Turnaround costs, net Turnaround Costs, Net Turnaround Costs, Net Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Related Party Transactions [Abstract] Related Party Transactions [Abstract] Entity Address, Postal Zip Code Entity Address, Postal Zip Code General Partner General Partner [Member] Partners' Equity Schedule of Stockholders Equity [Table Text Block] Deferred Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Debt Instrument [Axis] Debt Instrument [Axis] Property, plant and equipment, net, before construction in progress Property, Plant and Equipment, Net Excluding Construction In-Progress Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. Does not include construction in progress. Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Property, plant and equipment Deferred Tax Liabilities, Property, Plant and Equipment Inventory, Net [Abstract] Inventory, Net [Abstract] Units outstanding Limited Partners' Capital Account, Units Outstanding Interest earned related to the IMA Interest earned related to the IMA Interest earned related to the IMA Basis spread on variable rate, percent Debt Instrument, Basis Spread on Variable Rate Other Payments for (Proceeds from) Other Investing Activities Statistical Measurement [Domain] Statistical Measurement [Domain] Depreciation expense Depreciation Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Number of units sold in public offering Partners' Capital Account, Units, Sold in Public Offering Accrued interest included in receivable under IMA Accrued interest included in receivable under IMA Accrued interest included in receivable under IMA Other Noncash Income (Expense) Other Noncash Income (Expense) Number of directors that retired in period Deferred Compensation Arrangement with Individual, Number of Directors That Retired in Period Deferred Compensation Arrangement with Individual, Number of Directors That Retired in Period State and local Current State and Local Tax Expense (Benefit) Income taxes paid Income Taxes Paid Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income Limited partners' interest in net income subsequent to IPO Net Income (Loss) Attributable to Parent Document Information [Line Items] Document Information [Line Items] Limited partners' distribution declared on common units Distribution Distributed Earnings Subsequent Event Type [Axis] Subsequent Event Type [Axis] Trade customers Accounts Receivable, before Allowance for Credit Loss, Current Equity Component [Domain] Equity Component [Domain] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Amortization period, maximum (in years) Plant And Equipment Planned Major Maintenance Activities Amortization Period Maximum The maximum amortization period of planned major maintenance activities. Repayment of debt payable to Westlake Repayments of Related Party Debt Ownership [Axis] Ownership [Axis] Receivable under the Investment Management Agreement—Westlake Corporation ("Westlake") Receivables under Investment Management Agreements with Related Parties, Current Receivables under Investment Management Agreements with Related Parties, Current Receivables under Investment Management Agreements with Related Parties, Current Distribution declared per unit (usd per share) Distribution Made to Limited Partner, Distributions Declared, Per Unit Related Party [Domain] Related Party [Domain] Westlake Parent Company And Subsidiaries, Excluding Reporting Entity And Subsidiaries [Member] Parent Company and Subsidiaries, Excluding Reporting Entity and Subsidiaries [Member] Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Plan Name [Axis] Plan Name [Axis] Phantom Share Units (PSUs) Phantom Share Units (PSUs) [Member] Leverage capital ratio required during other periods Leverage Capital Ratio Required During Other Periods Represents the consolidated leverage ratio required per the debt agreement during periods other than than one-year period following certain types of acquisitions Units issued Limited Partners' Capital Account, Units Issued Unrecognized compensation cost Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Plan Name [Domain] Plan Name [Domain] Limited partners' capital Limited Partners' Capital Account Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Entity Address, State or Province Entity Address, State or Province Schedule of Distributions Schedule of Distributions [Table Text Block] Schedule of Distributions Accounts receivable - third parties Increase (Decrease) in Accounts and Other Receivables Award Type [Axis] Award Type [Axis] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Number of years used to calculate average expenses Long-term Purchase Commitment, Terms of Fee, Number Of Years Used To Calculate Average Expenses Long-term Purchase Commitment, Terms of Fee, Number Of Years Used To Calculate Average Expenses Diluted units Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted Related Party Transaction [Domain] Related Party Transaction [Domain] Accounts Receivable, after Allowance for Credit Loss [Abstract] Accounts Receivable, after Allowance for Credit Loss [Abstract] Document Annual Report Document Annual Report Legal Entity [Axis] Legal Entity [Axis] Feedstock, additives and chemicals Inventory, Work in Process and Raw Materials Accounts Receivable—Third Parties Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Total liabilities Liabilities Total Westlake Chemical Partners LP partners' capital Partners' Capital Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Period of default in performance that can allow a party to terminate agreement Related Party Transaction, Counterparty Default, Period Of Default, Allowing Termination Of Agreement Related Party Transaction, Counterparty Default, Period Of Default, Allowing Termination Of Agreement Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Allowance For Doubtful Accounts Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block] Schedule Of Property, Plant And Equipment Property, Plant and Equipment [Table Text Block] Revenue Recognition Revenue from Contract with Customer [Policy Text Block] Current Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Document Type Document Type Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Property, plant and equipment, useful life (in years) Property, Plant and Equipment, Useful Life Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Weighted Average Fair Value, beginning balance (usd per share) Weighted Average Fair Value, ending balance (usd per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Entity Shell Company Entity Shell Company Accrued and other liabilities Increase (Decrease) in Accrued Liabilities Long-term Commitment (Excluding Unconditional Purchase Obligation) [Abstract] Long-Term Commitment (Excluding Unconditional Purchase Obligation) [Abstract] Accounts receivable, net—Westlake Accounts receivable, net—Westlake Accounts Receivable, Related Parties, Current Partnership income not subject to entity-level federal income tax Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Affiliated Entity Affiliated Entity [Member] Revenue Benchmark Revenue Benchmark [Member] Subsequent Event Subsequent Event [Member] Purchase commitment, renewal term Long-term Purchase Commitment, Renewal Term Long-term Purchase Commitment, Renewal Term Weighted average limited partner units outstanding (basic and diluted) Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted Document Period End Date Document Period End Date Exchange agreement amount of purchase agreement Purchase Commitment, Purchase Agreement, Mass Purchase Commitment, Purchase Agreement, Mass Investments with Westlake under the Investment Management Agreement Investments with Westlake under the Investment Management Agreement Investments with Westlake under the Investment Management Agreement Total assets Assets Debt Disclosure [Abstract] Debt Disclosure [Abstract] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Income Statement Location [Axis] Income Statement Location [Axis] Accrued and other liabilities Accrued Liabilities, Current Net cash used for financing activities Net Cash Provided by (Used in) Financing Activities Long-term debt payable to Westlake, fair value Long-Term Debt, Fair Value Line of Credit Line of Credit [Member] Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest EQUITY Stockholders' Equity Attributable to Parent [Abstract] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Distributions and Net Income Per Limited Partner Unit Earnings Per Share [Text Block] Customer [Axis] Customer [Axis] Additional ownership interest acquired Additional ownership interest Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Additional Ownership Interest Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Additional Ownership Interest Goodwill, Gross Goodwill, Gross Cash And Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Schedule Of The Provision For (Benefit From) Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Award Type [Domain] Award Type [Domain] Building and improvements Buildings and Improvements, Gross Unrecognized compensation weighted average remaining term Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Schedule Of Carrying And Fair Values Of Long-Term Debt Fair Value, by Balance Sheet Grouping [Table Text Block] Finished products Inventory, Finished Goods, Gross Gross profit Gross Profit Entity Registrant Name Entity Registrant Name Site Lease Agreement Site Lease Agreement [Member] Site Lease Agreement [Member] Entity Address, City or Town Entity Address, City or Town MLP Revolver MLP Revolver [Member] MLP Revolver [Member] Net accounts receivable - Westlake Increase (Decrease) in Accounts Receivable, Related Parties Plant and equipment Plant And Equipment [Member] Plant And Equipment [Member] Minimum Minimum [Member] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Auditor Name Auditor Name Fair Value Measurements Fair Value Disclosures [Text Block] Deferred Charges and Other Assets Other Assets Disclosure [Text Block] Trading Symbol Trading Symbol Entity File Number Entity File Number Goods and services purchased from Westlake and capitalized as assets Related Party Transaction Purchases From Related Party Capitalized As Assets Related Party Transaction Purchases From Related Party Capitalized As Assets Distribution Made to Limited Partner [Line Items] Distribution Made to Limited Partner [Line Items] Statement of Partners' Capital [Abstract] Statement of Partners' Capital [Abstract] Turnaround Costs Property, Plant and Equipment, Planned Major Maintenance Activities, Policy [Policy Text Block] Accrued Liabilities Accrued Liabilities [Abstract] Accrued interest on related party debt Interest Payable, Current Feedstock Supply Agreement Feedstock Supply Agreement [Member] Feedstock Supply Agreement [Member] Title of Individual [Axis] Title of Individual [Axis] Amortization period, minimum (in years) Plant And Equipment Planned Major Maintenance Activities Amortization Period Minimum The minimum amortization period of planned major maintenance activities. Derivative Instruments Derivatives, Policy [Policy Text Block] Vested Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Exercised Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] IDR Holders IDR Holders [Member] Incentive Distribution Rights Holders [Member] Use Of Estimates Use of Estimates, Policy [Policy Text Block] Westlake Chemical OpCo LP Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo LP [Member] Long-term debt payable to Westlake Long-term debt payable to Westlake, carrying value Due to Related Parties, Noncurrent Accounts payable Increase (Decrease) in Accounts Payable Other charges from Westlake and included in cost of sales Cost Of Goods Sold, Other Cost Of Goods Sold, Other LIBOR London Interbank Offered Rate (LIBOR) [Member] Common units Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax Concentration Risk, Percentage Concentration Risk, Percentage Total net sales Revenues Above $1.2938 up to $1.4063 Cash Distribution, Tranche One [Member] Cash Distribution, Tranche One [Member] Westlake Chemical Partners LP Westlake Chemical Partners LP [Member] Westlake Chemical Partners LP Income Taxes Income Tax Disclosure [Text Block] Net sales—Westlake Revenue from Related Parties State and local Deferred State and Local Income Tax Expense (Benefit) Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Granted Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Units sold in secondary offering price per unit Partners' Capital Account, Units, Sold in Public Offering, Price per Unit Partners' Capital Account, Units, Sold in Public Offering, Price per Unit Construction in progress Construction in Progress, Gross Fair value of phantom units vested Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Other Assets Other Assets [Member] Quarterly distributions to noncontrolling interest retained in OpCo by Westlake Payments to Noncontrolling Interests Inventories Inventory, Policy [Policy Text Block] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Counterparty Name [Domain] Counterparty Name [Domain] Director Director [Member] Ethylene Sales Agreement Ethylene Sales Agreement [Member] Ethylene Sales Agreement [Member] Ownership [Domain] Ownership [Domain] Entity Interactive Data Current Entity Interactive Data Current Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Changes in operating assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Deferred charges and other assets, net Deferred charges and other assets, net Deferred Costs and Other Assets Distributions Made to Limited Partner, by Distribution Distributions Made to Limited Partner, by Distribution [Table Text Block] Total units available for grant Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Class of Stock [Axis] Class of Stock [Axis] Schedule of Nonvested Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Statement [Table] Statement [Table] Weighted Average Grant Date Fair Value, Vested (usd per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Accounts receivable, net—third parties Receivables, Net, Current Current assets Assets, Current [Abstract] Cash Distribution Cash Distribution [Member] Other receivables Nontrade Receivables, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Additional Financial Information Disclosure Additional Financial Information Disclosure [Text Block] Related Party Transaction [Axis] Related Party Transaction [Axis] Related party transactions, term of agreements Related Party Transaction, Term Of Agreement Related Party Transaction, Term Of Agreement Maximum mass required to be purchased Long-term Purchase Commitment, Maximum Volume Required Long-term Purchase Commitment, Maximum Volume Required Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Description Of Business Description Of Business [Policy Text Block] Description Of Business [Policy Text Block] Equity Components [Axis] Equity Components [Axis] Buyer deficiency fee Buyer deficiency fee Buyer deficiency fee Related Party Transactions Related Party Transactions Disclosure [Text Block] Above $1.4063 up to $1.6875 Cash Distribution, Tranche Two [Member] Cash Distribution, Tranche Two [Member] Reimbursement to Parent for State Tax Reimbursement to Parent for State Tax [Member] Reimbursement to Parent for State Tax [Member] Comprehensive Income Comprehensive Income, Policy [Policy Text Block] Segment Reporting Segment Reporting, Policy [Policy Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Statement [Line Items] Statement [Line Items] Beginning balance Ending balance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Other Property, Plant and Equipment, Other, Gross Other income, net Nonoperating Income (Expense) Variable Rate [Domain] Variable Rate [Domain] Selling, general and administrative expenses Services received from Westlake and included in selling, general and administrative expenses Selling, General and Administrative Expense Goodwill Goodwill Disclosure [Text Block] Net income attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted) Earnings Per Unit [Abstract] Auditor Firm ID Auditor Firm ID Operating lease expense Operating Lease, Expense Document Transition Report Document Transition Report Local Phone Number Local Phone Number Income from operations Operating Income (Loss) Inventories Increase (Decrease) in Inventories Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Document Information [Table] Document Information [Table] State and Local Jurisdiction State and Local Jurisdiction [Member] Goodwill Goodwill Other Noncurrent Assets, Other, Net Noncurrent Assets, Other, Net Property, Plant and Equipment by Type [Axis] Long-Lived Tangible Asset [Axis] Westlake Chemical OpCo GP LLC Westlake Chemical OpCo GP LLC [Member] Westlake Chemical OpCo GP LLC [Member] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Provision for income taxes Total provision Income Tax Expense (Benefit) Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Deferred income taxes Noncurrent deferred tax liability Deferred Income Tax Liabilities, Net Amount paid to purchase additional limited partner interest Payments to Acquire Limited Partnership Interests Income Statement [Abstract] Income Statement [Abstract] Entity Public Float Entity Public Float Balance Sheet Location [Domain] Balance Sheet Location [Domain] Document Fiscal Period Focus Document Fiscal Period Focus Cost of sales Cost of Goods and Services Sold Incentive Distribution, Recipient [Domain] Incentive Distribution, Recipient [Domain] Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Other Assets, Amortization Period Deferred charges and other assets, net, amortization period Deferred Charges and Other Assets, Remaining Amortization Period Less: Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Schedule Of Inventory Schedule of Inventory, Current [Table Text Block] Distributions per common unit Distribution Made to Limited Partner, Distributions Paid, Per Unit IMA, Partnership earned amount added to market rate, basis points IMA, Partnership earned amount added to market rate, basis points IMA, Partnership earned amount added to market rate, basis points Number of Production Facilities Number of Production Facilities Number of Production Facilities Schedule of Limited Partners' Capital Account by Class [Table] Schedule of Limited Partners' Capital Account by Class [Table] Buildings and improvements Building and Building Improvements [Member] Accounts Receivable Accounts Receivable [Member] ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Total Related Parties Amount in Cost of Sales Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Weighted Average Grant Date Fair Value, Granted (usd per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Senior Unsecured Revolving Credit Facility Senior Unsecured Revolving Credit Facility [Member] Senior Unsecured Revolving Credit Facility [Member] Excess Production Option Excess Production Option [Member] Excess Production Option [Member] Distributions Made to Limited Partner [Table] Distributions Made to Limited Partner [Table] Other Other Capitalized Property Plant and Equipment [Member] Property, Plant and Equipment, Net [Abstract] Property, Plant and Equipment, Net [Abstract] Limited Partner Limited Partner [Member] Above $1.6875 Cash Distribution, Tranche Three [Member] Cash Distribution, Tranche Three [Member] Organization Consolidation And Presentation Of Financial Statements [Line Items] Organization Consolidation And Presentation Of Financial Statements [Line Items] Organization consolidation and presentation of financial statements [Line Items]. Cash and cash equivalents at beginning of the year Cash and cash equivalents at end of the year Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Less: Net income attributable to noncontrolling interest in OpCo Net Income (Loss) Attributable to Noncontrolling Interest Distribution Type [Domain] Distribution Type [Domain] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Current liabilities Liabilities, Current [Abstract] Ethylene pipeline Ethylene Pipeline [Member] Ethylene Pipeline [Member] Capital expenditures incurred but not yet paid Capital Expenditures Incurred but Not yet Paid Partner Type [Axis] Partner Type [Axis] Westlake Chemical Partners LP Long-Term Incentive Plan Westlake Chemical Partners LP Long-Term Incentive Plan [Member] Westlake Chemical Partners LP Long-Term Incentive Plan [Member] Distributions per common unit [Abstract] Distributions per common unit [Abstract] Distributions per common unit [Abstract] Income Statement Location [Domain] Income Statement Location [Domain] Purchase commitment, fixed margin on variable pricing Long-term Purchase Commitment, Exchange Fee, Fixed Margin Long-term Purchase Commitment, Exchange Fee, Fixed Margin Amendment Flag Amendment Flag Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities Schedule Of Estimated Useful Lives Of Assets Schedule Of Estimated Useful Lives Of Assets [Table Text Block] Table of estimated useful lives of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Net income in excess of distribution (Distribution in excess of net income) Net income in excess of distribution (Distribution in excess of net income) Undistributed Earnings, Basic Other assets amortization period Finite-Lived Intangible Assets, Remaining Amortization Period Accounts payable—Westlake Accounts Payable, Related Parties, Current Entity Current Reporting Status Entity Current Reporting Status Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Services And Secondment Agreement Services And Secondment Agreement [Member] Services And Secondment Agreement [Member] Depreciation and amortization Depreciation, Depletion and Amortization Shortfall fees Shortfall fees Shortfall fees Environmental Costs Environmental Costs, Policy [Policy Text Block] Investee Investee [Member] Rate used to discount future cash flows for goodwill impairment test Discounted Cash Flow Methodology, Goodwill Impairment, Discount Rate The discount rate percentage utilized when developing discounted cash flow projections in determining projected future cash flows as they relate to goodwill impairment. Term of operating lease Lessee, Operating Lease, Term of Contract Property, plant and equipment, gross Property, Plant and Equipment, Gross Excluding Construction In-Progress Gross amount, at the balance sheet date, of long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. Does not include construction in progress. Threshold period past due accounts receivable reviewed Threshold Period Past Due Accounts Receivable Reviewed Threshold Period Past Due Accounts Receivable Reviewed Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Counterparty Name [Axis] Counterparty Name [Axis] Related Party Transactions (Related Party Leases) [Abstract] Related Party Transactions (Related Party Leases) [Abstract] Related Party Transactions (Related Party Leases) [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Turnaround costs Deferred Tax Liabilities, Deferred Expense, Other Capitalized Costs Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Auditor [Abstract] Auditor [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Property, plant and equipment, net Property, plant and equipment, net Property, Plant and Equipment, Net Feedstock purchased from Westlake and included in cost of sales Related Parties Amount In Cost Of Sales, Feedstock Purchased Related Parties Amount In Cost Of Sales, Feedstock Purchased Title of Individual [Domain] Title of Individual [Domain] Accrued maintenance expense Accrued Maintenance Expense, Current Accrued Maintenance Expense, Current Allowance for credit losses Accounts Receivable, Allowance for Credit Loss, Current Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Quarterly distribution per unit threshold (usd per share) Incentive Distribution, Quarterly Distribution Per Unit, Distribution Threshold Incentive Distribution, Quarterly Distribution Per Unit, Distribution Threshold Maximum Maximum [Member] Other Assets [Abstract] Other Assets [Abstract] Operating lease, rental amount Operating Leases, Rent Expense Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Related Party Transactions (Major Customer and Credit Risk) [Abstract] Related Party Transactions (Major Customer and Credit Risk) [Abstract] Related Party Transactions (Major Customer and Credit Risk) [Abstract] Total current assets Assets, Current Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Entity Small Business Entity Small Business Phantom units accelerated Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period Quarterly distribution to noncontrolling interest retained in OpCo by Westlake Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Noncontrolling interest in Westlake Chemical OpCo LP ("OpCo") Noncontrolling Interest in Limited Partnerships Property, Plant And Equipment Property, Plant and Equipment Disclosure [Text Block] Minimum quarterly distribution per unit (usd per share) Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders Transportation and Freight Shipping and Handling Cost, Policy [Policy Text Block] Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Title of 12(b) Security Title of 12(b) Security Site lease agreement, number Site lease agreement, number Site lease agreement, number Managing Member or General Partner [Axis] Managing Member or General Partner [Axis] Term of Investment Management Agreement with Related Party, Maximum Term of Investment Management Agreement with Related Party, Maximum Term of Investment Management Agreement with Related Party, Maximum Distributions [Line Items] Subsequent Event [Line Items] Exchange Agreement Exchange Agreement [Member] Exchange Agreement Class of Stock [Line Items] Class of Stock [Line Items] Quarterly distribution to unitholders Limited Partners' Capital Account, Distribution Amount Selling, General and Administrative Expenses Selling, General and Administrative Expenses [Member] Organization, Consolidation, And Presentation Of Financial Statements [Table] Organization, Consolidation, And Presentation Of Financial Statements [Table] Organization, Consolidation, And Presentation Of Financial Statements [Table] Total deferred tax liabilities Deferred Tax Liabilities, Net Common units Common Units [Member] Common Units [Member] LIABILITIES Liabilities and Equity [Abstract] Loss from disposition of property, plant and equipment Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Inventories Inventories Inventory, Net Accounts payable—third parties Accounts Payable, Current Income Tax Authority [Axis] Income Tax Authority [Axis] Agreements with Westlake and Related Parties Agreements with Westlake and Related Parties [Text Block] Agreements with Westlake and Related Parties [Text Block] Maturities of investments with Westlake under the Investment Management Agreement Maturities of investments with Westlake under the Investment Management Agreement Maturities of investments with Westlake under the Investment Management Agreement Auditor Location Auditor Location Entity Filer Category Entity Filer Category Total compensation cost Share-Based Payment Arrangement, Expense Commitments and contingencies (Note 16) Commitments and Contingencies Security Exchange Name Security Exchange Name Interest expense—Westlake Interest on related party debt payable Interest Expense, Related Party Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Net co-products, ethylene and other sales—third parties Revenue from Contract with Customer, Excluding Assessed Tax Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Cover [Abstract] Cover [Abstract] Capitalized interest Interest Costs Capitalized Entity Voluntary Filers Entity Voluntary Filers Unit-based Compensation Share-Based Payment Arrangement [Text Block] Shortfall fees recovered Shortfall fees recovered Shortfall fees recovered Long-term Purchase Commitment, Compliance Surcharge Amount Long-term Purchase Commitment, Compliance Surcharge Amount Long-term Purchase Commitment, Compliance Surcharge Intercompany interest expenses, accrued Intercompany interest expenses, accrued Intercompany interest expenses, accrued Noncontrolling Interest in OpCo Noncontrolling Interest [Member] Alternate Base Rate Alternate Base Rate [Member] Alternate Base Rate Total liabilities and equity Liabilities and Equity Schedule Of Deferred Tax Assets And Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Related Party [Axis] Related Party [Axis] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Current Fiscal Year End Date Current Fiscal Year End Date Deferred Charges and Other Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Distributions declared with respect to the incentive distribution rights Incentive Distribution, Subsequent Distribution Amount Amount of incentive obligation earned in cash or stock during the period by the Partnership's incentive distribution rights holders and paid after the end of the accounting period. Schedule of Other Assets Schedule of Other Assets [Table Text Block] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Total current liabilities Liabilities, Current Minimum percentage required to be purchased Long-term Purchase Commitment, Minimum Percentage Required Long-term Purchase Commitment, Minimum Percentage Required Schedule Of Accounts Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Customer Concentration Risk Customer Concentration Risk [Member] Term of sales agreement Long-Term Purchase Commitment, Period General partner—Westlake General Partners' Capital Account Total equity Equity, beginning balance Equity, ending balance Partners' Capital, Including Portion Attributable to Noncontrolling Interest Publicly and Privately Held Unidentified Third Parties [Member] Unidentified Third Parties [Member] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Other income (expense) Nonoperating Income (Expense) [Abstract] Accounts receivable, net—third parties Accounts and Other Receivables, Net, Current Majority-Owned Subsidiary, Unconsolidated Majority-Owned Subsidiary, Unconsolidated [Member] Amortization Amortization Entity Address, Address Line Two Entity Address, Address Line Two Entity Address, Address Line One Entity Address, Address Line One Income Tax Authority [Domain] Income Tax Authority [Domain] Limited Partners' Capital Account [Line Items] Limited Partners' Capital Account [Line Items] Distribution Type [Axis] Distribution Type [Axis] Number of lease agreements Lessee Leasing Arrangements, Operating Leases, Number Lessee Leasing Arrangement, Operating Leases, Number Class of Stock [Domain] Class of Stock [Domain] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Partners' Equity [Abstract] Partners' Equity [Abstract] Partners' Equity [Abstract] Unitholders Unit Holders [Member] Unit Holders [Member] Maximum consolidated leverage ratio during one year following acquisitions Maximum Consolidated Leverage Ratio During One Year Following Acquisitions Represents the consolidated leverage ratio required per the debt agreement during any one-year period following certain acquisitions. Inventories Inventory Disclosure [Text Block] Schedule Of Long-Term Debt Schedule of Long-Term Debt Instruments [Table Text Block] Equity [Abstract] Equity [Abstract] Distributions [Table] Subsequent Event [Table] Partnership's ownership interest (percent) Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest Entity Tax Identification Number Entity Tax Identification Number Number of units authorized Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Partners' capital account, units, sold to related party Partners' Capital Account, Units, Sold to Related Party Partners' Capital Account, Units, Sold to Related Party Reconciliation Of Taxes Computed At The Statutory Rate To Income Tax Expense Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect State income tax provision, net of federal income tax effect Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Accrued Liabilities Accrued Liabilities [Member] Impairment Of Long-Lived Assets and Intangible Assets Impairment or Disposal of Long-Lived Assets, Including Intangible Assets, Policy [Policy Text Block] Entity Central Index Key Entity Central Index Key Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Site lease expense Site lease expense Site lease expense Concentration Of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Entity [Domain] Entity [Domain] City Area Code City Area Code ASSETS Assets [Abstract] Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Long-Term Debt Related Party Transactions, Long-term Debt [Text Block] Related Party Transactions, Long-term Debt [Text Block] Common and Subordinated units Common And Subordinated Units [Member] Common And Subordinated Units [Member] Provision for federal income tax, at statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] OpCo Revolver OpCo Revolver [Member] OpCo Revolver [Member] Limited Liability Company Limited Liability Company [Member] Weighted average interest rate on all long-term debt Long-Term Debt, Weighted Average Interest Rate, at Point in Time Business Description and Accounting Policies Business Description and Accounting Policies [Text Block] Units issued for vested phantom units Stock Issued During Period, Value, Other Variable Rate [Axis] Variable Rate [Axis] Quarterly distributions to unitholders Distribution Made to Limited Partner, Cash Distributions Paid Partners units, maximum aggregate offering amount, ATM Partners Units, Maximum Aggregate Offering Amount, ATM Partners Units, Maximum Aggregate Offering Amount, ATM Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Plant and equipment Machinery and Equipment, Gross Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Proceeds from debt payable to Westlake Proceeds from Related Party Debt Westlake Chemical Corporation Westlake Chemical Corporation [Member] Westlake Chemical Corporation Customer [Domain] Customer [Domain]