View Filing Data

Derivative Liabilities

Derivative in Cash Flow Hedging Relationship

Balance Sheet Location

Fair Value as of
September 30,
2015

Derivative in Cash Flow Hedging Relationship

Balance Sheet Location

Fair Value as of
September 30,
2015

Interest rate contract

Other liabilities

Print Document View Excel Document

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2015	Oct. 28, 2015
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Trading Symbol	WLKP
Entity Registrant Name	WESTLAKE CHEMICAL PARTNERS LP
Entity Central Index Key	0001604665
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Common units [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		14,373,615
Subordinated units [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		12,686,115

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 154,257	$ 133,750
Accounts receivable, net—Westlake Chemical Corporation (Westlake)	44,035	18,529
Accounts receivable, net—third parties	14,479	37,520
Inventories	3,272	6,634
Prepaid expenses and other current assets	382	212
Total current assets	216,425	196,645
Property, plant and equipment, net	962,221	842,057
Other assets, net
Goodwill	5,814	5,814
Deferred charges and other assets, net	40,728	51,919
Total other assets, net	46,542	57,733
Total assets	1,225,188	1,096,435
Current liabilities
Accounts payable—Westlake	9,288	7,470
Accounts payable—third parties	24,871	12,614
Accrued liabilities	22,352	11,900
Total current liabilities	56,511	31,984
Long-term debt payable to Westlake	330,495	227,638
Deferred income taxes	1,489	1,848
Other liabilities	219	15
Total liabilities	388,714	261,485
Commitments and contingencies (Notes 9 and 16)
EQUITY
Accumulated other comprehensive loss	(173)	0
Total Westlake Chemical Partners LP partners' capital	93,425	87,524
Noncontrolling interest in Westlake Chemical OpCo LP (OpCo)	743,049	747,426
Total equity	836,474	834,950
Total liabilities and equity	1,225,188	1,096,435
Limited Partner [Member] \| Common units [Member] \| Public [Member]
EQUITY
Limited Partners' Capital Account	293,282	290,377
Total equity	293,282	290,377
Limited Partner [Member] \| Common units [Member] \| Westlake [Member]
EQUITY
Limited Partners' Capital Account	4,360	4,038
Total equity	4,360	4,038
Limited Partner [Member] \| Subordinated units [Member] \| Westlake [Member]
EQUITY
Limited Partners' Capital Account	38,528	35,681
Total equity	38,528	35,681
General Partner [Member] \| Westlake [Member]
EQUITY
General Partners' Capital Account	(242,572)	(242,572)
Total equity	$ (242,572)	$ (242,572)

Consolidated Balance Sheets (Parenthetical) - shares	Sep. 30, 2015	Dec. 31, 2014
Common units [Member] \| Westlake [Member]
Units issued	1,436,115	1,436,115
Units outstanding	1,436,115	1,436,115
Common units [Member] \| Public [Member]
Units issued	12,937,500	12,937,500
Units outstanding	12,937,500	12,937,500
Subordinated units [Member] \| Westlake [Member]
Units issued	12,686,115	12,686,115
Units outstanding	12,686,115	12,686,115

Combined and Consolidated Statements of Operations - USD ($) $ in Thousands	2 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net sales - Westlake		$ 207,856	$ 289,601	$ 621,438	$ 1,088,561
Net co-product, ethylene and feedstock sales—third parties		40,763	102,407	137,277	387,596
Total net sales		248,619	392,008	758,715	1,476,157
Cost of sales		154,474	227,015	473,815	832,304
Gross profit		94,145	164,993	284,900	643,853
Selling, general and administrative expenses		5,831	8,860	17,826	22,803
Income from operations		88,314	156,133	267,074	621,050
Other income (expense)
Interest expense—Westlake		(1,054)	(2,137)	(3,794)	(9,833)
Other (expense) income, net		(73)	486	(35)	3,135
Income before income taxes		87,187	154,482	263,245	614,352
Provision for income taxes		141	36,309	567	198,461
Net income	$ 54,557	87,046	$ 118,173	262,678	$ 415,891
Less: Net income attributable to noncontrolling interest in OpCo	49,542	76,943		233,632
Net income attributable to Westlake Chemical Partners LP subsequent to initial public offering	$ 5,015	$ 10,103		$ 29,046
Net income attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Income per limited partner unit (usd per share)		$ 0.37		$ 1.07
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (shares)		27,059,730		27,059,730
Common units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP subsequent to initial public offering		$ 5,365		$ 15,429
Net income attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Income per limited partner unit (usd per share)		$ 0.37	$ 0.19	$ 1.07	$ 0.19
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (shares)		14,373,615		14,373,615
Common units [Member] \| Public [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (shares)		12,937,500	12,937,500	12,937,500	12,937,500
Common units [Member] \| Westlake [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (shares)		1,436,115	1,436,115	1,436,115	1,436,115
Subordinated units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP subsequent to initial public offering		$ 4,738		$ 13,617
Net income attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Income per limited partner unit (usd per share)		$ 0.37	$ 0.19	$ 1.07	$ 0.19
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (shares)		12,686,115		12,686,115
Subordinated units [Member] \| Westlake [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (shares)		12,686,115	12,686,115	12,686,115	12,686,115

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 87,046	$ 118,173	$ 262,678	$ 415,891
Change in fair value of cash flow hedge	(223)	0	(223)	0
Reclassification of loss to net income	50	0	50	0
Total other comprehensive loss	(173)	0	(173)	0
Comprehensive income	86,873	54,557	262,505	54,557
Comprehensive income attributable to noncontrolling interest in OpCo	76,943	49,542	233,632	49,542
Comprehensive income attributable to Westlake Chemical Partners LP subsequent to initial public offering	$ 9,930	$ 5,015	$ 28,873	$ 5,015

Combined and Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Noncontrolling Interest in OpCo [Member]	Accumulated Other Comprehensive Loss [Member]	Westlake [Member] General Partner [Member]	Common units [Member] Public [Member] Limited Partner [Member]	Common units [Member] Westlake [Member] Limited Partner [Member]	Subordinated units [Member] Westlake [Member] Limited Partner [Member]
Equity, beginning balance (Predecessor [Member]) at Dec. 31, 2013	$ 455,432
Equity, beginning balance at Dec. 31, 2013	455,432
Net income \| Predecessor [Member]	361,334
Net income	361,334
Net distributions to Westlake prior to initial public offering \| Predecessor [Member]	(448,101)
Net distributions to Westlake prior to initial public offering	(448,101)
Predecessor net liabilities not assume by OpCo \| Predecessor [Member]	239,706
Predecessor net liabilities not assume by OpCo	239,706
Equity, ending balance (Predecessor [Member]) at Aug. 03, 2014	608,371
Equity, ending balance at Aug. 03, 2014	608,371
Equity, beginning balance (Predecessor [Member]) at Dec. 31, 2013	455,432
Equity, beginning balance at Dec. 31, 2013	455,432
Net income	415,891
Equity, ending balance (Predecessor [Member]) at Sep. 30, 2014	0
Equity, ending balance at Sep. 30, 2014	797,287	$ 713,714	$ 0	$ (242,572)	$ 288,487	$ 3,828	$ 33,830
Equity, beginning balance (Predecessor [Member]) at Aug. 03, 2014	608,371
Equity, beginning balance at Aug. 03, 2014	608,371
Net income	54,557	49,542			2,399	265	2,351
Allocation of net investment to unitholders \| Predecessor [Member]	(608,371)
Allocation of net investment to unitholders	0	573,329				3,563	31,479
Proceeds from initial public offering, net of finance and other offering costs	286,088				286,088
Distribution to the noncontrolling interest in OpCo	(151,729)	(151,729)
Purchase of additional interest in OpCo		242,572		(242,572)
Equity, ending balance (Predecessor [Member]) at Sep. 30, 2014	0
Equity, ending balance at Sep. 30, 2014	797,287	713,714	0	(242,572)	288,487	3,828	33,830
Equity, beginning balance (Predecessor [Member]) at Dec. 31, 2014	0
Equity, beginning balance at Dec. 31, 2014	834,950	747,426	0	(242,572)	290,377	4,038	35,681
Net income	262,678	233,632			13,887	1,542	13,617
Net effect of cash flow hedge	(173)		(173)
Quarterly distributions to unitholders	(22,972)				(10,982)	(1,220)	(10,770)
Quarterly distributions to noncontrolling interest retained in OpCo by Westlake	(238,009)	(238,009)
Equity, ending balance (Predecessor [Member]) at Sep. 30, 2015	0
Equity, ending balance at Sep. 30, 2015	$ 836,474	$ 743,049	$ (173)	$ (242,572)	$ 293,282	$ 4,360	$ 38,528

Combined and Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities
Net income	$ 262,678	$ 415,891
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	60,637	58,501
Provision for doubtful accounts	170	65
Loss from disposition of fixed assets	278	1,244
Deferred income taxes	(359)	8,267
Income from equity method investment, net of dividends	0	1,073
Changes in operating assets and liabilities
Accounts receivable—third parties	22,871	(23,637)
Net accounts receivable—Westlake	(23,688)	(10,373)
Inventories	3,362	25,769
Prepaid expenses and other current assets	(170)	(715)
Accounts payable	4,851	(8,226)
Accrued and other liabilities	2,039	7,633
Other, net	(1,466)	10,498
Net cash provided by operating activities	331,203	485,990
Cash flows from investing activities
Additions to property, plant and equipment	(152,572)	(144,348)
Settlements of derivative instruments	0	(133)
Net cash used for investing activities	(152,572)	(144,481)
Cash flows from financing activities
Proceeds from debt payable to Westlake	238,198	141,161
Repayment of debt payable to Westlake	(135,341)	0
Repayment of related party debt with proceeds from the initial public offering	0	(78,940)
Net proceeds from issuance of common units	0	286,088
Proceeds from initial public offering distributed to Westlake	0	(151,729)
Net distributions to Westlake prior to initial public offering	0	(448,101)
Quarterly distributions to noncontrolling interest retained in OpCo by Westlake	(238,009)	0
Quarterly distributions to unitholders	(22,972)	0
Net cash used for financing activities	(158,124)	(251,521)
Net increase in cash and cash equivalents	20,507	89,988
Cash and cash equivalents at beginning of period	133,750	0
Cash and cash equivalents at end of period	$ 154,257	$ 89,988

Description of Business and Basis of Presentation

9 Months Ended

Sep. 30, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Description of Business and Basis of Presentation

Description of Business

Westlake Chemical Partners LP (the "Partnership") is a Delaware limited partnership formed in March 2014 to operate, acquire and develop facilities and related assets for the processing of natural gas liquids. On August 4, 2014, the Partnership completed its initial public offering (the "IPO") of 12,937,500 common units representing limited partner interests. In connection with the IPO, the Partnership acquired a 10.6% interest in Westlake Chemical OpCo LP ("OpCo") and a 100% interest in Westlake Chemical OpCo GP LLC ("OpCo GP"), which is the general partner of OpCo. On April 29, 2015, the Partnership purchased an additional 2.7% newly-issued limited partner interest in OpCo for approximately $135,341, resulting in an aggregate 13.3% limited partner interest in OpCo effective April 1, 2015. OpCo owns three natural gas liquids processing facilities and a common carrier ethylene pipeline.

Basis of Presentation

The accompanying unaudited combined and 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 combined and consolidated financial statements should be read in conjunction with the December 31, 2014 combined and consolidated financial statements and notes thereto of the Partnership included in the annual report on Form 10-K for the fiscal year ended December 31, 2014 (the "2014 Form 10-K"), filed with the SEC on March 9, 2015. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the combined and consolidated financial statements of the Partnership for the fiscal year ended December 31, 2014.

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

The Partnership holds a 13.3% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 86.7% limited partner interest in OpCo is owned by Westlake, which has no rights to direct the activities that most significantly impact the economic performance of OpCo. As a result of the fact that substantially all of OpCo's activities are conducted on behalf of Westlake, and the fact that OpCo exhibits disproportionality of voting rights to economic interest, OpCo was deemed to be a variable interest entity. The Partnership, through its ownership of OpCo's general partner, has the power to direct the activities that most significantly impact the economic performance of OpCo, and it also has the obligation or right to absorb losses or receive benefits from OpCo that could potentially be significant to OpCo. As such, the Partnership was determined to be OpCo's primary beneficiary and therefore consolidates OpCo's results of operations and financial position. Westlake's retained interest of 86.7% is recorded as noncontrolling interest in the Partnership's consolidated financial statements.

Financial information of the Predecessor is derived from the financial statements and accounting records of Westlake. Subsequent to the IPO, the Partnership's financial position, results of operations, changes in equity and cash flows consist of the consolidated activities and balances of the Partnership. The Partnership's consolidated financial statements include the accounts of the Partnership and its consolidated subsidiary, OpCo. The combined and consolidated financial statements for the three and nine months ended September 30, 2014 were prepared as follows:

•

The combined and consolidated statement of operations for the three months ended September 30, 2014 consists of the consolidated results of the Partnership 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 combined and consolidated statement of operations for the nine months ended September 30, 2014 consists of the consolidated results of the Partnership 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 consolidated statement of other comprehensive income for the three and nine months ended September 30, 2014 consists of the consolidated results of the Partnership for the period from August 4, 2014 through September 30, 2014.


•	The combined and consolidated 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 consolidated activity for the Partnership completed at and subsequent to the IPO on August 4, 2014.


•	The combined and consolidated statement of cash flows for the nine months ended September 30, 2014 consists of the consolidated results of the Partnership 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.

In the opinion of the Partnership's management, the accompanying unaudited combined and consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of September 30, 2015, its results of operations for the three and nine months ended September 30, 2015 and 2014 and the changes in its cash position for the nine months ended September 30, 2015 and 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, 2015 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.

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. In July 2015, the FASB deferred the effective date for the revenue recognition standard. The accounting standard will now be effective for reporting periods beginning after December 15, 2017. The Partnership 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.

Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items

In January 2015, the FASB issued an accounting standards update to simplify income statement classification by removing the concept of extraordinary items from U.S. GAAP. Under the new standard, an unusual and infrequent event or transaction is no longer allowed to be separately disclosed as "extraordinary." The standard retains the existing requirement to separately present items that are of an unusual nature or occur infrequently on a pre-tax basis within income from continuing operations. The new guidance also requires similar separate presentation of items that are both unusual and infrequent on a pre-tax basis within income from continuing operations. The standard allows for either prospective or retrospective application. If adopted prospectively, both the nature and amount of any subsequent adjustments to previously reported extraordinary items must be disclosed. The accounting standard will be effective for reporting periods beginning after December 15, 2015 and is not expected to have an impact on the Partnership's consolidated financial position, results of operations and cash flows.

Amendments to the Consolidation Analysis

In February 2015, the FASB issued an accounting standards update making certain changes to the current consolidation guidance. The amendments affect both the variable interest entity and voting interest entity consolidation models. The new standard changes the consideration of substantive rights, related party interests and fees paid to the decision maker when applying the variable interest entity consolidation model and eliminate certain guidance for limited partnerships and similar entities under the voting interest consolidation model. The accounting standard will be effective for reporting periods beginning after December 15, 2015 and is not expected to have an impact on the Partnership's consolidated financial position, results of operations and cash flows.

Effects on Historical Earnings per Unit of Master Limited Partnership Dropdown Transactions

In April 2015, the FASB issued an accounting standard update requiring that the earnings of transferred net assets from a general partner prior to the dropdown date of the net assets to a master limited partnership be allocated entirely to the general partner when calculating earnings per unit under the two class method. As a result, previously reported earnings per unit of the limited partners will not change as a result of a dropdown transaction. The accounting standard will be effective for reporting periods and interim periods within those reporting periods beginning after December 15, 2015.

Simplifying the Measurement of Inventory

In July 2015, the FASB issued an accounting standards update that requires entities to measure inventory at the lower of cost or net realizable value rather than at the lower of cost or market. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. Under the new standard, entities will no longer need to calculate other measures of "market." The new accounting guidance applies only to inventories for which cost is determined by methods other than last-in first-out and the retail inventory method. The accounting standard will be effective for reporting periods beginning after December 15, 2016 and is not expected to have a significant impact on the Partnership's consolidated financial position, results of operations and cash flows.

Financial Instruments	9 Months Ended
Financial Instruments	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Financial Instruments	Financial Instruments Cash Equivalents The Partnership had $75,025 and $40,003 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, 2015 and December 31, 2014, respectively. The Partnership's investments in held-to-maturity securities are held at amortized cost, which approximates fair value.

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References + Details

Accounts Receivable - Third Parties

9 Months Ended

Sep. 30, 2015

Accounts Receivable, Net [Abstract]

Accounts Receivable - Third Parties

Accounts Receivable—Third Parties

Accounts receivable—third parties consist of the following:



	September 30, 2015			December 31, 2014
Trade customers	$	14,649		$	37,514
Allowance for doubtful accounts	(170		)	—
	14,479			37,514
Other	—			6
Accounts receivable, net—third parties	$	14,479		$	37,520

Inventories

9 Months Ended

Sep. 30, 2015

Inventory Disclosure [Abstract]

Inventories

Inventories consist of the following:



	September 30, 2015		December 31, 2014
Finished products	$	2,895	$	6,257
Feedstock, additives and chemicals	377		377
Inventories	$	3,272	$	6,634

Property, Plant and Equipment	9 Months Ended
Property, Plant and Equipment	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment As of September 30, 2015, the Partnership had property, plant and equipment, net totaling $962,221. The Partnership 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 Partnership 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 $16,231 and $14,900 is included in cost of sales in the combined and consolidated statements of operations for the three months ended September 30, 2015 and 2014, respectively. Depreciation expense on property, plant and equipment of $48,006 and $45,104 is included in cost of sales in the combined and consolidated statements of operations for the nine months ended September 30, 2015 and 2014, respectively.

Other Assets	9 Months Ended
Other Assets	Sep. 30, 2015
Other Assets [Abstract]
Other Assets	Other Assets Amortization expense on other assets of $4,211 and $4,319 is included in the combined and consolidated statements of operations for the three months ended September 30, 2015 and 2014, respectively. Amortization expense on other assets of $12,631 and $13,397 is included in the combined and consolidated statements of operations for the nine months ended September 30, 2015 and 2014, respectively.

Net Income Per Limited Partner Unit

9 Months Ended

Sep. 30, 2015

Earnings Per Share [Abstract]

Net Income Per Limited Partner Unit

Net income per unit applicable to common limited partner units and to subordinated limited partner units is computed by dividing the respective limited partners' interest in net income for the period by the weighted-average number of common units and subordinated units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units, subordinated units and incentive distribution rights. Basic and diluted net income per unit are the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented.

On October 28, 2015, the board of directors of Westlake Chemical Partners GP LLC ("Westlake GP"), the Partnership's general partner, declared a quarterly cash distribution for the period from July 1, 2015 through September 30, 2015 of $0.2994 per unit, or $8,102 in total. This distribution is payable on November 27, 2015 to unitholders of record as of November 9, 2015.

On July 29, 2015, the board of directors of Westlake GP declared a quarterly cash distribution for the period from April 1, 2015 through June 30, 2015 of $0.2910 per unit, or $7,874 in total. This distribution was paid on August 27, 2015 to unitholders of record as of August 13, 2015. On April 29, 2015, the board of directors of Westlake GP declared a quarterly cash distribution for the period from January 1, 2015 through March 31, 2015 of $0.2829 per unit, or $7,655 in total. This distribution was paid on May 27, 2015 to unitholders of record as of May 12, 2015.



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Net income attributable to the Partnership	$	10,103	$	5,015	$	29,046	$	5,015
Less:
Limited partners' distribution declared on common units	4,304		2,449		12,552		2,449
Limited partners' distribution declared on subordinated units	3,798		2,162		11,079		2,162
Net income in excess of distribution	$	2,001	$	404	$	5,415	$	404



	Three Months Ended September 30, 2015
	Limited Partners' Common Units		Limited Partners' Subordinated Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	4,304	$	3,798	$	—	$	8,102
Net income in excess of distribution	1,061		940		—		2,001
Net income	$	5,365	$	4,738	$	—	$	10,103
Weighted average units outstanding:
Basic and diluted	14,373,615		12,686,115				27,059,730
Net income per limited partner unit:
Basic and diluted	$	0.37	$	0.37			$	0.37



	Nine Months Ended September 30, 2015
	Limited Partners' Common Units		Limited Partners' Subordinated Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	12,552	$	11,079	$	—	$	23,631
Net income in excess of distribution	2,877		2,538		—		5,415
Net income	$	15,429	$	13,617	$	—	$	29,046
Weighted average units outstanding:
Basic and diluted	14,373,615		12,686,115				27,059,730
Net income per limited partner unit:
Basic and diluted	$	1.07	$	1.07			$	1.07

Related Party Transactions

9 Months Ended

Sep. 30, 2015

Related Party Transactions

The Partnership and OpCo regularly enter 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. Additionally, each of the Partnership and OpCo from time to time provide 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,
	2015		2014		2015		2014
Net sales—Westlake	$	207,856	$	289,601	$	621,438	$	1,088,561

Cost of Sales from Related Parties

Charges for goods and services purchased by the Partnership and 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. 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. was 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,
	2015		2014		2015		2014
Feedstock purchased from Westlake and included in cost of sales	$	75,752	$	63,108	$	232,584	$	63,108
Other charges from Westlake and included in cost of sales	20,457		13,879		53,948		47,000
Total	$	96,209	$	76,987	$	286,532	$	110,108

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

Charges for services purchased by the Partnership from Westlake and included in selling, general and administrative expenses primarily relate to services Westlake performs on behalf of the Partnership under the Omnibus Agreement, including the Partnership'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 allocations 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,
	2015		2014		2015		2014
Services received from Westlake and included in selling, general and administrative expenses	$	4,772	$	4,283	$	14,891	$	15,901

Goods and Services from Related Parties Capitalized as Assets

Charges for goods and services purchased by the Partnership and 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,
	2015		2014		2015		2014
Goods and services purchased from Westlake and capitalized as assets	$	1,304	$	830	$	3,241	$	2,074

Accounts Receivable from and Accounts Payable to Related Parties

The Partnership's accounts receivable from Westlake result primarily from ethylene sales to Westlake under the Ethylene Sales Agreement. The Partnership'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.

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



	September 30, 2015			December 31, 2014
Accounts receivable, net—Westlake	$	44,035		$	18,529
Accounts payable—Westlake	(9,288		)	(7,470		)

Debt Payable to Related Parties

OpCo assumed promissory notes payable to Westlake and entered into a senior unsecured revolving credit facility with Westlake in connection with the IPO. Prior to the IPO, the Predecessor funded certain capital expenditures through promissory notes payable to Westlake, a portion of which were assumed by the Partnership in connection with the IPO. See Note 9 for description of related party debt payable balances. Interest on related party debt payable balances for the three months ended September 30, 2015 and 2014 were $1,054 and $2,137, respectively, and for the nine months ended September 30, 2015 and 2014 were $3,794 and $9,833, respectively, and are reflected as a component of other income (expense) in the combined and consolidated statements of operations. Interest capitalized as a component of property, plant and equipment on related party debt was $1,284 for the three months ended September 30, 2015 and $3,394 for the nine months ended September 30, 2015. At September 30, 2015 and December 31, 2014, accrued interest on related party debt was $2,284 and $2,403, respectively, and is reflected as a component of accrued liabilities in the consolidated balance sheets.

Debt payable to related parties was as follows:



	September 30, 2015		December 31, 2014
Long-term debt payable to Westlake	$	330,495	$	227,638

General

OpCo, together with other subsidiaries of Westlake not included in these combined and consolidated financial statements, is a guarantor under Westlake's revolving credit facility and the indentures governing its senior notes. As of September 30, 2015 and December 31, 2014, Westlake had outstanding letters of credit totaling $29,953 and $31,392 under its revolving credit facility and $754,000 and $754,000 outstanding under its senior notes (less the unamortized discount of $803 and $892), respectively.

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.

During August 2015, the Partnership entered into an interest rate contract with Westlake to fix the LIBOR component of the interest rate for a portion of the MLP Revolver balance. See note 11 for additional information on the interest rate contract.

OpCo has entered into two site lease agreements with Westlake in connection with the IPO, and each has a term of 50 years. Pursuant to the site lease agreements, OpCo pays Westlake one dollar per site per year.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Long-term Debt Payable to Westlake

9 Months Ended

Sep. 30, 2015

Long-term Debt Payable to Westlake

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



	September 30, 2015		December 31, 2014
August 2013 Promissory Notes (variable interest rate of prime plus 1.5%, original scheduled maturity of August 1, 2023)	$	31,775	$	167,116
OpCo Revolver (variable interest rate of London Interbank Offered Rate ("LIBOR") plus 3.0%, original scheduled maturity of August 4, 2019)	163,379		60,522
MLP Revolver (variable interest rate of LIBOR plus 2.0%, original scheduled maturity of April 29, 2018)	135,341		—
	$	330,495	$	227,638

In 2013, three intercompany promissory notes were issued for capital expenditures incurred by Westlake on behalf of the Predecessor's operations (together, the "August 2013 Promissory Notes"). In connection with the IPO, OpCo assumed a portion of the August 2013 Promissory Notes. Proceeds drawn under the August 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 on August 4, 2014, OpCo entered into a $600,000 senior unsecured revolving credit facility agreement with Westlake (the "OpCo Revolver"). The OpCo Revolver 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. Proceeds drawn under the OpCo Revolver during the nine months ended September 30, 2015 were used to fund capital expenditures at the Partnership's ethylene plants.

On April 29, 2015, the Partnership entered into a $300,000 revolving credit facility agreement with Westlake (the "MLP Revolver") to fund the Partnership's purchase of an additional 2.7% newly-issued, limited partner interest in OpCo for $135,341. Borrowings under the MLP Revolver bear interest at LIBOR plus a spread ranging from 2.0% to 3.0% (depending on the Partnership's consolidated leverage ratio), payable quarterly. The MLP Revolver provides that the Partnership may pay all or a portion of the interest on any borrowings in kind, in which case any such amounts would be added to the principal amount of the loan. The MLP Revolver requires that the Partnership maintain a consolidated leverage ratio of either (1) during any one-year period following certain types of acquisitions (including acquisitions of additional interests in OpCo), 5.50:1.00 or less, or (2) during any other period, 4.50:1.00 or less. The MLP Revolver also contains certain other customary covenants. The repayment of borrowings under the MLP Revolver is subject to acceleration upon the occurrence of an event of default. During August 2015, the Partnership entered into an interest rate contract with Westlake to fix the LIBOR component of the interest rate for a portion of the MLP Revolver balance. See note 11 for additional information on the interest rate contract.

As of September 30, 2015, the Partnership was in compliance with all of the covenants under the August 2013 Promissory Notes, the OpCo Revolver and the MLP Revolver.

Accumulated Other Comprehensive Loss

9 Months Ended

Sep. 30, 2015

Equity [Abstract]

Accumulated Other Comprehensive Loss

Accumulated other comprehensive income or loss primarily reflects the effective portion of the gain or loss on derivative instrument designated and qualified as a cash flow hedge. Gain or loss amounts related to a cash flow hedge recorded in accumulated other comprehensive income or loss are reclassified to income in the same period in which the underlying hedged forecasted transaction affects income. If it becomes probable that a forecasted transaction will not occur, the related net gain or loss in accumulated other comprehensive income or loss is immediately reclassified into income.

The following sets forth the amounts included in accumulated other comprehensive loss for the nine months ended September 30, 2015:



	Nine Months Ended September 30, 2015
Interest rate contract—Loss recognized on cash flow hedge	$	(223	)
Interest rate contract—Loss reclassified to net income on cash flow hedge	50
Net effect of cash flow hedge	$	(173	)

- Definition

The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e689-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669619-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e640-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e716-108580

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e709-108580

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e681-108580

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Reclassification Adjustments
-URI http://asc.fasb.org/extlink&oid=6522872

+ Details

Derivative Instruments

9 Months Ended

Sep. 30, 2015

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments

The accounting guidance for derivative instruments and hedging activities requires that the Partnership and the Predecessor recognize all derivative instruments on the balance sheet at fair value, and changes in the derivative's fair value must be currently recognized in earnings or comprehensive income, depending on the designation of the derivative. If the derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized in earnings. If the derivative is designated as a cash flow hedge, the effective portion of the change in the fair value of the derivative is recorded in comprehensive income and is recognized in the statement of operations when the hedged item affects earnings. Ineffective portions of changes in the fair value of cash flow hedges are recognized in earnings currently.

There were no derivative instruments that were designated as fair value hedges for the nine months ended September 30, 2015 and 2014.

Commodity Risk Management

The Predecessor utilized commodity derivative instruments to reduce price risks by purchasing or selling futures on established exchanges. The Predecessor took both fixed and variable positions, depending upon anticipated future physical purchases and sales of these commodities. The fair value of derivative financial instruments was estimated using quoted market prices in active markets and observable market-based inputs or unobservable inputs that were corroborated by market data when active markets were not available. The Predecessor assessed both counterparty as well as its own nonperformance risk when measuring the fair value of derivative liabilities. The Predecessor did not consider its nonperformance risk to be significant. The Partnership has not entered into any commodity derivative instruments since the date of the IPO, August 4, 2014.

The Partnership had no non-designated hedging instruments for the nine months ended September 30, 2015. 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 and consolidated statements of operations for the three and nine months ended September 30, 2014 as follows:



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

Interest Rate Risk Management

During August 2015, the Partnership entered into an interest rate contract with Westlake to reduce the risks of variability of the interest rates under the MLP Revolver. The interest rate contract fixed the LIBOR component of the interest rate for a portion of the MLP Revolver balance. This contract was designated as a cash flow hedge. With the exception of this interest rate contract, the Partnership did not have any other derivative financial instruments during the three and nine months ended September 30, 2015. As of and for the three and nine months ended September 30, 2014, neither the Partnership nor the Predecessor had any interest rate contracts.

There were no open derivatives as of December 31, 2014. The fair value of the derivative instrument on the Partnership's consolidated balance sheet as of September 30, 2015 was as follows:

The following tables present the effect of derivative instrument designated as cash flow hedge on the combined and consolidated statements of operations and the consolidated statements of comprehensive income for the three and nine months ended September 30, 2015:



Derivative in Cash Flow Hedging Relationship	Location of Gain (Loss) Recognized in Statement of Operations	Three Months Ended September 30, 2015			Nine Months Ended September 30, 2015
Derivative in Cash Flow Hedging Relationship		Three Months Ended September 30, 2015			Nine Months Ended September 30, 2015
Interest rate contract—Loss reclassified from accumulated other comprehensive loss	Interest expense	$	(50	)	$	(50	)



Derivative in Cash Flow Hedging Relationship	Three Months Ended September 30, 2015		Nine Months Ended September 30, 2015
Derivative in Cash Flow Hedging Relationship	Three Months Ended September 30, 2015		Nine Months Ended September 30, 2015
Interest rate contract—Change in value recognized in other comprehensive loss	$	223	$	223

There was no ineffective portion of a derivative instrument during the three and nine months ended September 30, 2015.

See Note 12 for the fair value of derivative instruments.

- Definition

The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6441202&loc=d3e80720-113993

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=56946850&loc=d3e41620-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624163-113959

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5579240-113959

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624177-113959

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80784-113994

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=56946850&loc=d3e41641-113959

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5579245-113959

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624258-113959

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5708775-113959

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5708773-113959

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5618551-113959

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5580258-113959

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4E
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624181-113959

Reference 17: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

Reference 18: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=56946850&loc=d3e41638-113959

Reference 19: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(n))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Fair Value Measurements

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Fair Value Measurements

The Partnership 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 December 31, 2014. The following table summarizes, by level within the fair value hierarchy, the Partnership's liability under the interest rate contract that was accounted for at fair value on a recurring basis at September 30, 2015:



	September 30, 2015
	Level 2			Total
Derivative instruments
Liability—Interest rate contract	$	(173	)	$	(173	)

The fair value of the level 2 interest rate contract is determined using standard valuation methodologies which incorporate relevant contract terms along with readily available market data (i.e. the 3 month LIBOR forward curve). There were no transfers in or out of Levels 1 and 2 of the fair value hierarchy for the nine months ended September 30, 2015 and 2014.

The Partnership 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 consolidated 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 the Partnership's long-term debt at September 30, 2015 and December 31, 2014 are summarized in the table below. The Partnership's long-term debt includes the August 2013 Promissory Notes, the OpCo Revolver and the MLP Revolver. The fair value of debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because the Partnership's valuation methodology used for long-term debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of the Partnership's long-term debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of the Partnership's long-term debt include the selection of an appropriate discount rate.



	September 30, 2015				December 31, 2014
	Carrying Value		Fair Value		Carrying Value		Fair Value
August 2013 Promissory Notes	$	31,775	$	31,775	$	167,116	$	167,116
OpCo Revolver	163,379		170,613		60,522		60,522
MLP Revolver	135,341		134,514		—		—

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Partnership 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 Partnership is, however, subject to state and local 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 pertaining to the period 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 combined financial statements. The effective income tax rates were 0.2% and 0.2% for the three and nine months ended September 30, 2015, respectively. The effective income tax rates for the three and nine months ended September 30, 2015 are not comparable to the effective income tax rate for the prior-year comparative periods as the Partnership is not subject to federal income taxes subsequent to the IPO. 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 due to state income taxes, mostly offset by the domestic manufacturing deduction and state income tax credits. The Partnership's effective tax rate was less than one percent for the 2014 period subsequent to the IPO.

Supplemental Information	9 Months Ended
Supplemental Information	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Information	Supplemental Information Accrued Liabilities Accrued liabilities were $22,352 and $11,900 at September 30, 2015 and December 31, 2014, respectively. The accrual related to capital expenditures, which is a component of accrued liabilities, was $14,452 at September 30, 2015. Accrued taxes, interest on long-term debt and the accrual related to capital expenditures, which are components of accrued liabilities, were $1,622, $2,403, and $5,026 at December 31, 2014, respectively. No other component of accrued liabilities was more than five percent of total current liabilities. Non-cash Operating Activity The Predecessor settled $2,089 and $9,530 of its total interest expense incurred on long-term debt payable to Westlake as an addition to principal on debt outstanding for the three and nine months ended September 30, 2014, respectively. Non-cash Investing Activity The change in capital expenditure accrual reducing additions to property, plant and equipment was $15,850 for the nine months ended September 30, 2015. The change in capital expenditure accrual reducing additions to property, plant and equipment was $8,564 for the nine months ended September 30, 2014.

Major Customer and Concentration Risk	9 Months Ended
Major Customer and Concentration Risk	Sep. 30, 2015
Risks and Uncertainties [Abstract]
Major Customer and Concentration of Credit Risk	Major Customer and Concentration of Credit Risk During the three months ended September 30, 2015 and 2014, Westlake accounted for approximately 83.6% and 73.9%, respectively, of the Partnership's and the Predecessor's net sales. During the nine months ended September 30, 2015 and 2014, Westlake accounted for approximately 81.9% and 73.7%, respectively, of the Partnership's and the Predecessor's net sales.

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Partnership 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. Because several of the Partnership's processing sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on the Partnership. Westlake has agreed to indemnify the Partnership for liabilities that occurred or existed prior to August 4, 2014. Contract Disputes with Goodrich and PolyOne. In connection with the 1990 and 1997 acquisitions of the Goodrich Corporation ("Goodrich") chemical manufacturing facility in Calvert City, Kentucky, which is a portion of the B.F. Goodrich superfund site, Goodrich agreed to indemnify Westlake for any liabilities related to preexisting contamination at the site. Westlake agreed to indemnify Goodrich for post-closing contamination caused by Westlake's operations. The soil and groundwater at the site 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 Westlake, 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 100.0% 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 Westlake 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) Westlake and PolyOne would negotiate a new environmental remediation utilities and services agreement to cover Westlake'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 site do not have a specified termination date but are expected to last for the foreseeable future. The costs incurred by Westlake that have been invoiced to PolyOne to provide the environmental remediation services were $2,805 in 2014. By letter dated March 16, 2010, PolyOne notified Westlake 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 Westlake in reimbursement of previously paid remediation costs. The arbitration is currently stayed pending the outcome of discussions between other parties and their insurance carriers. State Administrative Proceedings. There are several administrative proceedings in Kentucky involving Westlake, Goodrich and PolyOne related to the same manufacturing site in Calvert City, which includes OpCo's processing facility 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 site. Both Goodrich and PolyOne challenged various terms of the permit in an attempt to shift Goodrich's clean-up obligations under the permit to Westlake. Westlake 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. 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 the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"). In its response to the Cabinet, 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 Partnership's plant which had been operated by Goodrich and which was being remediated pursuant to CERCLA. The EPA has directed Goodrich and PolyOne to conduct additional investigation activities at the landfill and at the Calvert City site. In June 2009, the EPA notified Westlake that Westlake 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. Westlake negotiated, in conjunction with the other potentially responsible parties, an AOC and an order to conduct an RIFS. Due to the Partnership's ownership and current operation of the property, the Partnership may be subject to additional requirements and liabilities under CERCLA. Potential Flare Modifications. For several years, the EPA has been conducting an enforcement initiative against petroleum refineries and petrochemical plants with respect to emissions from flares. A number of companies have entered into consent agreements with the EPA requiring both modifications to reduce flare emissions and the installation of additional equipment to better track flare operations and emissions. On April 21, 2014, Westlake received a Clean Air Act Section 114 Information Request from the EPA which sought information regarding flares at the Calvert City and Lake Charles facilities. Westlake submitted information pursuant to such request, including information regarding three flares that the Partnership owns. The EPA has informed Westlake that the information provided leads the EPA to believe that some of the flares are out of compliance with applicable standards. The EPA has demanded that Westlake conduct additional flare sampling and provide supplemental information. Westlake is currently in negotiations with the EPA regarding these demands, some of which are applicable to the Partnership's flares. The EPA has indicated that it is seeking a consent decree with that would obligate Westlake to take corrective actions relating to the alleged noncompliance. Westlake has not agreed that any flares are out of compliance or that any corrective actions are warranted. Depending on the outcome of Westlake's negotiations with the EPA, additional controls on emissions from the Partnership's flares may be required and these could result in increased capital and operating costs. Louisiana Notice of Violations. The Louisiana Department of Environmental Quality ("LDEQ") has issued notices of violations regarding the Partnership's assets, and those of Westlake, for various air compliance issues. The Partnership and Westlake are working with LDEQ to settle these claims, and a global settlement of all claims is being discussed. While settlement may result in a total civil penalty of approximately $200, such a settlement will likely cover assets owned by the Partnership and Westlake, and to the extent it covers the Partnership's assets, Westlake has agreed to indemnify the Partnership for liabilities to the extent such liabilities occurred or existed prior to August 4, 2014. In addition to the matters described above, the Partnership is involved in various routine legal proceedings incidental to the conduct of its business. The Partnership 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.

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 28, 2015, the board of directors of Westlake GP declared a quarterly distribution for the period from July 1, 2015 through September 30, 2015 of $0.2994 per unit or $8,102 in total. This distribution is payable on November 27, 2015 to unitholders of record as of November 9, 2015. Subsequent events were evaluated through the date on which the financial statements were issued.

Description of Business and Basis of Presentation (Policies)

9 Months Ended

Sep. 30, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis of Presentation

•


•	The consolidated statement of other comprehensive income for the three and nine months ended September 30, 2014 consists of the consolidated results of the Partnership for the period from August 4, 2014 through September 30, 2014.


•	The combined and consolidated 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 consolidated activity for the Partnership completed at and subsequent to the IPO on August 4, 2014.


•	The combined and consolidated statement of cash flows for the nine months ended September 30, 2014 consists of the consolidated results of the Partnership 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.

Derivative Instruments

Accounts Receivable - Third Parties (Tables)

9 Months Ended

Sep. 30, 2015

Accounts Receivable, Net [Abstract]

Schedule Of Accounts Receivable - Third Parties

Accounts receivable—third parties consist of the following:



	September 30, 2015			December 31, 2014
Trade customers	$	14,649		$	37,514
Allowance for doubtful accounts	(170		)	—
	14,479			37,514
Other	—			6
Accounts receivable, net—third parties	$	14,479		$	37,520

Inventories (Tables)

9 Months Ended

Sep. 30, 2015

Inventory Disclosure [Abstract]

Schedule Of Inventory

Inventories consist of the following:



	September 30, 2015		December 31, 2014
Finished products	$	2,895	$	6,257
Feedstock, additives and chemicals	377		377
Inventories	$	3,272	$	6,634

Net Income Per Limited Partner Unit (Tables)

9 Months Ended

Sep. 30, 2015

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Net income attributable to the Partnership	$	10,103	$	5,015	$	29,046	$	5,015
Less:
Limited partners' distribution declared on common units	4,304		2,449		12,552		2,449
Limited partners' distribution declared on subordinated units	3,798		2,162		11,079		2,162
Net income in excess of distribution	$	2,001	$	404	$	5,415	$	404



	Three Months Ended September 30, 2015
	Limited Partners' Common Units		Limited Partners' Subordinated Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	4,304	$	3,798	$	—	$	8,102
Net income in excess of distribution	1,061		940		—		2,001
Net income	$	5,365	$	4,738	$	—	$	10,103
Weighted average units outstanding:
Basic and diluted	14,373,615		12,686,115				27,059,730
Net income per limited partner unit:
Basic and diluted	$	0.37	$	0.37			$	0.37



	Nine Months Ended September 30, 2015
	Limited Partners' Common Units		Limited Partners' Subordinated Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	12,552	$	11,079	$	—	$	23,631
Net income in excess of distribution	2,877		2,538		—		5,415
Net income	$	15,429	$	13,617	$	—	$	29,046
Weighted average units outstanding:
Basic and diluted	14,373,615		12,686,115				27,059,730
Net income per limited partner unit:
Basic and diluted	$	1.07	$	1.07			$	1.07

Related Party Transactions (Tables)

9 Months Ended

Sep. 30, 2015

Schedule of Related Party Transactions

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



	September 30, 2015			December 31, 2014
Accounts receivable, net—Westlake	$	44,035		$	18,529
Accounts payable—Westlake	(9,288		)	(7,470		)

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



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Goods and services purchased from Westlake and capitalized as assets	$	1,304	$	830	$	3,241	$	2,074

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



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Services received from Westlake and included in selling, general and administrative expenses	$	4,772	$	4,283	$	14,891	$	15,901

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



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Feedstock purchased from Westlake and included in cost of sales	$	75,752	$	63,108	$	232,584	$	63,108
Other charges from Westlake and included in cost of sales	20,457		13,879		53,948		47,000
Total	$	96,209	$	76,987	$	286,532	$	110,108

Sales to related parties were as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Net sales—Westlake	$	207,856	$	289,601	$	621,438	$	1,088,561

Debt payable to related parties was as follows:



	September 30, 2015		December 31, 2014
Long-term debt payable to Westlake	$	330,495	$	227,638

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



	September 30, 2015		December 31, 2014
August 2013 Promissory Notes (variable interest rate of prime plus 1.5%, original scheduled maturity of August 1, 2023)	$	31,775	$	167,116
OpCo Revolver (variable interest rate of London Interbank Offered Rate ("LIBOR") plus 3.0%, original scheduled maturity of August 4, 2019)	163,379		60,522
MLP Revolver (variable interest rate of LIBOR plus 2.0%, original scheduled maturity of April 29, 2018)	135,341		—
	$	330,495	$	227,638

Long-term Debt Payable to Westlake (Tables)

9 Months Ended

Sep. 30, 2015

Schedule of Related Party Transactions

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



	September 30, 2015			December 31, 2014
Accounts receivable, net—Westlake	$	44,035		$	18,529
Accounts payable—Westlake	(9,288		)	(7,470		)

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



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Goods and services purchased from Westlake and capitalized as assets	$	1,304	$	830	$	3,241	$	2,074

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



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Services received from Westlake and included in selling, general and administrative expenses	$	4,772	$	4,283	$	14,891	$	15,901

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



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Feedstock purchased from Westlake and included in cost of sales	$	75,752	$	63,108	$	232,584	$	63,108
Other charges from Westlake and included in cost of sales	20,457		13,879		53,948		47,000
Total	$	96,209	$	76,987	$	286,532	$	110,108

Sales to related parties were as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Net sales—Westlake	$	207,856	$	289,601	$	621,438	$	1,088,561

Debt payable to related parties was as follows:



	September 30, 2015		December 31, 2014
Long-term debt payable to Westlake	$	330,495	$	227,638

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



	September 30, 2015		December 31, 2014
August 2013 Promissory Notes (variable interest rate of prime plus 1.5%, original scheduled maturity of August 1, 2023)	$	31,775	$	167,116
OpCo Revolver (variable interest rate of London Interbank Offered Rate ("LIBOR") plus 3.0%, original scheduled maturity of August 4, 2019)	163,379		60,522
MLP Revolver (variable interest rate of LIBOR plus 2.0%, original scheduled maturity of April 29, 2018)	135,341		—
	$	330,495	$	227,638

Accumulated Other Comprehensive Loss (Tables)

9 Months Ended

Sep. 30, 2015

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Loss

The following sets forth the amounts included in accumulated other comprehensive loss for the nine months ended September 30, 2015:



	Nine Months Ended September 30, 2015
Interest rate contract—Loss recognized on cash flow hedge	$	(223	)
Interest rate contract—Loss reclassified to net income on cash flow hedge	50
Net effect of cash flow hedge	$	(173	)

Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2015

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Impact of Derivative Instrument Not Designated as Fair Value Hedges

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 and consolidated statements of operations for the three and nine months ended September 30, 2014 as follows:



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

Fair Values of Derivatives Instruments in Consolidated Balance Sheet

The fair value of the derivative instrument on the Partnership's consolidated balance sheet as of September 30, 2015 was as follows:

Derivative Instruments, Gain (Loss)



Derivative in Cash Flow Hedging Relationship	Location of Gain (Loss) Recognized in Statement of Operations	Three Months Ended September 30, 2015			Nine Months Ended September 30, 2015
Derivative in Cash Flow Hedging Relationship		Three Months Ended September 30, 2015			Nine Months Ended September 30, 2015
Interest rate contract—Loss reclassified from accumulated other comprehensive loss	Interest expense	$	(50	)	$	(50	)



Derivative in Cash Flow Hedging Relationship	Three Months Ended September 30, 2015		Nine Months Ended September 30, 2015
Derivative in Cash Flow Hedging Relationship	Three Months Ended September 30, 2015		Nine Months Ended September 30, 2015
Interest rate contract—Change in value recognized in other comprehensive loss	$	223	$	223

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Fair Value, Liabilities Measured on Recurring Basis



	September 30, 2015
	Level 2			Total
Derivative instruments
Liability—Interest rate contract	$	(173	)	$	(173	)

Summary Of Carrying And Fair Values Of Long-Term Debt

The carrying and fair values of the Partnership's long-term debt at September 30, 2015 and December 31, 2014 are summarized in the table below. The Partnership's long-term debt includes the August 2013 Promissory Notes, the OpCo Revolver and the MLP Revolver. The fair value of debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because the Partnership's valuation methodology used for long-term debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of the Partnership's long-term debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of the Partnership's long-term debt include the selection of an appropriate discount rate.



	September 30, 2015				December 31, 2014
	Carrying Value		Fair Value		Carrying Value		Fair Value
August 2013 Promissory Notes	$	31,775	$	31,775	$	167,116	$	167,116
OpCo Revolver	163,379		170,613		60,522		60,522
MLP Revolver	135,341		134,514		—		—

Description of Business and Basis of Presentation (Details) $ in Thousands	Apr. 29, 2015 USD ($)	Apr. 01, 2015	Aug. 04, 2014 shares	Sep. 30, 2015 production_facility
Westlake [Member] \| Affiliated Entity [Member]
Limited Partners' Capital Account [Line Items]
Amount paid to purchase additional limited partner interest	$ 135,341
Westlake Chemical OpCo LP [Member] \| Affiliated Entity [Member]
Limited Partners' Capital Account [Line Items]
Amount paid to purchase additional limited partner interest	$ 135,341
Limited partner interest		13.30%	10.60%
Westlake Chemical OpCo GP LLC [Member] \| Limited Liability Company [Member]
Limited Partners' Capital Account [Line Items]
Limited partner interest			100.00%
Westlake [Member] \| Westlake Chemical OpCo LP [Member] \| Majority-Owned Subsidiary, Unconsolidated [Member]
Limited Partners' Capital Account [Line Items]
Limited partner interest		86.70%
Westlake Chemical OpCo LP [Member]
Limited Partners' Capital Account [Line Items]
Number of ethylene production facilities \| production_facility				3
Limited Partner [Member]
Limited Partners' Capital Account [Line Items]
Number of units sold in public offering \| shares			12,937,500

Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Held-to-maturity Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 75,025	$ 40,003

Accounts Receivable - Third Parties (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade customers	$ 14,649	$ 37,514
Allowance for doubtful accounts	(170)	0
Receivables from trade customers, net	14,479	37,514
Other	0	6
Accounts receivable, net - third parties	$ 14,479	$ 37,520

Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Finished products	$ 2,895	$ 6,257
Feedstock, additives and chemicals	377	377
Inventories	$ 3,272	$ 6,634

Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, plant and equipment	$ 962,221		$ 962,221		$ 842,057
Depreciation expense on property, plant and equipment	$ 16,231	$ 14,900	$ 48,006	$ 45,104

Other Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Other Assets [Member]
Entity Information [Line Items]
Amortization expense	$ 4,211	$ 4,319	$ 12,631	$ 13,397

Net Income Per Limited Partner Unit (Distributions Declared) (Details) - Westlake Chemical OpCo LP [Member] - USD ($) $ / shares in Units, $ in Thousands	Oct. 28, 2015	Jul. 29, 2015	Apr. 29, 2015
Distribution Made to Limited Partner [Line Items]
Distribution declared per unit		$ 0.2910	$ 0.2829
Distribution declared		$ 7,874	$ 7,655
Subsequent Event [Member]
Distribution Made to Limited Partner [Line Items]
Distribution declared per unit	$ 0.2994
Distribution declared	$ 8,102

Net Income Per Limited Partner Unit (Income In Excess Of Distribution) (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net income attributable to the Partnership	$ 5,015	$ 10,103		$ 29,046
Distribution declared		8,102		23,631
Net income in excess of distribution		2,001	$ 404	5,415	$ 404
Common units [Member]
Net income attributable to the Partnership		5,365		15,429
Distribution declared		4,304	2,449	12,552	2,449
Net income in excess of distribution		1,061		2,877
Subordinated units [Member]
Net income attributable to the Partnership		4,738		13,617
Distribution declared		3,798	$ 2,162	11,079	$ 2,162
Net income in excess of distribution		$ 940		$ 2,538

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Net Income Per Limited Partner Unit (Basic and Diluted Income Per Limited Partner Unit) (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Limited Partners' Capital Account [Line Items]
Distribution declared		$ 8,102		$ 23,631
Net income in excess of distribution		2,001	$ 404	5,415	$ 404
Net income	$ 5,015	$ 10,103		$ 29,046
Weighted average units outsanding:
Basic and diluted (shares)		27,059,730		27,059,730
Net income per limited partner unit:
Income per limited partner unit (usd per share)		$ 0.37		$ 1.07
Limited Partners' Common Units [Member]
Limited Partners' Capital Account [Line Items]
Distribution declared		$ 4,304	$ 2,449	$ 12,552	$ 2,449
Net income in excess of distribution		1,061		2,877
Net income		$ 5,365		$ 15,429
Weighted average units outsanding:
Basic and diluted (shares)		14,373,615		14,373,615
Net income per limited partner unit:
Income per limited partner unit (usd per share)		$ 0.37	$ 0.19	$ 1.07	$ 0.19
Limited Partners' Subordinated Units [Member]
Limited Partners' Capital Account [Line Items]
Distribution declared		$ 3,798	$ 2,162	$ 11,079	$ 2,162
Net income in excess of distribution		940		2,538
Net income		$ 4,738		$ 13,617
Weighted average units outsanding:
Basic and diluted (shares)		12,686,115		12,686,115
Net income per limited partner unit:
Income per limited partner unit (usd per share)		$ 0.37	$ 0.19	$ 1.07	$ 0.19

Related Party Transactions (Sales to Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Related Party Transaction [Line Items]
Net sales - Westlake	$ 207,856	$ 289,601	$ 621,438	$ 1,088,561
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Net sales - Westlake	$ 207,856	$ 289,601	$ 621,438	$ 1,088,561

Related Party Transactions (Cost of Sales from Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Related Party Transaction [Line Items]
Total	$ 154,474	$ 227,015	$ 473,815	$ 832,304
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Feedstock purchased from Westlake and included in cost of sales	75,752	63,108	232,584	63,108
Other charges from Westlake and included in cost of sales	20,457	13,879	53,948	47,000
Total	$ 96,209	$ 76,987	$ 286,532	$ 110,108

Related Party Transactions (Services from Related Parties Included in SG&A Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Services received from Westlake and included in selling, general and administrative expenses	$ 4,772	$ 4,283	$ 14,891	$ 15,901

Related Party Transactions (Goods and Services from Related Parties that have been Capitalized) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Goods and services purchased from Westlake and capitalized as assets	$ 1,304	$ 830	$ 3,241	$ 2,074

Related Party Transactions (Accounts Receivable from and Accounts Payable to Related Parties) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Accounts receivable, net—Westlake	$ 44,035	$ 18,529
Accounts payable—Westlake	(9,288)	(7,470)
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Accounts receivable, net—Westlake	44,035	18,529
Accounts payable—Westlake	$ (9,288)	$ (7,470)

Related Party Transactions (Debt Payable to Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Interest on related party debt payable	$ 1,054	$ 2,137	$ 3,794	$ 9,833
Accrued interest on related party debt					$ 2,403
Long-term debt payable to Westlake	330,495		330,495		227,638
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Interest capitalized	1,284		3,394
Long-term debt payable to Westlake	330,495		330,495		227,638
Other Nonoperating Income (Expense) [Member] \| Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Interest on related party debt payable	1,054	$ 2,137	3,794	$ 9,833
Accrued Liabilities [Member] \| Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Accrued interest on related party debt	$ 2,284		$ 2,284		$ 2,403

Related Party Transactions (General) (Details) - Westlake [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Senior unsecured revolving credit facility [Member]
Related Party Transaction [Line Items]
Outstanding letters of credit	$ 29,953	$ 31,392
Senior Notes [Member]
Related Party Transaction [Line Items]
Outstanding debt	754,000	754,000
Unamortized discount on senior notes	$ 803	$ 892

Related Party Transactions (Site Lease Agreements) (Details) - Westlake Chemical OpCo LP [Member] - Affiliated Entity [Member] - Site Lease Agreement [Member]	Aug. 04, 2014 USD ($) lease
Related Party Transaction [Line Items]
Number of site lease agreements \| lease	2
Lease term	50 years
Operating lease rent expense \| $	$ 1

Long-term Debt Payable to Westlake (Details) $ in Thousands			5 Months Ended	9 Months Ended
Long-term Debt Payable to Westlake (Details) $ in Thousands	Apr. 29, 2015 USD ($)	Apr. 01, 2015	Sep. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 note	Dec. 31, 2014 USD ($)	Aug. 04, 2014 USD ($)
Related Party Transaction [Line Items]
Long-term debt			$ 330,495	$ 330,495		$ 227,638
Westlake [Member] \| MLP Revolver [Member]
Related Party Transaction [Line Items]
Maximum borrowing capacity	$ 300,000
Limited Partner [Member]
Related Party Transaction [Line Items]
Number of intercompany promissory notes \| note					3
Limited Partner [Member] \| 2013 Promissory Note [Member] \| Senior Notes [Member]
Related Party Transaction [Line Items]
Long-term debt			31,775	$ 31,775		167,116
Limited Partner [Member] \| 2013 Promissory Note [Member] \| Senior Notes [Member] \| Prime Rate [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent				1.50%
Limited Partner [Member] \| OpCo Revolver [Member] \| Line of Credit [Member] \| LIBOR [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent				3.00%
Limited Partner [Member] \| OpCo Revolver [Member] \| Senior Unsecured Revolving Credit Facility [Member]
Related Party Transaction [Line Items]
Long-term debt			163,379	$ 163,379		60,522
Limited Partner [Member] \| MLP Revolver [Member] \| Line of Credit [Member] \| LIBOR [Member] \| Minimum [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent				2.00%
Limited Partner [Member] \| MLP Revolver [Member] \| Senior Unsecured Revolving Credit Facility [Member]
Related Party Transaction [Line Items]
Long-term debt			$ 135,341	$ 135,341		0
Limited Partner [Member] \| Westlake [Member] \| MLP Revolver [Member] \| Line of Credit [Member]
Related Party Transaction [Line Items]
Maximum consolidated leverage ration during one year following acquisitions			5.50
Leverage capital ration required during other periods			4.50
Limited Partner [Member] \| Westlake [Member] \| MLP Revolver [Member] \| Line of Credit [Member] \| LIBOR [Member] \| Minimum [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent			2.00%
Limited Partner [Member] \| Westlake [Member] \| MLP Revolver [Member] \| Line of Credit [Member] \| LIBOR [Member] \| Maximum [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent			3.00%
Limited Partner [Member] \| Westlake Chemical OpCo LP [Member] \| Westlake [Member] \| OpCo Revolver [Member]
Related Party Transaction [Line Items]
Maximum borrowing capacity							$ 600,000
Limited Partner [Member] \| Westlake Chemical OpCo LP [Member] \| Westlake [Member] \| OpCo Revolver [Member] \| Line of Credit [Member] \| LIBOR [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent				3.00%
Affiliated Entity [Member] \| Westlake Chemical OpCo LP [Member]
Related Party Transaction [Line Items]
Additional ownership interest		2.70%
Amount paid to purchase additional limited partner interest	135,341
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Long-term debt			$ 330,495	$ 330,495		$ 227,638
Amount paid to purchase additional limited partner interest	$ 135,341

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Equity [Abstract]
Interest rate contract - Loss recognized on cash flow hedge	$ (223)	$ 0	$ (223)	$ 0
Interest rate contract - Loss reclassified to net income on cash flow hedge	50	$ 0	50	$ 0
Net effect of cash flow hedge	$ (173)		$ (173)		$ 0

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References + Details

Derivative Instruments (Details) $ in Thousands	3 Months Ended		9 Months Ended
Derivative Instruments (Details) $ in Thousands	Sep. 30, 2015 USD ($) derivative	Sep. 30, 2014 USD ($) derivative	Sep. 30, 2015 USD ($) derivative	Sep. 30, 2014 USD ($) derivative	Dec. 31, 2014 derivative
Derivative [Line Items]
Number of derivatives \| derivative					0
Forward Contracts [Member] \| Designated as Hedging Instrument [Member]
Derivative [Line Items]
Number of derivatives \| derivative	0	0	0	0
Forward Contracts [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Number of derivatives \| derivative	0		0
Forward Contracts [Member] \| Not Designated as Hedging Instrument [Member] \| Cost of Sales [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income on Derivative		$ (8,873)		$ (9,244)
Interest Rate Contract [Member] \| Cash Flow Hedging [Member]
Derivative [Line Items]
Change in value recognized in other comprehensive loss	$ 223		$ 223
Interest Rate Contract [Member] \| Cash Flow Hedging [Member] \| Other Liabilities [Member]
Derivative [Line Items]
Fair Value of Derivative	173		173
Interest Rate Contract [Member] \| Interest Expense [Member] \| Cash Flow Hedging [Member]
Derivative [Line Items]
Loss Recognized in Statement of Operations	$ (50)		$ (50)

Derivative Instruments (Ineffective Portion) (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Ineffective portion of a derivative instrument	$ 0	$ 0

Fair Value Measurements (Summary of Assets and Liabilities Accounted at Fair Value on Recurring and Nonrecurring Basis) (Details) - Interest Rate Contract [Member] - Fair Value, Measurements, Recurring [Member] $ in Thousands	Sep. 30, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability - Interest rate contract	$ (173)
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability - Interest rate contract	$ (173)

Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
2013 Promissory Note [Member] \| Senior Notes [Member] \| Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	$ 31,775	$ 167,116
2013 Promissory Note [Member] \| Senior Notes [Member] \| Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	31,775	167,116
OpCo Revolver [Member] \| Senior Unsecured Revolving Credit Facility [Member] \| Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	163,379	60,522
OpCo Revolver [Member] \| Senior Unsecured Revolving Credit Facility [Member] \| Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	170,613	60,522
MLP Revolver [Member] \| Senior Unsecured Revolving Credit Facility [Member] \| Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	135,341	0
MLP Revolver [Member] \| Senior Unsecured Revolving Credit Facility [Member] \| Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	$ 134,514	$ 0

Income Taxes (Detail)	3 Months Ended	7 Months Ended	9 Months Ended
Income Taxes (Detail)	Sep. 30, 2015	Aug. 03, 2014	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Effective income tax rate	0.20%	35.40%	0.20%
U.S. federal statutory income tax rate		35.00%

Supplemental Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Supplemental Information (Details) - USD ($) $ in Thousands	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Accrued Liabilities [Abstract]
Accrued liabilities		$ 22,352		$ 11,900
Accrued Income Taxes, Current				1,622
Accrued interest on related party debt				2,403
Accrued Capital Expenditures, Current		14,452		$ 5,026
Related Party Transaction [Line Items]
Increase (reduction) in capital expenditure accrual		$ (15,850)	$ (8,564)
Westlake [Member] \| Affiliated Entity [Member]
Related Party Transaction [Line Items]
Interest incurred, added to principal on promissory notes outstanding	$ 2,089		$ 9,530

Major Customer and Concentration Risk (Details)	3 Months Ended		9 Months Ended
Major Customer and Concentration Risk (Details)	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net sales [Member] \| Customer Concentration Risk [Member] \| Westlake [Member] \| Affiliated Entity [Member]
Concentration Risk [Line Items]
Concentration risk percentage	83.60%	73.90%	81.90%	73.70%

Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended	98 Months Ended
	Dec. 31, 2014	Sep. 30, 2015
Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Possible amount of claims in settlement for compliance violations		$ 200
Goodrich and PolyOne [Member]
Loss Contingencies [Line Items]
Costs incurred for environmental remediation services	$ 2,805
Goodrich and PolyOne [Member] \| Settled Litigation [Member]
Loss Contingencies [Line Items]
Percentage of costs related to environmental issues to be paid by PolyOne		100.00%
Minimum number of years between arbitrations		5 years
Goodrich and PolyOne [Member] \| Pending Litigation [Member]
Loss Contingencies [Line Items]
Reimbursement of remediation costs sought by PolyOne		$ 1,400

Subsequent Events (Details) - Westlake Chemical OpCo LP [Member] - USD ($) $ / shares in Units, $ in Thousands	Oct. 28, 2015	Jul. 29, 2015	Apr. 29, 2015
Subsequent Event [Line Items]
Distribution declared per unit		$ 0.2910	$ 0.2829
Distribution declared		$ 7,874	$ 7,655
Subsequent Event [Member]
Subsequent Event [Line Items]
Distribution declared per unit	$ 0.2994
Distribution declared	$ 8,102