Document and Entity Information
Document and Entity Information - shares | 9 Months Ended | |
Sep. 30, 2018 | Oct. 30, 2018 | |
Document Information [Line Items] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Sep. 30, 2018 | |
Document Fiscal Year Focus | 2,018 | |
Document Fiscal Period Focus | Q3 | |
Trading Symbol | WLKP | |
Entity Registrant Name | WESTLAKE CHEMICAL PARTNERS LP | |
Entity Central Index Key | 1,604,665 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Accelerated Filer | |
Entity Small Business | false | |
Entity Emerging Growth Company | false | |
Entity Common Units, Units Outstanding | 32,247,371 |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Current assets | ||
Cash and cash equivalents | $ 17,041 | $ 27,008 |
Receivables under Investment Management Agreements with Related Parties, Current | 151,875 | 136,510 |
Accounts receivable, net—Westlake | 65,628 | 43,884 |
Accounts receivable, net—third parties | 22,544 | 18,083 |
Inventories | 5,004 | 5,590 |
Prepaid expenses and other current assets | 491 | 314 |
Total current assets | 262,583 | 231,389 |
Property, plant and equipment, net | 1,161,203 | 1,196,245 |
Other assets, net | ||
Goodwill | 5,814 | 5,814 |
Deferred charges and other assets, net | 65,403 | 81,828 |
Total assets | 1,495,003 | 1,515,276 |
Current liabilities | ||
Accounts payable—Westlake | 41,274 | 14,027 |
Accounts payable—third parties | 6,402 | 10,516 |
Accrued liabilities | 18,911 | 15,697 |
Total current liabilities | 66,587 | 40,240 |
Long-term debt payable to Westlake | 477,608 | 473,960 |
Deferred income taxes | 1,626 | 2,220 |
Other liabilities | 53 | 107 |
Total liabilities | 545,874 | 516,527 |
Commitments and contingencies (Note 12) | ||
EQUITY | ||
Accumulated other comprehensive income | 0 | 279 |
Total Westlake Chemical Partners LP partners' capital | 217,493 | 219,814 |
Noncontrolling interest in Westlake Chemical OpCo LP (OpCo) | 731,636 | 778,935 |
Total equity | 949,129 | 998,749 |
Total liabilities and equity | 1,495,003 | 1,515,276 |
Limited Partner [Member] | Common units [Member] | Public [Member] | ||
EQUITY | ||
Limited Partners' Capital Account | 410,555 | 411,228 |
Total equity | 410,555 | 411,228 |
Limited Partner [Member] | Common units [Member] | Westlake [Member] | ||
EQUITY | ||
Limited Partners' Capital Account | 49,511 | 50,265 |
Total equity | 49,511 | 50,265 |
Limited Partner [Member] | Subordinated units [Member] | Westlake [Member] | ||
EQUITY | ||
Total equity | 0 | 0 |
General Partner [Member] | Westlake [Member] | ||
EQUITY | ||
General partner—Westlake | (242,573) | (241,958) |
Total equity | $ (242,573) | $ (241,958) |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - shares | Sep. 30, 2018 | Dec. 31, 2017 |
Common units [Member] | Public [Member] | ||
Units issued | 18,125,141 | 18,112,500 |
Units outstanding | 18,125,141 | 18,112,500 |
Common units [Member] | Westlake [Member] | ||
Units issued | 14,122,230 | 14,122,230 |
Units outstanding | 14,122,230 | 14,122,230 |
Subordinated units [Member] | Westlake [Member] | ||
Units issued | 0 | 0 |
Units outstanding | 0 | 0 |
Consolidated Statements of Ope
Consolidated Statements of Operations - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Net sales - Westlake | $ 313,381 | $ 258,049 | $ 802,085 | $ 711,968 |
Total net sales | 363,650 | 296,775 | 949,897 | 864,336 |
Cost of Goods and Services Sold | 269,743 | 201,372 | 666,367 | 571,401 |
Gross profit | 93,907 | 95,403 | 283,530 | 292,935 |
Selling, general and administrative expenses | 5,909 | 6,805 | 20,417 | 21,519 |
Income from operations | 87,998 | 88,598 | 263,113 | 271,416 |
Other income (expense) | ||||
Interest expense—Westlake | (5,639) | (6,190) | (16,052) | (17,592) |
Other income, net | 668 | 162 | 1,742 | 1,844 |
Income before income taxes | 83,027 | 82,570 | 248,803 | 255,668 |
Income tax provision (benefit) | (772) | 325 | (186) | 925 |
Net income | 83,799 | 82,245 | 248,989 | 254,743 |
Less: Net income attributable to noncontrolling interest in OpCo | 71,387 | 68,860 | 211,525 | 221,619 |
Net income attributable to Westlake Chemical Partners LP | $ 12,412 | $ 13,385 | $ 37,464 | $ 33,124 |
Weighted average limited partner units outstanding (basic and diluted) | ||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 32,242,210 | 27,172,230 | 32,238,663 | 27,097,642 |
Common units [Member] | ||||
Other income (expense) | ||||
Net income attributable to Westlake Chemical Partners LP | $ 12,412 | $ 12,887 | $ 36,731 | $ 23,078 |
Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted) | ||||
Income per limited partner unit (usd per share) | $ 0.38 | $ 0.47 | $ 1.14 | $ 1.23 |
Weighted average limited partner units outstanding (basic and diluted) | ||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 32,242,210 | 27,172,230 | 32,238,663 | 18,686,701 |
Common units [Member] | Public [Member] | ||||
Weighted average limited partner units outstanding (basic and diluted) | ||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 18,119,980 | 13,050,000 | 18,116,433 | 12,975,412 |
Common units [Member] | Westlake [Member] | ||||
Weighted average limited partner units outstanding (basic and diluted) | ||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 14,122,230 | 14,122,230 | 14,122,230 | 5,711,289 |
Subordinated units [Member] | ||||
Other income (expense) | ||||
Net income attributable to Westlake Chemical Partners LP | $ 8,994 | |||
Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted) | ||||
Income per limited partner unit (usd per share) | $ 0 | $ 0 | $ 0 | $ 1.07 |
Weighted average limited partner units outstanding (basic and diluted) | ||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 8,410,941 | |||
Subordinated units [Member] | Westlake [Member] | ||||
Weighted average limited partner units outstanding (basic and diluted) | ||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 0 | 0 | 0 | 8,410,941 |
Product and Service, Other [Member] | ||||
Total net sales | $ 50,269 | $ 38,726 | $ 147,812 | $ 152,368 |
Consolidated Statements of Chan
Consolidated Statements of Changes in Equity - USD ($) $ in Thousands | Total | Accumulated Other Comprehensive Income (Loss) [Member] | Noncontrolling Interest in OpCo [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 at Dec. 31, 2016 | $ 920,963 | $ 200 | $ 818,479 | $ (242,430) | $ 297,367 | $ 4,813 | $ 42,534 |
Net income | 254,743 | 0 | 221,619 | 1,052 | 15,355 | 3,389 | 13,328 |
Net effect of cash flow hedge | 26 | 26 | 0 | 0 | 0 | 0 | 0 |
Net proceeds from equity offering | 110,739 | 0 | 0 | 0 | 110,739 | 0 | 0 |
Conversion of Units, Amount | 0 | 0 | 0 | 0 | 0 | 42,352 | (42,352) |
Quarterly distributions to unitholders | (29,512) | 0 | 0 | (696) | (13,777) | (1,529) | (13,510) |
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake | (263,480) | 0 | (263,480) | 0 | 0 | 0 | 0 |
Equity, ending balance at Sep. 30, 2017 | 993,479 | 226 | 776,618 | (242,074) | 409,684 | 49,025 | 0 |
Equity, beginning balance at Dec. 31, 2017 | 998,749 | 279 | 778,935 | (241,958) | 411,228 | 50,265 | 0 |
Net income | 248,989 | 0 | 211,525 | 733 | 20,641 | 16,090 | 0 |
Net effect of cash flow hedge | (279) | (279) | 0 | 0 | 0 | 0 | 0 |
Net proceeds from equity offering | 0 | ||||||
Units issued for vested phantom units | 292 | 0 | 0 | 0 | 292 | 0 | 0 |
Quarterly distributions to unitholders | (39,798) | 0 | 0 | (1,348) | (21,606) | (16,844) | 0 |
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake | (258,824) | 0 | (258,824) | 0 | 0 | 0 | 0 |
Equity, ending balance at Sep. 30, 2018 | $ 949,129 | $ 0 | $ 731,636 | $ (242,573) | $ 410,555 | $ 49,511 | $ 0 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 9 Months Ended | |
Sep. 30, 2018 | Sep. 30, 2017 | |
Cash flows from operating activities | ||
Net income | $ 248,989 | $ 254,743 |
Adjustments to reconcile net income to net cash provided by operating activities | ||
Depreciation and amortization | 82,176 | 86,502 |
Loss from disposition of property, plant and equipment | 593 | 2,627 |
Other gains, net | (96) | (1,334) |
Changes in operating assets and liabilities | ||
Accounts receivable—third parties | (4,959) | (4,541) |
Net accounts receivable—Westlake | 5,088 | 68,556 |
Inventories | 586 | 53 |
Prepaid expenses and other current assets | (177) | (144) |
Accounts payable | (4,267) | 1,026 |
Accrued and other liabilities | 2,279 | 5,018 |
Other, net | (208) | (10,590) |
Cash flows from investing activities | 330,004 | 401,916 |
Cash flows from investing activities | ||
Additions to property, plant and equipment | (30,047) | (56,607) |
Maturities of investments with Westlake under the Investment Management Agreement | 270,050 | 0 |
Investments with Westlake under the Investment Management Agreement | (285,000) | (119,000) |
Other | 0 | 1,801 |
Net cash used for investing activities | (44,997) | (173,806) |
Cash flows from financing activities | ||
Net proceeds from equity offering | 0 | 110,739 |
Proceeds from debt payable to Westlake | 3,648 | 155,257 |
Repayment of debt payable to Westlake | 0 | (272,765) |
Quarterly distributions to noncontrolling interest retained in OpCo by Westlake | (258,824) | (263,480) |
Quarterly distributions to unitholders | (39,798) | (29,512) |
Net cash used for financing activities | (294,974) | (299,761) |
Net decrease in cash and cash equivalents | (9,967) | (71,651) |
Cash and cash equivalents at beginning of period | 27,008 | 88,900 |
Cash and cash equivalents at end of period | $ 17,041 | $ 17,249 |
Description of Business and Bas
Description of Business and Basis of Presentation | 9 Months Ended |
Sep. 30, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Description of Business and Basis of Presentation | 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 ethylene production facilities and related assets. On August 4, 2014, the Partnership completed its initial public offering (the "IPO") of 12,937,500 common units representing limited partner interests. On September 29, 2017, the Partnership completed its secondary offering of 5,175,000 common units at a price of $22.00 per unit. 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. On September 29, 2017, the Partnership purchased an additional 5.0% newly-issued limited partner interest in OpCo for approximately $229,207 , resulting in an aggregate 18.3% limited partner interest in OpCo, effective as of July 1, 2017. The remaining 81.7% limited partner interest in OpCo is owned by Westlake Chemical Corporation. OpCo owns three ethylene production facilities and a common carrier ethylene pipeline. Basis of Presentation The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the December 31, 2017 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, 2017 (the "2017 Form 10-K"), filed with the SEC on March 1, 2018. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2017 with the exceptions of those accounting standards adopted in 2018 as discussed in Note 1 . References to "Westlake" refer collectively to Westlake Chemical Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP. The Partnership holds an 18.3% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 81.7% 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 81.7% is recorded as noncontrolling interest in the Partnership's consolidated financial statements. In the opinion of the Partnership's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of September 30, 2018 , its results of operations for the three and nine months ended September 30, 2018 and 2017 and the changes in its cash position for the nine months ended September 30, 2018 and 2017 . 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, 2018 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates. Recent Accounting Pronouncements Leases (ASU No. 2016-02) In February 2016, the Financial Accounting Standards Board ("FASB") issued an accounting standards update on a new lease standard that will supersede the existing lease guidance. The standard requires a lessee to recognize assets and liabilities related to long-term leases that are classified as operating leases under current guidance on its balance sheet. An asset would be recognized related to the right to use the underlying asset and a liability would be recognized related to the obligation to make lease payments over the term of the lease. The standard also requires expanded disclosures related to leases. The accounting standard will be effective for reporting periods beginning after December 15, 2018. The standard requires adoption using a modified retrospective approach and allows for the election of certain transition practical expedients. The accounting standards update allows for certain transition expedients for leases that commenced prior to the adoption of the new standard. Under the optional transition expedients an entity is not required to reassess (1) whether any expired or existing lease contracts are or contain leases, (2) the classification of leases as operating or capital leases and (3) whether any initial direct costs qualify for capitalization under the new accounting standard. These expedients are required to be elected as a group. The accounting standards update also allows the use of hindsight to determine lease term when considering lease renewal or termination options. During 2018, the FASB issued additional authoritative guidance that provides an optional transition method which allows entities to continue applying the existing lease guidance in the comparative periods and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The FASB also issued an accounting standards update that allows entities to apply their existing policy for accounting for land easements that exist as of, or expired before, the effective date of the new lease standard. The Partnership is in the process of evaluating the transition method and other expedients it may elect. The accounting standard will be effective for reporting periods beginning after December 15, 2018. The Partnership is in the process of reviewing its existing lease agreements and evaluating the impact that the new accounting guidance will have on the Partnership's consolidated financial position, results of operations and cash flows. Credit Losses (ASU No. 2016-13) In June 2016, the FASB issued an accounting standards update providing new guidance for the accounting for credit losses on loans and other financial instruments. The new guidance introduces an approach based on expected losses to estimate credit losses on certain types of financial instruments. The standard also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. The accounting standard will be effective for reporting periods beginning after December 15, 2019 and is not expected to have a material impact on the Partnership's consolidated financial position, results of operations and cash flows. Fair Value Measurement (ASU No. 2018-13) In August 2018, the FASB issued an accounting standards update to modify the disclosure requirements on fair value measurements. The amendments are effective beginning after December 15, 2019. An entity is permitted to early adopt any removed or modified disclosures and delay adoption of the additional disclosures until the effective date. Most amendments should be applied retrospectively but certain amendments should be applied prospectively. The Partnership is in the process of evaluating the impact that the new accounting guidance will have on the Partnership's consolidated financial position, results of operations and cash flows. Intangibles - Goodwill and Other (ASU No. 2018-15) In August 2018, the FASB issued an accounting standards update to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The amendments are effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. The amendments should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Partnership adopted the standard on October 1, 2018, prospectively, and the adoption did not have a material impact on the Partnership's consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Revenue from Contracts with Customers (ASU No. 2014-09) In May 2014, the Financial Accounting Standards Board ("FASB") issued an accounting standards update on a comprehensive new revenue recognition standard that supersedes virtually all previously issued 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 are 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 "modified retrospective" adoption, meaning the standard is applied only to the most current period presented in the financial statements with a cumulative catch-up as of the current period. The Partnership adopted ASC No. 2014-09, Revenue from Contracts with Customers (“ASC 606”), effective January 1, 2018. The Partnership applied the modified retrospective transition method to all contracts that were not completed as of the adoption date. Periods prior to January 1, 2018 were not adjusted and are reported under the accounting standards that were in place during those periods. There was no cumulative effect to the Partnership’s consolidated January 1, 2018 balance sheet for the adoption of this accounting standard. There was no impact of ASC 606 adoption on the financial statements for the nine months ended September 30, 2018 as compared with the guidance that was in effect prior to January 1, 2018. Revenue is recognized when OpCo transfers control of inventories to customers. Amounts recognized as revenues reflect the consideration to which OpCo expects to be entitled in exchange for those inventories. The Partnership and OpCo incorporate production volume and production cost forecasts in the estimated transaction prices from sales to Westlake under the Ethylene Sales Agreement. The Partnership recognizes revenue and accounts receivable upon transferring control of inventories to its customers. Ethylene sold to Westlake under the Ethylene Sales Agreement is transferred to Westlake immediately after production and recognized in sales. Control of inventories sold to third parties generally transfers upon shipment to the customer. The Partnership excludes taxes collected on behalf of customers from the estimated contract price. Provisions for discounts, rebates and returns are incorporated in the estimate of variable consideration and reflected as reduction to revenue in the same period as the related sales. The Partnership does not disclose the value of unsatisfied performance obligations because its contracts with customers (i) have an original expected duration of one year or less or (ii) have only variable consideration which is allocated to wholly unsatisfied performance obligations that is calculated based on market prices at a specified date and is allocated to wholly unsatisfied performance obligations. The Partnership generates a substantial majority of its revenue from sales to Westlake under the Ethylene Sales Agreement (discussed in Note 2 to the 2017 Form 10-K). The Ethylene Sales Agreement is intended to generate a long-term, fixed cash margin per pound. Partnership’s direct commodity price risk is limited to the sales to third parties. Refer to the Partnership’s Consolidated Statement of Operations for the disaggregation of net sales to Westlake and net sales to third parties. Cash Flows (ASU No. 2016-15) In August 2016, the FASB issued an accounting standards update providing new guidance on the classification of certain cash receipts and payments including debt extinguishment costs, debt prepayment costs, settlement of zero-coupon debt instruments, contingent consideration payments, proceeds from the settlement of insurance claims and life insurance policies and distributions received from equity method investees in the statement of cash flows. This update is required to be applied using the retrospective transition method to each period presented unless it is impracticable to be applied retrospectively. In such situation, this guidance is to be applied prospectively. The accounting standard became effective for reporting periods beginning after December 15, 2017. The Partnership adopted this accounting standard effective January 1, 2018, and the adoption did not have any impact on the Partnership's consolidated financial position, results of operations and cash flow. Business Combinations (ASU No. 2017-01) In January 2017, the FASB issued an accounting standards update to assist entities with evaluating when a set of transferred assets and activities is a business. The guidance requires an entity to evaluate if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of transferred assets and activities is not a business. The guidance also requires a business to include at least one substantive process and narrows the definition of outputs by more closely aligning it with how outputs are described in the FASB ASC Topic 606, Revenue from contracts with customers. The accounting standard became effective for reporting periods beginning after December 15, 2017. The Partnership adopted this accounting standard effective January 1, 2018, and the adoption did not have any impact on the Partnership's consolidated financial position, results of operations and cash flow. Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (ASU No. 2017-05) In February 2017, the FASB issued an accounting standards update to clarify the scope of guidance related to other income—gains and losses from the derecognition of nonfinancial assets, and to add guidance for partial sales of nonfinancial assets. The new guidance clarifies that an in substance nonfinancial asset is an asset or group of assets for which substantially all of the fair value consists of nonfinancial assets and the group or subsidiary is not a business. The guidance also outlines that when an entity transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling interest, it will measure the retained interest at fair value resulting in full gain or loss recognition upon sale of the controlling interest. The accounting standard became effective for reporting periods beginning after December 15, 2017. The Partnership adopted this accounting standard effective January 1, 2018, and the adoption did not have any impact on the Partnership's consolidated financial position, results of operations and cash flow. |
Accounts Receivable - Third Par
Accounts Receivable - Third Parties | 9 Months Ended |
Sep. 30, 2018 | |
Accounts Receivable, Net [Abstract] | |
Accounts Receivable - Third Parties | Accounts Receivable—Third Parties Accounts receivable—third parties consist of the following: September 30, December 31, Trade customers $ 23,676 $ 18,794 Allowance for doubtful accounts (1,209 ) (711 ) 22,467 18,083 Other 77 — Accounts receivable, net—third parties $ 22,544 $ 18,083 |
Inventories
Inventories | 9 Months Ended |
Sep. 30, 2018 | |
Inventory Disclosure [Abstract] | |
Inventories | Inventories Inventories consist of the following: September 30, December 31, Finished products $ 4,596 $ 5,244 Feedstock, additives and chemicals 408 346 Inventories $ 5,004 $ 5,590 |
Property, Plant and Equipment
Property, Plant and Equipment | 9 Months Ended |
Sep. 30, 2018 | |
Property, Plant and Equipment [Abstract] | |
Property, Plant and Equipment | Property, Plant and Equipment Depreciation expense on property, plant and equipment of $21,960 and $23,525 is included in cost of sales in the consolidated statements of operations for the three months ended September 30, 2018 and 2017 , respectively. Depreciation expense on property, plant and equipment of $66,161 and $69,189 is included in cost of sales in the consolidated statements of operations for the nine months ended September 30, 2018 and 2017 , respectively. |
Other Assets
Other Assets | 9 Months Ended |
Sep. 30, 2018 | |
Other Assets, Noncurrent [Abstract] | |
Other Assets | Other Assets Amortization expense on other assets of $4,932 and $5,528 is included in costs of sales in the consolidated statements of operations for the three months ended September 30, 2018 and 2017 , respectively. Amortization expense on other assets of $16,015 and $17,313 is included in costs of sales in the consolidated statements of operations for the nine months ended September 30, 2018 and 2017 , respectively. |
Distributions and Net Income Pe
Distributions and Net Income Per Limited Partner Unit | 9 Months Ended |
Sep. 30, 2018 | |
Earnings Per Share [Abstract] | |
Distributions and Net Income Per Limited Partner Unit | Distributions and Net Income Per Limited Partner Unit On October 31, 2018 , 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, 2018 through September 30, 2018 of $0.4207 per unit. This distribution is payable on November 26, 2018 to the unitholders of record as of November 9, 2018 . On July 27, 2018, the Partnership Agreement was amended to revise the minimum quarterly distribution thresholds for the Partnership's incentive distribution rights. The amended Partnership Agreement provides that the Partnership will distribute cash each quarter to all the unitholders, pro-rata, until each unit has received a distribution of $1.2938 . If cash distributions to the Partnership's unitholders exceed $1.2938 per unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations: Marginal Percentage Interest in Distributions Total Quarterly Distribution Per Unit Unitholders IDR Holders Above $1.2938 up to $1.4063 85.0 % 15.0 % Above $1.4063 up to $1.6875 75.0 % 25.0 % Above $1.6875 50.0 % 50.0 % The Partnership's distribution for the three months ended September 30, 2018 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights. Prior to the amendment, the Partnership Agreement provided that the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, would receive distributions according to the following percentage allocations: Marginal Percentage Interest in Distributions Total Quarterly Distribution Per Unit Unitholders IDR Holders Above $0.3163 up to $0.3438 85.0 % 15.0 % Above $0.3438 up to $0.4125 75.0 % 25.0 % Above $0.4125 50.0 % 50.0 % The distributions are declared subsequent to quarter end; therefore, the table below represents total distributions declared from earnings of the related periods pertaining to such distributions. Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Net income attributable to the Partnership $ 12,412 $ 13,385 $ 37,464 $ 33,124 Less: Limited partners' distributions declared on common units 13,566 12,107 39,559 22,454 Limited partners' distributions declared on subordinated units — — — 9,133 Distributions declared with respect to the incentive distribution rights — 498 733 1,052 Net income in excess of distribution (Distribution in excess of net income) $ (1,154 ) $ 780 $ (2,828 ) $ 485 Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common 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 and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statement of equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented. The 12,686,115 subordinated units, all of which were owned by Westlake, were converted into common units during the third quarter of 2017 and were considered converted as of July 1, 2017 for purposes of calculating net income per unit. Therefore, the subordinated units did not share in the distribution of cash generated nor did the Partnership allocate any earnings to the subordinated unitholders for the determination of net income per unit subsequent to June 30, 2017. Three Months Ended September 30, 2018 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 13,566 $ — $ 13,566 Distribution in excess of net income (1,154 ) — (1,154 ) Net income $ 12,412 $ — $ 12,412 Weighted average units outstanding: Basic and diluted 32,242,210 32,242,210 Net income per limited partner unit: Basic and diluted $ 0.38 Three Months Ended September 30, 2017 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 12,107 $ 498 $ 12,605 Net income in excess of distribution 780 — 780 Net income $ 12,887 $ 498 $ 13,385 Weighted average units outstanding: Basic and diluted 27,172,230 27,172,230 Net income per limited partner unit: Basic and diluted $ 0.47 Nine Months Ended September 30, 2018 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 39,559 $ 733 $ 40,292 Distribution in excess of net income (2,828 ) — (2,828 ) Net income $ 36,731 $ 733 $ 37,464 Weighted average units outstanding: Basic and diluted 32,238,663 32,238,663 Net income per limited partner unit: Basic and diluted $ 1.14 Nine Months Ended September 30, 2017 Limited Partners' Common Units Limited Partners' Subordinated Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 22,454 $ 9,133 $ 1,052 $ 32,639 Net income in excess of distribution (distribution in excess of net income) 624 (139 ) — 485 Net income $ 23,078 $ 8,994 $ 1,052 $ 33,124 Weighted average units outstanding: Basic and diluted 18,686,701 8,410,941 27,097,642 Net income per limited partner unit: Basic and diluted $ 1.23 $ 1.07 Distribution Per Common Unit Distributions per common unit for the three months ended September 30, 2018 and 2017 and for the nine months ended September 30, 2018 and 2017 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Distributions per common unit $ 0.4088 $ 0.3650 $ 1.1927 $ 1.0649 |
Partners' Equity
Partners' Equity | 9 Months Ended |
Sep. 30, 2018 | |
Equity [Abstract] | |
Equity | 7. Partners' Equity Following the Partnership’s cash distribution for the second quarter of 2017, the requirement under the Partnership’s partnership agreement for the conversion of all subordinated units was satisfied. As a result, effective August 30, 2017, the 12,686,115 subordinated units owned by Westlake were converted into common units on a one-for-one basis and thereafter participate on terms equal with all other common units in distributions of available cash. As discussed in Note 6 , the subordinated units were considered converted as of July 1, 2017 for purposes of calculating net income per unit and, therefore, the subordinated units did not share in the distribution of cash generated nor did the Partnership allocate any earnings to the subordinated unitholders for the determination of net income per unit subsequent to June 30, 2017. On September 29, 2017, the Partnership completed its secondary offering of 5,175,000 common units at a price of $22.00 per unit. Net proceeds to the Partnership from the sale of the units were $110,739 , net of underwriting discounts, structuring fees and estimated offering expenses of approximately $3,111 . |
Related Party Transactions
Related Party Transactions | 9 Months Ended |
Sep. 30, 2018 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | 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, the Partnership and OpCo from time to time provide other services or products for which each charges Westlake a fee. Sales to related parties were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Net sales—Westlake $ 313,381 $ 258,049 $ 802,085 $ 711,968 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. Charges from related parties in cost of sales were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Feedstock purchased from Westlake and included in cost of sales $ 178,493 $ 110,241 $ 403,833 $ 313,231 Other charges from Westlake and included in cost of sales 28,693 23,954 83,636 74,896 Total $ 207,186 $ 134,195 $ 487,469 $ 388,127 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. Charges from related parties included within selling, general and administrative expenses were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Services received from Westlake and included in selling, general and administrative expenses $ 4,655 $ 6,633 $ 17,947 $ 20,311 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. Charges from related parties for goods and services capitalized as assets were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Goods and services purchased from Westlake and capitalized as assets $ 846 $ 619 $ 1,988 $ 3,131 Receivable under the Investment Management Agreement On August 1, 2017, the Partnership, OpCo and Westlake executed an investment management agreement (the "Investment Management Agreement") that authorized Westlake to invest the Partnership's and OpCo’s excess cash with Westlake for a term of up to a maximum of nine months. Per the terms of the Investment Management Agreement, the Partnership earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo. Accrued interest of $703 and $340 was included in the receivable under the Investment Management Agreement balance at September 30, 2018 and December 31, 2017 , respectively. Total interest earned related to the Investment Management Agreement was $703 and $9 for the three months ended September 30, 2018 and 2017 , respectively. The interest earned related to the Investment Management Agreement was $1,861 and $9 for the nine months ended September 30, 2018 and 2017 , respectively. The Partnership's receivable under the Investment Management Agreement was as follows: September 30, December 31, Receivable under the Investment Management Agreement $ 151,875 $ 136,510 Accounts Receivables The Partnership's accounts receivable from Westlake result primarily from ethylene sales to Westlake under the Ethylene Sales Agreement. The Partnership's accounts receivable from Westlake were as follows: September 30, December 31, Accounts receivable—Westlake $ 65,628 $ 43,884 Accounts Payable to Related Parties 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 payable balances were as follows: September 30, December 31, Accounts payable—Westlake $ 41,274 $ 14,027 Debt Payable to Related Parties See Note 9 for a description of related party debt payable balances. Interest on related party debt payable balances for the three months ended September 30, 2018 and 2017 was $5,639 and $6,190 , respectively, and for the nine months ended September 30, 2018 and 2017 was $16,052 and $17,592 , respectively. Interest on related party debt payable is presented as interest expense—Westlake in the consolidated statements of operations. Interest capitalized as a component of property, plant and equipment on related party debt was $63 and $7 for the three months ended September 30, 2018 and 2017 , respectively, and for the nine months ended September 30, 2018 and 2017 was $108 and $426 , respectively. At September 30, 2018 and December 31, 2017 , accrued interest on related party debt was $5,712 and $4,590 , 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, December 31, Long-term debt payable to Westlake $ 477,608 $ 473,960 Major Customer and Concentration of Credit Risk During the three months ended September 30, 2018 and 2017 , Westlake accounted for approximately 86.2% and 87.0% , respectively, of the Partnership's net sales. During the nine months ended September 30, 2018 and 2017 , Westlake accounted for approximately 84.4% and 82.4% , respectively, of the Partnership's net sales. Income Taxes During the three and nine months ended September 30, 2018 , the Partnership reimbursed $418 of income tax payments to Westlake. General In 2015, the Partnership entered into an interest rate contract with Westlake to fix the London Interbank Offered Rate ("LIBOR") component of the interest rate for a portion of the MLP Revolver balance. The interest rate contract expired in August 2018. OpCo has two site lease agreements with Westlake, and each has a term of 50 years. Pursuant to the site lease agreements, OpCo pays Westlake one dollar per site per year. |
Long-term Debt Payable to Westl
Long-term Debt Payable to Westlake | 9 Months Ended |
Sep. 30, 2018 | |
Related Party Transactions [Abstract] | |
Long-term Debt Payable to Westlake | Long-term Debt Payable to Westlake Long-term debt payable to Westlake consists of the following: September 30, December 31, OpCo Revolver (variable interest rate of LIBOR plus 2.0%, original scheduled maturity of September 25, 2023) $ 224,064 $ 220,416 MLP Revolver (variable interest rate of LIBOR plus 2.0%, original scheduled maturity of April 29, 2021) 253,544 253,544 $ 477,608 $ 473,960 On September 25, 2018, the OpCo Revolver was amended to extend the maturity date from August 4, 2019 to September 25, 2023 and revise the applicable margin from 3% to 2% . The weighted average interest rate on all long-term debt was 4.34% and 3.74% at September 30, 2018 and December 31, 2017 , respectively. As of September 30, 2018 , the Partnership was in compliance with all of the covenants under the OpCo Revolver and the MLP Revolver. |
Fair Value Measurements
Fair Value Measurements | 9 Months Ended |
Sep. 30, 2018 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 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. The Partnership has 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, 2018 and December 31, 2017 are summarized in the table below. The Partnership's long-term debt includes the OpCo Revolver and the MLP Revolver at September 30, 2018 . 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, 2018 December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value OpCo Revolver $ 224,064 $ 229,622 $ 220,416 $ 228,180 MLP Revolver 253,544 255,008 253,544 258,234 |
Supplemental Information
Supplemental Information | 9 Months Ended |
Sep. 30, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Supplemental Information | Supplemental Information Accrued Liabilities Accrued liabilities were $18,911 and $15,697 at September 30, 2018 and December 31, 2017 , respectively. The accrued interest, accrued maintenance and accrued taxes, which are components of accrued liabilities, were $5,712 , $5,323 and $4,156 , respectively, at September 30, 2018 , and $4,590 , $3,698 and $1,422 , respectively, at December 31, 2017 . No other component of accrued liabilities was more than five percent of total current liabilities. Non-cash Investing Activity The change in capital expenditure accrual resulted in a decrease in additions to property, plant and equipment by $1,380 for the nine months ended September 30, 2018 . The change in capital expenditure accrual resulted in an increase in additions to property, plant and equipment by $894 for the nine months ended September 30, 2017 . |
Commitments and Contingencies
Commitments and Contingencies | 9 Months Ended |
Sep. 30, 2018 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | Commitments and Contingencies The Partnership is subject to environmental laws and regulations that can impose civil and criminal sanctions and that may require the Partnership to mitigate the effects of contamination caused by the release or disposal of hazardous substances into the environment. These laws include the federal Clean Air Act, the federal Water Pollution Control Act, the Resource Conservation and Recovery Act ("RCRA"), the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), the Toxic Substances Control Act and various other federal, state and local laws and regulations. Under CERCLA, an owner or operator of property may be held strictly liable for remediating contamination without regard to whether that person caused the contamination, and without regard to whether the practices that resulted in the contamination were legal at the time they occurred. Because the Partnership's production sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on the Partnership. Westlake will indemnify the Partnership for liabilities that occurred or existed prior to August 4, 2014. The Partnership is involved in various legal proceedings incidental to the conduct of its business. The Partnership does not believe that any of these legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows. |
Subsequent Events Subsequent Ev
Subsequent Events Subsequent Events - USD ($) $ in Thousands | Oct. 04, 2018 | Sep. 30, 2018 |
Subsequent Event [Line Items] | ||
Subsequent Events [Text Block] | Subsequent Events At-The-Market Program On October 4, 2018, the Partnership and Westlake Chemical Partners GP LLC, the general partner of the Partnership, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell the Partnership's common units, from time to time, up to an aggregate offering amount of $50,000 . Ethylene Sales Agreement On November 1, 2018, OpCo and Westlake entered into an amendment to the Ethylene Sales Agreement in order to provide OpCo with the option to curtail up to approximately 5% of its ethylene production annually in the event OpCo reasonably determines that its sales of such ethylene to third parties during the relevant period would be uneconomic. | |
Subsequent Event [Member] | ||
Subsequent Event [Line Items] | ||
Partners Units, Maximum Aggregate Offering Amount, ATM | $ 50,000 |
Description of Business and B_2
Description of Business and Basis of Presentation (Policies) | 9 Months Ended |
Sep. 30, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Basis of Presentation | Basis of Presentation The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the December 31, 2017 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, 2017 (the "2017 Form 10-K"), filed with the SEC on March 1, 2018. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2017 with the exceptions of those accounting standards adopted in 2018 as discussed in Note 1 . References to "Westlake" refer collectively to Westlake Chemical Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP. The Partnership holds an 18.3% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 81.7% 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 81.7% is recorded as noncontrolling interest in the Partnership's consolidated financial statements. In the opinion of the Partnership's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of September 30, 2018 , its results of operations for the three and nine months ended September 30, 2018 and 2017 and the changes in its cash position for the nine months ended September 30, 2018 and 2017 . 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, 2018 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates. |
Recent Accounting Pronouncements | Recent Accounting Pronouncements Leases (ASU No. 2016-02) In February 2016, the Financial Accounting Standards Board ("FASB") issued an accounting standards update on a new lease standard that will supersede the existing lease guidance. The standard requires a lessee to recognize assets and liabilities related to long-term leases that are classified as operating leases under current guidance on its balance sheet. An asset would be recognized related to the right to use the underlying asset and a liability would be recognized related to the obligation to make lease payments over the term of the lease. The standard also requires expanded disclosures related to leases. The accounting standard will be effective for reporting periods beginning after December 15, 2018. The standard requires adoption using a modified retrospective approach and allows for the election of certain transition practical expedients. The accounting standards update allows for certain transition expedients for leases that commenced prior to the adoption of the new standard. Under the optional transition expedients an entity is not required to reassess (1) whether any expired or existing lease contracts are or contain leases, (2) the classification of leases as operating or capital leases and (3) whether any initial direct costs qualify for capitalization under the new accounting standard. These expedients are required to be elected as a group. The accounting standards update also allows the use of hindsight to determine lease term when considering lease renewal or termination options. During 2018, the FASB issued additional authoritative guidance that provides an optional transition method which allows entities to continue applying the existing lease guidance in the comparative periods and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The FASB also issued an accounting standards update that allows entities to apply their existing policy for accounting for land easements that exist as of, or expired before, the effective date of the new lease standard. The Partnership is in the process of evaluating the transition method and other expedients it may elect. The accounting standard will be effective for reporting periods beginning after December 15, 2018. The Partnership is in the process of reviewing its existing lease agreements and evaluating the impact that the new accounting guidance will have on the Partnership's consolidated financial position, results of operations and cash flows. Credit Losses (ASU No. 2016-13) In June 2016, the FASB issued an accounting standards update providing new guidance for the accounting for credit losses on loans and other financial instruments. The new guidance introduces an approach based on expected losses to estimate credit losses on certain types of financial instruments. The standard also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. The accounting standard will be effective for reporting periods beginning after December 15, 2019 and is not expected to have a material impact on the Partnership's consolidated financial position, results of operations and cash flows. Fair Value Measurement (ASU No. 2018-13) In August 2018, the FASB issued an accounting standards update to modify the disclosure requirements on fair value measurements. The amendments are effective beginning after December 15, 2019. An entity is permitted to early adopt any removed or modified disclosures and delay adoption of the additional disclosures until the effective date. Most amendments should be applied retrospectively but certain amendments should be applied prospectively. The Partnership is in the process of evaluating the impact that the new accounting guidance will have on the Partnership's consolidated financial position, results of operations and cash flows. Intangibles - Goodwill and Other (ASU No. 2018-15) In August 2018, the FASB issued an accounting standards update to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The amendments are effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. The amendments should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Partnership adopted the standard on October 1, 2018, prospectively, and the adoption did not have a material impact on the Partnership's consolidated financial position, results of operations and cash flows. Recently Adopted Accounting Standards Revenue from Contracts with Customers (ASU No. 2014-09) In May 2014, the Financial Accounting Standards Board ("FASB") issued an accounting standards update on a comprehensive new revenue recognition standard that supersedes virtually all previously issued 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 are 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 "modified retrospective" adoption, meaning the standard is applied only to the most current period presented in the financial statements with a cumulative catch-up as of the current period. The Partnership adopted ASC No. 2014-09, Revenue from Contracts with Customers (“ASC 606”), effective January 1, 2018. The Partnership applied the modified retrospective transition method to all contracts that were not completed as of the adoption date. Periods prior to January 1, 2018 were not adjusted and are reported under the accounting standards that were in place during those periods. There was no cumulative effect to the Partnership’s consolidated January 1, 2018 balance sheet for the adoption of this accounting standard. There was no impact of ASC 606 adoption on the financial statements for the nine months ended September 30, 2018 as compared with the guidance that was in effect prior to January 1, 2018. Revenue is recognized when OpCo transfers control of inventories to customers. Amounts recognized as revenues reflect the consideration to which OpCo expects to be entitled in exchange for those inventories. The Partnership and OpCo incorporate production volume and production cost forecasts in the estimated transaction prices from sales to Westlake under the Ethylene Sales Agreement. The Partnership recognizes revenue and accounts receivable upon transferring control of inventories to its customers. Ethylene sold to Westlake under the Ethylene Sales Agreement is transferred to Westlake immediately after production and recognized in sales. Control of inventories sold to third parties generally transfers upon shipment to the customer. The Partnership excludes taxes collected on behalf of customers from the estimated contract price. Provisions for discounts, rebates and returns are incorporated in the estimate of variable consideration and reflected as reduction to revenue in the same period as the related sales. The Partnership does not disclose the value of unsatisfied performance obligations because its contracts with customers (i) have an original expected duration of one year or less or (ii) have only variable consideration which is allocated to wholly unsatisfied performance obligations that is calculated based on market prices at a specified date and is allocated to wholly unsatisfied performance obligations. The Partnership generates a substantial majority of its revenue from sales to Westlake under the Ethylene Sales Agreement (discussed in Note 2 to the 2017 Form 10-K). The Ethylene Sales Agreement is intended to generate a long-term, fixed cash margin per pound. Partnership’s direct commodity price risk is limited to the sales to third parties. Refer to the Partnership’s Consolidated Statement of Operations for the disaggregation of net sales to Westlake and net sales to third parties. Cash Flows (ASU No. 2016-15) In August 2016, the FASB issued an accounting standards update providing new guidance on the classification of certain cash receipts and payments including debt extinguishment costs, debt prepayment costs, settlement of zero-coupon debt instruments, contingent consideration payments, proceeds from the settlement of insurance claims and life insurance policies and distributions received from equity method investees in the statement of cash flows. This update is required to be applied using the retrospective transition method to each period presented unless it is impracticable to be applied retrospectively. In such situation, this guidance is to be applied prospectively. The accounting standard became effective for reporting periods beginning after December 15, 2017. The Partnership adopted this accounting standard effective January 1, 2018, and the adoption did not have any impact on the Partnership's consolidated financial position, results of operations and cash flow. Business Combinations (ASU No. 2017-01) In January 2017, the FASB issued an accounting standards update to assist entities with evaluating when a set of transferred assets and activities is a business. The guidance requires an entity to evaluate if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of transferred assets and activities is not a business. The guidance also requires a business to include at least one substantive process and narrows the definition of outputs by more closely aligning it with how outputs are described in the FASB ASC Topic 606, Revenue from contracts with customers. The accounting standard became effective for reporting periods beginning after December 15, 2017. The Partnership adopted this accounting standard effective January 1, 2018, and the adoption did not have any impact on the Partnership's consolidated financial position, results of operations and cash flow. Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (ASU No. 2017-05) In February 2017, the FASB issued an accounting standards update to clarify the scope of guidance related to other income—gains and losses from the derecognition of nonfinancial assets, and to add guidance for partial sales of nonfinancial assets. The new guidance clarifies that an in substance nonfinancial asset is an asset or group of assets for which substantially all of the fair value consists of nonfinancial assets and the group or subsidiary is not a business. The guidance also outlines that when an entity transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling interest, it will measure the retained interest at fair value resulting in full gain or loss recognition upon sale of the controlling interest. The accounting standard became effective for reporting periods beginning after December 15, 2017. The Partnership adopted this accounting standard effective January 1, 2018, and the adoption did not have any impact on the Partnership's consolidated financial position, results of operations and cash flow. |
Accounts Receivable - Third P_2
Accounts Receivable - Third Parties (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Accounts Receivable, Net [Abstract] | |
Schedule Of Accounts Receivable - Third Parties | Accounts receivable—third parties consist of the following: September 30, December 31, Trade customers $ 23,676 $ 18,794 Allowance for doubtful accounts (1,209 ) (711 ) 22,467 18,083 Other 77 — Accounts receivable, net—third parties $ 22,544 $ 18,083 |
Inventories (Tables)
Inventories (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Inventory Disclosure [Abstract] | |
Schedule Of Inventory | Inventories consist of the following: September 30, December 31, Finished products $ 4,596 $ 5,244 Feedstock, additives and chemicals 408 346 Inventories $ 5,004 $ 5,590 |
Distributions and Net Income _2
Distributions and Net Income Per Limited Partner Unit (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Earnings Per Share [Abstract] | |
Schedule of Incentive Distributions Made to Managing Members or General Partners by Distribution | On July 27, 2018, the Partnership Agreement was amended to revise the minimum quarterly distribution thresholds for the Partnership's incentive distribution rights. The amended Partnership Agreement provides that the Partnership will distribute cash each quarter to all the unitholders, pro-rata, until each unit has received a distribution of $1.2938 . If cash distributions to the Partnership's unitholders exceed $1.2938 per unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations: Marginal Percentage Interest in Distributions Total Quarterly Distribution Per Unit Unitholders IDR Holders Above $1.2938 up to $1.4063 85.0 % 15.0 % Above $1.4063 up to $1.6875 75.0 % 25.0 % Above $1.6875 50.0 % 50.0 % The Partnership's distribution for the three months ended September 30, 2018 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights. Prior to the amendment, the Partnership Agreement provided that the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, would receive distributions according to the following percentage allocations: Marginal Percentage Interest in Distributions Total Quarterly Distribution Per Unit Unitholders IDR Holders Above $0.3163 up to $0.3438 85.0 % 15.0 % Above $0.3438 up to $0.4125 75.0 % 25.0 % Above $0.4125 50.0 % 50.0 % The distributions are declared subsequent to quarter end; therefore, the table below represents total distributions declared from earnings of the related periods pertaining to such distributions. Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Net income attributable to the Partnership $ 12,412 $ 13,385 $ 37,464 $ 33,124 Less: Limited partners' distributions declared on common units 13,566 12,107 39,559 22,454 Limited partners' distributions declared on subordinated units — — — 9,133 Distributions declared with respect to the incentive distribution rights — 498 733 1,052 Net income in excess of distribution (Distribution in excess of net income) $ (1,154 ) $ 780 $ (2,828 ) $ 485 |
Schedule of Earnings Per Share, Basic and Diluted | Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statement of equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented. The 12,686,115 subordinated units, all of which were owned by Westlake, were converted into common units during the third quarter of 2017 and were considered converted as of July 1, 2017 for purposes of calculating net income per unit. Therefore, the subordinated units did not share in the distribution of cash generated nor did the Partnership allocate any earnings to the subordinated unitholders for the determination of net income per unit subsequent to June 30, 2017. Three Months Ended September 30, 2018 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 13,566 $ — $ 13,566 Distribution in excess of net income (1,154 ) — (1,154 ) Net income $ 12,412 $ — $ 12,412 Weighted average units outstanding: Basic and diluted 32,242,210 32,242,210 Net income per limited partner unit: Basic and diluted $ 0.38 Three Months Ended September 30, 2017 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 12,107 $ 498 $ 12,605 Net income in excess of distribution 780 — 780 Net income $ 12,887 $ 498 $ 13,385 Weighted average units outstanding: Basic and diluted 27,172,230 27,172,230 Net income per limited partner unit: Basic and diluted $ 0.47 Nine Months Ended September 30, 2018 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 39,559 $ 733 $ 40,292 Distribution in excess of net income (2,828 ) — (2,828 ) Net income $ 36,731 $ 733 $ 37,464 Weighted average units outstanding: Basic and diluted 32,238,663 32,238,663 Net income per limited partner unit: Basic and diluted $ 1.14 Nine Months Ended September 30, 2017 Limited Partners' Common Units Limited Partners' Subordinated Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution declared $ 22,454 $ 9,133 $ 1,052 $ 32,639 Net income in excess of distribution (distribution in excess of net income) 624 (139 ) — 485 Net income $ 23,078 $ 8,994 $ 1,052 $ 33,124 Weighted average units outstanding: Basic and diluted 18,686,701 8,410,941 27,097,642 Net income per limited partner unit: Basic and diluted $ 1.23 $ 1.07 Distribution Per Common Unit Distributions per common unit for the three months ended September 30, 2018 and 2017 and for the nine months ended September 30, 2018 and 2017 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Distributions per common unit $ 0.4088 $ 0.3650 $ 1.1927 $ 1.0649 |
Related Party Transactions (Tab
Related Party Transactions (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Related Party Transactions [Abstract] | |
Schedule of Related Party Transactions | The related party accounts payable balances were as follows: September 30, December 31, Accounts payable—Westlake $ 41,274 $ 14,027 Charges from related parties included within selling, general and administrative expenses were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Services received from Westlake and included in selling, general and administrative expenses $ 4,655 $ 6,633 $ 17,947 $ 20,311 The Partnership's receivable under the Investment Management Agreement was as follows: September 30, December 31, Receivable under the Investment Management Agreement $ 151,875 $ 136,510 The Partnership's accounts receivable from Westlake were as follows: September 30, December 31, Accounts receivable—Westlake $ 65,628 $ 43,884 Charges from related parties for goods and services capitalized as assets were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Goods and services purchased from Westlake and capitalized as assets $ 846 $ 619 $ 1,988 $ 3,131 Sales to related parties were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Net sales—Westlake $ 313,381 $ 258,049 $ 802,085 $ 711,968 Charges from related parties in cost of sales were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Feedstock purchased from Westlake and included in cost of sales $ 178,493 $ 110,241 $ 403,833 $ 313,231 Other charges from Westlake and included in cost of sales 28,693 23,954 83,636 74,896 Total $ 207,186 $ 134,195 $ 487,469 $ 388,127 Debt payable to related parties was as follows: September 30, December 31, Long-term debt payable to Westlake $ 477,608 $ 473,960 |
Long-term Debt Payable to Wes_2
Long-term Debt Payable to Westlake (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Related Party Transactions [Abstract] | |
Related Party Transactions, Long-term Debt | Long-term debt payable to Westlake consists of the following: September 30, December 31, OpCo Revolver (variable interest rate of LIBOR plus 2.0%, original scheduled maturity of September 25, 2023) $ 224,064 $ 220,416 MLP Revolver (variable interest rate of LIBOR plus 2.0%, original scheduled maturity of April 29, 2021) 253,544 253,544 $ 477,608 $ 473,960 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Fair Value Disclosures [Abstract] | |
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, 2018 and December 31, 2017 are summarized in the table below. The Partnership's long-term debt includes the OpCo Revolver and the MLP Revolver at September 30, 2018 . 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, 2018 December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value OpCo Revolver $ 224,064 $ 229,622 $ 220,416 $ 228,180 MLP Revolver 253,544 255,008 253,544 258,234 |
Description of Business and B_3
Description of Business and Basis of Presentation (Details) $ / shares in Units, $ in Thousands | Sep. 30, 2017 | Sep. 29, 2017USD ($)$ / sharesshares | Apr. 29, 2015USD ($) | Apr. 01, 2015 | Aug. 04, 2014shares | Sep. 30, 2018production_facility |
Limited Partners' Capital Account [Line Items] | ||||||
Underwriting discounts, structuring fees and offering expenses on issuance of equity | $ 3,111 | |||||
Westlake Chemical OpCo LP [Member] | Affiliated Entity [Member] | ||||||
Limited Partners' Capital Account [Line Items] | ||||||
Limited partner interest | 18.30% | 18.30% | 13.30% | 10.60% | ||
Limited partner interest, additional ownership | 5.00% | 2.70% | ||||
Amount paid to purchase additional limited partner interest | $ 229 | $ 135,341 | ||||
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 | 81.70% | 81.70% | ||||
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 | 5,175,000 | 12,937,500 | ||||
Units sold in secondary offering price per unit (in dollars per share) | $ / shares | $ 22 |
Accounts Receivable - Third P_3
Accounts Receivable - Third Parties Accounts Receivable—Third Parties (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Accounts Receivable, Net [Abstract] | ||
Trade customers | $ 23,676 | $ 18,794 |
Allowance for doubtful accounts | (1,209) | (711) |
Trade Customer Receivable Net Current | 22,467 | 18,083 |
Other | 77 | 0 |
Accounts receivable, net—third parties | $ 22,544 | $ 18,083 |
Inventories (Details)
Inventories (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Inventory Disclosure [Abstract] | ||
Finished products | $ 4,596 | $ 5,244 |
Feedstock, additives and chemicals | 408 | 346 |
Inventories | $ 5,004 | $ 5,590 |
Property, Plant and Equipment (
Property, Plant and Equipment (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Property, Plant and Equipment [Abstract] | ||||
Depreciation expense on property, plant and equipment | $ 21,960 | $ 23,525 | $ 66,161 | $ 69,189 |
Other Assets (Details)
Other Assets (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Other Assets [Member] | ||||
Other Assets [Line Items] | ||||
Amortization expense | $ 4,932 | $ 5,528 | $ 16,015 | $ 17,313 |
Distributions and Net Income _3
Distributions and Net Income Per Limited Partner Unit (Distributions Declared) (Details) - USD ($) $ / shares in Units, $ in Thousands | Oct. 31, 2018 | Sep. 30, 2018 | Sep. 30, 2018 | Sep. 30, 2017 | Jul. 26, 2018 | Sep. 30, 2018 | Sep. 30, 2017 |
Distribution Made to Limited Partner [Line Items] | |||||||
Net income attributable to the Partnership | $ 12,412 | $ 13,385 | $ 37,464 | $ 33,124 | |||
Distributions declared | 13,566 | 12,605 | 40,292 | 32,639 | |||
Net income in excess of distribution (Distribution in excess of net income) | $ (1,154) | $ 780 | $ (2,828) | $ 485 | |||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 32,242,210 | 27,172,230 | 32,238,663 | 27,097,642 | |||
IDR Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Net income attributable to the Partnership | $ 0 | $ 498 | $ 733 | $ 1,052 | |||
Distributions declared with respect to the incentive distribution rights | 0 | 498 | 733 | 1,052 | |||
Net income in excess of distribution (Distribution in excess of net income) | 0 | 0 | 0 | 0 | |||
Common units [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Net income attributable to the Partnership | 12,412 | 12,887 | 36,731 | 23,078 | |||
Distributions declared | 13,566 | 12,107 | 39,559 | 22,454 | |||
Net income in excess of distribution (Distribution in excess of net income) | $ (1,154) | $ 780 | $ (2,828) | $ 624 | |||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 32,242,210 | 27,172,230 | 32,238,663 | 18,686,701 | |||
Income per limited partner unit (usd per share) | $ 0.38 | $ 0.47 | $ 1.14 | $ 1.23 | |||
Common units [Member] | Westlake [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 14,122,230 | 14,122,230 | 14,122,230 | 5,711,289 | |||
Subordinated units [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Net income attributable to the Partnership | $ 8,994 | ||||||
Distributions declared | 9,133 | ||||||
Net income in excess of distribution (Distribution in excess of net income) | $ (139) | ||||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 8,410,941 | ||||||
Income per limited partner unit (usd per share) | $ 0 | $ 0 | $ 0 | $ 1.07 | |||
Subordinated units [Member] | Westlake [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Weighted average limited partner units outstanding (basic and diluted) (in shares) | 0 | 0 | 0 | 8,410,941 | |||
Cash Distribution [Member] | IDR Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Distributions declared with respect to the incentive distribution rights | $ 0 | $ 498 | $ 733 | $ 1,052 | |||
Cash Distribution [Member] | Common units [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Distributions declared | 13,566 | 12,107 | 39,559 | 22,454 | |||
Cash Distribution [Member] | Subordinated units [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Distributions declared | $ 0 | $ 0 | $ 0 | $ 9,133 | |||
Cash Distribution [Member] | Common And Subordinated Units [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Target distribution per unit requiring marginal percentage distribution to IDR Holders (in usd per unit) | $ 1.2938 | ||||||
Cash Distribution [Member] | Common And Subordinated Units [Member] | Subsequent Event [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Distribution declared per unit (in usd per unit) | $ 0.4207 | ||||||
Above $0.3163 up to $0.3438 | Minimum [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Target distribution per unit requiring marginal percentage distribution to IDR Holders (in usd per unit) | $ 1.2938 | $ 0.3163 | |||||
Above $0.3163 up to $0.3438 | Maximum [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Target distribution per unit requiring marginal percentage distribution to IDR Holders (in usd per unit) | $ 1.4063 | $ 0.3438 | |||||
Above $0.3163 up to $0.3438 | Unit Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Marginal percentage interest in distributions | 85.00% | 85.00% | |||||
Above $0.3163 up to $0.3438 | IDR Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Marginal percentage interest in distributions | 15.00% | 15.00% | |||||
Cash Distribution, Tranche Two [Member] | Minimum [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Target distribution per unit requiring marginal percentage distribution to IDR Holders (in usd per unit) | $ 1.4063 | $ 0.3438 | |||||
Cash Distribution, Tranche Two [Member] | Maximum [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Quarterly incentive distribution, per unit, distribution threshold | $ 1.6875 | $ 0.4125 | |||||
Cash Distribution, Tranche Two [Member] | Unit Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Marginal percentage interest in distributions | 75.00% | 75.00% | |||||
Cash Distribution, Tranche Two [Member] | IDR Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Marginal percentage interest in distributions | 25.00% | 25.00% | |||||
Cash Distribution, Tranche Three [Member] | Minimum [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Quarterly incentive distribution, per unit, distribution threshold | $ 1.6875 | $ 0.4125 | |||||
Cash Distribution, Tranche Three [Member] | Unit Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Marginal percentage interest in distributions | 50.00% | 50.00% | |||||
Cash Distribution, Tranche Three [Member] | IDR Holders [Member] | |||||||
Distribution Made to Limited Partner [Line Items] | |||||||
Marginal percentage interest in distributions | 50.00% | 50.00% |
Distributions and Net Income _4
Distributions and Net Income Per Limited Partner Unit (Income In Excess Of Distribution) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Incentive Distribution Made to Managing Member or General Partner [Line Items] | ||||
Net income attributable to the Partnership | $ 12,412 | $ 13,385 | $ 37,464 | $ 33,124 |
Distributions declared | 13,566 | 12,605 | 40,292 | 32,639 |
Net income in excess of distribution (Distribution in excess of net income) | (1,154) | 780 | (2,828) | 485 |
IDR Holders [Member] | ||||
Incentive Distribution Made to Managing Member or General Partner [Line Items] | ||||
Net income attributable to the Partnership | 0 | 498 | 733 | 1,052 |
Distributions declared with respect to the incentive distribution rights | 0 | 498 | 733 | 1,052 |
Net income in excess of distribution (Distribution in excess of net income) | 0 | 0 | 0 | 0 |
Common units [Member] | ||||
Incentive Distribution Made to Managing Member or General Partner [Line Items] | ||||
Net income attributable to the Partnership | 12,412 | 12,887 | 36,731 | 23,078 |
Distributions declared | 13,566 | 12,107 | 39,559 | 22,454 |
Net income in excess of distribution (Distribution in excess of net income) | (1,154) | 780 | (2,828) | 624 |
Subordinated units [Member] | ||||
Incentive Distribution Made to Managing Member or General Partner [Line Items] | ||||
Net income attributable to the Partnership | 8,994 | |||
Distributions declared | 9,133 | |||
Net income in excess of distribution (Distribution in excess of net income) | (139) | |||
Cash Distribution [Member] | IDR Holders [Member] | ||||
Incentive Distribution Made to Managing Member or General Partner [Line Items] | ||||
Distributions declared with respect to the incentive distribution rights | 0 | 498 | 733 | 1,052 |
Cash Distribution [Member] | Common units [Member] | ||||
Incentive Distribution Made to Managing Member or General Partner [Line Items] | ||||
Distributions declared | 13,566 | 12,107 | 39,559 | 22,454 |
Cash Distribution [Member] | Subordinated units [Member] | ||||
Incentive Distribution Made to Managing Member or General Partner [Line Items] | ||||
Distributions declared | $ 0 | $ 0 | $ 0 | $ 9,133 |
Distributions and Net Income _5
Distributions and Net Income Per Limited Partner Unit (Basic and Diluted Income Per Limited Partner Unit) (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Limited Partners' Capital Account [Line Items] | ||||
Distributions declared | $ 13,566 | $ 12,605 | $ 40,292 | $ 32,639 |
Net income in excess of distribution (Distribution in excess of net income) | (1,154) | 780 | (2,828) | 485 |
Net income | $ 12,412 | $ 13,385 | $ 37,464 | $ 33,124 |
Weighted average units outsanding: | ||||
Basic and diluted (shares) | 32,242,210 | 27,172,230 | 32,238,663 | 27,097,642 |
Common units [Member] | ||||
Limited Partners' Capital Account [Line Items] | ||||
Distributions declared | $ 13,566 | $ 12,107 | $ 39,559 | $ 22,454 |
Net income in excess of distribution (Distribution in excess of net income) | (1,154) | 780 | (2,828) | 624 |
Net income | $ 12,412 | $ 12,887 | $ 36,731 | $ 23,078 |
Weighted average units outsanding: | ||||
Basic and diluted (shares) | 32,242,210 | 27,172,230 | 32,238,663 | 18,686,701 |
Net income per limited partner unit: | ||||
Income per limited partner unit (usd per share) | $ 0.38 | $ 0.47 | $ 1.14 | $ 1.23 |
Subordinated units [Member] | ||||
Limited Partners' Capital Account [Line Items] | ||||
Distributions declared | $ 9,133 | |||
Net income in excess of distribution (Distribution in excess of net income) | (139) | |||
Net income | $ 8,994 | |||
Weighted average units outsanding: | ||||
Basic and diluted (shares) | 8,410,941 | |||
Net income per limited partner unit: | ||||
Income per limited partner unit (usd per share) | $ 0 | $ 0 | $ 0 | $ 1.07 |
IDR Holders [Member] | ||||
Limited Partners' Capital Account [Line Items] | ||||
Subsequent distribution to IDR holders | $ 0 | $ 498 | $ 733 | $ 1,052 |
Net income in excess of distribution (Distribution in excess of net income) | 0 | 0 | 0 | 0 |
Net income | $ 0 | $ 498 | $ 733 | $ 1,052 |
Distributions and Net Income _6
Distributions and Net Income Per Limited Partner Unit (Distribution Per Common Unit) (Details) - $ / shares | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Distribution Per Common Unit [Abstract] | ||||
Distribution Made to Limited Partner, Distributions Paid, Per Unit | $ 0.4088 | $ 0.3650 | $ 1.1927 | $ 1.0649 |
Partners' Equity (Details)
Partners' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands | Sep. 29, 2017 | Aug. 04, 2014 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | Aug. 30, 2017 |
Class of Stock [Line Items] | ||||||
Net proceeds from equity offering | $ 110,739 | $ 0 | $ 110,739 | |||
Underwriting discounts, structuring fees and offering expenses on issuance of equity | $ 3,111 | |||||
Westlake [Member] | Subordinated units [Member] | ||||||
Class of Stock [Line Items] | ||||||
Units outstanding | 0 | 0 | 12,686,115 | |||
Limited Partner [Member] | ||||||
Class of Stock [Line Items] | ||||||
Number of units sold in public offering | 5,175,000 | 12,937,500 | ||||
Units sold in secondary offering price per unit (in dollars per share) | $ 22 | |||||
Limited Partner [Member] | Westlake [Member] | Subordinated units [Member] | ||||||
Class of Stock [Line Items] | ||||||
Net proceeds from equity offering | $ 0 |
Related Party Transactions (Cos
Related Party Transactions (Cost of Sales from Related Parties) (Details) - Affiliated Entity [Member] - Westlake [Member] - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Related Party Transaction [Line Items] | ||||
Charges from related parties in cost of sales | $ 207,186 | $ 134,195 | $ 487,469 | $ 388,127 |
Feedstock purchased [Member] | ||||
Related Party Transaction [Line Items] | ||||
Charges from related parties in cost of sales | 178,493 | 110,241 | 403,833 | 313,231 |
Other service charges [Member] | ||||
Related Party Transaction [Line Items] | ||||
Charges from related parties in cost of sales | $ 28,693 | $ 23,954 | $ 83,636 | $ 74,896 |
Related Party Transactions (Ser
Related Party Transactions (Services from Related Parties Included in SG&A Expenses) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Affiliated Entity [Member] | Westlake [Member] | ||||
Related Party Transaction [Line Items] | ||||
Services received from Westlake and included in selling, general and administrative expenses | $ 4,655 | $ 6,633 | $ 17,947 | $ 20,311 |
Related Party Transactions (Goo
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, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Affiliated Entity [Member] | Westlake [Member] | ||||
Related Party Transaction [Line Items] | ||||
Goods and services purchased from Westlake and capitalized as assets | $ 846 | $ 619 | $ 1,988 | $ 3,131 |
Related Party Transactions (Acc
Related Party Transactions (Accounts Receivable from and Accounts Payable to Related Parties) (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Related Party Transaction [Line Items] | ||
Receivables under Investment Management Agreements with Related Parties, Current | $ 151,875 | $ 136,510 |
Accounts payable—Westlake | 41,274 | 14,027 |
Affiliated Entity [Member] | Westlake [Member] | ||
Related Party Transaction [Line Items] | ||
Accounts receivable—Westlake, current and non-current | $ 65,628 | $ 43,884 |
Related Party Transactions (Deb
Related Party Transactions (Debt Payable to Related Parties) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | |
Related Party Transaction [Line Items] | |||||
Interest on related party debt payable | $ 5,639 | $ 6,190 | $ 16,052 | $ 17,592 | |
Accrued interest on related party debt | 5,712 | 5,712 | $ 4,590 | ||
Long-term debt payable to Westlake | 477,608 | 477,608 | 473,960 | ||
Affiliated Entity [Member] | Westlake [Member] | |||||
Related Party Transaction [Line Items] | |||||
Interest capitalized | 63 | 7 | 108 | 426 | |
Other income (expense) | Affiliated Entity [Member] | Westlake [Member] | |||||
Related Party Transaction [Line Items] | |||||
Interest on related party debt payable | 5,639 | $ 6,190 | 16,052 | $ 17,592 | |
Accrued Liabilities [Member] | Affiliated Entity [Member] | Westlake [Member] | |||||
Related Party Transaction [Line Items] | |||||
Accrued interest on related party debt | $ 5,712 | $ 5,712 | $ 4,590 |
Related Party Transactions (Gen
Related Party Transactions (General) (Details) - USD ($) | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | |
Related Party Transaction [Line Items] | |||||
Reimbursed income tax payments | $ 418 | ||||
Affiliated Entity [Member] | Westlake [Member] | |||||
Related Party Transaction [Line Items] | |||||
Interest earned related to the IMA | 703,000 | $ 9,000 | $ 1,861,000 | $ 9,000 | |
Accrued Liabilities [Member] | Affiliated Entity [Member] | Westlake [Member] | |||||
Related Party Transaction [Line Items] | |||||
Accrued interest included in receivable under IMA | $ 703,000 | $ 703,000 | $ 340,000 |
Related Party Transactions (Sit
Related Party Transactions (Site Lease Agreements) (Details) - Westlake Chemical OpCo LP [Member] - Affiliated Entity [Member] - Site Lease Agreement [Member] | 9 Months Ended | |
Sep. 30, 2018USD ($)lease | Sep. 30, 2017 | |
Related Party Transaction [Line Items] | ||
Number of site lease agreements | lease | 2 | |
Lease term | 50 years | |
Operating lease rent expense | $ | $ 1 |
Related Party Transactions (Maj
Related Party Transactions (Major Customer and Concentration Risk) (Details) | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Affiliated Entity [Member] | Westlake [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | ||||
Concentration Risk [Line Items] | ||||
Concentration Risk, Percentage | 86.20% | 87.00% | 84.40% | 82.40% |
Long-term Debt Payable to Wes_3
Long-term Debt Payable to Westlake (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended |
Sep. 30, 2018 | Dec. 31, 2017 | |
Related Party Transaction [Line Items] | ||
Long-term debt payable to Westlake | $ 477,608 | $ 473,960 |
Weighted average interest rate | 4.34% | 3.74% |
Limited Partner [Member] | OpCo Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | ||
Related Party Transaction [Line Items] | ||
Long-term debt payable to Westlake | $ 224,064 | $ 220,416 |
Limited Partner [Member] | OpCo Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | LIBOR [Member] | ||
Related Party Transaction [Line Items] | ||
Basis spread on variable rate, percent | 2.00% | 3.00% |
Limited Partner [Member] | MLP Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | ||
Related Party Transaction [Line Items] | ||
Long-term debt payable to Westlake | $ 253,544 | $ 253,544 |
Limited Partner [Member] | MLP Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | LIBOR [Member] | ||
Related Party Transaction [Line Items] | ||
Basis spread on variable rate, percent | 2.00% | 2.00% |
Fair Value Measurements (Summar
Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Long-term debt payable to Westlake, carrying value | $ 477,608 | $ 473,960 |
OpCo Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Long-term debt payable to Westlake, fair value | 229,622 | 228,180 |
OpCo Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | Limited Partner [Member] | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Long-term debt payable to Westlake, carrying value | 224,064 | 220,416 |
MLP Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Long-term debt payable to Westlake, fair value | 255,008 | 258,234 |
MLP Revolver [Member] | Senior Unsecured Revolving Credit Facility [Member] | Limited Partner [Member] | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Long-term debt payable to Westlake, carrying value | $ 253,544 | $ 253,544 |
Supplemental Information (Detai
Supplemental Information (Details) - USD ($) $ in Thousands | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | |
Accrued Liabilities [Abstract] | |||
Accrued liabilities | $ 18,911 | $ 15,697 | |
Accrued interest | 5,712 | 4,590 | |
Accrued taxes | 4,156 | 1,422 | |
Accrued maintenance | 5,323 | $ 3,698 | |
Increase (reduction) in capital expenditure accrual | $ 1,380 | $ 894 |
Subsequent Events (Details)
Subsequent Events (Details) $ in Thousands | Oct. 04, 2018USD ($) |
Subsequent Event [Member] | |
Subsequent Event [Line Items] | |
Partners Units, Maximum Aggregate Offering Amount, ATM | $ 50,000 |