Equity [Abstract] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Balance at beginning of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Interest rate contract - Other comprehensive income before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Interest rate contract - Amounts reclassified to net income Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Balance at end of period Derivative Instruments and Hedges, Assets [Abstract] Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Earnings Per Share [Abstract] Distributions Made to Limited Partner [Table] Distributions Made to Limited Partner [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Distribution Type [Axis] Distribution Type [Axis] Distribution Type [Domain] Distribution Type [Domain] Above $0.3163 up to $0.3438 [Member] Cash Distribution, Tranche One [Member] Cash Distribution, Tranche One [Member] Above $0.3438 up to $0.4125 [Member] Cash Distribution, Tranche Two [Member] Cash Distribution, Tranche Two [Member] Above $0.4125 [Member] Cash Distribution, Tranche Three [Member] Cash Distribution, Tranche Three [Member] Managing Member or General Partner [Axis] Managing Member or General Partner [Axis] Incentive Distribution, Recipient [Domain] Incentive Distribution, Recipient [Domain] Unit Holders [Member] Unit Holders [Member] Unit Holders [Member] IDR Holders [Member] IDR Holders [Member] Incentive Distribution Rights Holders [Member] Distribution Made to Limited Partner [Line Items] Distribution Made to Limited Partner [Line Items] Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Quarterly distribution per unit threshold (usd per share) Incentive Distribution, Quarterly Distribution Per Unit, Distribution Threshold Incentive Distribution, Quarterly Distribution Per Unit, Distribution Threshold Fair Value Disclosures [Abstract] Schedule Of Assets And Liabilities On A Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule Of Carrying And Fair Values Of Long-Term Debt Fair Value, by Balance Sheet Grouping [Table Text Block] Commitments and Contingencies Disclosure [Abstract] 2017 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2018 Operating Leases, Future Minimum Payments, Due in Two Years 2019 Operating Leases, Future Minimum Payments, Due in Three Years 2020 Operating Leases, Future Minimum Payments, Due in Four Years 2021 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total future minimum lease commitments Operating Leases, Future Minimum Payments Due Approximate rental expense Operating Leases, Rent Expense, Net Future Minimum Lease Commitments Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Inventory, Net [Abstract] Inventories Inventory Disclosure [Text Block] Related Party Transactions [Abstract] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Share-based Compensation [Abstract] Unit-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Investments, Debt and Equity Securities [Abstract] Risks and Uncertainties [Abstract] Major Customer and Concentration of Credit Risk Concentration Risk Disclosure [Text Block] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Ethylene Sales Agreement [Member] Ethylene Sales Agreement [Member] Ethylene Sales Agreement [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Investee [Member] Investee [Member] Affiliated Entity [Member] Affiliated Entity [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo LP [Member] Westlake [Member] Parent Company And Subsidiaries, Excluding Reporting Entity And Subsidiaries [Member] Parent Company and Subsidiaries, Excluding Reporting Entity and Subsidiaries [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Predecessor [Member] Predecessor [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Minimum percentage required to be purchased Long-term Purchase Commitment, Minimum Percentage Required Long-term Purchase Commitment, Minimum Percentage Required Deficiency amount Long-Term Purchase Commitment, Deficiency Amount Long-Term Purchase Commitment, Deficiency Amount Accounts receivable, net—Westlake Accounts Receivable, Related Parties, Current Accounts payable—Westlake Accounts Payable, Related Parties, Current Derivative [Table] Derivative [Table] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedging [Member] Cash Flow Hedging [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Assets [Member] Other Assets [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Interest Rate Contract [Member] Interest Rate Contract [Member] Commodity forward contracts [Member] Commodity Forward Contracts [Member] Commodity forward contracts [Member] Derivative [Line Items] Derivative [Line Items] Derivative, Fair Value, Net Derivative, Fair Value, Net Organization, Consolidation and Presentation of Financial Statements [Abstract] Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] 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. Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Cash Distribution [Member] Cash Distribution [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Distribution declared per unit (usd per share) Distribution Made to Limited Partner, Distributions Declared, Per Unit Incentive distribution Incentive Distribution, Distribution Related Party Transactions Related Party Transactions Disclosure [Text Block] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior Notes [Member] Senior Notes [Member] Reimbursement to Parent for State Tax [Member] Reimbursement to Parent for State Tax [Member] Reimbursement to Parent for State Tax [Member] Site Lease Agreement [Member] Site Lease Agreement [Member] Site Lease Agreement [Member] Outstanding letters of credit Letters of Credit Outstanding, Amount Outstanding debt Long-term Debt Unamortized discount Debt Instrument, Unamortized Amount of unamortized debt discount (premium) and debt issuance costs. Income Taxes Paid Income Taxes Paid Number of lease agreements Lessee Leasing Arrangements, Operating Leases, Number Lessee Leasing Arrangement, Operating Leases, Number Term of operating lease Lessee Leasing Arrangements, Operating Leases, Term of Contract Operating lease, rental amount Operating Leases, Rent Expense Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Other Nonoperating Income (Expense) [Member] Other Nonoperating Income (Expense) [Member] Balance Sheet Location [Axis] Accrued Liabilities [Member] Accrued Liabilities [Member] Interest on related party debt payable Interest Expense, Related Party Interest capitalized Interest Costs Capitalized Accrued interest on related party debt Interest Payable, Current Long-term debt payable to Westlake Due to Related Parties, Noncurrent Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Director [Member] Director [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Westlake Chemical Partners LP Long-Term Incentive Plan [Member] Westlake Chemical Partners LP Long-Term Incentive Plan [Member] Westlake Chemical Partners LP Long-Term Incentive Plan [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Phantom Share Units (PSUs) [Member] Phantom Share Units (PSUs) [Member] Selling, General and Administrative Expenses [Member] Selling, General and Administrative Expenses [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] 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] Beginning balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Vested Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised Ending balance 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] Weighted Average Fair Value, beginning 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 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 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 Weighted Average Fair Value, ending balance (usd per share) Number of units authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Total units available for grant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Total compensation cost Allocated Share-based Compensation Expense Unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Deferred Compensation Arrangement with Individual, 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 Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Quarterly Financial Information Disclosure [Abstract] Quarterly Financial Information (Unaudited) Quarterly Financial Information [Text Block] Document And Entity Information [Abstract] Document And Entity Information (Abstract) Document Information [Table] Document Information [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common units [Member] Common Units [Member] Common Units [Member] Subordinated units [Member] Subordinated Units [Member] Subordinated Units [Member] Document Information [Line Items] Document Information [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Entity Filer Category Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Common Stock, Shares Outstanding Entity Public Float Net sales - Westlake Revenue from Related Parties Debt Disclosure [Abstract] Schedule Of Long-Term Debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Accumulated Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Long-Term Debt Related Party Transactions, Long-term Debt [Text Block] Related Party Transactions, Long-term Debt [Text Block] Accumulated Other Comprehensive Income Comprehensive Income (Loss) Note [Text Block] Schedule of Cash Equivalents [Table] Schedule of Cash and Cash Equivalents [Table] Investments by Category [Axis] Investments by Category [Axis] Marketable Securities and Investments Held at Cost [Domain] Marketable Securities and Investments Held at Cost [Domain] Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Unfavorable Regulatory Action [Member] Unfavorable Regulatory Action [Member] Litigation Status [Axis] Litigation Status [Axis] Litigation Status [Domain] Litigation Status [Domain] Pending Litigation [Member] Pending Litigation [Member] Settled Litigation [Member] Settled Litigation [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Estimate of possible loss Loss Contingency, Estimate of Possible Loss Number of claims settled Loss Contingency, Claims Settled, Number Amount of settlements Litigation Settlement, Amount Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Partner Type [Axis] Partner Type [Axis] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Limited Partner [Member] Limited Partner [Member] General Partner [Member] General Partner [Member] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Public [Member] Unidentified Third Parties [Member] Unidentified Third Parties [Member] Statement [Line Items] Statement [Line Items] ASSETS Assets [Abstract] Current assets Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable, net—Westlake Chemical Corporation (Westlake) Accounts receivable, net—third parties Receivables, Net, Current Inventories Inventory, Net Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property, plant and equipment, net Property, Plant and Equipment, Net Goodwill Goodwill Other assets, net Other Assets [Abstract] Deferred charges and other assets, net Deferred Costs and Other Assets Total other assets, net Other Assets, Noncurrent Total assets Assets LIABILITIES Liabilities and Equity [Abstract] Current liabilities Liabilities, Current [Abstract] Accounts payable—third parties Accounts Payable, Current Accrued liabilities Accrued Liabilities, Current Total current liabilities Liabilities, Current Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Other liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (Notes 8 and 18) Commitments and Contingencies EQUITY Stockholders' Equity Attributable to Parent [Abstract] Limited partners' capital Limited Partners' Capital Account General partner—Westlake General Partners' Capital Account Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Total Westlake Chemical Partners LP partners' capital Partners' Capital Noncontrolling interest in Westlake Chemical OpCo LP (OpCo) Noncontrolling Interest in Limited Partnerships Total equity Partners' Capital, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Amortization Amortization Discounted cash flow projections period Discounted Cash Flow Methodology, Asset Impairment, Number Of Years Forecasted The number of forecast years utilized in developing discounted cash flow projections in determining asset impairment. 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. Percentage future cash flows of segment could decrease by and not be impaired Discounted Cash Flow Methodology, Goodwill Impairment, Cash Flow Percentage Decrease Without Impairment Percentage used in the sensitivity analysis of future discounted cash flows analyzed for goodwill impairment under the discounted cash flow methodology. Percentage of minimum quarterly distribution partnership must pay to end subordination period Percentage Paid Of Minimum Quarterly Distribution Ending Subordination Period Percentage Paid Of Minimum Quarterly Distribution Ending Subordination Period Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as Fair Value Hedges [Member] Designated as Hedging Instrument [Member] Interest Expense [Member] Interest Expense [Member] Cost of Sales [Member] Cost of Sales [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Derivative, Gain (Loss) on Derivative, Net Derivative, Gain (Loss) on Derivative, Net Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion Finished products Inventory, Finished Goods, Gross Feedstock, additives, and chemicals Inventory, Work in Process and Raw Materials Inventories Fair Value Measurements Fair Value Disclosures [Text Block] Income Tax Disclosure [Abstract] Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Provision for federal income tax, at statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount State income tax provision, net of federal income tax effect Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Partnership income not subject to entity-level tax Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Manufacturing deduction Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Amount Other, net Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount Total provision Income Tax Expense (Benefit) Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 2013 Promissory Note [Member] Promissory Notes, 2013 [Member] Promissory Notes, 2013 [Member] OpCo Revolver [Member] OpCo Revolver [Member] OpCo Revolver [Member] MLP Revolver [Member] MLP Revolver [Member] MLP Revolver [Member] Senior Unsecured Revolving Credit Facility [Member] Senior Unsecured Revolving Credit Facility [Member] Senior Unsecured Revolving Credit Facility [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Long-term debt Long-term debt, fair value Long-term Debt, Fair Value Schedule Of The Provision For (Benefit From) Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Reconciliation Of Taxes Computed At The Statutory Rate To Income Tax Expense Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule Of Deferred Tax Assets And Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Fair Value Hedging [Member] Fair Value Hedging [Member] Derivatives Not Designated As Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Gain (Loss) Recognized in Income on Derivative Number of contracts Derivative, Number of Instruments Held Ineffective portion of a derivative instrument Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Property, Plant and Equipment, Net [Abstract] Schedule Of Property, Plant And Equipment Property, Plant and Equipment [Table Text Block] Initial Public Offering and Purchase of Additional Interests Stockholders' Equity Note Disclosure [Text Block] Services received from Westlake and included in selling, general and administrative expenses Selling, General and Administrative Expense Schedule Of Other Assets Schedule of Other Assets, Noncurrent [Table Text Block] Other Assets Other Assets Disclosure [Text Block] Distribution declared Distributed Earnings 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. Net income subsequent to the IPO in excess of distribution Undistributed Earnings, Basic Limited partners' interest in net income subsequent to IPO Net Income (Loss) Attributable to Parent Distributions per common unit (usd per unit) Distribution Made to Limited Partner, Distributions Paid, Per Unit Units issued Limited Partners' Capital Account, Units Issued Units outstanding Limited Partners' Capital Account, Units Outstanding Summary Of Quarterly Financial Information Quarterly Financial Information [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Nonvested Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Schedule of Limited Partners' Capital Account by Class [Table] Schedule of Limited Partners' Capital Account by Class [Table] Limited Partners' Common Units [Member] Limited Partners' Subordinated Units [Member] Limited Partners' Capital Account [Line Items] Limited Partners' Capital Account [Line Items] Distribution Net income in excess of distribution Weighted average units outsanding: Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract] Basic and diluted (units) Weighted Average Number of Shares Outstanding, Basic and Diluted Net income per limited partner unit: Earnings Per Share, Basic and Diluted [Abstract] Income per limited partner unit (usd per unit) Earnings Per Share, Basic and Diluted Statement of Cash Flows [Abstract] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest 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] Depreciation and amortization Depreciation, Depletion and Amortization Charged to Expense Provision for Doubtful Accounts Loss from disposition of property, plant and equipment Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Deferred income taxes Deferred Income Tax Expense (Benefit) Income from equity method investment, net of dividends Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Changes in operating assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Accounts receivable - third parties Increase (Decrease) in Accounts and Other Receivables Net accounts receivable - Westlake Increase (Decrease) in Accounts Receivable, Related Parties Inventories Increase (Decrease) in Inventories Prepaid expenses and other current assets Increase (Decrease) In Prepaid Expenses And Other Current Assets Increase (Decrease) In Prepaid Expenses And Other Current Assets Accounts payable Increase (Decrease) in Accounts Payable Accrued and other liabilities Increase (Decrease) in Accrued Liabilities Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from disposition of assets Proceeds from Sale of Property, Plant, and Equipment Settlements of derivative instruments Payments for (Proceeds from) Derivative Instrument, Investing Activities Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from debt payable to Westlake Proceeds from Related Party Debt Repayment of debt payable to Westlake Repayments of Related Party Debt Quarterly distributions to noncontrolling interest retained in OpCo by Westlake Payments to Noncontrolling Interests Quarterly distributions to unitholders Distribution Made to Limited Partner, Cash Distributions Paid Repayment of related party debt with proceeds from the initial public offering Repayment of related party debt with proceeds from the initial public offering Repayment of related party debt with proceeds from the initial public offering Net proceeds from issuance of common units Proceeds from Issuance of Common Limited Partners Units Proceeds from initial public offering distributed to Westlake Payments of Capital Distribution Net distributions to Westlake prior to initial public offering Payments of Distributions to Affiliates Net cash used for financing activities Net Cash Provided by (Used in) Financing Activities Net (decrease) increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Description Of Business Description Of Business [Policy Text Block] Description Of Business [Policy Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Cash And Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Allowance For Doubtful Accounts Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block] Inventories Inventory, Policy [Policy Text Block] Impairment Of Long-Lived Assets and Intangible Assets Impairment or Disposal of Long-Lived Assets, Including Intangible Assets, Policy [Policy Text Block] Turnaround Costs Property, Plant and Equipment, Planned Major Maintenance Activities, Policy [Policy Text Block] Exchanges Inventory Exchange [Policy Text Block] Disclosure of accounting policy for the basis and manner that goods are exchanged and settled in like-kind quantities. This disclosure includes the nature of the cost elements included in inventory and how cost is determined (such as FIFO, LIFO, average). Concentration Of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Revenue Recognition Revenue Recognition Accounting Policy, Gross and Net Revenue Disclosure [Policy Text Block] Net Income per Unit Earnings Per Share, Policy [Policy Text Block] Derivative Instruments Derivatives, Policy [Policy Text Block] Environmental Costs Environmental Costs, Policy [Policy Text Block] Fair Value Of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Segment Reporting Segment Reporting, Policy [Policy Text Block] Use Of Estimates Use of Estimates, Policy [Policy Text Block] Net Investment Net Investment [Policy Text Block] Net Investment [Policy Text Block] Other Assets Other Assets [Policy Text Block] Disclosure of accounting policy for the method of amortizing debt issuance costs and certain other assets. Comprehensive Income Comprehensive Income, Policy [Policy Text Block] Impact Of Derivative Instruments Not Designated As Fair Value Hedges Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Fair Values Of Derivative Instruments In Consolidated Balance Sheets Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Derivative Instruments, Gain (Loss) Derivative Instruments, Gain (Loss) [Table Text Block] Recent Accounting Pronouncements New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Interest Rate Derivative Assets, at Fair Value Interest Rate Derivative Assets, at Fair Value Statement of Comprehensive Income [Abstract] Net income Adjustments in fair value of cash flow hedge Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Reclassification of losses to net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Total other comprehensive income Other Comprehensive Income (Loss), Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interest in OpCo Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to Westlake Chemical Partners LP Comprehensive Income (Loss), Net of Tax, Attributable to Parent Property, Plant And Equipment Property, Plant and Equipment Disclosure [Text Block] Description Of Business And Significant Accounting Policies Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Statement of Partners' Capital [Abstract] Noncontrolling Interest in OpCo [Member] Noncontrolling Interest [Member] AOCI Attributable to Parent [Member] AOCI Attributable to Parent [Member] Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Equity, beginning balance Net distributions to Westlake Partners' Capital Account, Distributions Predecessor net liabilities not assumed by OpCo Partners' Capital, Predecessor Net Liabilities Not Assumed By Subsidiary Partners' Capital, Predecessor Net Liabilities Not Assumed By Subsidiary Allocation of net investment to unitholders Partners' Capital Allocation Of Net Investment To Unitholders Partners' Capital Allocation Of Net Investment To Unitholders Proceeds from initial public offering, net of finance and other offering costs Partners' Capital Account, Public Sale of Units Distribution to the noncontrolling interest in OpCo Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders, Reimbursement Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders, Reimbursement Purchase of additional interest in OpCo Noncontrolling Interest, Increase from Subsidiary Equity Issuance Net effect of cash flow hedge Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Quarterly distribution to unitholders Limited Partners' Capital Account, Distribution Amount Quarterly distribution to noncontrolling interest retained in OpCo by Westlake Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Equity, ending balance Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Common and Subordinated units [Member] Common And Subordinated Units [Member] Common And Subordinated Units [Member] Minimum Quarterly Distribution Per Unit Minimum Quarterly Distribution Per Unit Minimum Quarterly Distribution Per Unit 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 Federal Current Federal Tax Expense (Benefit) Property, plant and equipment Deferred Tax Liabilities, Property, Plant and Equipment Turnaround costs Deferred Tax Liabilities, Deferred Expense, Other Capitalized Costs Deferred tax liabilities-total Deferred Tax Liabilities, Net Balance sheet classifications Deferred Tax Assets, Net, Classification [Abstract] Noncurrent deferred tax liability State and local Current State and Local Tax Expense (Benefit) Current Income Tax Expense (Benefit) Current Income Tax Expense (Benefit) Federal Deferred Federal Income Tax Expense (Benefit) State and local Deferred State and Local Income Tax Expense (Benefit) Deferred Income Tax Expense (Benefit) Supplemental Information Other Income and Other Expense Disclosure [Text Block] Accounts Receivable, Net [Abstract] Schedule Of Accounts Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment by Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Buildings And Improvements [Member] Building and Building Improvements [Member] Plant And Equipment [Member] Plant And Equipment [Member] Plant And Equipment [Member] Ethylene Pipeline [Member] Ethylene Pipeline [Member] Ethylene Pipeline [Member] Other [Member] Other Capitalized Property Plant and Equipment [Member] Property, Plant and Equipment [Line Items] Capitalized interest Property, plant and equipment, useful life (in years) Property, Plant and Equipment, Useful Life Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] State and Local Jurisdiction [Member] State and Local Jurisdiction [Member] Interest incurred, added to principal on promissory notes outstanding Interest Incurred, Added to Debt Outstanding Interest Incurred, Added to Debt Outstanding Reduction in capital expenditure accrual Increase (Decrease) in Capital Expenditure Accrual Increase (Decrease) in Capital Expenditure Accrual Related party notes payable deemed settled through net investment Increase (Decrease) in Notes Payable, Related Parties Cash transferred in related party notes payable settlement Cash Transferred In Notes Payable Settlement, Related Parties Cash Transferred In Notes Payable Settlement, Related Parties Interest Paid, Net Interest Paid, Net Designated as Hedging Instrument [Member] Concentration Risk [Table] Concentration Risk [Table] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Net sales [Member] Sales Revenue, Net [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Customer Concentration Risk [Member] Customer Concentration Risk [Member] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Concentration Risk [Line Items] Concentration Risk [Line Items] Concentration risk percentage Concentration Risk, Percentage Net Income Per Limited Partner Unit Earnings Per Share [Text Block] 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 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 Other charges from Westlake and included in cost of sales Cost Of Goods Sold, Other Cost Of Goods Sold, Other Cost of sales Cost of Goods Sold Trade customers Accounts Receivable, Gross, Current Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Trade Customer Receivable Net Current Trade Customer Receivable Net Current Trade Customer Receivable Net Current Other Receivables, Net, Current Other Receivables, Net, Current Accounts receivable, net—third parties Allowance for Doubtful Accounts Receivable [Roll Forward] Allowance for Doubtful Accounts Receivable [Roll Forward] Beginning balance Allowance for Doubtful Accounts Receivable Deductions Allowance for Doubtful Accounts Receivable, Period Increase (Decrease) Ending balance Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table] Schedule Of Finite-Lived And Indefinite-Lived Intangible Assets [Table] Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Schedule of Finite-Lived And Indefinite-Lived Intangible Assets [Line Items] Schedule of Finite-Lived And Indefinite-Lived Intangible Assets [Line Items] Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line items] Goodwill, Cost Goodwill, Gross Goodwill, Net Interest Rate Contract, Gross Interest Rate Contract, Gross Interest Rate Contract, Gross Schedule Of Other Assets [Table] Schedule Of Other Assets [Table] Schedule Of Other Assets [Table] Other Assets, Noncurrent [Axis] Other Assets, Noncurrent [Axis] Other Assets, Noncurrent [Axis] Other Assets Noncurrent By Type [Domain] Other Assets Noncurrent By Type [Domain] Other Assets, Noncurrent, By Type [Domain] Deferred Turnaround Costs [Member] Deferred Turnaround Costs [Member] Deferred Turnaround Costs [Member] Other Amortizable Assets [Member] Other Amortizable Assets [Member] Other Amortizable Assets [Member] Other Assets [Line Items] Other Assets [Line Items] Other Assets [Line Items] Interest rate contract Interest Rate Contract, Net Interest Rate Contract, Net Turnaround costs, Cost Turnaround Costs, Gross Turnaround Costs, Gross Turnaround costs, Accumulated Amortization Accumulated Amortization, Turnaround Costs Accumulated Amortization, Turnaround Costs Turnaround costs, Net Turnaround Costs, Net Turnaround Costs, Net Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Asset, Useful Life Other, Costs Noncurrent Assets, Other, Gross Noncurrent Assets, Other, Gross Other, Accumulated Amortization Accumulated Amortization, Noncurrent Assets, Other Accumulated Amortization, Noncurrent Assets, Other Other, Net Noncurrent Assets, Other, Net Noncurrent Assets, Other, Net Total deferred charges and other assets, Cost Total Deferred Charges and Other Assets, Noncurrent, Gross Total Deferred Charges and Other Assets, Noncurrent, Gross Total deferred charges and other assets, Accumulated Amortization Accumulated Amortization, Total Deferred Charges and Other Assets, NonCurrent Accumulated Amortization, Total Deferred Charges and Other Assets, NonCurrent Total deferred charges and other assets, Net Total Deferred Charges and Other Assets, NonCurrent, Net Total Deferred Charges and Other Assets, NonCurrent, Net Other assets, Cost Other Assets, Noncurrent, Gross Represents the gross amount (cost) of a specified group of non-current assets. Other assets, Accumulated Amortization Other Assets, Noncurrent, Accumulated Amortization Represents the accumulated amortization of a specified group of non-current assets. Income Statement [Abstract] Net co-products, ethylene and feedstock sales—third parties Other Revenue, Net Net sales Revenue, Net Gross profit Gross Profit Selling, general and administrative expenses Income from operations Operating Income (Loss) Other income (expense) Nonoperating Income (Expense) [Abstract] Interest expense—Westlake Other income, net Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Provision for income taxes Net income Less: Net income attributable to noncontrolling interest in OpCo Net Income (Loss) Attributable to Noncontrolling Interest Limited partners' interest in net income subsequent to IPO Net income attributable to Westlake Chemical Partners LP subsequent to initial public offering per limited partner unit (basic and diluted) Weighted average limited partner units outstanding (basic and diluted) Weighted average limited units outstanding (basic and diluted) Net sales Gross profit Income from operations Net income attributable to Westlake Chemical Partners LP Basic and diluted earnings per common unit holder (usd per unit) Subsequent Events Subsequent Events [Text Block] Partners' Equity Partners' Capital Notes Disclosure [Text Block] Weslake [Member] Line of Credit [Member] Line of Credit [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Prime Rate [Member] Prime Rate [Member] LIBOR [Member] London Interbank Offered Rate (LIBOR) [Member] Basis spread on variable rate, percent Debt Instrument, Basis Spread on Variable Rate Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity 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 Amount paid to purchase additional limited partner interest Payments to Acquire Limited Partnership Interests 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. 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 Weighted average interest rate on all long-term debt Long-term Debt, Weighted Average Interest Rate Westlake [Member] Subsidiary, Sale of Stock [Axis] Sale of Stock [Axis] Sale of Stock, Name of Transaction [Domain] Sale of Stock [Domain] Over-Allotment Option [Member] Over-Allotment Option [Member] IPO [Member] IPO [Member] Loans Payable [Member] Loans Payable [Member] Preformation Capital Expenditure [Member] Preformation Capital Expenditure [Member] Preformation Capital Expenditure [Member] Cash Reserve Turnaround [Member] Cash Reserve Turnaround [Member] Cash Reserve Turnaround [Member] Intercompany Debt [Member] Intercompany Debt [Member] Intercompany Debt [Member] Excess Production Option [Member] Excess Production Option [Member] Excess Production Option [Member] Feedstock Supply Agreement [Member] Feedstock Supply Agreement [Member] Feedstock Supply Agreement [Member] Services And Secondment Agreement [Member] Services And Secondment Agreement [Member] Services And Secondment Agreement [Member] Majority-Owned Subsidiary, Unconsolidated [Member] Majority-Owned Subsidiary, Unconsolidated [Member] Partnership's ownership interest (percent) Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest Debt assumed by acquiree Intercompany Debt Intercompany Debt Number of units sold in public offering Partners' Capital Account, Units, Sold in Public Offering Price per unit (usd per unit) Sale of Unit, Price Per Unit Sale of Unit, Price Per Unit Price per unit, net of underwriting discount (usd per unit) Sale of Unit, Price Per Unit, Net of Underwriting Discount Sale of Unit, Price Per Unit, Net of Underwriting Discount Payments of unit issuance costs Payments of Unit Issuance Costs Payments of Unit Issuance Costs Additional ownership interest acquired Carrying value of additional partnership interest purchased Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Excess cash paid over carrying value of partnership interest Noncontrolling Interest, Decrease Due To Excess Cash Paid Over Carrying Value Noncontrolling Interest, Decrease Due To Excess Cash Paid Over Carrying Value Use of proceeds from public offering Subsidiary Initial Public Offering, Use Of Proceeds Subsidiary Initial Public Offering, Use Of Proceeds Long-term Commitment (Excluding Unconditional Purchase Obligation) [Abstract] Long-term Commitment (Excluding Unconditional Purchase Obligation) [Abstract] Term of sales agreement Long-term Purchase Commitment, Period Maximum mass required to be purchased Long-term Purchase Commitment, Maximum Volume Required Long-term Purchase Commitment, Maximum Volume Required Percentage of excess production that can be purchased Long-term Purchase Commitment, Option To Purchase Excess Production, Percentage Long-term Purchase Commitment, Option To Purchase Excess Production, Percentage 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 Exchange agreement amount of purchase agreement Purchase Commitment, Purchase Agreement, Mass Purchase Commitment, Purchase Agreement, Mass Purchase commitment, fixed margin on variable pricing Long-term Purchase Commitment, Exchange Fee, Fixed Margin Long-term Purchase Commitment, Exchange Fee, Fixed Margin Purchase commitment, renewal term Long-term Purchase Commitment, Renewal Term Long-term Purchase Commitment, Renewal Term Related party transactions, term of agreements Related Party Transaction, Term Of Agreement Related Party Transaction, Term Of Agreement 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 Schedule of Incentive Distributions Made to Managing Members or General Partners by Distribution Schedule of Incentive Distributions Made to Managing Members or General Partners by Distribution [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Income Taxes Income Tax Disclosure [Text Block] Accrued Liabilities Accrued Liabilities [Abstract] Accrued interest Accrual related to capital expenditures Accrued Capital Expenditures, Current Accrued Capital Expenditures, Current Accrued maintenance expense Accrued Maintenance Expense, Current Accrued Maintenance Expense, Current Building and improvements Buildings and Improvements, Gross Plant and equipment Machinery and Equipment, Gross Other Property, Plant and Equipment, Other, Gross 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. Less: Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment 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. Construction in progress Construction in Progress, Gross Property, plant and equipment, net Depreciation expense Depreciation Accounts Receivable—Third Parties Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Organization, Consolidation, And Presentation Of Financial Statements [Table] Organization, Consolidation, And Presentation Of Financial Statements [Table] Organization, Consolidation, And Presentation Of Financial Statements [Table] Limited Liability Company [Member] Limited Liability Company [Member] Westlake Chemical OpCo GP LLC [Member] Westlake Chemical OpCo GP LLC [Member] Westlake Chemical OpCo GP LLC [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]. Number of Production Facilities Number of Production Facilities Number of Production Facilities Threshold period past due accounts receivable reviewed Threshold Period Past Due Accounts Receivable Reviewed Threshold Period Past Due Accounts Receivable Reviewed Amortization period, minimum (in years) Plant And Equipment Planned Major Maintenance Activities Amortization Period Minimum The minimum amortization period of planned major maintenance activities. Amortization period, maximum (in years) Plant And Equipment Planned Major Maintenance Activities Amortization Period Maximum The maximum amortization period of planned major maintenance activities. Other assets amortization period, minimum (in years) Finite Lived Intangible Assets Amortization Period Minimum The minimum amortization period of finite-lived intangible assets. Other assets amortization period, maximum (in years) Finite Lived Intangible Assets Amortization Period Maximum The maximum amortization period of finite-lived intangible assets. Federal Total Current Federal State and local Total deferred Schedule Of Inventory Schedule of Inventory, Current [Table Text Block]