customer and Concentration of Credit Risk

During the three months ended September 30, 2014 and 2013, Westlake or the Predecessor's accounted for approximately 73.9% and 72.5%, respectively, of OpCo's or the Predecessor's net sales. During the nine months ended September 30, 2014 and 2013, Westlake accounted for approximately 73.7% and 76.4%, respectively, of OpCo’s or the Predecessor's net sales.

16

WESTLAKE CHEMICAL OPCO LP

NOTES TO COMBINED FINANCIAL STATEMENTS - Continued

(Unaudited)

(in thousands of dollars)

15. Commitments and Contingencies

OpCo is subject to environmental laws and regulations that can impose civil and criminal sanctions and that may require it to mitigate the effects of contamination caused by the release or disposal of hazardous substances into the environment. Under one law, an owner or operator of property may be held strictly liable for remediating contamination without regard to whether that person caused the contamination, and without regard to whether the practices that resulted in the contamination were legal at the time they occurred. Because several of OpCo’s production sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on OpCo.

Contract Disputes with Goodrich and PolyOne. In connection with the 1990 and 1997 acquisitions of the Goodrich Corporation ("Goodrich") chemical manufacturing complex in Calvert City, Goodrich agreed to indemnify the Predecessor for any liabilities related to preexisting contamination at the complex. For its part, the Predecessor agreed to indemnify Goodrich for post-closing contamination caused by the Predecessor’s operations. The soil and groundwater at the complex, which does not include the Predecessor’s nearby PVC facility, had been extensively contaminated under Goodrich’s operations. In 1993, Goodrich spun off the predecessor of PolyOne Corporation ("PolyOne"), and the Predecessor assumed Goodrich’s indemnification obligations relating to preexisting contamination.

In 2003, litigation arose among the Predecessor, Goodrich and PolyOne with respect to the allocation of the cost of remediating contamination at the site. The parties settled this litigation in December 2007 and PolyOne agreed to assume 100% of responsibility for site contamination subject to the right to seek reallocation through an arbitration process. By letter dated March 16, 2010, PolyOne notified Westlake that it was initiating an arbitration proceeding under the settlement agreement. This arbitration is currently stayed.

State Administrative Proceedings. There are several administrative proceedings in Kentucky pertaining to the Calvert City site involving Goodrich’s Resource Conservation and Recovery Act permit which requires Goodrich to remediate contamination at the site. Site contamination is currently being addressed under the U.S. Comprehensive Environmental Response, Compensation, and Liability Act by the Predecessor, Goodrich and PolyOne pursuant to an Administrative Settlement with the U.S. Environmental Protection Agency which requires the parties to conduct a remedial investigation and feasibility study. As a result, the state proceedings are currently stayed and corrective action under the permit has been suspended.

Monetary Relief. Except as noted above with respect to the settlement of the contract litigation among the Predecessor, Goodrich and PolyOne, there has been no determination of responsibility or any allocation of the costs of remediation among the various parties that are involved in the judicial and administrative proceedings discussed above. At this time, OpCo is not able to estimate the loss or reasonable possible loss, if any, on the Predecessor’s financial statements that could result from the resolution of these proceedings. These matters will have no impact on OpCo’s financial statements since Westlake has agreed to indemnify OpCo for any liabilities related to pre-existing contamination at the Calvert City plant, and OpCo has agreed to indemnity Westlake for any post-closing contamination caused by its operations of the Calvert City plant.

In addition to the matters described above, OpCo is involved in various routine legal proceedings incidental to the conduct of its business. OpCo does not believe that any of these routine legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows.

16. Subsequent Events

Distribution

On October 28, 2014, the board of directors of the general partner of the Partnership, declared an initial prorated quarterly distribution for the period August 5, 2014 through September 30, 2014 of $57,763, in total, that will be paid on November 25, 2014 to interest holders of record on November 10, 2014.

General

Subsequent events were evaluated through the date on which the financial statements were issued.

17

FORWARD-LOOKING STATEMENTS

Certain of the statements contained in this report are forward-looking statements. All statements, other than statements of historical facts, included in this report that address activities, events or developments that we expect, project, believe or anticipate will or may occur in the future are forward-looking statements. Forward-looking statements can be identified by the use of words such as "believes," "intends," "may," "should," "could," "anticipates," "expects", "will" or comparable terminology, or by discussions of strategies or trends. Although we believe that the expectations reflected in such forward-looking statements are reasonable, we cannot give any assurances that these expectations will prove to be correct. Forward-looking statements relate to matters such as:

• the amount of ethane that we are able to process, which could be adversely affected by, among other things, operating difficulties;

• the volume of ethylene that we are able to sell;

• the price at which we are able to sell ethylene;

• changes in the price and availability of electricity;

• changes in prevailing economic conditions;

• unanticipated ground, grade or water conditions;

• inclement or hazardous weather conditions, including flooding, and the physical impacts of climate change;

• environmental hazards;

• industrial accidents;

• changes in laws and regulations (or the interpretation thereof);

• inability to acquire or maintain necessary permits;

• inability to obtain necessary production equipment or replacement parts;

• technical difficulties or failures;

• labor disputes;

• late delivery of raw materials;

• difficulty collecting receivables;

• inability of our customers to take delivery;

• changes in the price and availability of transportation;

• fires, explosions or other accidents;

• our ability to borrow funds and access capital markets; and

• certain factors discussed elsewhere in this report.

We have based these statements on assumptions and analysis in light of our experience and perception of historical trends, current conditions, expected future developments and other factors we believe were appropriate in the circumstances when the statements were made. Forward-looking statements by their nature involve substantial risks and uncertainties that could significantly impact expected results, and actual future results could differ materially from those described in such statements. These statements are subject to a number of assumptions, risks and uncertainties, including those described in "Risk Factors" in the WLKP Prospectus.

Many of these factors are beyond our ability to control or predict. Any of the factors, or a combination of these factors, could materially affect our future results of operations and the ultimate accuracy of the forward-looking statements. These forward-looking statements are not guarantees of our future performance, and our actual results and future developments may differ materially from those projected in the forward-looking statements. Management cautions against putting undue reliance on forward-looking statements or projecting any future results based on such statements or present or prior earnings levels. Every forward-looking statement speaks only as of the date of the particular statement, and we undertake no obligation to publicly update or revise any forward-looking statements.

18

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Pension and Post-Retirement Benefit Costs (Tables)

9 Months Ended

Sep. 30, 2014

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Components of Net Periodic Benefit Cost

Components of net periodic benefit cost are as follows:

	Three Months Ended September 30,										Nine Months Ended September 30,
	Pension						Post-retirement Healthcare				Pension						Post-retirement Healthcare
	2014			2013			2014		2013		2014			2013			2014		2013
Service cost	$	331		$	275		$	6	$	2	$	498		$	815		$	16	$	7
Interest cost	1,138			515			185		147		2,309			1,531			548		442
Expected return on    plan assets	(777		)	(713		)	—		—		(2,363		)	(2,140		)	—		—
Amortization of prior    service cost	74			74			13		21		223			223			38		63
Amortization of net loss	71			510			82		90		204			1,449			220		269
Net periodic benefit cost	$	837		$	661		$	286	$	260	$	871		$	1,878		$	822	$	781

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Long-Term Debt (Revolving Credit Facility) (Details) (Line of Credit, USD $)	3 Months Ended
	Sep. 30, 2014
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 400,000,000
Long-term Line of Credit	0
Percentage of commitment on borrowing availability	0.25%
Letters of credit outstanding	32,399,000
Remaining borrowing capacity	367,601,000
Revolving Credit Facility, Covenant Terms
Covenant terms, distributions restrictions, borrowing availability threshold, percent of commitments, option 1	20.00%
Covenant terms, distributions restrictions, borrowing availability threshold, option 1	80,000,000
Covenant terms, distributions restrictions, borrowing availability threshold, percent of commitments, option 2	15.00%
Covenant terms, distributions restrictions, borrowing availability threshold, option 2	60,000,000
Covenant terms, distributions restrictions, fixed coverage ratio, option 2	100.00%
Covenant terms, acquisitions and investments, borrowing availability threshold, percent of commitments, option 1	15.00%
Covenant terms, acquisitions and investments, borrowing availability threshold, option 2	50,000,000
Covenant terms, acquisitions and investments, borrowing availability threshold, percent of commitments, option 2	12.50%
Covenant terms, acquisitions and investments restrictions, fixed coverage ration, option 2	100.00%
Covenant terms, specified investments permissible	50,000,000
Covenant terms, specified investments permissible, percentage of tangible assets and acquisitions	1.25%
Covenant terms, specified acquisitions permissible	100,000,000
Covenant terms, specified acquisitions permissible, percentage of tangible assets	2.50%
Covenant terms, acquisitions restrictions, borrowing availability threshold, percent of commitments, option 2	100.00%
Minimum
Line of Credit Facility [Line Items]
Increase in credit facility borrowings	25,000,000
Revolving Credit Facility, Covenant Terms
Covenant terms, acquisitions restrictions, borrowing availability threshold, percent of commitments, option 1	12.50%
Covenant terms, acquisitions restrictions, borrowing availability threshold, option 1	50,000,000
Maximum
Line of Credit Facility [Line Items]
Increase in credit facility borrowings	200,000,000
Revolving Credit Facility, Covenant Terms
Covenant terms, specified distributions permissible	75,000,000
Covenant terms, specified distributions permissible, annual increase, percentage	5.00%
Covenant terms, acquisitions restrictions, borrowing availability threshold, percent of commitments, option 1	15.00%
Covenant terms, acquisitions restrictions, borrowing availability threshold, option 1	60,000,000
LIBOR [Member]
Line of Credit Facility [Line Items]
Maximum basis spread, provided company is rated investment grade	1.50%
Revolving Credit Facility, Covenant Terms
Covenant terms, acquisitions and investments, borrowing availability threshold, option 1	$ 60,000,000
LIBOR [Member] | Minimum
Line of Credit Facility [Line Items]
Percentage added to basis to find interest rate	1.25%
LIBOR [Member] | Maximum
Line of Credit Facility [Line Items]
Percentage added to basis to find interest rate	1.75%
Base Rate [Member] | Minimum
Line of Credit Facility [Line Items]
Percentage added to basis to find interest rate	0.00%
Base Rate [Member] | Maximum
Line of Credit Facility [Line Items]
Percentage added to basis to find interest rate	0.50%

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Financial Instruments Available-for-sale Securities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 15,044	$ 239,113
GrossUnrealizedGain	6,022	434
GrossUnrealizedLoss	0	(159)
Fair Value	(21,066)	(239,388)
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax	3,858	176
Available-for-sale Securities, Income Tax Expense on Change in Unrealized Holding Gain (Loss)	2,164	99
Proceeds from Sale of Available-for-sale Securities	342,045
Gross Realized Gains	1,311
Gross Realized Losses	(99)
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Cost		108,300
GrossUnrealizedGain		340
GrossUnrealizedLoss		(69)
Fair Value		(108,571)
U.S. government debt
Schedule of Available-for-sale Securities [Line Items]
Cost		106,335
GrossUnrealizedGain		60
GrossUnrealizedLoss		(79)
Fair Value		(106,316)
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Cost		24,478
GrossUnrealizedGain		34
GrossUnrealizedLoss		(11)
Fair Value		(24,501)
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	15,044
GrossUnrealizedGain	6,022
GrossUnrealizedLoss	0
Fair Value	$ (21,066)

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Share Capital (Details) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended
	Aug. 31, 2011	Sep. 30, 2014	May 16, 2014	May 15, 2014	Dec. 31, 2013
Equity [Abstract]
Common stock, shares authorized		300,000,000	300,000,000	150,000,000	150,000,000
Common stock, par value		$ 0.01	$ 0.01		$ 0.01
Common stock, shares issued		134,680,164			134,580,208
Common stock, held in treasury		1,220,544			1,252,922
Stock repurchase program, authorized amount	$ 100,000
Shares repurchased		1,357,085			1,252,922

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Stock-Based Compensation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense	$ 2,346	$ 1,680	$ 6,856	$ 4,804

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Acquisitions (Narrative) (Details) (Vinnolit [Member], USD $) In Thousands, unless otherwise specified	0 Months Ended	2 Months Ended	9 Months Ended
	Jul. 31, 2014	Sep. 30, 2014	Sep. 30, 2014
Business Acquisition [Line Items]
Purchase price	$ 736,224
Net sales contributed by acquired business since acquisition date		195,477
Net loss contributed by acquired business since acquisition date		(2,992)
Transaction-related costs			$ 11,235
PVC Resin Member [Member]
Business Acquisition [Line Items]
Combined annual capacity	1,700,000,000
Vinyl Chloride Monomer [Member]
Business Acquisition [Line Items]
Combined annual capacity	1,500,000,000
Caustic Soda [Member]
Business Acquisition [Line Items]
Combined annual capacity	1,000,000,000

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Financial Instruments Cash Equivalents (Details) (Held-to-maturity Securities, USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Held-to-maturity Securities
Cash Equivalents [Line Items]
Cash Equivalents, at Carrying Value	$ 747,008	$ 263,967

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Accounts Receivable (Tables)

9 Months Ended

Sep. 30, 2014

Accounts Receivable, Net [Abstract]

Schedule Of Accounts Receivable

Accounts receivable consist of the following:

	September 30, 2014			December 31, 2013
Trade customers	$	576,735		$	410,302
Affiliates	631			315
Allowance for doubtful accounts	(13,772		)	(11,741		)
	563,594			398,876
Federal and state taxes	5,374			20,820
Other	23,996			8,761
Accounts receivable, net	$	592,964		$	428,457

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Acquisitions (Pro Forma Information) (Details) (Vinnolit [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Vinnolit [Member]
Pro Forma Information:
Net sales	$ 4,016,935	$ 3,747,619
Net income	550,667	480,964
Net income attributable to noncontrolling interests	2,399	0
Net income attributable to Westlake Chemical Corporation	$ 548,268	$ 480,964
Earnings per common share attributable to Westlake Chemical Corporation:
Basic, in dollars per share	$ 4.11	$ 3.59
Diluted, in dollars per share	$ 4.09	$ 3.58

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Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Net external sales	$ 1,253,227	$ 1,004,165	$ 3,279,479	$ 2,807,859
Income (loss) from operations	306,761	266,602	821,604	695,884
Depreciation and amortization	53,920	40,728	148,394	116,294
Other (expense) income, net	(2,670)	(287)	4,440	3,137
Provision for (benefit from) income taxes	124,449	92,728	300,231	244,647
Capital expenditures	94,271	200,418	311,183	498,290
Olefins
Segment Reporting Information [Line Items]
Net external sales	703,097	679,339	2,124,948	1,885,525
Income (loss) from operations	259,277	237,239	770,267	585,958
Depreciation and amortization	26,443	26,515	79,811	76,415
Other (expense) income, net	1,609	728	4,262	5,889
Provision for (benefit from) income taxes	105,030	82,553	282,082	208,170
Capital expenditures	48,519	27,577	121,041	105,656
Vinyls
Segment Reporting Information [Line Items]
Net external sales	550,130	324,826	1,154,531	922,334
Income (loss) from operations	59,445	39,554	76,460	136,123
Depreciation and amortization	27,336	14,089	68,127	39,507
Other (expense) income, net	1,189	(742)	942	(1,687)
Provision for (benefit from) income taxes	21,761	10,710	22,121	44,120
Capital expenditures	44,067	172,565	187,449	391,864
Corporate and Other
Segment Reporting Information [Line Items]
Income (loss) from operations	(11,961)	(10,191)	(25,123)	(26,197)
Depreciation and amortization	141	124	456	372
Other (expense) income, net	(5,468)	(273)	(764)	(1,065)
Provision for (benefit from) income taxes	(2,342)	(535)	(3,972)	(7,643)
Capital expenditures	1,685	276	2,693	770
Polyethylene | Olefins
Segment Reporting Information [Line Items]
Net external sales	498,450	460,105	1,461,097	1,294,566
Ethylene, Styrene And Other | Olefins
Segment Reporting Information [Line Items]
Net external sales	204,647	219,234	663,851	590,959
PVC, Caustic Soda And Other | Vinyls
Segment Reporting Information [Line Items]
Net external sales	416,771	212,041	776,060	612,391
Building Products | Vinyls
Segment Reporting Information [Line Items]
Net external sales	133,359	112,785	378,471	309,943
Intersegment sales
Segment Reporting Information [Line Items]
Net external sales	26,873	85,857	119,182	231,718
Intersegment sales | Olefins
Segment Reporting Information [Line Items]
Net external sales	26,518	85,454	118,153	230,607
Intersegment sales | Vinyls
Segment Reporting Information [Line Items]
Net external sales	$ 355	$ 403	$ 1,029	$ 1,111

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Derivative Instruments (Fair Values of Derivative Instruments in Consolidated Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Accrued Liabilities
Derivatives, Fair Value [Line Items]
Total derivative liabilities	$ 6,477	$ 176
Accounts Receivable
Derivatives, Fair Value [Line Items]
Total derivative assets	451	296
Forward Contracts [Member] | Accrued Liabilities
Derivatives, Fair Value [Line Items]
Not designated as hedging instruments, Derivative Liabilities	6,477	176
Forward Contracts [Member] | Accounts Receivable
Derivatives, Fair Value [Line Items]
Not designated as hedging instruments, Derivative Assets	$ 451	$ 296

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Westlake Chemical Partners LP (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended		0 Months Ended				0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Aug. 04, 2014 IPO [Member] Limited Partner [Member]	Aug. 04, 2014 Subsidiaries [Member] Westlake Chemical Partners LP [Member] IPO [Member]	Aug. 04, 2014 Subsidiaries [Member] Westlake Chemical Partners LP [Member] IPO [Member] Limited Partner [Member]	Aug. 04, 2014 Subsidiaries [Member] Westlake Chemical Partners LP [Member] IPO [Member] Limited Partner [Member]	Aug. 04, 2014 Subsidiaries [Member] Westlake Chemical Partners LP [Member] Over-Allotment Option [Member] Limited Partner [Member]	Aug. 04, 2014 Cash Reserve Turnaround [Member] Subsidiaries [Member] Westlake Chemical OpCo LP [Member] IPO [Member]	Aug. 04, 2014 Preformation Capital Expenditure [Member] Subsidiaries [Member] Westlake Chemical OpCo LP [Member] IPO [Member]	Aug. 04, 2014 Intercompany Debt [Member] Subsidiaries [Member] Westlake Chemical OpCo LP [Member] IPO [Member]
Number of units sold in public offering					12,937,500		1,687,500
Price per unit						$ 24.00
Approximate proceeds from sale of units	$ 286,088	$ 0			$ 286,088
Estimated offering expenses from sale of partnership units					(24,412)
Limited partner interest			89.40%		10.60%
Percentage sold to public in IPO				47.80%
Amount used from proceeds								$ (55,419)	$ (151,729)	$ (78,940)

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Related Party and Affiliate Transactions (Details) (Affiliated Entity [Member], USD $) In Thousands, unless otherwise specified	2 Months Ended
	Sep. 30, 2014
InfraServ Knapsack GmbH & Co. KG [Member]
Related Party Transaction [Line Items]
Ownership percentage in provider	15.00%
InfraServ Knapsack GmbH & Co. KG [Member] | Electricity And Technical Services [Member]
Related Party Transaction [Line Items]
Amount of charges incurred during period	$ 11,581
InfraServ Gendorf GmbH & Co. KG [Member]
Related Party Transaction [Line Items]
Ownership percentage in provider	11.00%
InfraServ Gendorf GmbH & Co. KG [Member] | Electricity And Technical Services [Member]
Related Party Transaction [Line Items]
Amount of charges incurred during period	$ 10,489

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Westlake Chemical Partners LP (Reconciliation of Proceeds from IPO) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Aug. 04, 2014 Westlake Chemical Partners LP [Member] IPO [Member] Subsidiaries [Member]	Aug. 04, 2014 Limited Partner [Member] Westlake Chemical Partners LP [Member] IPO [Member] Subsidiaries [Member]	Aug. 04, 2014 Cash Reserve Turnaround [Member] Westlake Chemical OpCo LP [Member] IPO [Member] Subsidiaries [Member]
Total proceeds from the initial public offering				$ 310,500
Less: Offering Costs				24,412
Net proceeds from issuance of Westlake Chemical Partners LP common units	286,088	0		286,088
Less: Cash retained by OpCo					55,419
Net proceeds distributed to the Company from the initial public offering			$ 230,669

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Supplemental Information (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Other liabilities	$ 153,158	$ 35,593
Noncurrent pension obligation	$ 117,293	$ 8,710

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Segment Information

9 Months Ended

Sep. 30, 2014

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 September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Net external sales
Olefins
Polyethylene	$	498,450		$	460,105		$	1,461,097		$	1,294,566
Styrene, feedstock and other	204,647			219,234			663,851			590,959
Total Olefins	703,097			679,339			2,124,948			1,885,525
Vinyls
PVC, caustic soda and other	416,771			212,041			776,060			612,391
Building products	133,359			112,785			378,471			309,943
Total Vinyls	550,130			324,826			1,154,531			922,334
	$	1,253,227		$	1,004,165		$	3,279,479		$	2,807,859
Intersegment sales
Olefins	$	26,518		$	85,454		$	118,153		$	230,607
Vinyls	355			403			1,029			1,111
	$	26,873		$	85,857		$	119,182		$	231,718
Income (loss) from operations
Olefins	$	259,277		$	237,239		$	770,267		$	585,958
Vinyls	59,445			39,554			76,460			136,123
Corporate and other	(11,961		)	(10,191		)	(25,123		)	(26,197		)
	$	306,761		$	266,602		$	821,604		$	695,884
Depreciation and amortization
Olefins	$	26,443		$	26,515		$	79,811		$	76,415
Vinyls	27,336			14,089			68,127			39,507
Corporate and other	141			124			456			372
	$	53,920		$	40,728		$	148,394		$	116,294
Other income (expense), net
Olefins	$	1,609		$	728		$	4,262		$	5,889
Vinyls	1,189			(742		)	942			(1,687		)
Corporate and other	(5,468		)	(273		)	(764		)	(1,065		)
	$	(2,670	)	$	(287	)	$	4,440		$	3,137
Provision for (benefit from) income taxes
Olefins	$	105,030		$	82,553		$	282,082		$	208,170
Vinyls	21,761			10,710			22,121			44,120
Corporate and other	(2,342		)	(535		)	(3,972		)	(7,643		)
	$	124,449		$	92,728		$	300,231		$	244,647
Capital expenditures
Olefins	$	48,519		$	27,577		$	121,041		$	105,656
Vinyls	44,067			172,565			187,449			391,864
Corporate and other	1,685			276			2,693			770
	$	94,271		$	200,418		$	311,183		$	498,290

A reconciliation of total segment income from operations to consolidated income before income taxes is as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Income from operations	$	306,761		$	266,602		$	821,604		$	695,884
Interest expense	(9,486		)	(3,297		)	(28,182		)	(14,921		)
Other (expense) income, net	(2,670		)	(287		)	4,440			3,137
Income before income taxes	$	294,605		$	263,018		$	797,862		$	684,100

	September 30, 2014		December 31, 2013
Total assets
Olefins	$	1,740,878	$	1,557,510
Vinyls	2,898,250		1,740,595
Corporate and other	487,155		762,804
	$	5,126,283	$	4,060,909

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Inventories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]
Finished products	$ 268,969	$ 232,658
Feedstock, additives and chemicals	166,268	180,646
Materials and supplies	65,315	58,575
Inventories	$ 500,552	$ 471,879

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Westlake Chemical Partners LP (Tables)

9 Months Ended

Sep. 30, 2014

Equity [Abstract]

Reconciliation Of Proceeds From Initial Public Offering [Table Text Block]

The following table is a reconciliation of proceeds from the initial public offering:

Total proceeds from the initial public offering	$	310,500
Less: Offering Costs	(24,412		)
Net proceeds from the initial public offering	286,088
Less: Cash retained by OpCo	(55,419		)
Net proceeds distributed to the Company from the initial public offering	$	230,669

XML

Segment Information (Total Assets) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 5,126,283	$ 4,060,909
Olefins
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,740,878	1,557,510
Vinyls
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,898,250	1,740,595
Corporate and Other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 487,155	$ 762,804

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Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2014

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:

	September 30, 2014
	Level 1			Level 2			Total
Derivative instruments
Risk management assets - Commodity forward contracts	$	428		$	23		$	451
Risk management liabilities - Commodity forward contracts	(119		)	(6,358		)	(6,477		)
Available-for-sale marketable securities	21,066			—			21,066
	December 31, 2013
	Level 1			Level 2			Total
Derivative instruments
Risk management assets - Commodity forward contracts	$	48		$	248		$	296
Risk management liabilities - Commodity forward contracts	—			(176		)	(176		)
Available-for-sale marketable securities	91,595			147,793			239,388

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 Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy.

	September 30, 2014				December 31, 2013
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.60% senior notes due 2022	$	249,079	$	247,633	$	248,990	$	236,905
6 ½% senior notes due 2029	100,000		114,624		100,000		109,490
6 ¾% senior notes due 2032	250,000		275,313		250,000		265,148
6 ½% GO Zone Senior Notes Due 2035	89,000		101,855		89,000		94,606
6 ½% IKE Zone Senior Notes Due 2035	65,000		74,389		65,000		69,094
Loan related to tax-exempt waste disposal revenue    bonds due 2027	10,889		10,889		10,889		10,889

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Other Assets (Additional Information) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Assets [Line Items]
Amortization expense on intangible assets, included in other assets	$ 9,283	$ 8,634	$ 26,566	$ 21,392
Olefins
Other Assets [Line Items]
Goodwill	29,990		29,990
Vinyls
Other Assets [Line Items]
Goodwill	$ 32,026		$ 32,026

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Accumulated Other Comprehensive Income Changes in AOCI (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance			$ (2,616)	$ (10,840)	$ (10,840)
Other comprehensive loss before reclassifications			(33,462)	(1,314)
Amounts reclassified from accumulated other comprehensive loss			(355)	1,233
Other comprehensive (loss) income	(36,301)	805	(33,817)	(81)	8,224
Accumulated other comprehensive income (loss), ending balance	(36,433)	(10,921)	(36,433)	(10,921)	(2,616)
Benefits Liability, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance			(6,696)	(16,351)	(16,351)
Other comprehensive loss before reclassifications			(39)	(601)
Amounts reclassified from accumulated other comprehensive loss			422	1,233
Other comprehensive (loss) income			383	632
Accumulated other comprehensive income (loss), ending balance	(6,313)	(15,719)	(6,313)	(15,719)
Cumulative Foreign Currency Exchange
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance			3,904	5,511	5,511
Other comprehensive loss before reclassifications			(37,882)	(844)
Amounts reclassified from accumulated other comprehensive loss			0	0
Other comprehensive (loss) income			(37,882)	(844)
Accumulated other comprehensive income (loss), ending balance	(33,978)	4,667	(33,978)	4,667
Net Unrealized Holding Gains on Investmetnts, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance			176	0	0
Other comprehensive loss before reclassifications			4,459	131
Amounts reclassified from accumulated other comprehensive loss			(777)	0
Other comprehensive (loss) income			3,682	131
Accumulated other comprehensive income (loss), ending balance	$ 3,858	$ 131	$ 3,858	$ 131

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Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Effective income tax rate	37.60%	35.80%
U.S. federal statutory income tax rate	35.00%	35.00%
Anticipated reductions to unrecognized tax benefits within next twelve months	$ 2,501

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Financial Instruments Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Current	$ 0	$ 239,388
Noncurrent	21,066	0
Total Available-for-sale Securities	$ 21,066	$ 239,388

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Financial Instruments

9 Months Ended

Sep. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Financial Instruments

Financial Instruments

Cash Equivalents

The Company had $747,008 and $263,967 of held-to-maturity securities with original maturities of three months or less, primarily consisting of corporate debt securities, classified as cash equivalents at September 30, 2014 and December 31, 2013, respectively. The Company's investments in held-to-maturity securities are held at amortized cost, which approximates fair value.

Available-for-Sale Marketable Securities

Investments in available-for-sale securities were classified as follows:

	September 30, 2014		December 31, 2013
Current	$	—	$	239,388
Non-current	21,066		—
Total available-for-sale securities	$	21,066	$	239,388

The cost, gross unrealized gains, gross unrealized losses and fair value of the Company’s available-for-sale securities were as follows:

	September 30, 2014
	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Equity securities	$	15,044	$	6,022	$	—	$	21,066
Total available-for-sale securities	$	15,044	$	6,022	$	—	$	21,066

	December 31, 2013
	Cost		Gross Unrealized Gains		Gross Unrealized Losses (1)			Fair Value
Debt securities
Corporate bonds	$	108,300	$	340	$	(69	)	$	108,571
U.S. government debt (2)	106,335		60		(79		)	106,316
Asset-backed securities	24,478		34		(11		)	24,501
Total available-for-sale securities	$	239,113	$	434	$	(159	)	$	239,388

_____________

(1) All unrealized loss positions were held at a loss for less than 12 months.

(2) U.S. Treasury obligations, U.S. government agency obligations and U.S government agency mortgage-backed securities.

As of September 30, 2014 and December 31, 2013, net unrealized gains on the Company's available-for-sale securities of $3,858 and $176, respectively, net of income tax expense of $2,164 and $99, respectively, were recorded in accumulated other comprehensive income. See Note 10 for the fair value hierarchy of the Company’s available-for-sale securities.

The proceeds from sales and maturities of available-for-sale securities and the gross realized gains and losses included in the consolidated statement of operations are reflected in the table below. The cost of securities sold was determined using the specific identification method. There were no sales or maturities of available-for-sale securities during the three and nine months ended September 30, 2013.

	Nine Months Ended September 30,
	2014
Proceeds from sales and maturities of securities	$	342,045
Gross realized gains	$	1,311
Gross realized losses	$	(99	)

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Earnings per Share (Additional Information) (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Number of options excluded from computation of diluted earnings per share	0	137,324	0	115,518

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Acquisitions (Tables)

9 Months Ended

Sep. 30, 2014

Business Combinations [Abstract]

Business Acquisition, Pro Forma Information

The following unaudited consolidated pro forma information presents consolidated information as if the acquisition had occurred on January 1, 2013:

	Pro Forma Nine Months Ended September 30,
	2014		2013
Net sales	$	4,016,935	$	3,747,619
Net income	$	550,667	$	480,964
Net income attributable to noncontrolling interests	2,399		—
Net income attributable to Westlake Chemical Corporation	$	548,268	$	480,964
Earnings per common share attributable to Westlake Chemical Corporation:
Basic	$	4.11	$	3.59
Diluted	$	4.09	$	3.58

The pro forma amounts above have been calculated after applying the Company’s accounting policies and adjusting the Vinnolit results to reflect (1) the additional depreciation and amortization that would have been charged assuming the fair value adjustments to property, plant and equipment and intangible assets had been applied from January 1, 2013; (2) the elimination of interest expense assuming the long-term debt paid off on behalf of the Sellers as of the acquisition date had been retired as of January 1, 2013; (3) the elimination of transaction-related costs; and (4) an adjustment to tax-effect the aforementioned pro forma adjustments using an estimated aggregate statutory income tax rate of the jurisdictions to which the above adjustments relate. The pro forma amounts do not include any potential synergies, cost savings or other expected benefits of the Vinnolit acquisition, are presented for illustrative purposes only and are not necessarily indicative of results that would have been achieved if the acquisition had occurred as of January 1, 2013 or of future operating performance.

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed

The following table summarizes the purchase consideration transferred and the estimated fair value of identified assets acquired and liabilities assumed at the date of acquisition. The preliminary allocation of the purchase consideration is based on management’s 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 the fair value of the net assets acquired equals consideration paid. Therefore, no goodwill was recorded. The final allocation of purchase consideration could include changes in the estimated fair value of (1) inventories; (2) property, plant and equipment; (3) equity investments; (4) trademark and trade name, developed technologies and customer relationships; (5) power purchase agreement liability; and (6) deferred income taxes.

Fair value of consideration transferred:
Cash paid to Sellers	$	309,619
Cash deposited in escrow (1)	13,390
Retirement of long-term debt as of July 31, 2014, on behalf of the Sellers (2)	413,215
Total purchase consideration	$	736,224
Preliminary allocation of consideration transferred to net assets acquired:
Cash	$	125,137
Working capital, excluding inventory and cash (3)	23,072
Inventories (4)	114,961
Property, plant and equipment	471,123
Investments	51,552
Other assets (5)	65,366
Intangible assets:
Trademarks and trade name (weighted average life of 20 years)	40,170
Developed technologies (weighted average life of 20 years)	31,600
Other intangibles (weighted average life of 9.4 years)	1,422
Deferred income tax asset - current	8,697
Deferred income tax asset - non-current	27,387
Pension obligation	(117,970		)
Other long-term liabilities	(10,723		)
Power purchase agreement liability (6)	(10,826		)
Deferred income tax liability - current	(6,845		)
Deferred income tax liability - non-current	(77,899		)
Total identifiable net assets	736,224
Goodwill (7)	—
Consideration transferred	$	736,224

_____________

(1) None of the cash held in escrow is considered contingent consideration as it is expected to be released to the Sellers pending the Sellers’ satisfaction of general representations and warranties made in connection with the execution of the purchase agreement.

(2) Vinnolit’s long-term debt paid on behalf of the Sellers was not legally assumed by Westlake in the acquisition and was a condition of the consummation of the purchase agreement. Therefore, the retirement has been included in the total purchase consideration.

(3) The fair value of accounts receivable acquired is $181,826, with the gross contractual amount being $183,769. The Company expects $1,943 to be uncollectible.

(4) An adjustment of approximately $16,900 was recorded to reflect Vinnolit's inventories at fair value and increased cost of sales by the same amount for the three months ended September 30, 2014.

(5) Included in other assets was a loan acquired that was repaid prior to September 30, 2014.

(6) A liability arising from unfavorable forward purchase contracts for the purchase of power was recognized at fair value. This liability will be amortized over a period of approximately 3.0 years, being the weighted-average life of the forward purchase contracts.

(7) Management estimated that the fair value of the net assets acquired equals consideration paid. Therefore, no goodwill was recorded.

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Subsequent Events

9 Months Ended

Sep. 30, 2014

Subsequent Events [Abstract]

Subsequent Events

Subsequent Events

Subsequent events were evaluated through the date on which the financial statements were issued.

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Related Party and Affiliate Transactions

9 Months Ended

Sep. 30, 2014

Related Party Transactions [Abstract]

Related Party and Affiliate Transactions

Related Party and Affiliate Transactions

InfraServ Knapsack GmbH & Co. KG, an on-site chemical complex provider in which the Company owns a 15% equity stake, provides electricity and technical services to the Company's Knapsack, Germany production facility. For the period from July 31, 2014 to September 30, 2014, the Company incurred charges aggregating approximately $11,581.

InfraServ Gendorf GmbH & Co. KG, an on-site chemical complex provider in which the Company owns an 11% equity stake, provides electricity and technical services to the Company's Gendorf, Germany production facility. For the period from July 31, 2014 to September 30, 2014, the Company incurred charges aggregating approximately $10,489.

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Derivative Instruments (Textual) (Detail) (Commodity Forward Contracts [Member], Designated As Fair Value Hedges)	Sep. 30, 2014 instrument
Commodity Forward Contracts [Member] | Designated As Fair Value Hedges
Derivative [Line Items]
Number of derivative instruments	0

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Guarantor Disclosures (Tables)

9 Months Ended

Sep. 30, 2014

Guarantees [Abstract]

Condensed Consolidating Financial Information Balance Sheet

Condensed Consolidating Financial Information as of September 30, 2014

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries		OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries		Eliminations			Consolidated
Balance Sheet
Current assets
Cash and cash equivalents	$	652,709	$	1,644	$	89,144	$	69,971	$	—		$	813,468
Accounts receivable, net	15,064		1,377,250		58,106		170,833		(1,028,289		)	592,964
Inventories	—		385,826		5,551		109,175		—			500,552
Prepaid expenses and other current assets	137		14,737		303		3,707		—			18,884
Deferred income taxes	342		25,446		—		292		—			26,080
Total current assets	668,252		1,804,903		153,104		353,978		(1,028,289		)	1,951,948
Property, plant and equipment, net	—		1,451,807		806,648		452,020		—			2,710,475
Equity investments	3,878,703		1,207,569		—		356,286		(5,371,730		)	70,828
Other assets, net	34,847		351,271		61,679		137,990		(192,755		)	393,032
Total assets	$	4,581,802	$	4,815,550	$	1,021,431	$	1,300,274	$	(6,592,774	)	$	5,126,283
Current liabilities
Accounts payable	$	979,414	$	157,562	$	29,856	$	100,129	$	(1,003,596	)	$	263,365
Accrued liabilities	15,448		238,225		3,412		77,279		(24,693		)	309,671
Total current liabilities	994,862		395,787		33,268		177,408		(1,028,289		)	573,036
Long-term debt	753,079		10,889		188,523		—		(188,523		)	763,968
Deferred income taxes	—		473,343		1,507		43,155		(4,232		)	513,773
Other liabilities	—		31,616		—		121,542		—			153,158
Total liabilities	1,747,941		911,635		223,298		342,105		(1,221,044		)	2,003,935
Total Westlake Chemical Corporation stockholders' equity	2,833,861		3,903,915		798,133		669,682		(5,371,730		)	2,833,861
Noncontrolling interests	—		—		—		288,487		—			288,487
Total equity	2,833,861		3,903,915		798,133		958,169		(5,371,730		)	3,122,348
Total liabilities and equity	$	4,581,802	$	4,815,550	$	1,021,431	$	1,300,274	$	(6,592,774	)	$	5,126,283

Condensed Consolidating Financial Information as of December 31, 2013

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries		OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non-Guarantor Subsidiaries		Eliminations			Consolidated
Balance Sheet
Current assets
Cash and cash equivalents	$	420,948	$	6,227	$	—	$	34,126	$	—		$	461,301
Marketable securities	239,388		—		—		—		—			239,388
Accounts receivable, net	3,879		666,344		71,812		2,755		(316,333		)	428,457
Inventories	—		339,929		116,377		15,573		—			471,879
Prepaid expenses and other current assets	778		11,055		257		1,798		—			13,888
Deferred income taxes	441		28,974		4,448		306		—			34,169
Total current assets	665,434		1,052,529		192,894		54,558		(316,333		)	1,649,082
Property, plant and equipment, net	—		1,318,119		762,972		6,923		—			2,088,014
Equity investments	2,815,752		636,461		10,411		31,518		(3,427,267		)	66,875
Other assets, net	15,393		423,901		75,197		1,199		(258,752		)	256,938
Total assets	$	3,496,579	$	3,431,010	$	1,041,474	$	94,198	$	(4,002,352	)	$	4,060,909
Current liabilities
Accounts payable	$	316,652	$	100,570	$	122,564	$	10,649	$	(300,822	)	$	249,613
Accrued liabilities	8,334		134,452		26,688		1,282		(15,511		)	155,245
Total current liabilities	324,986		235,022		149,252		11,931		(316,333		)	404,858
Long-term debt	752,990		10,889		252,973		—		(252,973		)	763,879
Deferred income taxes	—		260,171		182,855		729		(5,779		)	437,976
Other liabilities	—		34,571		962		60		—			35,593
Total equity	2,418,603		2,890,357		455,432		81,478		(3,427,267		)	2,418,603
Total liabilities and equity	$	3,496,579	$	3,431,010	$	1,041,474	$	94,198	$	(4,002,352	)	$	4,060,909

Condensed Consolidating Financial Information Statement Of Operations

Condensed Consolidating Financial Information for the Three Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	1,026,282		$	392,008		$	208,313		$	(373,376	)	$	1,253,227
Cost of sales	—			831,675			227,015			202,110			(369,093		)	891,707
Gross profit	—			194,607			164,993			6,203			(4,283		)	361,520
Selling, general and administrative expenses	399			36,445			8,014			14,184			(4,283		)	54,759
(Loss) income from operations	(399		)	158,162			156,979			(7,981		)	—			306,761
Interest expense	(10,343		)	(2		)	(2,137		)	(39		)	3,035			(9,486		)
Other income (expense), net	2,138			(2,942		)	486			683			(3,035		)	(2,670		)
(Loss) income before income taxes	(8,604		)	155,218			155,328			(7,337		)	—			294,605
(Benefit from) provision for income taxes	(3,088		)	93,366			36,309			(2,138		)	—			124,449
Equity in net income of subsidiaries	173,273			113,157			—			5,862			(292,292		)	—
Net income (loss)	167,757			175,009			119,019			663			(292,292		)	170,156
Net income attributable to noncontrolling interests	—			—			—			2,399			—			2,399
Net income (loss) attributable to Westlake Chemical Corporation	$	167,757		$	175,009		$	119,019		$	(1,736	)	$	(292,292	)	$	167,757
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	131,456		$	175,137		$	119,019		$	(39,528	)	$	(254,628	)	$	131,456

Condensed Consolidating Financial Information for the Three Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	844,081		$	540,133		$	13,337		$	(393,386	)	$	1,004,165
Cost of sales	—			754,037			327,152			11,891			(393,386		)	699,694
Gross profit	—			90,044			212,981			1,446			—			304,471
Selling, general and administrative expenses	514			29,323			6,391			1,641			—			37,869
(Loss) income from operations	(514		)	60,721			206,590			(195		)	—			266,602
Interest expense	(3,292		)	(5		)	(2,295		)	—			2,295			(3,297		)
Other income (expense), net	3,585			(2,688		)	1,162			(51		)	(2,295		)	(287		)
(Loss) income before income taxes	(221		)	58,028			205,457			(246		)	—			263,018
(Benefit from) provision for income taxes	(70		)	19,973			72,876			(51		)	—			92,728
Equity in net income of subsidiaries	170,441			132,581			—			—			(303,022		)	—
Net income (loss) attributable to Westlake Chemical Corporation	$	170,290		$	170,636		$	132,581		$	(195	)	$	(303,022	)	$	170,290
Comprehensive income attributable to Westlake Chemical    Corporation	$	171,095		$	170,764		$	132,581		$	351		$	(303,696	)	$	171,095

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	2,809,844		$	1,476,157		$	229,183		$	(1,235,705	)	$	3,279,479
Cost of sales	—			2,476,608			832,304			221,233			(1,205,167		)	2,324,978
Gross profit	—			333,236			643,853			7,950			(30,538		)	954,501
Selling, general and administrative expenses	1,474			123,050			21,957			16,954			(30,538		)	132,897
(Loss) income from operations	(1,474		)	210,186			621,896			(9,004		)	—			821,604
Interest expense	(29,032		)	(8		)	(9,833		)	(39		)	10,730			(28,182		)
Other income (expense), net	14,488			(1,729		)	3,135			(724		)	(10,730		)	4,440
(Loss) income before income taxes	(16,018		)	208,449			615,198			(9,767		)	—			797,862
(Benefit from) provision for income taxes	(5,686		)	109,920			198,461			(2,464		)	—			300,231
Equity in net income of subsidiaries	505,564			410,875			—			5,862			(922,301		)	—
Net income (loss)	495,232			509,404			416,737			(1,441		)	(922,301		)	497,631
Net income attributable to noncontrolling interests	—			—			—			2,399			—			2,399
Net income (loss) attributable to Westlake Chemical Corporation	$	495,232		$	509,404		$	416,737		$	(3,840	)	$	(922,301	)	$	495,232
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	461,415		$	509,787		$	416,737		$	(41,722	)	$	(884,802	)	$	461,415

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	2,407,341		$	1,565,809		$	37,561		$	(1,202,852	)	$	2,807,859
Cost of sales	—			2,247,338			924,663			32,943			(1,202,852		)	2,002,092
Gross profit	—			160,003			641,146			4,618			—			805,767
Selling, general and administrative expenses	1,576			84,152			19,326			4,829			—			109,883
(Loss) income from operations	(1,576		)	75,851			621,820			(211		)	—			695,884
Interest expense	(14,882		)	(39		)	(4,893		)	—			4,893			(14,921		)
Other income (expense), net	7,490			(4,002		)	6,422			(1,880		)	(4,893		)	3,137
(Loss) income before income taxes	(8,968		)	71,810			623,349			(2,091		)	—			684,100
(Benefit from) provision for income taxes	(3,202		)	27,292			221,009			(452		)	—			244,647
Equity in net income of subsidiaries	445,219			402,340			—			—			(847,559		)	—
Net income (loss) attributable to Westlake Chemical Corporation	$	439,453		$	446,858		$	402,340		$	(1,639	)	$	(847,559	)	$	439,453
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	439,372		$	447,490		$	402,340		$	(2,483	)	$	(847,347	)	$	439,372

Condensed Consolidating Financial Information Statement Of Cash Flows

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Cash Flows
Cash flows from operating activities
Net income (loss)	$	495,232		$	509,404		$	416,737		$	(1,441	)	$	(922,301	)	$	497,631
Adjustments to reconcile net income (loss) to net cash (used for)    provided by operating activities
Depreciation and amortization	1,172			82,597			58,501			7,296			—			149,566
Deferred income taxes	(418		)	26,991			8,267			(381		)	—			34,459
Net changes in working capital and other	(509,862		)	(919,521		)	1,641			599,909			922,301			94,468
Net cash (used for) provided by operating activities	(13,876		)	(300,529		)	485,146			605,383			—			776,124
Cash flows from investing activities
Acquisition of business, net of cash acquired	—			—			—			(611,087		)	—			(611,087		)
Additions to property, plant and equipment	—			(160,147		)	(144,348		)	(6,688		)	—			(311,183		)
Proceeds from disposition of assets	—			144			—			1			—			145
Proceeds from repayment of loan acquired	—			—			—			45,923			—			45,923
Proceeds from sales and maturities of securities	342,045			—			—			—			—			342,045
Purchase of securities	(117,332		)	—			—			—			—			(117,332		)
Settlements of derivative instruments	—			(556		)	(133		)	—			—			(689		)
Net cash provided by (used for) investing activities	224,713			(160,559		)	(144,481		)	(571,851		)	—			(652,178		)
Cash flows from financing activities
Intercompany financing	75,104			(143,325		)	62,221			6,000			—			—
Net distributions prior to WLKP initial public offering	—			448,101			(448,101		)	—			—			—
Capitalized debt issuance costs	(1,167		)	—			—			—			—			(1,167		)
Dividends paid	(55,690		)	151,729			(151,729		)	—			—			(55,690		)
Net proceeds from issuance of WLKP common units	—			—			—			286,088			—			286,088
Purchase of limited partner interests	—			—			286,088			(286,088		)	—			—
Proceeds from exercise of stock options	5,502			—			—			—			—			5,502
Repurchase of common stock for treasury	(9,495		)	—			—			—			—			(9,495		)
Windfall tax benefits from share-based payment arrangements	6,670			—			—			—			—			6,670
Net cash provided by (used for) financing activities	20,924			456,505			(251,521		)	6,000			—			231,908

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries			Eliminations		Consolidated
Effect of exchange rate changes on cash and cash equivalents	—		—			—		(3,687		)	—		(3,687		)
Net increase (decrease) in cash and cash equivalents	231,761		(4,583		)	89,144		35,845			—		352,167
Cash and cash equivalents at beginning of period	420,948		6,227			—		34,126			—		461,301
Cash and cash equivalents at end of period	$	652,709	$	1,644		$	89,144	$	69,971		$	—	$	813,468

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Cash Flows
Cash flows from operating activities
Net income (loss)	$	439,453		$	446,858		$	402,340		$	(1,639	)	$	(847,559	)	$	439,453
Adjustments to reconcile net income (loss) to net cash (used for)    provided by operating activities
Depreciation and amortization	1,094			59,893			54,539			1,861			—			117,387
Deferred income taxes	(1,102		)	57,279			27,253			13			—			83,443
Net changes in working capital and other	(458,336		)	(421,066		)	(68,604		)	7,664			847,559			(92,783		)
Net cash (used for) provided by operating activities	(18,891		)	142,964			415,528			7,899			—			547,500
Cash flows from investing activities
Acquisition of business	—			(178,309		)	—			—			—			(178,309		)
Additions to equity investments	—			(23,338		)	—			—			—			(23,338		)
Additions to property, plant and equipment	—			(337,158		)	(158,869		)	(2,263		)	—			(498,290		)
Construction of assets pending sale-leaseback	—			(136		)	—			—			—			(136		)
Proceeds from disposition of assets	—			6			—			72			—			78
Proceeds from repayment of loan to affiliate	—			—			—			167			—			167
Proceeds from sales and maturities of securities	239,764			—			—			—			—			239,764
Purchase of securities	(232,286		)	—			—			—			—			(232,286		)
Settlements of derivative instruments	—			—			(2,297		)	—			—			(2,297		)
Net cash provided by (used for) investing activities	7,478			(538,935		)	(161,166		)	(2,024		)	—			(694,647		)
Cash flows from financing activities
Intercompany financing	(130,832		)	(28,499		)	167,629			(8,298		)	—			—
Net distributions prior to WLKP initial public offering	—			421,991			(421,991		)	—			—			—
Dividends paid	(40,204		)	—			—			—			—			(40,204		)
Proceeds from exercise of stock options	3,182			—			—			—			—			3,182
Repurchase of common stock for treasury	(19,409		)	—			—			—			—			(19,409		)
Windfall tax benefits from share-based payment arrangements	5,056			—			—			—			—			5,056
Net cash (used for) provided by financing activities	(182,207		)	393,492			(254,362		)	(8,298		)	—			(51,375		)

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries			Eliminations		Consolidated
Net decrease in cash and cash equivalents	(193,620		)	(2,479		)	—		(2,423		)	—		(198,522		)
Cash and cash equivalents at beginning of period	753,881			6,973			—		29,224			—		790,078
Cash and cash equivalents at end of period	$	560,261		$	4,494		$	—	$	26,801		$	—	$	591,556

XML

Guarantor Disclosures

9 Months Ended

Sep. 30, 2014

Guarantees [Abstract]

Guarantor Disclosures

ndensed Consolidating Financial Information as of September 30, 2014

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries		OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries		Eliminations			Consolidated
Balance Sheet
Current assets
Cash and cash equivalents	$	652,709	$	1,644	$	89,144	$	69,971	$	—		$	813,468
Accounts receivable, net	15,064		1,377,250		58,106		170,833		(1,028,289		)	592,964
Inventories	—		385,826		5,551		109,175		—			500,552
Prepaid expenses and other current assets	137		14,737		303		3,707		—			18,884
Deferred income taxes	342		25,446		—		292		—			26,080
Total current assets	668,252		1,804,903		153,104		353,978		(1,028,289		)	1,951,948
Property, plant and equipment, net	—		1,451,807		806,648		452,020		—			2,710,475
Equity investments	3,878,703		1,207,569		—		356,286		(5,371,730		)	70,828
Other assets, net	34,847		351,271		61,679		137,990		(192,755		)	393,032
Total assets	$	4,581,802	$	4,815,550	$	1,021,431	$	1,300,274	$	(6,592,774	)	$	5,126,283
Current liabilities
Accounts payable	$	979,414	$	157,562	$	29,856	$	100,129	$	(1,003,596	)	$	263,365
Accrued liabilities	15,448		238,225		3,412		77,279		(24,693		)	309,671
Total current liabilities	994,862		395,787		33,268		177,408		(1,028,289		)	573,036
Long-term debt	753,079		10,889		188,523		—		(188,523		)	763,968
Deferred income taxes	—		473,343		1,507		43,155		(4,232		)	513,773
Other liabilities	—		31,616		—		121,542		—			153,158
Total liabilities	1,747,941		911,635		223,298		342,105		(1,221,044		)	2,003,935
Total Westlake Chemical Corporation stockholders' equity	2,833,861		3,903,915		798,133		669,682		(5,371,730		)	2,833,861
Noncontrolling interests	—		—		—		288,487		—			288,487
Total equity	2,833,861		3,903,915		798,133		958,169		(5,371,730		)	3,122,348
Total liabilities and equity	$	4,581,802	$	4,815,550	$	1,021,431	$	1,300,274	$	(6,592,774	)	$	5,126,283

Condensed Consolidating Financial Information as of December 31, 2013

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries		OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non-Guarantor Subsidiaries		Eliminations			Consolidated
Balance Sheet
Current assets
Cash and cash equivalents	$	420,948	$	6,227	$	—	$	34,126	$	—		$	461,301
Marketable securities	239,388		—		—		—		—			239,388
Accounts receivable, net	3,879		666,344		71,812		2,755		(316,333		)	428,457
Inventories	—		339,929		116,377		15,573		—			471,879
Prepaid expenses and other current assets	778		11,055		257		1,798		—			13,888
Deferred income taxes	441		28,974		4,448		306		—			34,169
Total current assets	665,434		1,052,529		192,894		54,558		(316,333		)	1,649,082
Property, plant and equipment, net	—		1,318,119		762,972		6,923		—			2,088,014
Equity investments	2,815,752		636,461		10,411		31,518		(3,427,267		)	66,875
Other assets, net	15,393		423,901		75,197		1,199		(258,752		)	256,938
Total assets	$	3,496,579	$	3,431,010	$	1,041,474	$	94,198	$	(4,002,352	)	$	4,060,909
Current liabilities
Accounts payable	$	316,652	$	100,570	$	122,564	$	10,649	$	(300,822	)	$	249,613
Accrued liabilities	8,334		134,452		26,688		1,282		(15,511		)	155,245
Total current liabilities	324,986		235,022		149,252		11,931		(316,333		)	404,858
Long-term debt	752,990		10,889		252,973		—		(252,973		)	763,879
Deferred income taxes	—		260,171		182,855		729		(5,779		)	437,976
Other liabilities	—		34,571		962		60		—			35,593
Total equity	2,418,603		2,890,357		455,432		81,478		(3,427,267		)	2,418,603
Total liabilities and equity	$	3,496,579	$	3,431,010	$	1,041,474	$	94,198	$	(4,002,352	)	$	4,060,909

Condensed Consolidating Financial Information for the Three Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	1,026,282		$	392,008		$	208,313		$	(373,376	)	$	1,253,227
Cost of sales	—			831,675			227,015			202,110			(369,093		)	891,707
Gross profit	—			194,607			164,993			6,203			(4,283		)	361,520
Selling, general and administrative expenses	399			36,445			8,014			14,184			(4,283		)	54,759
(Loss) income from operations	(399		)	158,162			156,979			(7,981		)	—			306,761
Interest expense	(10,343		)	(2		)	(2,137		)	(39		)	3,035			(9,486		)
Other income (expense), net	2,138			(2,942		)	486			683			(3,035		)	(2,670		)
(Loss) income before income taxes	(8,604		)	155,218			155,328			(7,337		)	—			294,605
(Benefit from) provision for income taxes	(3,088		)	93,366			36,309			(2,138		)	—			124,449
Equity in net income of subsidiaries	173,273			113,157			—			5,862			(292,292		)	—
Net income (loss)	167,757			175,009			119,019			663			(292,292		)	170,156
Net income attributable to noncontrolling interests	—			—			—			2,399			—			2,399
Net income (loss) attributable to Westlake Chemical Corporation	$	167,757		$	175,009		$	119,019		$	(1,736	)	$	(292,292	)	$	167,757
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	131,456		$	175,137		$	119,019		$	(39,528	)	$	(254,628	)	$	131,456

Condensed Consolidating Financial Information for the Three Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	844,081		$	540,133		$	13,337		$	(393,386	)	$	1,004,165
Cost of sales	—			754,037			327,152			11,891			(393,386		)	699,694
Gross profit	—			90,044			212,981			1,446			—			304,471
Selling, general and administrative expenses	514			29,323			6,391			1,641			—			37,869
(Loss) income from operations	(514		)	60,721			206,590			(195		)	—			266,602
Interest expense	(3,292		)	(5		)	(2,295		)	—			2,295			(3,297		)
Other income (expense), net	3,585			(2,688		)	1,162			(51		)	(2,295		)	(287		)
(Loss) income before income taxes	(221		)	58,028			205,457			(246		)	—			263,018
(Benefit from) provision for income taxes	(70		)	19,973			72,876			(51		)	—			92,728
Equity in net income of subsidiaries	170,441			132,581			—			—			(303,022		)	—
Net income (loss) attributable to Westlake Chemical Corporation	$	170,290		$	170,636		$	132,581		$	(195	)	$	(303,022	)	$	170,290
Comprehensive income attributable to Westlake Chemical    Corporation	$	171,095		$	170,764		$	132,581		$	351		$	(303,696	)	$	171,095

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	2,809,844		$	1,476,157		$	229,183		$	(1,235,705	)	$	3,279,479
Cost of sales	—			2,476,608			832,304			221,233			(1,205,167		)	2,324,978
Gross profit	—			333,236			643,853			7,950			(30,538		)	954,501
Selling, general and administrative expenses	1,474			123,050			21,957			16,954			(30,538		)	132,897
(Loss) income from operations	(1,474		)	210,186			621,896			(9,004		)	—			821,604
Interest expense	(29,032		)	(8		)	(9,833		)	(39		)	10,730			(28,182		)
Other income (expense), net	14,488			(1,729		)	3,135			(724		)	(10,730		)	4,440
(Loss) income before income taxes	(16,018		)	208,449			615,198			(9,767		)	—			797,862
(Benefit from) provision for income taxes	(5,686		)	109,920			198,461			(2,464		)	—			300,231
Equity in net income of subsidiaries	505,564			410,875			—			5,862			(922,301		)	—
Net income (loss)	495,232			509,404			416,737			(1,441		)	(922,301		)	497,631
Net income attributable to noncontrolling interests	—			—			—			2,399			—			2,399
Net income (loss) attributable to Westlake Chemical Corporation	$	495,232		$	509,404		$	416,737		$	(3,840	)	$	(922,301	)	$	495,232
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	461,415		$	509,787		$	416,737		$	(41,722	)	$	(884,802	)	$	461,415

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Operations
Net sales	$	—		$	2,407,341		$	1,565,809		$	37,561		$	(1,202,852	)	$	2,807,859
Cost of sales	—			2,247,338			924,663			32,943			(1,202,852		)	2,002,092
Gross profit	—			160,003			641,146			4,618			—			805,767
Selling, general and administrative expenses	1,576			84,152			19,326			4,829			—			109,883
(Loss) income from operations	(1,576		)	75,851			621,820			(211		)	—			695,884
Interest expense	(14,882		)	(39		)	(4,893		)	—			4,893			(14,921		)
Other income (expense), net	7,490			(4,002		)	6,422			(1,880		)	(4,893		)	3,137
(Loss) income before income taxes	(8,968		)	71,810			623,349			(2,091		)	—			684,100
(Benefit from) provision for income taxes	(3,202		)	27,292			221,009			(452		)	—			244,647
Equity in net income of subsidiaries	445,219			402,340			—			—			(847,559		)	—
Net income (loss) attributable to Westlake Chemical Corporation	$	439,453		$	446,858		$	402,340		$	(1,639	)	$	(847,559	)	$	439,453
Comprehensive income (loss) attributable to Westlake Chemical    Corporation	$	439,372		$	447,490		$	402,340		$	(2,483	)	$	(847,347	)	$	439,372

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2014

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Cash Flows
Cash flows from operating activities
Net income (loss)	$	495,232		$	509,404		$	416,737		$	(1,441	)	$	(922,301	)	$	497,631
Adjustments to reconcile net income (loss) to net cash (used for)    provided by operating activities
Depreciation and amortization	1,172			82,597			58,501			7,296			—			149,566
Deferred income taxes	(418		)	26,991			8,267			(381		)	—			34,459
Net changes in working capital and other	(509,862		)	(919,521		)	1,641			599,909			922,301			94,468
Net cash (used for) provided by operating activities	(13,876		)	(300,529		)	485,146			605,383			—			776,124
Cash flows from investing activities
Acquisition of business, net of cash acquired	—			—			—			(611,087		)	—			(611,087		)
Additions to property, plant and equipment	—			(160,147		)	(144,348		)	(6,688		)	—			(311,183		)
Proceeds from disposition of assets	—			144			—			1			—			145
Proceeds from repayment of loan acquired	—			—			—			45,923			—			45,923
Proceeds from sales and maturities of securities	342,045			—			—			—			—			342,045
Purchase of securities	(117,332		)	—			—			—			—			(117,332		)
Settlements of derivative instruments	—			(556		)	(133		)	—			—			(689		)
Net cash provided by (used for) investing activities	224,713			(160,559		)	(144,481		)	(571,851		)	—			(652,178		)
Cash flows from financing activities
Intercompany financing	75,104			(143,325		)	62,221			6,000			—			—
Net distributions prior to WLKP initial public offering	—			448,101			(448,101		)	—			—			—
Capitalized debt issuance costs	(1,167		)	—			—			—			—			(1,167		)
Dividends paid	(55,690		)	151,729			(151,729		)	—			—			(55,690		)
Net proceeds from issuance of WLKP common units	—			—			—			286,088			—			286,088
Purchase of limited partner interests	—			—			286,088			(286,088		)	—			—
Proceeds from exercise of stock options	5,502			—			—			—			—			5,502
Repurchase of common stock for treasury	(9,495		)	—			—			—			—			(9,495		)
Windfall tax benefits from share-based payment arrangements	6,670			—			—			—			—			6,670
Net cash provided by (used for) financing activities	20,924			456,505			(251,521		)	6,000			—			231,908

	Westlake Chemical Corporation		100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries			Eliminations		Consolidated
Effect of exchange rate changes on cash and cash equivalents	—		—			—		(3,687		)	—		(3,687		)
Net increase (decrease) in cash and cash equivalents	231,761		(4,583		)	89,144		35,845			—		352,167
Cash and cash equivalents at beginning of period	420,948		6,227			—		34,126			—		461,301
Cash and cash equivalents at end of period	$	652,709	$	1,644		$	89,144	$	69,971		$	—	$	813,468

Condensed Consolidating Financial Information for the Nine Months Ended September 30, 2013

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)			Non- Guarantor Subsidiaries			Eliminations			Consolidated
Statement of Cash Flows
Cash flows from operating activities
Net income (loss)	$	439,453		$	446,858		$	402,340		$	(1,639	)	$	(847,559	)	$	439,453
Adjustments to reconcile net income (loss) to net cash (used for)    provided by operating activities
Depreciation and amortization	1,094			59,893			54,539			1,861			—			117,387
Deferred income taxes	(1,102		)	57,279			27,253			13			—			83,443
Net changes in working capital and other	(458,336		)	(421,066		)	(68,604		)	7,664			847,559			(92,783		)
Net cash (used for) provided by operating activities	(18,891		)	142,964			415,528			7,899			—			547,500
Cash flows from investing activities
Acquisition of business	—			(178,309		)	—			—			—			(178,309		)
Additions to equity investments	—			(23,338		)	—			—			—			(23,338		)
Additions to property, plant and equipment	—			(337,158		)	(158,869		)	(2,263		)	—			(498,290		)
Construction of assets pending sale-leaseback	—			(136		)	—			—			—			(136		)
Proceeds from disposition of assets	—			6			—			72			—			78
Proceeds from repayment of loan to affiliate	—			—			—			167			—			167
Proceeds from sales and maturities of securities	239,764			—			—			—			—			239,764
Purchase of securities	(232,286		)	—			—			—			—			(232,286		)
Settlements of derivative instruments	—			—			(2,297		)	—			—			(2,297		)
Net cash provided by (used for) investing activities	7,478			(538,935		)	(161,166		)	(2,024		)	—			(694,647		)
Cash flows from financing activities
Intercompany financing	(130,832		)	(28,499		)	167,629			(8,298		)	—			—
Net distributions prior to WLKP initial public offering	—			421,991			(421,991		)	—			—			—
Dividends paid	(40,204		)	—			—			—			—			(40,204		)
Proceeds from exercise of stock options	3,182			—			—			—			—			3,182
Repurchase of common stock for treasury	(19,409		)	—			—			—			—			(19,409		)
Windfall tax benefits from share-based payment arrangements	5,056			—			—			—			—			5,056
Net cash (used for) provided by financing activities	(182,207		)	393,492			(254,362		)	(8,298		)	—			(51,375		)

	Westlake Chemical Corporation			100% Owned Guarantor Subsidiaries			OpCo (Less Than 100% Owned Guarantor Subsidiary)		Non- Guarantor Subsidiaries			Eliminations		Consolidated
Net decrease in cash and cash equivalents	(193,620		)	(2,479		)	—		(2,423		)	—		(198,522		)
Cash and cash equivalents at beginning of period	753,881			6,973			—		29,224			—		790,078
Cash and cash equivalents at end of period	$	560,261		$	4,494		$	—	$	26,801		$	—	$	591,556

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Basis of Financial Statements (Policies)

9 Months Ended

Sep. 30, 2014

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, 2013 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, 2013 (the "2013 Form 10-K"), filed with the SEC on February 21, 2014. 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, 2013.

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 September 30, 2014, its results of operations for the three and nine months ended September 30, 2014 and 2013 and the changes in its cash position for the nine months ended September 30, 2014 and 2013.

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, 2014 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.

On February 14, 2014, the Company's Board of Directors authorized a two-for-one split of the Company's common stock. Stockholders of record as of February 28, 2014 were entitled to one additional share for every share outstanding, which was distributed on March 18, 2014. The total number of authorized common stock shares and associated par value were unchanged by this stock split. All share amounts and per share data included in the accompanying consolidated financial statements and related notes have been restated to reflect the effect of the stock split.

In March 2014, the Company formed Westlake Chemical Partners LP ("WLKP") to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, WLKP closed its initial public offering of 12,937,500 common units. See Note 19 for additional information. The Company consolidates WLKP and records a noncontrolling interest for the interest in WLKP not owned by the Company.

Recent Accounting Pronouncements

Recent Accounting Pronouncements

Revenue from Contracts with Customers

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. The accounting standard will be effective for reporting periods beginning after December 15, 2016. The Company is in the process of evaluating the impact that the new accounting guidance will have on its consolidated financial position, results of operations and cash flows.

Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern

In August 2014, the FASB issued an accounting standards update on management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern. The new accounting guidance requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if "conditions or events raise substantial doubt about the entity's ability to continue as a going concern." The accounting standard will be effective for reporting periods ending after December 15, 2016 and is not expected to have an impact on the Company's consolidated financial position, results of operations and cash flows.

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Basis of Financial Statements

9 Months Ended

Sep. 30, 2014

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, 2013 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, 2013 (the "2013 Form 10-K"), filed with the SEC on February 21, 2014. 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, 2013.

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 September 30, 2014, its results of operations for the three and nine months ended September 30, 2014 and 2013 and the changes in its cash position for the nine months ended September 30, 2014 and 2013.

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, 2014 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.

On February 14, 2014, the Company's Board of Directors authorized a two-for-one split of the Company's common stock. Stockholders of record as of February 28, 2014 were entitled to one additional share for every share outstanding, which was distributed on March 18, 2014. The total number of authorized common stock shares and associated par value were unchanged by this stock split. All share amounts and per share data included in the accompanying consolidated financial statements and related notes have been restated to reflect the effect of the stock split.

In March 2014, the Company formed Westlake Chemical Partners LP ("WLKP") to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, WLKP closed its initial public offering of 12,937,500 common units. See Note 19 for additional information. The Company consolidates WLKP and records a noncontrolling interest for the interest in WLKP not owned by the Company.

Recent Accounting Pronouncements

Revenue from Contracts with Customers

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. The accounting standard will be effective for reporting periods beginning after December 15, 2016. The Company is in the process of evaluating the impact that the new accounting guidance will have on its consolidated financial position, results of operations and cash flows.

Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern

In August 2014, the FASB issued an accounting standards update on management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern. The new accounting guidance requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if "conditions or events raise substantial doubt about the entity's ability to continue as a going concern." The accounting standard will be effective for reporting periods ending after December 15, 2016 and is not expected to have an impact on the Company's consolidated financial position, results of operations and cash flows.

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Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

Investments in available-for-sale securities were classified as follows:

	September 30, 2014		December 31, 2013
Current	$	—	$	239,388
Non-current	21,066		—
Total available-for-sale securities	$	21,066	$	239,388

Available-for-sale Securities

The cost, gross unrealized gains, gross unrealized losses and fair value of the Company’s available-for-sale securities were as follows:

	September 30, 2014
	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Equity securities	$	15,044	$	6,022	$	—	$	21,066
Total available-for-sale securities	$	15,044	$	6,022	$	—	$	21,066

	December 31, 2013
	Cost		Gross Unrealized Gains		Gross Unrealized Losses (1)			Fair Value
Debt securities
Corporate bonds	$	108,300	$	340	$	(69	)	$	108,571
U.S. government debt (2)	106,335		60		(79		)	106,316
Asset-backed securities	24,478		34		(11		)	24,501
Total available-for-sale securities	$	239,113	$	434	$	(159	)	$	239,388

_____________

(1) All unrealized loss positions were held at a loss for less than 12 months.

(2) U.S. Treasury obligations, U.S. government agency obligations and U.S government agency mortgage-backed securities.

Schedule of Realized Gain (Loss)

	Nine Months Ended September 30,
	2014
Proceeds from sales and maturities of securities	$	342,045
Gross realized gains	$	1,311
Gross realized losses	$	(99	)

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Guarantor Disclosures (Condensed Consolidating Financial Information Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 813,468	$ 461,301	$ 591,556	$ 790,078
Marketable Securities, Current	0	239,388
Accounts receivable, net	592,964	428,457
Inventories	500,552	471,879
Prepaid expenses and other current assets	18,884	13,888
Deferred income taxes	26,080	34,169
Total current assets	1,951,948	1,649,082
Property, plant and equipment, net	2,710,475	2,088,014
Equity investments	70,828	66,875
Other assets, net	393,032	256,938
Total assets	5,126,283	4,060,909
Accounts payable	263,365	249,613
Accrued liabilities	309,671	155,245
Total current liabilities	573,036	404,858
Long-term debt	763,968	763,879
Deferred income taxes	513,773	437,976
Other liabilities	153,158	35,593
Total liabilities	2,003,935	1,642,306
Total Westlake Chemical Corporation stockholders' equity	2,833,861	2,418,603
Noncontrolling interests	288,487	0
Total equity	3,122,348	2,418,603		1,872,256
Total liabilities and equity	5,126,283	4,060,909
Westlake Chemical Corporation
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	652,709	420,948	560,261	753,881
Marketable Securities, Current		239,388
Accounts receivable, net	15,064	3,879
Inventories	0	0
Prepaid expenses and other current assets	137	778
Deferred income taxes	342	441
Total current assets	668,252	665,434
Property, plant and equipment, net	0	0
Equity investments	3,878,703	2,815,752
Other assets, net	34,847	15,393
Total assets	4,581,802	3,496,579
Accounts payable	979,414	316,652
Accrued liabilities	15,448	8,334
Total current liabilities	994,862	324,986
Long-term debt	753,079	752,990
Deferred income taxes	0	0
Other liabilities	0	0
Total liabilities	1,747,941
Total Westlake Chemical Corporation stockholders' equity	2,833,861	2,418,603
Noncontrolling interests	0
Total equity	2,833,861
Total liabilities and equity	4,581,802	3,496,579
100% Owned Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	1,644	6,227	4,494	6,973
Marketable Securities, Current		0
Accounts receivable, net	1,377,250	666,344
Inventories	385,826	339,929
Prepaid expenses and other current assets	14,737	11,055
Deferred income taxes	25,446	28,974
Total current assets	1,804,903	1,052,529
Property, plant and equipment, net	1,451,807	1,318,119
Equity investments	1,207,569	636,461
Other assets, net	351,271	423,901
Total assets	4,815,550	3,431,010
Accounts payable	157,562	100,570
Accrued liabilities	238,225	134,452
Total current liabilities	395,787	235,022
Long-term debt	10,889	10,889
Deferred income taxes	473,343	260,171
Other liabilities	31,616	34,571
Total liabilities	911,635
Total Westlake Chemical Corporation stockholders' equity	3,903,915	2,890,357
Noncontrolling interests	0
Total equity	3,903,915
Total liabilities and equity	4,815,550	3,431,010
OpCo (Less Than 100% Owned Guarantor Subsidiary)
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	89,144	0	0	0
Marketable Securities, Current		0
Accounts receivable, net	58,106	71,812
Inventories	5,551	116,377
Prepaid expenses and other current assets	303	257
Deferred income taxes	0	4,448
Total current assets	153,104	192,894
Property, plant and equipment, net	806,648	762,972
Equity investments	0	10,411
Other assets, net	61,679	75,197
Total assets	1,021,431	1,041,474
Accounts payable	29,856	122,564
Accrued liabilities	3,412	26,688
Total current liabilities	33,268	149,252
Long-term debt	188,523	252,973
Deferred income taxes	1,507	182,855
Other liabilities	0	962
Total liabilities	223,298
Total Westlake Chemical Corporation stockholders' equity	798,133	455,432
Noncontrolling interests	0
Total equity	798,133
Total liabilities and equity	1,021,431	1,041,474
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	69,971	34,126	26,801	29,224
Marketable Securities, Current		0
Accounts receivable, net	170,833	2,755
Inventories	109,175	15,573
Prepaid expenses and other current assets	3,707	1,798
Deferred income taxes	292	306
Total current assets	353,978	54,558
Property, plant and equipment, net	452,020	6,923
Equity investments	356,286	31,518
Other assets, net	137,990	1,199
Total assets	1,300,274	94,198
Accounts payable	100,129	10,649
Accrued liabilities	77,279	1,282
Total current liabilities	177,408	11,931
Long-term debt	0	0
Deferred income taxes	43,155	729
Other liabilities	121,542	60
Total liabilities	342,105
Total Westlake Chemical Corporation stockholders' equity	669,682	81,478
Noncontrolling interests	288,487
Total equity	958,169
Total liabilities and equity	1,300,274	94,198
Eliminations
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Marketable Securities, Current		0
Accounts receivable, net	(1,028,289)	(316,333)
Inventories	0	0
Prepaid expenses and other current assets	0	0
Deferred income taxes	0	0
Total current assets	(1,028,289)	(316,333)
Property, plant and equipment, net	0	0
Equity investments	(5,371,730)	(3,427,267)
Other assets, net	(192,755)	(258,752)
Total assets	(6,592,774)	(4,002,352)
Accounts payable	(1,003,596)	(300,822)
Accrued liabilities	(24,693)	(15,511)
Total current liabilities	(1,028,289)	(316,333)
Long-term debt	(188,523)	(252,973)
Deferred income taxes	(4,232)	(5,779)
Other liabilities	0	0
Total liabilities	(1,221,044)
Total Westlake Chemical Corporation stockholders' equity	(5,371,730)	(3,427,267)
Noncontrolling interests	0
Total equity	(5,371,730)
Total liabilities and equity	$ (6,592,774)	$ (4,002,352)

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Accumulated Other Comprehensive Income (Tables)

9 Months Ended

Sep. 30, 2014

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

Changes in accumulated other comprehensive income (loss) by component for the nine months ended September 30, 2014 and 2013 were as follows:

	Benefits Liability, Net of Tax			Cumulative Foreign Currency Exchange			Net Unrealized Holding Gains on Investments, Net of Tax			Total
Balances at December 31, 2013	$	(6,696	)	$	3,904		$	176		$	(2,616	)
Other comprehensive (loss) income before    reclassifications	(39		)	(37,882		)	4,459			(33,462		)
Amounts reclassified from accumulated other    comprehensive loss	422			—			(777		)	(355		)
Net other comprehensive income (loss) for the period	383			(37,882		)	3,682			(33,817		)
Balances at September 30, 2014	$	(6,313	)	$	(33,978	)	$	3,858		$	(36,433	)

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]

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 and nine months ended September 30, 2014 and 2013:

Details about Accumulated Other Comprehensive    Income (Loss) Components	Location of Reclassification (Income (Expense)) in Consolidated Statements of Operations	Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
Amortization of pension and    other post-retirement items
Prior service costs	(1)	$	(87	)	$	(95	)	$	(261	)	$	(286	)
Net loss	(1)	(153		)	(600		)	(424		)	(1,718		)
		(240		)	(695		)	(685		)	(2,004		)
	Provision for income    taxes	92			267			263			771
		(148		)	(428		)	(422		)	(1,233		)
Net unrealized gains on    available-for-sale    investments
Realized gain on    available-for-sale    investments	Other income, net	—			—			1,212			—
	Provision for income    taxes	—			—			(435		)	—
		—			—			$	777		$	—
Total reclassifications for    the period		$	(148	)	$	(428	)	$	355		$	(1,233	)

_____________

(1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, please read Note 10 (Employee Benefits) to the financial statements included in the 2013 Form 10-K.

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Long-Term Debt (Schedule of Long-term Debt) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$ 763,968	$ 763,879
3.60% Senior Notes Due 2022
Debt Instrument [Line Items]
Maturity	2022
Stated interest rate	3.60%
Senior notes	249,079	248,990
6 1/2% Senior Notes Due 2029
Debt Instrument [Line Items]
Maturity	2029
Stated interest rate	6.50%
Senior notes	100,000	100,000
6 3/4% Senior Notes Due 2032
Debt Instrument [Line Items]
Maturity	2032
Stated interest rate	6.75%
Senior notes	250,000	250,000
2035 GO Zone 6 1/2% Notes
Debt Instrument [Line Items]
Maturity	2035
Stated interest rate	6.50%
Senior notes	89,000	89,000
2035 IKE Zone 6 1/2% Notes
Debt Instrument [Line Items]
Maturity	2035
Stated interest rate	6.50%
Senior notes	65,000	65,000
Loan Related To Tax-Exempt Waste Disposal Revenue Bonds Due 2027
Debt Instrument [Line Items]
Maturity	2027
Non-current loan payable	$ 10,889	$ 10,889

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Segment Information (Additional Information) (Detail)	3 Months Ended
	Sep. 30, 2014 Segment
Segment Reporting [Abstract]
Number of segments	2

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Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 813,468	$ 461,301
Marketable Securities, Current	0	239,388
Accounts receivable, net	592,964	428,457
Inventories	500,552	471,879
Prepaid expenses and other current assets	18,884	13,888
Deferred income taxes	26,080	34,169
Total current assets	1,951,948	1,649,082
Property, plant and equipment, net	2,710,475	2,088,014
Equity investments	70,828	66,875
Other assets, net
Intangible assets, net	222,728	159,046
Deferred charges and other assets	170,304	97,892
Total other assets, net	393,032	256,938
Total assets	5,126,283	4,060,909
Current liabilities
Accounts payable	263,365	249,613
Accrued liabilities	309,671	155,245
Total current liabilities	573,036	404,858
Long-term debt	763,968	763,879
Deferred income taxes	513,773	437,976
Other liabilities	153,158	35,593
Total liabilities	2,003,935	1,642,306
Commitments and contingencies (Notes 7 and 15)
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; 134,680,164 and 134,580,208 shares issued at September 30, 2014 and December 31, 2013, respectively (Note 1)	1,347	1,346
Common stock, held in treasury, at cost; 1,220,544 and 1,252,922 shares at September 30, 2014 and December 31, 2013, respectively (Note 1)	(53,248)	(46,220)
Additional paid-in capital	527,992	511,432
Retained earnings	2,394,203	1,954,661
Accumulated other comprehensive loss	(36,433)	(2,616)
Total Westlake Chemical Corporation stockholders' equity	2,833,861	2,418,603
Noncontrolling interests	288,487	0
Total equity	3,122,348	2,418,603
Total liabilities and equity	$ 5,126,283	$ 4,060,909

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Basis of Financial Statements Basis (Details)	0 Months Ended
	Feb. 14, 2014	Aug. 04, 2014 Limited Partner [Member] Subsidiaries [Member] Westlake Chemical Partners LP [Member] IPO [Member]
Number of units sold in public offering		12,937,500
Stock split conversion ratio	2

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Consolidated Statements of Changes in Stockholders' Equity Statement (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Benefits Liability Net Of Tax [Member]	Cumulative Foreign Currency Exchange [Member]	Unrealized Holding Losses On Investments Net Of Tax [Member]	Noncontrolling Interest [Member]
Amount, beginning balance at Dec. 31, 2012	$ 1,872,256	$ 1,345	$ (13,302)	$ 495,581	$ 1,399,472	$ (16,351)	$ 5,511	$ 0	$ 0
Number of Shares, beginning balance at Dec. 31, 2012		134,374,448	568,986
Net income	610,425				610,425				0
Other comprehensive (loss) income	8,224					9,655	(1,607)	176	0
Common stock repurchased, shares			683,936
Common stock repurchased	(32,918)		(32,918)						0
Shares issued - stock- based compensation, shares	3,437	1		3,436
Shares issued - stock- based compensation		225,924
Stock-based compensation, net of tax on stock options exercised, shares		(20,164)
Stock-based compensation, net of tax on stock options exercised	12,415			12,415
Dividends paid	(55,236)				(55,236)
Amount, ending balance at Dec. 31, 2013	2,418,603	1,346	(46,220)	511,432	1,954,661	(6,696)	3,904	176	0
Number of Shares, ending balance at Dec. 31, 2013		134,580,208	1,252,922
Net income	497,631				495,232				2,399
Net income	495,232
Other comprehensive (loss) income	(33,817)					383	(37,882)	3,682	0
Common stock repurchased, shares			104,163
Common stock repurchased	(9,495)		(9,495)						0
Shares issued - stock- based compensation, shares	5,502	1	2,467	3,034
Shares issued - stock- based compensation		124,566	(136,541)
Stock-based compensation, net of tax on stock options exercised, shares		(24,610)
Stock-based compensation, net of tax on stock options exercised	13,526			13,526
Dividends paid	(55,690)				(55,690)
Issuance of Westlake Chemical Partners LP common units	286,088								286,088
Amount, ending balance at Sep. 30, 2014	$ 3,122,348	$ 1,347	$ (53,248)	$ 527,992	$ 2,394,203	$ (6,313)	$ (33,978)	$ 3,858	$ 288,487
Number of Shares, ending balance at Sep. 30, 2014		134,680,164	1,220,544

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Fair Value Measurements (Summary of Assets and Liabilities Accounted at Fair Value on Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for Sale	$ 0	$ 239,388
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for Sale	21,066	239,388
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for Sale	21,066	91,595
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for Sale	0	147,793
Recurring | Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk management assets - Commodity forward contracts	451	296
Risk management liabilities - Commodity forward contracts	(6,477)	(176)
Recurring | Forward Contracts [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk management assets - Commodity forward contracts	428	48
Risk management liabilities - Commodity forward contracts	(119)	0
Recurring | Forward Contracts [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk management assets - Commodity forward contracts	23	248
Risk management liabilities - Commodity forward contracts	$ (6,358)	$ (176)

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Long-Term Debt (Tables)

9 Months Ended

Sep. 30, 2014

Debt Disclosure [Abstract]

Schedule Of Long-Term Debt

Long-term debt consists of the following:

	September 30, 2014		December 31, 2013
3.60% senior notes due 2022	$	249,079	$	248,990
6 ½% senior notes due 2029	100,000		100,000
6 ¾% senior notes due 2032	250,000		250,000
6 ½% senior notes due 2035 (the "6 ½% GO Zone Senior Notes Due 2035")	89,000		89,000
6 ½% senior notes due 2035 (the "6 ½% IKE Zone Senior Notes Due 2035")	65,000		65,000
Loan related to tax-exempt waste disposal revenue bonds due 2027	10,889		10,889
Long-term debt, net	$	763,968	$	763,879

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Pension and Post-Retirement Benefit Costs (Components of Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 331	$ 275	$ 498	$ 815
Interest cost	1,138	515	2,309	1,531
Expected return on plan assets	(777)	(713)	(2,363)	(2,140)
Amortization of prior service cost	74	74	223	223
Amortization of net loss	71	510	204	1,449
Net periodic benefit cost	837	661	871	1,878
Post-Retirement Healthcare
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	2	16	7
Interest cost	185	147	548	442
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	13	21	38	63
Amortization of net loss	82	90	220	269
Net periodic benefit cost	$ 286	$ 260	$ 822	$ 781

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Commitments and Contingencies

9 Months Ended

Sep. 30, 2014

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments and Contingencies

The Company is subject to environmental laws and regulations that can impose civil and criminal sanctions and that may require it to mitigate the effects of contamination caused by the release or disposal of hazardous substances into the environment. Under one law, the U.S. Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), an owner or operator of property may be held strictly liable for remediating contamination without regard to whether that person caused the contamination, and without regard to whether the practices that resulted in the contamination were legal at the time they occurred. Because several of the Company's production sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on the Company.

Contract Disputes with Goodrich and PolyOne. In connection with the 1990 and 1997 acquisitions of the Goodrich Corporation ("Goodrich") chemical manufacturing complex in Calvert City, Kentucky, Goodrich agreed to indemnify the Company for any liabilities related to preexisting contamination at the complex. For its part, the Company agreed to indemnify Goodrich for post-closing contamination caused by the Company's operations. The soil and groundwater at the complex, which does not include the Company's nearby polyvinyl chloride ("PVC") facility, had been extensively contaminated under Goodrich's operations. In 1993, Goodrich spun off the predecessor of PolyOne Corporation ("PolyOne"), and that predecessor assumed Goodrich's indemnification obligations relating to preexisting contamination.

In 2003, litigation arose among the Company, Goodrich and PolyOne with respect to the allocation of the cost of remediating contamination at the site. The parties settled this litigation in December 2007 and the case was dismissed. In the settlement the parties agreed that, among other things: (1) PolyOne would pay 100% of the costs (with specified exceptions), net of recoveries or credits from third parties, incurred with respect to environmental issues at the Calvert City site from August 1, 2007 forward; (2) either the Company or PolyOne might, from time to time in the future (but not more than once every five years), institute an arbitration proceeding to adjust that percentage; and (3) the Company and PolyOne would negotiate a new environmental remediation utilities and services agreement to cover the Company's provision to, or on behalf of, PolyOne of certain environmental remediation services at the site. The current environmental remediation activities at the Calvert City complex do not have a specified termination date but are expected to last for the foreseeable future. The costs incurred by the Company that have been invoiced to PolyOne to provide the environmental remediation services were $3,284 in 2013. By letter dated March 16, 2010, PolyOne notified the Company that it was initiating an arbitration proceeding under the settlement agreement. In this proceeding, PolyOne seeks to readjust the percentage allocation of costs and to recover approximately $1,400 from the Company in reimbursement of previously paid remediation costs. The arbitration is currently stayed.

State Administrative Proceedings. There are several administrative proceedings in Kentucky involving the Company, Goodrich and PolyOne related to the same manufacturing complex in Calvert City. In 2003, the Kentucky Environmental and Public Protection Cabinet (the "Cabinet") re-issued Goodrich's Resource Conservation and Recovery Act ("RCRA") permit which requires Goodrich to remediate contamination at the Calvert City manufacturing complex. Both Goodrich and PolyOne challenged various terms of the permit in an attempt to shift Goodrich's clean-up obligations under the permit to the Company. The Company intervened in the proceedings. The Cabinet has suspended all corrective action under the RCRA permit in deference to a remedial investigation and feasibility study ("RIFS") being conducted, under the auspices of the U.S. Environmental Protection Agency ("EPA"), pursuant to an Administrative Settlement Agreement ("AOC"), which became effective on December 9, 2009. See "Federal Administrative Proceedings" below. The proceedings have been postponed. Periodic status conferences will be held to evaluate whether additional proceedings will be required.

Federal Administrative Proceedings. In May 2009, the Cabinet sent a letter to the EPA requesting the EPA's assistance in addressing contamination at the Calvert City site under CERCLA. In its response to the Cabinet also in May 2009, the EPA stated that it concurred with the Cabinet's request and would incorporate work previously conducted under the Cabinet's RCRA authority into the EPA's cleanup efforts under CERCLA. Since 1983, the EPA has been addressing contamination at an abandoned landfill adjacent to the Company's plant which had been operated by Goodrich and which was being remediated pursuant to CERCLA. During the past three years, the EPA has directed Goodrich and PolyOne to conduct additional investigation activities at the landfill and at the Company's plant. In June 2009, the EPA notified the Company that the Company may have potential liability under section 107(a) of CERCLA at its plant site. Liability under section 107(a) of CERCLA is strict and joint and several. The EPA also identified Goodrich and PolyOne, among others, as potentially responsible parties at the plant site. The Company negotiated, in conjunction with the other potentially responsible parties, the AOC and an order to conduct the RIFS. On July 12, 2013, the parties submitted separate draft RIFS reports to the EPA. The EPA has hired a contractor to complete the remedial investigation report.

Monetary Relief. Except as noted above with respect to the settlement of the contract litigation among the Company, Goodrich and PolyOne, none of the court, the Cabinet nor the EPA has established any allocation of the costs of remediation among the various parties that are involved in the judicial and administrative proceedings discussed above. At this time, the Company is not able to estimate the loss or reasonable possible loss, if any, on the Company's financial statements that could result from the resolution of these proceedings. Any cash expenditures that the Company might incur in the future with respect to the remediation of contamination at the complex would likely be spread out over an extended period. As a result, the Company believes it is unlikely that any remediation costs allocable to it will be material in terms of expenditures made in any individual reporting period.

In addition to the matters described above, the Company is involved in various routine legal proceedings incidental to the conduct of its business. The Company does not believe that any of these routine legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows.

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Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2014

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Fair Values of Derivatives Instruments in Consolidated Balance Sheets

The fair values of derivative instruments in the Company's consolidated balance sheets were as follows:

	Derivative Assets
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
Not designated as hedging instruments
Commodity forward contracts	Accounts receivable, net	$	451	$	296
Total derivative assets		$	451	$	296

	Derivative Liabilities
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
Not designated as hedging instruments
Commodity forward contracts	Accrued liabilities	$	6,477	$	176
Total derivative liabilities		$	6,477	$	176

Impact of Derivatives Instruments Designated as Fair Value Hedges

The following tables reflect the impact of derivative instruments designated as fair value hedges and the related hedged item on the Company's consolidated statements of operations. For the three and nine months ended September 30, 2013, there was no material ineffectiveness with regard to the Company's qualifying fair value hedges.

Derivatives in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Derivative	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
Commodity forward contracts	Cost of sales	$	—	$	(232	)	$	—	$	(342	)
Hedged Items in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Hedged Items	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
Firm commitment designated    as the hedged item	Cost of sales	$	—	$	236		$	—	$	15

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 September 30,					Nine Months Ended September 30,
		2014			2013		2014			2013
Commodity forward contracts	Gross profit	$	(6,937	)	$	4,854	$	(7,308	)	$	9,897

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Supplemental Information

9 Months Ended

Sep. 30, 2014

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Supplemental Information

Supplemental Information

Other Liabilities

Other liabilities were $153,158 and $35,593 at September 30, 2014 and December 31, 2013, respectively. Non-current pension obligation, which is a component of other liabilities, was $117,293 and $8,710 at September 30, 2014 and December 31, 2013, respectively. No other component of other liabilities was more than five percent of total liabilities.

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Accumulated Other Comprehensive Income Reclassifications in AOCI (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income taxes	$ 294,605		$ 263,018		$ 797,862		$ 684,100
Realized gain on available-for-sale investments	(2,670)		(287)		4,440		3,137
Provision for income taxes	(124,449)		(92,728)		(300,231)		(244,647)
Net income to Westlake Chemical Corporation	167,757		170,290		495,232		439,453
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income to Westlake Chemical Corporation	(148)		(428)		355		(1,233)
Accumulated Defined Benefit Plans Adjustment | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Prior service costs	(87)	[1]	(95)	[1]	(261)	[1]	(286)	[2]
Net loss	(153)	[1]	(600)	[1]	(424)	[1]	(1,718)	[2]
Income before income taxes	(240)		(695)		(685)		(2,004)
Provision for income taxes	92		267		263		771
Net income to Westlake Chemical Corporation	(148)		(428)		(422)		(1,233)
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Realized gain on available-for-sale investments	0		0		1,212		0
Provision for income taxes	0		0		(435)		0
Net income to Westlake Chemical Corporation	$ 0		$ 0		$ 777		$ 0

[1] These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, please read Note 10 (Employee Benefits) to the financial statements included in the 2013 Form 10-K.

[2] Share amounts and per share data for the three and nine months ended September 30, 2013 have been restated to reflect the effect of a two-for-one stock split on March 18, 2014. See Note 1 for additional information.

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Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities
Net income	$ 497,631	$ 439,453
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	148,394	116,294
Provision for doubtful accounts	295	3,600
Amortization of debt issuance costs	1,172	1,093
Stock-based compensation expense	6,856	4,804
Loss from disposition of fixed assets	2,635	4,679
Deferred income taxes	34,459	83,443
Windfall tax benefits from share-based payment arrangements	(6,670)	(5,056)
(Income) loss from equity method investments, net of dividends	(3,199)	1,586
Other gains, net	(495)	0
Changes in operating assets and liabilities
Accounts receivable	6,055	(18,874)
Inventories	80,492	(26,325)
Prepaid expenses and other current assets	458	(5,038)
Accounts payable	(98,769)	19,518
Accrued liabilities	111,965	(15,755)
Other, net	(5,155)	(55,922)
Net cash provided by operating activities	776,124	547,500
Cash flows from investing activities
Acquisition of business, net of cash acquired	(611,087)	(178,309)
Additions to equity investments	0	(23,338)
Additions to property, plant and equipment	(311,183)	(498,290)
Construction of assets pending sale-leaseback	0	(136)
Proceeds from disposition of assets	145	78
Proceeds from repayment of loan acquired	45,923	0
Proceeds from repayment of loan to affiliate	0	167
Proceeds from sale and maturities of securities	342,045	239,764
Purchase of securities and other investments	(117,332)	(232,286)
Settlements of derivative instruments	(689)	(2,297)
Net cash used for investing activities	(652,178)	(694,647)
Cash flows from financing activities
Capitalized debt issuance costs	(1,167)
Dividends paid	(55,690)	(40,204)
Net proceeds from issuance of Westlake Chemical Partners LP common units	286,088	0
Proceeds from exercise of stock options	5,502	3,182
Repurchase of common stock for treasury	(9,495)	(19,409)
Windfall tax benefits from share-based payment arrangements	6,670	5,056
Net cash provided by financing activities	231,908	(51,375)
Effect of exchange rate changes on cash	(3,687)	0
Net increase in cash and cash equivalents	352,167	(198,522)
Cash and cash equivalents at beginning of period	461,301	790,078
Cash and cash equivalents at end of period	$ 813,468	$ 591,556

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Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 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	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	150,000,000
Common stock, shares issued	134,680,164	134,580,208
Common stock, held in treasury	1,220,544	1,252,922

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Fair Value Measurements

9 Months Ended

Sep. 30, 2014

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:

	September 30, 2014
	Level 1			Level 2			Total
Derivative instruments
Risk management assets - Commodity forward contracts	$	428		$	23		$	451
Risk management liabilities - Commodity forward contracts	(119		)	(6,358		)	(6,477		)
Available-for-sale marketable securities	21,066			—			21,066
	December 31, 2013
	Level 1			Level 2			Total
Derivative instruments
Risk management assets - Commodity forward contracts	$	48		$	248		$	296
Risk management liabilities - Commodity forward contracts	—			(176		)	(176		)
Available-for-sale marketable securities	91,595			147,793			239,388

The Level 2 measurements for the Company's commodity contracts are derived using forward curves supplied by industry-recognized and unrelated third-party services. The Level 2 measurements for the Company's available-for-sale securities are derived using market-based pricing provided by unrelated third-party services.

There were no transfers in or out of Levels 1 and 2 of the fair value hierarchy for the nine months ended September 30, 2014 and 2013.

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 long-term debt, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Company's long-term debt are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy.

	September 30, 2014				December 31, 2013
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.60% senior notes due 2022	$	249,079	$	247,633	$	248,990	$	236,905
6 ½% senior notes due 2029	100,000		114,624		100,000		109,490
6 ¾% senior notes due 2032	250,000		275,313		250,000		265,148
6 ½% GO Zone Senior Notes Due 2035	89,000		101,855		89,000		94,606
6 ½% IKE Zone Senior Notes Due 2035	65,000		74,389		65,000		69,094
Loan related to tax-exempt waste disposal revenue    bonds due 2027	10,889		10,889		10,889		10,889

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Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q3
Trading Symbol	WLK
Entity Registrant Name	WESTLAKE CHEMICAL CORP
Entity Central Index Key	0001262823
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		133,082,630

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Income Taxes

9 Months Ended

Sep. 30, 2014

Income Tax Disclosure [Abstract]

Income Taxes

Income Taxes

The effective income tax rate was 37.6% for the nine months ended September 30, 2014. The effective income tax rate for the 2014 period was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, partially offset by the domestic manufacturing deduction. The effective income tax rate was 35.8% for the nine months ended September 30, 2013. The effective income tax rate for the 2013 period was above the U.S. federal statutory rate of 35.0% primarily due to state income taxes, partially offset by the domestic manufacturing deduction.

There was no material change to the total gross unrecognized tax benefits for the nine months ended September 30, 2014. Management anticipates that all of the gross unrecognized tax benefits of $2,501 will be recognized within the next twelve months due to expiring statutes of limitations. The impact from the recognition of these tax benefits on the Company's effective tax rate is expected to be immaterial.

The Company recognizes penalties and interest accrued related to unrecognized tax benefits in income tax expense. As of September 30, 2014, the Company had no material accrued interest and penalties related to uncertain tax positions.

The Company files income tax returns in the U.S. federal jurisdiction, various states and foreign jurisdictions. The Company is no longer subject to examinations by tax authorities before the year 2007.

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Acquisitions (Purchase Consideration Transferred) (Details) (Vinnolit [Member], USD $) In Thousands, unless otherwise specified	0 Months Ended
	Jul. 31, 2014		Jul. 31, 2014
Business Acquisition [Line Items]
Cash paid to Sellers	$ 309,619
Cash deposited in escrow	13,390	[1]
Retirement of long-term debt as of July 31, 2014, on behalf of the Sellers	413,215	[2]
Total purchase consideration	736,224
Assets:
Cash			125,137
Working capital, excluding inventory and cash			23,072	[3]
Inventories			114,961	[4]
Property, plant and equipment			471,123
Investments			51,552
Other assets			65,366	[5]
Intangible assets:
Deferred income tax asset - current			8,697
Deferred income tax asset - non-current			27,387
Liabilities:
Pension obligation			(117,970)
Other long-term liabilities			(10,723)
Power purchase agreement liability			(10,826)	[6]
Deferred income tax liability - current			(6,845)
Deferred income tax liability - non-current			(77,899)
Total identifiable net assets			736,224
Goodwill			0	[7]
Consideration transferred			736,224
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables			181,826	[3]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables, Gross Contractual Amount			183,769	[3]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Uncollectable Receivables			1,943	[3]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Adjustment			16,900	[3]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Power Purchase Agreement Liability, Weighted Average Life	36 months	[2]
Trademarks and Trade Names [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	20 years
Intangible assets:
Intangible assets			40,170
Developed Technology Rights [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	20 years
Intangible assets:
Intangible assets			31,600
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years 4 months 24 days
Intangible assets:
Intangible assets			$ 1,422

[1] None of the cash held in escrow is considered contingent consideration as it is expected to be released to the Sellers pending the Sellers’ satisfaction of general representations and warranties made in connection with the execution of the purchase agreement.

[2] Vinnolit’s long-term debt paid on behalf of the Sellers was not legally assumed by Westlake in the acquisition and was a condition of the consummation of the purchase agreement. Therefore, the retirement has been included in the total purchase consideration.

[3] The fair value of accounts receivable acquired is $181,826, with the gross contractual amount being $183,769. The Company expects $1,943 to be uncollectible.

[4] An adjustment of approximately $16,900 was recorded to reflect Vinnolit's inventories at fair value and increased cost of sales by the same amount for the three months ended September 30, 2014.

[5] Included in other assets was a loan acquired that was repaid prior to September 30, 2014.

[6] A liability arising from unfavorable forward purchase contracts for the purchase of power was recognized at fair value. This liability will be amortized over a period of approximately 3.0 years, being the weighted-average life of the forward purchase contracts.

[7] Management estimated that the fair value of the net assets acquired equals consideration paid. Therefore, no goodwill was recorded.

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Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Income Statement [Abstract]
Net sales	$ 1,253,227		$ 1,004,165		$ 3,279,479		$ 2,807,859
Cost of sales	891,707		699,694		2,324,978		2,002,092
Gross profit	361,520		304,471		954,501		805,767
Selling, general and administrative expenses	54,759		37,869		132,897		109,883
Income from operations	306,761		266,602		821,604		695,884
Other income (expense)
Interest expense	(9,486)		(3,297)		(28,182)		(14,921)
Other (expense) income, net	(2,670)		(287)		4,440		3,137
Income before income taxes	294,605		263,018		797,862		684,100
Provision for income taxes	124,449		92,728		300,231		244,647
Net income	170,156		170,290		497,631		439,453
Net income attributable to noncontrolling interests	2,399		0		2,399		0
Net income to Westlake Chemical Corporation	$ 167,757		$ 170,290		$ 495,232		$ 439,453
Earnings per share:
Basic	$ 1.26	[1]	$ 1.28	[1]	$ 3.71	[1]	$ 3.29	[1]
Diluted	$ 1.25	[1]	$ 1.27	[1]	$ 3.69	[1]	$ 3.27	[1]
Weighted average shares outstanding:
Basic	133,299,458	[1]	133,257,494	[1]	133,199,304	[1]	133,256,054	[1]
Diluted	133,846,059	[1]	133,811,108	[1]	133,743,145	[1]	133,806,758	[1]
Dividends per common share	$ 0.1650		$ 0.1125		$ 0.4170		$ 0.3000

[1] Share amounts and per share data for the three and nine months ended September 30, 2013 have been restated to reflect the effect of a two-for-one stock split on March 18, 2014. See Note 1 for additional information.

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Property, Plant and Equipment

9 Months Ended

Sep. 30, 2014

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, Plant and Equipment

As of September 30, 2014, the Company had property, plant and equipment, net totaling $2,710,475. 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 $45,080 and $32,460 is included in cost of sales in the consolidated statements of operations for the three months ended September 30, 2014 and 2013, respectively. Depreciation expense on property, plant and equipment of $123,000 and $95,995 is included in cost of sales in the consolidated statements of operations for the nine months ended September 30, 2014 and 2013, respectively.

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Inventories

9 Months Ended

Sep. 30, 2014

Inventory Disclosure [Abstract]

Inventories

Inventories

Inventories consist of the following:

	September 30, 2014		December 31, 2013
Finished products	$	268,969	$	232,658
Feedstock, additives and chemicals	166,268		180,646
Materials and supplies	65,315		58,575
Inventories	$	500,552	$	471,879

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Share Capital

9 Months Ended

Sep. 30, 2014

Equity [Abstract]

Share Capital

Share Capital

Common Stock

On May 16, 2014, the stockholders of the Company approved an amendment to the Company's Amended and Restated Certificate of Incorporation to increase the Company's authorized shares of common stock from 150,000,000 shares to 300,000,000 shares, par value $0.01 per share. The Company is now authorized to issue 300,000,000 shares of common stock, par value $0.01 per share, of which 134,680,164 and 134,580,208 shares (on a post-split basis) were issued as of September 30, 2014 and December 31, 2013, respectively. Each share of common stock entitles the holder to one vote on all matters on which holders are permitted to vote, including the election of directors.

Stock Repurchase Program

In August 2011, the Company's Board of Directors authorized a stock repurchase program of the Company’s common stock totaling $100,000 (the "2011 Program"). Purchases under the 2011 Program began in September 2011. As of September 30, 2014 and December 31, 2013, the Company had repurchased 1,357,085 and 1,252,922 shares, respectively, of its common stock (on a post-split basis) under this program. Shares repurchased under the 2011 Program are held by the Company as treasury stock and may be used for general corporate purposes, including for the 2013 Omnibus Incentive Plan. Beginning in May 2014, the Company began issuing treasury shares to employees and nonemployee directors for options exercised and for the settlement of restricted stock units. The cost of treasury shares issued was determined using the specific identification method.

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Earnings per Share

9 Months Ended

Sep. 30, 2014

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 September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Net income attributable to Westlake Chemical    Corporation	$	167,757		$	170,290		$	495,232		$	439,453
Less:
Net income attributable to participating securities	(353		)	(587		)	(1,099		)	(1,691		)
Net income attributable to common shareholders	$	167,404		$	169,703		$	494,133		$	437,762

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 September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
Weighted average common shares—basic (1)	133,299,458		133,257,494		133,199,304		133,256,054
Plus incremental shares from:
Assumed exercise of options (1)	546,601		553,614		543,841		550,704
Weighted average common shares—diluted (1)	133,846,059		133,811,108		133,743,145		133,806,758
Earnings per common share attributable to    Westlake Chemical Corporation : (1)
Basic	$	1.26	$	1.28	$	3.71	$	3.29
Diluted	$	1.25	$	1.27	$	3.69	$	3.27

_____________

(1) Share amounts and per share data for the three and nine months ended September 30, 2013 have been restated to reflect the effect of a two-for-one stock split on March 18, 2014. See Note 1 for additional information.

There were no options excluded from the computation of diluted earnings per share for the three and nine months ended September 30, 2014. Excluded from the computation of diluted earnings per share for the three and nine months ended September 30, 2013 are options to purchase 137,324 and 115,518 shares of common stock, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive.

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Guarantor Disclosures (Condensed Consolidating Financial Information Statement of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,253,227	$ 1,004,165	$ 3,279,479	$ 2,807,859
Cost of sales	891,707	699,694	2,324,978	2,002,092
Gross profit	361,520	304,471	954,501	805,767
Selling, general and administrative expenses	54,759	37,869	132,897	109,883
Income from operations	306,761	266,602	821,604	695,884
Interest expense	(9,486)	(3,297)	(28,182)	(14,921)
Other (expense) income, net	(2,670)	(287)	4,440	3,137
Income before income taxes	294,605	263,018	797,862	684,100
Provision for (benefit from) income taxes	124,449	92,728	300,231	244,647
Equity in net income of subsidiaries	0	0	0	0
Net income	170,156	170,290	497,631	439,453	610,425
Net income attributable to noncontrolling interests	2,399	0	2,399	0
Net income to Westlake Chemical Corporation	167,757	170,290	495,232	439,453
Comprehensive income (loss)	131,456	171,095	461,415	439,372
Westlake Chemical Corporation
Condensed Financial Statements, Captions [Line Items]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative expenses	399	514	1,474	1,576
Income from operations	(399)	(514)	(1,474)	(1,576)
Interest expense	(10,343)	(3,292)	(29,032)	(14,882)
Other (expense) income, net	2,138	3,585	14,488	7,490
Income before income taxes	(8,604)	(221)	(16,018)	(8,968)
Provision for (benefit from) income taxes	(3,088)	(70)	(5,686)	(3,202)
Equity in net income of subsidiaries	173,273	170,441	505,564	445,219
Net income	167,757		495,232	439,453
Net income attributable to noncontrolling interests	0		0
Net income to Westlake Chemical Corporation	167,757	170,290	495,232	439,453
Comprehensive income (loss)	131,456	171,095	461,415	439,372
100% Owned Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	1,026,282	844,081	2,809,844	2,407,341
Cost of sales	831,675	754,037	2,476,608	2,247,338
Gross profit	194,607	90,044	333,236	160,003
Selling, general and administrative expenses	36,445	29,323	123,050	84,152
Income from operations	158,162	60,721	210,186	75,851
Interest expense	(2)	(5)	(8)	(39)
Other (expense) income, net	(2,942)	(2,688)	(1,729)	(4,002)
Income before income taxes	155,218	58,028	208,449	71,810
Provision for (benefit from) income taxes	93,366	19,973	109,920	27,292
Equity in net income of subsidiaries	113,157	132,581	410,875	402,340
Net income	175,009		509,404	446,858
Net income attributable to noncontrolling interests	0		0
Net income to Westlake Chemical Corporation	175,009	170,636	509,404	446,858
Comprehensive income (loss)	175,137	170,764	509,787	447,490
OpCo (Less Than 100% Owned Guarantor Subsidiary)
Condensed Financial Statements, Captions [Line Items]
Net sales	392,008	540,133	1,476,157	1,565,809
Cost of sales	227,015	327,152	832,304	924,663
Gross profit	164,993	212,981	643,853	641,146
Selling, general and administrative expenses	8,014	6,391	21,957	19,326
Income from operations	156,979	206,590	621,896	621,820
Interest expense	(2,137)	(2,295)	(9,833)	(4,893)
Other (expense) income, net	486	1,162	3,135	6,422
Income before income taxes	155,328	205,457	615,198	623,349
Provision for (benefit from) income taxes	36,309	72,876	198,461	221,009
Equity in net income of subsidiaries	0	0	0	0
Net income	119,019		416,737	402,340
Net income attributable to noncontrolling interests	0		0
Net income to Westlake Chemical Corporation	119,019	132,581	416,737	402,340
Comprehensive income (loss)	119,019	132,581	416,737	402,340
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	208,313	13,337	229,183	37,561
Cost of sales	202,110	11,891	221,233	32,943
Gross profit	6,203	1,446	7,950	4,618
Selling, general and administrative expenses	14,184	1,641	16,954	4,829
Income from operations	(7,981)	(195)	(9,004)	(211)
Interest expense	(39)	0	(39)	0
Other (expense) income, net	683	(51)	(724)	(1,880)
Income before income taxes	(7,337)	(246)	(9,767)	(2,091)
Provision for (benefit from) income taxes	(2,138)	(51)	(2,464)	(452)
Equity in net income of subsidiaries	5,862	0	5,862	0
Net income	663		(1,441)	(1,639)
Net income attributable to noncontrolling interests	2,399		2,399
Net income to Westlake Chemical Corporation	(1,736)	(195)	(3,840)	(1,639)
Comprehensive income (loss)	(39,528)	351	(41,722)	(2,483)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net sales	(373,376)	(393,386)	(1,235,705)	(1,202,852)
Cost of sales	(369,093)	(393,386)	(1,205,167)	(1,202,852)
Gross profit	(4,283)	0	(30,538)	0
Selling, general and administrative expenses	(4,283)	0	(30,538)	0
Income from operations	0	0	0	0
Interest expense	3,035	2,295	10,730	4,893
Other (expense) income, net	(3,035)	(2,295)	(10,730)	(4,893)
Income before income taxes	0	0	0	0
Provision for (benefit from) income taxes	0	0	0	0
Equity in net income of subsidiaries	(292,292)	(303,022)	(922,301)	(847,559)
Net income	(292,292)		(922,301)	(847,559)
Net income attributable to noncontrolling interests	0		0
Net income to Westlake Chemical Corporation	(292,292)	(303,022)	(922,301)	(847,559)
Comprehensive income (loss)	$ (254,628)	$ (303,696)	$ (884,802)	$ (847,347)

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Stock-Based Compensation

9 Months Ended

Sep. 30, 2014

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 nonemployee 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 nonemployee 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 $2,346 and $1,680 for the three months ended September 30, 2014 and 2013, respectively, and $6,856 and $4,804 for the nine months ended September 30, 2014 and 2013, respectively.

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Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended					3 Months Ended					3 Months Ended					3 Months Ended					3 Months Ended					3 Months Ended
	Sep. 30, 2014 3.60% Senior Notes Due 2022	Sep. 30, 2014 3.60% Senior Notes Due 2022 Carrying Value	Dec. 31, 2013 3.60% Senior Notes Due 2022 Carrying Value	Sep. 30, 2014 3.60% Senior Notes Due 2022 Fair Value	Dec. 31, 2013 3.60% Senior Notes Due 2022 Fair Value	Sep. 30, 2014 6 1/2% Senior Notes Due 2029	Sep. 30, 2014 6 1/2% Senior Notes Due 2029 Carrying Value	Dec. 31, 2013 6 1/2% Senior Notes Due 2029 Carrying Value	Sep. 30, 2014 6 1/2% Senior Notes Due 2029 Fair Value	Dec. 31, 2013 6 1/2% Senior Notes Due 2029 Fair Value	Sep. 30, 2014 6 3/4% Senior Notes Due 2032	Sep. 30, 2014 6 3/4% Senior Notes Due 2032 Carrying Value	Dec. 31, 2013 6 3/4% Senior Notes Due 2032 Carrying Value	Sep. 30, 2014 6 3/4% Senior Notes Due 2032 Fair Value	Dec. 31, 2013 6 3/4% Senior Notes Due 2032 Fair Value	Sep. 30, 2014 2035 GO Zone 6 1/2% Notes	Sep. 30, 2014 2035 GO Zone 6 1/2% Notes Carrying Value	Dec. 31, 2013 2035 GO Zone 6 1/2% Notes Carrying Value	Sep. 30, 2014 2035 GO Zone 6 1/2% Notes Fair Value	Dec. 31, 2013 2035 GO Zone 6 1/2% Notes Fair Value	Sep. 30, 2014 2035 IKE Zone 6 1/2% Notes	Sep. 30, 2014 2035 IKE Zone 6 1/2% Notes Carrying Value	Dec. 31, 2013 2035 IKE Zone 6 1/2% Notes Carrying Value	Sep. 30, 2014 2035 IKE Zone 6 1/2% Notes Fair Value	Dec. 31, 2013 2035 IKE Zone 6 1/2% Notes Fair Value	Sep. 30, 2014 Loan Related To Tax-Exempt Waste Disposal Revenue Bonds Due 2027	Sep. 30, 2014 Loan Related To Tax-Exempt Waste Disposal Revenue Bonds Due 2027 Carrying Value	Dec. 31, 2013 Loan Related To Tax-Exempt Waste Disposal Revenue Bonds Due 2027 Carrying Value	Sep. 30, 2014 Loan Related To Tax-Exempt Waste Disposal Revenue Bonds Due 2027 Fair Value	Dec. 31, 2013 Loan Related To Tax-Exempt Waste Disposal Revenue Bonds Due 2027 Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Maturity	2022					2029					2032					2035					2035					2027
Stated interest rate	3.60%					6.50%					6.75%					6.50%					6.50%
Senior notes		$ 249,079	$ 248,990	$ 247,633	$ 236,905		$ 100,000	$ 100,000	$ 114,624	$ 109,490		$ 250,000	$ 250,000	$ 275,313	$ 265,148		$ 89,000	$ 89,000	$ 101,855	$ 94,606		$ 65,000	$ 65,000	$ 74,389	$ 69,094
Loans																											$ 10,889	$ 10,889	$ 10,889	$ 10,889

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Other Assets

9 Months Ended

Sep. 30, 2014

Other Assets [Abstract]

Other Assets

Other Assets

Amortization expense on intangible and other assets of $9,283 and $8,634 is included in the consolidated statements of operations for the three months ended September 30, 2014 and 2013, respectively. Amortization expense on intangible and other assets of $26,566 and $21,392 is included in the consolidated statements of operations for the nine months ended September 30, 2014 and 2013, respectively.

Goodwill

Goodwill for the Olefins segment was $29,990 at September 30, 2014 and December 31, 2013. Goodwill for the Vinyls segment was $32,026 at September 30, 2014 and December 31, 2013. There were no changes in the carrying amount of goodwill by operating segments for the nine months ended September 30, 2014.

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Long-Term Debt

9 Months Ended

Sep. 30, 2014

Debt Disclosure [Abstract]

Long-Term Debt

Long-Term Debt

Long-term debt consists of the following:

	September 30, 2014		December 31, 2013
3.60% senior notes due 2022	$	249,079	$	248,990
6 ½% senior notes due 2029	100,000		100,000
6 ¾% senior notes due 2032	250,000		250,000
6 ½% senior notes due 2035 (the "6 ½% GO Zone Senior Notes Due 2035")	89,000		89,000
6 ½% senior notes due 2035 (the "6 ½% IKE Zone Senior Notes Due 2035")	65,000		65,000
Loan related to tax-exempt waste disposal revenue bonds due 2027	10,889		10,889
Long-term debt, net	$	763,968	$	763,879

Revolving Credit Facility

The Company has a $400,000 senior secured revolving credit facility. In July 2014, the Company entered into a third amendment and restatement to the revolving credit facility. The amendment and restatement extended the scheduled maturity date of the facility from September 16, 2016 to July 17, 2019, reduced the interest rate and facility fee payable under the facility and amended the covenants restricting the Company’s ability to make distributions and acquisitions and make investments, among other things. The facility includes a provision permitting the Company to increase the size of the facility, up to four times, in increments of at least $25,000 each (up to a maximum of $200,000) under certain circumstances if lenders agree to commit to such an increase.

At September 30, 2014, the Company had no borrowings outstanding under the revolving credit facility. Any borrowings under the facility will bear interest at either LIBOR plus a spread ranging from 1.75% to 1.25%, provided that so long as the Company is rated investment grade, the margin for LIBOR loans will not exceed 1.50%, or a base rate plus a spread ranging from 0.50% to 0.00%. The revolving credit facility also requires an unused commitment fee of 0.25% per annum. All interest rates under the facility are subject to monthly grid pricing adjustments based on prior month average daily loan availability. The revolving credit facility matures on July 17, 2019. As of September 30, 2014, the Company had outstanding letters of credit totaling $32,399 and borrowing availability of $367,601 under the revolving credit facility.

The Company's revolving credit facility generally restricts the Company's ability to make distributions unless, on a pro forma basis after giving effect to the distribution, the borrowing availability under the facility equals or exceeds the greater of (1) 20% of the commitments under the facility and (2) $80,000; or the borrowing availability under the facility equals or exceeds the greater of (1) 15% of the commitments under the facility and (2) $60,000, and the Company's fixed charge coverage ratio is at least 1.0:1. However, the Company may make specified distributions up to an aggregate of $75,000, to be increased by 5% in 2015, and in each fiscal year thereafter, on an aggregate basis, for each fiscal year.

In order to make acquisitions or investments, the Company's revolving credit facility generally provides that (1) the Company must maintain a minimum borrowing availability of at least the greater of $60,000 or 15% of the total bank commitments under its revolving credit facility or (2) the Company must maintain a minimum borrowing availability of at least the greater of $50,000 or 12.5% of the total bank commitments under its revolving credit facility and meet a minimum fixed charge coverage ratio of 1.0:1 under its revolving credit facility. Notwithstanding the foregoing, the Company may make investments in the aggregate up to the greater of $50,000 and 1.25% of tangible assets and acquisitions in the aggregate up to the greater of $100,000 and 2.5% of tangible assets, if, on a pro forma basis after giving effect to the acquisition or investment, either (X) the borrowing availability under the facility equals or exceeds the greater of (A) 12.5% of the total bank commitments under the facility and (B) $50,000, but is less than the greater of (A) 15% of the total bank commitments and (B) $60,000, or (Y) the Company's fixed charge coverage ratio is at least 1.0:1.

The revolving credit facility contains other customary covenants and events of default that impose significant operating and financial restrictions on the Company. These restrictions, among other things, limit the occurrence of additional indebtedness and the Company's ability to create liens, to engage in certain affiliate transactions and to engage in sale-leaseback transactions.

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Derivative Instruments

9 Months Ended

Sep. 30, 2014

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 raw materials and products as a substantial portion of its raw materials and products are commodities whose prices fluctuate as market supply and demand fundamentals change. Business strategies to protect against such instability include ethylene product feedstock flexibility and moving downstream into the olefins and vinyls products where pricing is more stable. The Company does not use derivative instruments to engage in speculative activities.

For derivative instruments that are designated and qualify as fair value hedges, the gains or losses on the derivative instruments, as well as the offsetting losses or gains on the hedged items attributable to the hedged risk, were included in cost of sales in the consolidated statements of operations for the three and nine months ended September 30, 2013. The Company had no derivative instruments that were designated as fair value hedges for the three and nine months ended September 30, 2014.

Gains and losses from changes in the fair value of derivative instruments that are not designated as hedging instruments were included in gross profit in the consolidated statements of operations for the three and nine months ended September 30, 2014 and 2013.

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).

Disclosures related to the Company's derivative assets and derivative liabilities subject to enforceable master netting arrangements have not been presented as they are not material to the Company's consolidated balance sheets at September 30, 2014 and December 31, 2013.

The fair values of derivative instruments in the Company's consolidated balance sheets were as follows:

	Derivative Assets
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
Not designated as hedging instruments
Commodity forward contracts	Accounts receivable, net	$	451	$	296
Total derivative assets		$	451	$	296

	Derivative Liabilities
	Balance Sheet Location	Fair Value as of
		September 30, 2014		December 31, 2013
Not designated as hedging instruments
Commodity forward contracts	Accrued liabilities	$	6,477	$	176
Total derivative liabilities		$	6,477	$	176

The following tables reflect the impact of derivative instruments designated as fair value hedges and the related hedged item on the Company's consolidated statements of operations. For the three and nine months ended September 30, 2013, there was no material ineffectiveness with regard to the Company's qualifying fair value hedges.

Derivatives in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Derivative	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
Commodity forward contracts	Cost of sales	$	—	$	(232	)	$	—	$	(342	)
Hedged Items in Fair Value    Hedging Relationships	Location of Gain (Loss) Recognized in  Income on Hedged Items	Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
Firm commitment designated    as the hedged item	Cost of sales	$	—	$	236		$	—	$	15

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 September 30,					Nine Months Ended September 30,
		2014			2013		2014			2013
Commodity forward contracts	Gross profit	$	(6,937	)	$	4,854	$	(7,308	)	$	9,897

See Note 10 for the fair value of the Company's derivative instruments.

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Earnings per Share (Reconciliation of Denominator for Basic and Diluted Earnings Per Share) (Details) (USD $)	0 Months Ended	3 Months Ended				9 Months Ended
	Feb. 14, 2014	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Earnings Per Share [Abstract]
Basic		133,299,458	[1]	133,257,494	[1]	133,199,304	[1]	133,256,054	[1]
Plus incremental shares from: Assumed exercise of options		546,601	[1]	553,614	[1]	543,841	[1]	550,704	[1]
Weighted average common shares-diluted		133,846,059	[1]	133,811,108	[1]	133,743,145	[1]	133,806,758	[1]
Earnings per share: Basic		$ 1.26	[1]	$ 1.28	[1]	$ 3.71	[1]	$ 3.29	[1]
Earnings per share: Diluted		$ 1.25	[1]	$ 1.27	[1]	$ 3.69	[1]	$ 3.27	[1]
Stock split conversion ratio	2

[1] Share amounts and per share data for the three and nine months ended September 30, 2013 have been restated to reflect the effect of a two-for-one stock split on March 18, 2014. See Note 1 for additional information.

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Guarantor Disclosures (Condensed Consolidating Financial Information Statement of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Net income	$ 497,631	$ 439,453	$ 610,425
Depreciation and amortization	149,566	117,387
Deferred income taxes	34,459	83,443
Net changes in working capital and other	94,468	(92,783)
Net cash provided by operating activities	776,124	547,500
Acquisition of business, net of cash acquired	(611,087)	(178,309)
Additions to equity investments	0	(23,338)
Additions to property, plant and equipment	(311,183)	(498,290)
Construction of assets pending sale-leaseback	0	(136)
Proceeds from disposition of assets	145	78
Proceeds from repayment of loan acquired	45,923	0
Proceeds from repayment of loan to affiliate	0	167
Proceeds from sale and maturities of securities	342,045	239,764
Purchase of securities and other investments	(117,332)	(232,286)
Settlements of derivative instruments	(689)	(2,297)
Net cash used for investing activities	(652,178)	(694,647)
Intercompany financing	0	0
Net distributions prior to WLKP initial public offering	0	0
Capitalized debt issuance costs	(1,167)
Dividends paid	(55,690)	(40,204)
Net proceeds from issuance of Westlake Chemical Partners LP common units	286,088	0
Purchase of limited partner interests	0
Proceeds from exercise of stock options	5,502	3,182
Repurchase of common stock for treasury	(9,495)	(19,409)
Windfall tax benefits from share-based payment arrangements	6,670	5,056
Net cash provided by financing activities	231,908	(51,375)
Effect of exchange rate changes on cash	(3,687)	0
Net increase in cash and cash equivalents	352,167	(198,522)
Cash and cash equivalents at beginning of period	461,301	790,078	790,078
Cash and cash equivalents at end of period	813,468	591,556	461,301
Westlake Chemical Corporation
Condensed Financial Statements, Captions [Line Items]
Net income	495,232	439,453
Depreciation and amortization	1,172	1,094
Deferred income taxes	(418)	(1,102)
Net changes in working capital and other	(509,862)	(458,336)
Net cash provided by operating activities	(13,876)	(18,891)
Acquisition of business, net of cash acquired	0	0
Additions to equity investments		0
Additions to property, plant and equipment	0	0
Construction of assets pending sale-leaseback		0
Proceeds from disposition of assets	0	0
Proceeds from repayment of loan acquired	0
Proceeds from repayment of loan to affiliate		0
Proceeds from sale and maturities of securities	342,045	239,764
Purchase of securities and other investments	(117,332)	(232,286)
Settlements of derivative instruments	0	0
Net cash used for investing activities	224,713	7,478
Intercompany financing	75,104	(130,832)
Net distributions prior to WLKP initial public offering	0	0
Capitalized debt issuance costs	(1,167)
Dividends paid	(55,690)	(40,204)
Net proceeds from issuance of Westlake Chemical Partners LP common units	0
Purchase of limited partner interests	0
Proceeds from exercise of stock options	5,502	3,182
Repurchase of common stock for treasury	(9,495)	(19,409)
Windfall tax benefits from share-based payment arrangements	6,670	5,056
Net cash provided by financing activities	20,924	(182,207)
Effect of exchange rate changes on cash	0
Net increase in cash and cash equivalents	231,761	(193,620)
Cash and cash equivalents at beginning of period	420,948	753,881	753,881
Cash and cash equivalents at end of period	652,709	560,261
100% Owned Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income	509,404	446,858
Depreciation and amortization	82,597	59,893
Deferred income taxes	26,991	57,279
Net changes in working capital and other	(919,521)	(421,066)
Net cash provided by operating activities	(300,529)	142,964
Acquisition of business, net of cash acquired	0	(178,309)
Additions to equity investments		(23,338)
Additions to property, plant and equipment	(160,147)	(337,158)
Construction of assets pending sale-leaseback		(136)
Proceeds from disposition of assets	144	6
Proceeds from repayment of loan acquired	0
Proceeds from repayment of loan to affiliate		0
Proceeds from sale and maturities of securities	0	0
Purchase of securities and other investments	0	0
Settlements of derivative instruments	(556)	0
Net cash used for investing activities	(160,559)	(538,935)
Intercompany financing	(143,325)	(28,499)
Net distributions prior to WLKP initial public offering	448,101	421,991
Capitalized debt issuance costs	0
Dividends paid	151,729	0
Net proceeds from issuance of Westlake Chemical Partners LP common units	0
Purchase of limited partner interests	0
Proceeds from exercise of stock options	0	0
Repurchase of common stock for treasury	0	0
Windfall tax benefits from share-based payment arrangements	0	0
Net cash provided by financing activities	456,505	393,492
Effect of exchange rate changes on cash	0
Net increase in cash and cash equivalents	(4,583)	(2,479)
Cash and cash equivalents at beginning of period	6,227	6,973	6,973
Cash and cash equivalents at end of period	1,644	4,494
OpCo (Less Than 100% Owned Guarantor Subsidiary)
Condensed Financial Statements, Captions [Line Items]
Net income	416,737	402,340
Depreciation and amortization	58,501	54,539
Deferred income taxes	8,267	27,253
Net changes in working capital and other	1,641	(68,604)
Net cash provided by operating activities	485,146	415,528
Acquisition of business, net of cash acquired	0	0
Additions to equity investments		0
Additions to property, plant and equipment	(144,348)	(158,869)
Construction of assets pending sale-leaseback		0
Proceeds from disposition of assets	0	0
Proceeds from repayment of loan acquired	0
Proceeds from repayment of loan to affiliate		0
Proceeds from sale and maturities of securities	0	0
Purchase of securities and other investments	0	0
Settlements of derivative instruments	(133)	(2,297)
Net cash used for investing activities	(144,481)	(161,166)
Intercompany financing	62,221	167,629
Net distributions prior to WLKP initial public offering	(448,101)	(421,991)
Capitalized debt issuance costs	0
Dividends paid	(151,729)	0
Net proceeds from issuance of Westlake Chemical Partners LP common units	0
Purchase of limited partner interests	286,088
Proceeds from exercise of stock options	0	0
Repurchase of common stock for treasury	0	0
Windfall tax benefits from share-based payment arrangements	0	0
Net cash provided by financing activities	(251,521)	(254,362)
Effect of exchange rate changes on cash	0
Net increase in cash and cash equivalents	89,144	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	89,144	0
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income	(1,441)	(1,639)
Depreciation and amortization	7,296	1,861
Deferred income taxes	(381)	13
Net changes in working capital and other	599,909	7,664
Net cash provided by operating activities	605,383	7,899
Acquisition of business, net of cash acquired	(611,087)	0
Additions to equity investments		0
Additions to property, plant and equipment	(6,688)	(2,263)
Construction of assets pending sale-leaseback		0
Proceeds from disposition of assets	1	72
Proceeds from repayment of loan acquired	45,923
Proceeds from repayment of loan to affiliate		167
Proceeds from sale and maturities of securities	0	0
Purchase of securities and other investments	0	0
Settlements of derivative instruments	0	0
Net cash used for investing activities	(571,851)	(2,024)
Intercompany financing	6,000	(8,298)
Net distributions prior to WLKP initial public offering	0	0
Capitalized debt issuance costs	0
Dividends paid	0	0
Net proceeds from issuance of Westlake Chemical Partners LP common units	286,088
Purchase of limited partner interests	(286,088)
Proceeds from exercise of stock options	0	0
Repurchase of common stock for treasury	0	0
Windfall tax benefits from share-based payment arrangements	0	0
Net cash provided by financing activities	6,000	(8,298)
Effect of exchange rate changes on cash	(3,687)
Net increase in cash and cash equivalents	35,845	(2,423)
Cash and cash equivalents at beginning of period	34,126	29,224	29,224
Cash and cash equivalents at end of period	69,971	26,801
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net income	(922,301)	(847,559)
Depreciation and amortization	0	0
Deferred income taxes	0	0
Net changes in working capital and other	922,301	847,559
Net cash provided by operating activities	0	0
Acquisition of business, net of cash acquired	0	0
Additions to equity investments		0
Additions to property, plant and equipment	0	0
Construction of assets pending sale-leaseback		0
Proceeds from disposition of assets	0	0
Proceeds from repayment of loan acquired	0
Proceeds from repayment of loan to affiliate		0
Proceeds from sale and maturities of securities	0	0
Purchase of securities and other investments	0	0
Settlements of derivative instruments	0	0
Net cash used for investing activities	0	0
Intercompany financing	0	0
Net distributions prior to WLKP initial public offering	0	0
Capitalized debt issuance costs	0
Dividends paid	0	0
Net proceeds from issuance of Westlake Chemical Partners LP common units	0
Purchase of limited partner interests	0
Proceeds from exercise of stock options	0	0
Repurchase of common stock for treasury	0	0
Windfall tax benefits from share-based payment arrangements	0	0
Net cash provided by financing activities	0	0
Effect of exchange rate changes on cash	0
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	$ 0	$ 0

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Pension and Post-Retirement Benefit Costs (Additional Information) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plan Disclosure [Line Items]
Document Fiscal Year Focus	2014
Salaried Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contribution	$ 2,447	$ 776
Expected additional contributions	330
Wage Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contribution	916	640
Expected additional contributions	$ 290

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Earnings per Share (Schedule of Net Income Attributable to Common Stockholders) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income to Westlake Chemical Corporation	$ 167,757	$ 170,290	$ 495,232	$ 439,453
Less: Net income attributable to participating securities	(353)	(587)	(1,099)	(1,691)
Net income attributable to common shareholders	$ 167,404	$ 169,703	$ 494,133	$ 437,762

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Inventories (Tables)

9 Months Ended

Sep. 30, 2014

Inventory Disclosure [Abstract]

Schedule Of Inventory

Inventories consist of the following:

	September 30, 2014		December 31, 2013
Finished products	$	268,969	$	232,658
Feedstock, additives and chemicals	166,268		180,646
Materials and supplies	65,315		58,575
Inventories	$	500,552	$	471,879

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Property, Plant and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
Property, plant and equipment	$ 2,710,475		$ 2,710,475		$ 2,088,014
Depreciation expense on property, plant and equipment	$ 45,080	$ 32,460	$ 123,000	$ 95,995

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Accumulated Other Comprehensive Income

9 Months Ended

Sep. 30, 2014

Equity [Abstract]

Accumulated Other Comprehensive Income

Accumulated Other Comprehensive Loss

Changes in accumulated other comprehensive income (loss) by component for the nine months ended September 30, 2014 and 2013 were as follows:

	Benefits Liability, Net of Tax			Cumulative Foreign Currency Exchange			Net Unrealized Holding Gains on Investments, Net of Tax			Total
Balances at December 31, 2013	$	(6,696	)	$	3,904		$	176		$	(2,616	)
Other comprehensive (loss) income before    reclassifications	(39		)	(37,882		)	4,459			(33,462		)
Amounts reclassified from accumulated other    comprehensive loss	422			—			(777		)	(355		)
Net other comprehensive income (loss) for the period	383			(37,882		)	3,682			(33,817		)
Balances at September 30, 2014	$	(6,313	)	$	(33,978	)	$	3,858		$	(36,433	)

	Benefits Liability, Net of Tax			Cumulative Foreign Currency Exchange			Net Unrealized Holding Gains on Investments, Net of Tax		Total
Balances at December 31, 2012	$	(16,351	)	$	5,511		$	—	$	(10,840	)
Other comprehensive (loss) income before    reclassifications	(601		)	(844		)	131		(1,314		)
Amounts reclassified from accumulated other    comprehensive loss	1,233			—			—		1,233
Net other comprehensive income (loss) for the period	632			(844		)	131		(81		)
Balances at September 30, 2013	$	(15,719	)	$	4,667		$	131	$	(10,921	)

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 and nine months ended September 30, 2014 and 2013:

Details about Accumulated Other Comprehensive    Income (Loss) Components	Location of Reclassification (Income (Expense)) in Consolidated Statements of Operations	Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
Amortization of pension and    other post-retirement items
Prior service costs	(1)	$	(87	)	$	(95	)	$	(261	)	$	(286	)
Net loss	(1)	(153		)	(600		)	(424		)	(1,718		)
		(240		)	(695		)	(685		)	(2,004		)
	Provision for income    taxes	92			267			263			771
		(148		)	(428		)	(422		)	(1,233		)
Net unrealized gains on    available-for-sale    investments
Realized gain on    available-for-sale    investments	Other income, net	—			—			1,212			—
	Provision for income    taxes	—			—			(435		)	—
		—			—			$	777		$	—
Total reclassifications for    the period		$	(148	)	$	(428	)	$	355		$	(1,233	)

_____________

(1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. For additional information, please read Note 10 (Employee Benefits) to the financial statements included in the 2013 Form 10-K.

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Westlake Chemical Partners LP

9 Months Ended

Sep. 30, 2014

Equity [Abstract]

Westlake Chemical Partners LP

Westlake Chemical Partners LP

Westlake Chemical Partners LP ("WLKP") is a publicly traded master limited partnership that was formed by the Company to operate, acquire and develop ethylene production facilities and related assets.

Initial Public Offering of WLKP

On August 4, 2014, WLKP completed its initial public offering of 12,937,500 common units at a price of $24.00 per unit, which included 1,687,500 units purchased by the underwriters pursuant to the exercise in full of their over-allotment option. Net proceeds to WLKP from the sale of the units was approximately $286,088, net of underwriting discounts, structuring fees and offering expenses (the "Offering Costs") of approximately $24,412. At the consummation of the offering, WLKP's assets consist of a 10.6% limited partner interest in Westlake Chemical OpCo LP ("OpCo"), as well as the general partner interest in OpCo. The Company retained an 89.4% limited partner interest in OpCo and a significant interest in WLKP. The Company consolidates WLKP for financial reporting purposes as the Company has a controlling financial interest. The initial public offering represented the sale of 47.8% of the common and subordinated units in WLKP. OpCo used the net proceeds from the purchase of its limited partner interest to establish a cash reserve of approximately $55,419 for turnaround expenditures, to reimburse approximately $151,729 for capital expenditures incurred by the Company with respect to certain of the assets contributed to OpCo and to repay intercompany debt to the Company of approximately $78,940.

The following table is a reconciliation of proceeds from the initial public offering:

Total proceeds from the initial public offering	$	310,500
Less: Offering Costs	(24,412		)
Net proceeds from the initial public offering	286,088
Less: Cash retained by OpCo	(55,419		)
Net proceeds distributed to the Company from the initial public offering	$	230,669

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Accounts Receivable (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Accounts Receivable, Net [Abstract]
Trade customers	$ 576,735	$ 410,302
Affiliates	631	315
Allowance for doubtful accounts	(13,772)	(11,741)
Receivables from trade customers and affiliates, net	563,594	398,876
Federal and state taxes	5,374	20,820
Other	23,996	8,761
Accounts receivable, net	$ 592,964	$ 428,457

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Segment Information (Tables)

9 Months Ended

Sep. 30, 2014

Segment Reporting [Abstract]

Segment Reporting Information

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Net external sales
Olefins
Polyethylene	$	498,450		$	460,105		$	1,461,097		$	1,294,566
Styrene, feedstock and other	204,647			219,234			663,851			590,959
Total Olefins	703,097			679,339			2,124,948			1,885,525
Vinyls
PVC, caustic soda and other	416,771			212,041			776,060			612,391
Building products	133,359			112,785			378,471			309,943
Total Vinyls	550,130			324,826			1,154,531			922,334
	$	1,253,227		$	1,004,165		$	3,279,479		$	2,807,859
Intersegment sales
Olefins	$	26,518		$	85,454		$	118,153		$	230,607
Vinyls	355			403			1,029			1,111
	$	26,873		$	85,857		$	119,182		$	231,718
Income (loss) from operations
Olefins	$	259,277		$	237,239		$	770,267		$	585,958
Vinyls	59,445			39,554			76,460			136,123
Corporate and other	(11,961		)	(10,191		)	(25,123		)	(26,197		)
	$	306,761		$	266,602		$	821,604		$	695,884
Depreciation and amortization
Olefins	$	26,443		$	26,515		$	79,811		$	76,415
Vinyls	27,336			14,089			68,127			39,507
Corporate and other	141			124			456			372
	$	53,920		$	40,728		$	148,394		$	116,294
Other income (expense), net
Olefins	$	1,609		$	728		$	4,262		$	5,889
Vinyls	1,189			(742		)	942			(1,687		)
Corporate and other	(5,468		)	(273		)	(764		)	(1,065		)
	$	(2,670	)	$	(287	)	$	4,440		$	3,137
Provision for (benefit from) income taxes
Olefins	$	105,030		$	82,553		$	282,082		$	208,170
Vinyls	21,761			10,710			22,121			44,120
Corporate and other	(2,342		)	(535		)	(3,972		)	(7,643		)
	$	124,449		$	92,728		$	300,231		$	244,647
Capital expenditures
Olefins	$	48,519		$	27,577		$	121,041		$	105,656
Vinyls	44,067			172,565			187,449			391,864
Corporate and other	1,685			276			2,693			770
	$	94,271		$	200,418		$	311,183		$	498,290

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 September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Income from operations	$	306,761		$	266,602		$	821,604		$	695,884
Interest expense	(9,486		)	(3,297		)	(28,182		)	(14,921		)
Other (expense) income, net	(2,670		)	(287		)	4,440			3,137
Income before income taxes	$	294,605		$	263,018		$	797,862		$	684,100

Total Assets

	September 30, 2014		December 31, 2013
Total assets
Olefins	$	1,740,878	$	1,557,510
Vinyls	2,898,250		1,740,595
Corporate and other	487,155		762,804
	$	5,126,283	$	4,060,909

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Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 170,156	$ 170,290	$ 497,631	$ 439,453
Pension and other post-retirement reserves adjustment (excluding amortization)	31	489	62	978
Pension and other post-retirement benefits liability
Amortization of benefits liability	240	695	685	2,004
Income tax provision on pension and other post-retirement benefits liability	(81)	(78)	(240)	(394)
Foreign currency translation adjustments	(37,792)	546	(37,882)	(844)
Available-for-sale investments
Unrealized holding gains on investments	2,129	205	6,960	205
Reclassification of net realized gains to net income	0	0	1,212	0
Income tax provision on available-for-sale investments	(766)	(74)	(2,066)	(74)
Other comprehensive (loss) income	(36,301)	805	(33,817)	(81)
Comprehensive income	133,855	171,095	463,814	439,372
Comprehensive income attributable to noncontrolling interests, net of tax	2,399	0	2,399	0
Comprehensive income attributable to Westlake Chemical Corporation	$ 131,456	$ 171,095	$ 461,415	$ 439,372

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Accounts Receivable

9 Months Ended

Sep. 30, 2014

Accounts Receivable, Net [Abstract]

Accounts Receivable

Accounts Receivable

Accounts receivable consist of the following:

	September 30, 2014			December 31, 2013
Trade customers	$	576,735		$	410,302
Affiliates	631			315
Allowance for doubtful accounts	(13,772		)	(11,741		)
	563,594			398,876
Federal and state taxes	5,374			20,820
Other	23,996			8,761
Accounts receivable, net	$	592,964		$	428,457

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Derivative Instruments (Impact of Derivative Instruments on Income) (Details) (Cost of Sales, USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Designated As Fair Value Hedges | Firm Commitment Derivative Items Designated As Hedged Item
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ 0	$ 236	$ 0	$ 15
Designated As Fair Value Hedges | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	0	(232)	0	(342)
Derivatives Not Designated As Hedging Instruments | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ (6,937)	$ 4,854	$ (7,308)	$ 9,897

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Guarantor Disclosures (Additional Information) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	0 Months Ended
	Sep. 30, 2014 3.60% Senior Notes Due 2022	Aug. 04, 2014 Limited Partner [Member] IPO [Member]	Aug. 04, 2014 Limited Partner [Member] Westlake Chemical Partners LP [Member] Subsidiaries [Member] IPO [Member]
Condensed Financial Statements, Captions [Line Items]
Stated interest rate	3.60%
Maturity	2022
Minimum debt amount guaranteed by subsidiaries	$ 5,000
Limited partner interest		89.40%	10.60%

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Commitments and Contingencies (Additional Information) (Detail) (USD $) In Thousands, unless otherwise specified	0 Months Ended	1 Months Ended		12 Months Ended
	Mar. 17, 2010	Dec. 31, 2007	Dec. 31, 2007 Polyone	Dec. 31, 2013 Polyone
Commitments and Contingencies Disclosure [Line Items]
Minimum number of years between arbitrations		5 years
Reimbursement of remediation costs sought by PolyOne	$ 1,400
Percentage of costs related to environmental issues to be paid by PolyOne			100.00%
Costs incurred environmental remediation services				$ 3,284

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Acquisitions

9 Months Ended

Sep. 30, 2014

Business Combinations [Abstract]

Acquisition

Acquisition

On July 31, 2014, the Company acquired all the equity interests in German-based Vinnolit Holdings GmbH and its subsidiary companies ("Vinnolit") from several entities associated with Advent International Corporation (the "Sellers"). Vinnolit is headquartered in Ismaning, Germany and is an integrated global leader in specialty PVC resins, with a combined annual capacity of 1.7 billion pounds of PVC, including specialty paste and suspension grades, 1.5 billion pounds of vinyl chloride monomer ("VCM") and 1.0 billion pounds of caustic soda. The Vinnolit acquisition comprised six production facilities located in Burghausen, Gendorf, Cologne, Knapsack and Schkopau in Germany and Hillhouse in the United Kingdom. The Company also acquired Vinnolit's technical centers, including a research and development facility in Gendorf and an applications laboratory in Burghausen. The Company’s management believes that this strategic acquisition will enhance its strategy of integration and expansion into new markets and specialty products, in addition to growing the Company's global presence with a footprint in Europe and surrounding markets.

The purchase price of $736,224 was paid with available cash on hand. The acquisition is being accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed and the results of operations of this acquired business are included in the Vinyls segment.

The acquired business contributed net sales and net loss of $195,477 and $2,992, respectively, to the Company for the period from July 31, 2014 to September 30, 2014. The following unaudited consolidated pro forma information presents consolidated information as if the acquisition had occurred on January 1, 2013:

	Pro Forma Nine Months Ended September 30,
	2014		2013
Net sales	$	4,016,935	$	3,747,619
Net income	$	550,667	$	480,964
Net income attributable to noncontrolling interests	2,399		—
Net income attributable to Westlake Chemical Corporation	$	548,268	$	480,964
Earnings per common share attributable to Westlake Chemical Corporation:
Basic	$	4.11	$	3.59
Diluted	$	4.09	$	3.58

The pro forma amounts above have been calculated after applying the Company’s accounting policies and adjusting the Vinnolit results to reflect (1) the additional depreciation and amortization that would have been charged assuming the fair value adjustments to property, plant and equipment and intangible assets had been applied from January 1, 2013; (2) the elimination of interest expense assuming the long-term debt paid off on behalf of the Sellers as of the acquisition date had been retired as of January 1, 2013; (3) the elimination of transaction-related costs; and (4) an adjustment to tax-effect the aforementioned pro forma adjustments using an estimated aggregate statutory income tax rate of the jurisdictions to which the above adjustments relate. The pro forma amounts do not include any potential synergies, cost savings or other expected benefits of the Vinnolit acquisition, are presented for illustrative purposes only and are not necessarily indicative of results that would have been achieved if the acquisition had occurred as of January 1, 2013 or of future operating performance.

For the nine months ended September 30, 2014, the Company recognized $11,235 of transaction-related costs. These costs are included in general and administrative expenses and other income, net in the consolidated statement of operations for the nine months ended September 30, 2014. The transaction-related costs included in other income, net pertained to losses incurred on forward foreign exchange contracts for the purchase consideration of Vinnolit.

The following table summarizes the purchase consideration transferred and the estimated fair value of identified assets acquired and liabilities assumed at the date of acquisition. The preliminary allocation of the purchase consideration is based on management’s 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 the fair value of the net assets acquired equals consideration paid. Therefore, no goodwill was recorded. The final allocation of purchase consideration could include changes in the estimated fair value of (1) inventories; (2) property, plant and equipment; (3) equity investments; (4) trademark and trade name, developed technologies and customer relationships; (5) power purchase agreement liability; and (6) deferred income taxes.

Fair value of consideration transferred:
Cash paid to Sellers	$	309,619
Cash deposited in escrow (1)	13,390
Retirement of long-term debt as of July 31, 2014, on behalf of the Sellers (2)	413,215
Total purchase consideration	$	736,224
Preliminary allocation of consideration transferred to net assets acquired:
Cash	$	125,137
Working capital, excluding inventory and cash (3)	23,072
Inventories (4)	114,961
Property, plant and equipment	471,123
Investments	51,552
Other assets (5)	65,366
Intangible assets:
Trademarks and trade name (weighted average life of 20 years)	40,170
Developed technologies (weighted average life of 20 years)	31,600
Other intangibles (weighted average life of 9.4 years)	1,422
Deferred income tax asset - current	8,697
Deferred income tax asset - non-current	27,387
Pension obligation	(117,970		)
Other long-term liabilities	(10,723		)
Power purchase agreement liability (6)	(10,826		)
Deferred income tax liability - current	(6,845		)
Deferred income tax liability - non-current	(77,899		)
Total identifiable net assets	736,224
Goodwill (7)	—
Consideration transferred	$	736,224

_____________

(1) None of the cash held in escrow is considered contingent consideration as it is expected to be released to the Sellers pending the Sellers’ satisfaction of general representations and warranties made in connection with the execution of the purchase agreement.

(2) Vinnolit’s long-term debt paid on behalf of the Sellers was not legally assumed by Westlake in the acquisition and was a condition of the consummation of the purchase agreement. Therefore, the retirement has been included in the total purchase consideration.

(3) The fair value of accounts receivable acquired is $181,826, with the gross contractual amount being $183,769. The Company expects $1,943 to be uncollectible.

(4) An adjustment of approximately $16,900 was recorded to reflect Vinnolit's inventories at fair value and increased cost of sales by the same amount for the three months ended September 30, 2014.

(5) Included in other assets was a loan acquired that was repaid prior to September 30, 2014.

(6) A liability arising from unfavorable forward purchase contracts for the purchase of power was recognized at fair value. This liability will be amortized over a period of approximately 3.0 years, being the weighted-average life of the forward purchase contracts.

(7) Management estimated that the fair value of the net assets acquired equals consideration paid. Therefore, no goodwill was recorded.

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Segment Information (Reconciliation of Total Segment Income from Operations to Consolidated Income before Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting [Abstract]
Income from operations	$ 306,761	$ 266,602	$ 821,604	$ 695,884
Interest expense	(9,486)	(3,297)	(28,182)	(14,921)
Other (expense) income, net	(2,670)	(287)	4,440	3,137
Income before income taxes	$ 294,605	$ 263,018	$ 797,862	$ 684,100

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Earnings per Share (Tables)

9 Months Ended

Sep. 30, 2014

Earnings Per Share [Abstract]

Schedule Of Net Income Attributable To Common Stockholders

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Net income attributable to Westlake Chemical    Corporation	$	167,757		$	170,290		$	495,232		$	439,453
Less:
Net income attributable to participating securities	(353		)	(587		)	(1,099		)	(1,691		)
Net income attributable to common shareholders	$	167,404		$	169,703		$	494,133		$	437,762

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 September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
Weighted average common shares—basic (1)	133,299,458		133,257,494		133,199,304		133,256,054
Plus incremental shares from:
Assumed exercise of options (1)	546,601		553,614		543,841		550,704
Weighted average common shares—diluted (1)	133,846,059		133,811,108		133,743,145		133,806,758
Earnings per common share attributable to    Westlake Chemical Corporation : (1)
Basic	$	1.26	$	1.28	$	3.71	$	3.29
Diluted	$	1.25	$	1.27	$	3.69	$	3.27

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Pension and Post-Retirement Benefit Costs

9 Months Ended

Sep. 30, 2014

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Pension and Post-Retirement Benefit Costs

Pension and Post-Retirement Benefit Costs

Components of net periodic benefit cost are as follows:

	Three Months Ended September 30,										Nine Months Ended September 30,
	Pension						Post-retirement Healthcare				Pension						Post-retirement Healthcare
	2014			2013			2014		2013		2014			2013			2014		2013
Service cost	$	331		$	275		$	6	$	2	$	498		$	815		$	16	$	7
Interest cost	1,138			515			185		147		2,309			1,531			548		442
Expected return on    plan assets	(777		)	(713		)	—		—		(2,363		)	(2,140		)	—		—
Amortization of prior    service cost	74			74			13		21		223			223			38		63
Amortization of net loss	71			510			82		90		204			1,449			220		269
Net periodic benefit cost	$	837		$	661		$	286	$	260	$	871		$	1,878		$	822	$	781

The Company contributed $2,447 and $776 to the Salaried pension plan in the first nine months of 2014 and 2013, respectively, and contributed $916 and $640 to the Wage pension plan in the first nine months of 2014 and 2013, respectively. The Company expects to make additional contributions of $330 to the Salaried pension plan and $290 to the Wage pension plan during the fiscal year ending December 31, 2014.