Limited Partners' Capital Account [Line Items] Limited Partners' Capital Account [Line Items] 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] Distribution Type [Axis] Distribution Type [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Related Party Transactions Related Party Transactions Disclosure [Text Block] Cover [Abstract] Feedstock Purchased Feedstock Purchased [Member] Feedstock Purchased [Member] Net increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Weighted average limited partner units outstanding (basic and diluted) (in units) Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted Trading Symbol Trading Symbol All Trading Arrangements All Trading Arrangements [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Non-NEOs Non-NEOs [Member] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Allowance for credit losses Accounts Receivable, Allowance for Credit Loss, Current Interest earned related to the IMA Interest earned related to the IMA Interest earned related to the IMA Distribution to noncontrolling interest retained in OpCo by Westlake Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Pay vs Performance Disclosure [Line Items] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Fair Value Measurements Fair Value Disclosures [Text Block] Deferred charges and other assets, net Deferred Costs and Other Assets Award Timing Disclosures [Line Items] Managing Member or General Partner [Axis] Managing Member or General Partner [Axis] Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Other Performance Measure, Amount Other Performance Measure, Amount Majority-Owned Subsidiary, Unconsolidated Majority-Owned Subsidiary, Nonconsolidated [Member] Other receivables Other Receivables, Net, Current Accrued interest included in receivable under IMA Accrued interest included in receivable under IMA Accrued interest included in receivable under IMA Net income in excess of distribution (Distribution in excess of net income) Undistributed Earnings, Basic Loss from disposition of property, plant and equipment Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Site lease agreements, term (in years) Site lease agreements, term (in years) Site lease agreements, term (in years) Entity Tax Identification Number Entity Tax Identification Number Accounts Receivable—Third Parties Loans, Notes, Trade and Other Receivables Disclosure [Text Block] 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 Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Charges from related parties in cost of sales Related Parties Amount in Cost of Sales Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Accrued taxes Taxes Payable, Current Westlake Westlake Parent Company And Subsidiaries, Excluding Reporting Entity And Subsidiaries [Member] Parent Company and Subsidiaries, Excluding Reporting Entity and Subsidiaries [Member] Equity Components [Axis] Equity Components [Axis] Award Timing Method Award Timing Method [Text Block] Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Entity Common Units, Units Outstanding Entity Common Stock, Shares Outstanding Insider Trading Policies and Procedures [Line Items] Long-term debt payable to Westlake Other Long-Term Debt, Noncurrent Adjustment to Compensation, Amount Adjustment to Compensation Amount Compensation Amount Outstanding Recovery Compensation Amount Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Entity Small Business Entity Small Business Company Selected Measure Amount Company Selected Measure Amount Distribution Type [Domain] Distribution Type [Domain] Tabular List, Table Tabular List [Table Text Block] Receivables, Net, Current Accounts receivable, net—third parties Receivables, Net, Current Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Accrued and other liabilities Accrued Liabilities, Current Operating lease expense Operating Lease, Expense Other service charges Other Service Charges [Member] Other Service Charges [Member] Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Current assets Assets, Current [Abstract] Goodwill Goodwill Inventories Inventory Disclosure [Text Block] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Employee Stock Option Share-Based Payment Arrangement, Option [Member] Depreciation expense on property, plant and equipment Depreciation Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Security Exchange Name Security Exchange Name Basis spread on variable rate, percent Debt Instrument, Basis Spread on Variable Rate Award Type Award Type [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Net income per limited partner unit: Earnings Per Share, Basic [Abstract] Common units (basic) (in usd per share) Basic (in usd per share) Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax Property, plant and equipment, net Property, Plant and Equipment, Net Total liabilities Liabilities Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Expiration Date Trading Arrangement Expiration Date Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Accounts Receivable, after Allowance for Credit Loss [Abstract] Accounts Receivable, after Allowance for Credit Loss [Abstract] 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 Shareholder Return Amount Total Shareholder Return Amount Entity [Domain] Entity [Domain] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Concentration risk percentage Concentration Risk, Percentage Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Limited partner interest, additional ownership 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 Accrued Liabilities Accrued Liabilities [Member] Other income (expense) Other Nonoperating Income (Expense) [Member] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Balance Sheet Location [Axis] Statement of Financial Position Location, Balance [Axis] Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Feedstock, additives and chemicals Inventory, Work in Process and Raw Materials Selling, general and administrative expenses Selling, General and Administrative Expense Selling, General and Administrative Expense Number of units sold in public offering (in shares) Partners' Capital Account, Units, Sold in Public Offering Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current MLP Revolver MLP Revolver [Member] MLP Revolver [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Document Fiscal Period Focus Document Fiscal Period Focus Units issued for vested phantom units Stock Issued During Period, Value, Other All Executive Categories All Executive Categories [Member] Balance Sheet Location [Domain] Statement of Financial Position Location, Balance [Domain] Trade customers Accounts Receivable, before Allowance for Credit Loss, Current Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] ASSETS Assets [Abstract] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Document Type Document Type Distributions to unitholders Distribution Made to Limited Partner, Cash Distributions Paid Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Noncontrolling interest in Westlake Chemical OpCo LP ("OpCo") Noncontrolling Interest in Limited Partnerships Nonrelated Party Nonrelated Party [Member] 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 Limited Liability Company Limited Liability Company [Member] Maximum Maximum [Member] Westlake Parent Company [Member] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Accounts payable Accounts Payable, Current IDR Holders IDR Holders [Member] Incentive Distribution Rights Holders [Member] Westlake Chemical OpCo LP Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo LP [Member] Current Fiscal Year End Date Current Fiscal Year End Date Statistical Measurement [Axis] Statistical Measurement [Axis] PEO Name PEO Name Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount All Award Types Award Type [Domain] Above $1.2938 up to $1.4063 Cash Distribution, Tranche One [Member] Cash Distribution, Tranche One [Member] Name Outstanding Recovery, Individual Name Common units, diluted (in usd per share) Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Non-PEO NEO Non-PEO NEO [Member] Units sold in secondary offering price per unit (in dollars per share) Partners' Capital Account, Units, Sold in Public Offering, Price per Unit Partners' Capital Account, Units, Sold in Public Offering, Price per Unit Schedule of Accounts, Notes, Loans and Financing Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Award Timing Predetermined Award Timing Predetermined [Flag] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Recently Issued Accounting Pronouncement and Recently Adopted Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Counterparty Name [Domain] Counterparty Name [Domain] Name Measure Name Entity Interactive Data Current Entity Interactive Data Current Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Limited partner interest Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest Ownership [Axis] Ownership [Axis] Total equity Total equity Total equity Partners' Capital, Including Portion Attributable to Noncontrolling Interest Customer [Axis] Customer [Axis] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Provision for income taxes Income Tax Expense (Benefit) Other income (expense) Nonoperating Income (Expense) [Abstract] Net co-products, ethylene and other sales—third parties Revenue from Contract with Customer, Excluding Assessed Tax Other income, net Nonoperating Income (Expense) Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities Income from operations Operating Income (Loss) Interest expense Interest expense Interest Expense, Operating and Nonoperating Variable Rate [Domain] Variable Rate [Domain] Amount paid to purchase additional limited partner interest Payments to Acquire Limited Partnership Interests Total liabilities and equity Liabilities and Equity Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] All Adjustments to Compensation All Adjustments to Compensation [Member] Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Above $1.4063 up to $1.6875 Cash Distribution, Tranche Two [Member] Cash Distribution, Tranche Two [Member] Distributions Made to Limited Partner, by Distribution Distributions Made to Limited Partner, by Distribution [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Legal Entity [Axis] Legal Entity [Axis] Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Underlying Security Market Price Change Underlying Security Market Price Change, Percent Distribution to unitholders Limited Partners' Capital Account, Distribution Amount Individual: Individual [Axis] Related Party Transaction [Axis] Related Party Transaction [Axis] Inventories Inventories Inventory, Net Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Entity Address, State or Province Entity Address, State or Province Statement [Line Items] Statement [Line Items] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] General Partner General Partner [Member] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] LIABILITIES Liabilities and Equity [Abstract] Other Assets, Noncurrent [Abstract] Other Assets, Noncurrent [Abstract] Accounts receivable—third parties Increase (Decrease) in Accounts and Other Receivables Minimum Minimum [Member] Restatement Determination Date Restatement Determination Date Westlake Chemical OpCo GP LLC Westlake Chemical OpCo GP LLC [Member] Westlake Chemical OpCo GP LLC [Member] Adoption Date Trading Arrangement Adoption Date Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Concentration Risk [Table] Concentration Risk [Table] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] General partner—Westlake General Partners' Capital Account Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] 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 Net accounts receivable—Westlake Increase (Decrease) in Accounts Receivable, Related Parties Exercise Price Award Exercise Price Number of production facilities Number of Production Facilities Number of Production Facilities Supplemental Information Additional Financial Information Disclosure [Text Block] Distributions and Net Income Per Limited Partner Unit Earnings Per Share [Text Block] Arrangement Duration Trading Arrangement Duration Subsequent Event Subsequent Event [Member] EQUITY Equity, Attributable to Parent [Abstract] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Repayment of debt payable to Westlake Repayments of Related Party Debt Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] All Individuals All Individuals [Member] Senior Unsecured Revolving Credit Facility Senior Unsecured Revolving Credit Facility [Member] Senior Unsecured Revolving Credit Facility [Member] Above $1.6875 Cash Distribution, Tranche Three [Member] Cash Distribution, Tranche Three [Member] PEO PEO [Member] Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted) Earnings Per Unit [Abstract] Variable Rate [Axis] Variable Rate [Axis] Name Trading Arrangement, Individual Name Distribution Made to Limited Partner [Line Items] Distribution Made to Limited Partner [Line Items] Cash Distribution Cash Distribution [Member] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Proceeds from debt payable to Westlake Proceeds from Related Party Debt Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Related Party [Domain] Related and Nonrelated Parties [Domain] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Local Phone Number Local Phone Number Shortfall Shortfall Fees Shortfall Fees Weighted average units outsanding: Earnings per Unit, Basic and Diluted, Other Disclosure [Abstract] Earnings per Unit, Basic and Diluted, Other Disclosure Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Deferred Charges and Other Assets Other Assets Disclosure [Text Block] Deferred income taxes Deferred Income Tax Liabilities, Net Changes in operating assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Statement of Partners' Capital [Abstract] Statement of Partners' Capital [Abstract] PEO Total Compensation Amount PEO Total Compensation Amount Distributions per common unit (in usd per share) Distribution Made to Limited Partner, Distributions Paid, Per Unit Accrued interest on related party debt Interest Payable, Current Income Statement Location [Axis] Statement of Income Location, Balance [Axis] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Measure: Measure [Axis] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Number of common carrier pipelines Number of Common Carrier Pipelines Number of Common Carrier Pipelines Entity Emerging Growth Company Entity Emerging Growth Company Distributions declared Distributed Earnings Weighted average interest rate Long-Term Debt, Weighted Average Interest Rate, at Point in Time Distribution declared per unit (in usd per unit) Distribution Made to Limited Partner, Distributions Declared, Per Unit Entity Central Index Key Entity Central Index Key Distributions Made to Limited Partner [Table] Distributions Made to Limited Partner [Table] Schedule of Incentive Distributions Made to Managing Members or General Partners by Distribution Schedule of Distributions [Table Text Block] Schedule of Distributions [Table Text Block] Units outstanding (in shares) Limited Partners' Capital Account, Units Outstanding Schedule Of Inventory Schedule of Inventory, Current [Table Text Block] Accrued Liabilities [Abstract] Accrued Liabilities [Abstract] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Common unitholders Limited Partners' Capital Account Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Partners' Equity Equity [Text Block] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Schedule of Limited Partners' Capital Account by Class [Table] Partners' Capital, Limited Partner's Capital Account, Class [Table] Equity Component [Domain] Equity Component [Domain] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Entity Shell Company Entity Shell Company Reduction to Net sales - Westlake from charges for non-variable costs of production Reduction to Net sales - Westlake from charges for non-variable costs of production Reduction to Net sales - Westlake from charges for non-variable costs of production Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Title Trading Arrangement, Individual Title Consolidated Entities [Axis] Consolidated Entities [Axis] Statement [Table] Statement [Table] Incentive distribution rights, target distribution per unit requiring marginal percentage distribution to IDR holders (in 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 Counterparty Name [Axis] Counterparty Name [Axis] City Area Code City Area Code Current liabilities Liabilities, Current [Abstract] Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Site lease agreement, number Site lease agreement, number Site lease agreement, number Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Limited Partner Limited Partner [Member] Accrued and other liabilities Increase (Decrease) in Accrued Liabilities Common units Common units Common Units [Member] Common Units [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Equity [Abstract] Equity [Abstract] Units issued (in shares) Limited Partners' Capital Account, Units Issued Related Party Transaction [Line Items] Related Party Transaction [Line Items] Inventories Increase (Decrease) in Inventories Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Equity Awards Adjustments Equity Awards Adjustments [Member] 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 Net cash used for financing activities Net Cash Provided by (Used in) Financing Activities Underlying Securities Award Underlying Securities Amount Amendment Flag Amendment Flag Long-term debt payable to Westlake, fair value Long-Term Debt, Fair Value Entity Registrant Name Entity Registrant Name Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Depreciation and amortization Depreciation, Depletion and Amortization Gross profit Gross Profit Fair Value as of Grant Date Award Grant Date Fair Value Customer Concentration Risk Customer Concentration Risk [Member] Affiliated Entity Affiliated Entity [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Distributions to noncontrolling interest retained in OpCo by Westlake Payments of Ordinary Dividends, Noncontrolling Interest Restatement Determination Date: Restatement Determination Date [Axis] Title of 12(b) Security Title of 12(b) Security Concentration Risk Type [Axis] Concentration Risk Type [Axis] Shortfall fees recovered Shortfall fees recovered Shortfall fees recovered Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Concentration Risk [Line Items] Concentration Risk [Line Items] Finished products Inventory, Finished Goods, Gross Accounts payable—third parties Increase (Decrease) in Accounts Payable Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Ownership [Domain] Ownership [Domain] Subsequent distribution to IDR holders 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. Capital expenditures incurred but not yet paid Capital Expenditures Incurred but Not yet Paid Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Amortization expense Amortization Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Total current liabilities Liabilities, Current Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Total assets Assets Site lease agreements, OpCo annual obligation to WLK Site lease agreements, annual proceeds per site Site lease agreements, annual proceeds per site Cost of sales Cost of Goods and Services Sold Total Westlake Chemical Partners LP partners' capital Partners' Capital Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Other liabilities Other Liabilities, Noncurrent Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Commitments and contingencies (Note 12) Commitments and Contingencies Publicly and Privately Held Unidentified Third Parties [Member] Unidentified Third Parties [Member] Termination Date Trading Arrangement Termination Date Description of Business and Basis of Presentation Business Description and Basis of Presentation [Text Block] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Total net sales Revenues Entity Address, City or Town Entity Address, City or Town Debt Instrument [Axis] Debt Instrument [Axis] Unit Holders Unit Holders [Member] Unit Holders [Member] Partner Type [Axis] Partner Type [Axis] Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income Net income Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Summary Of Carrying And Fair Values Of Long-Term Debt Fair Value, by Balance Sheet Grouping [Table Text Block] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Entity File Number Entity File Number Insurance Recoveries Insurance Recoveries Partners' capital account, units, sold to related party (in shares) Partners' Capital Account, Units, Sold to Related Party Partners' Capital Account, Units, Sold to Related Party Consolidated Entities [Domain] Consolidated Entities [Domain] Document Fiscal Year Focus Document Fiscal Year Focus Incentive Distribution, Recipient [Domain] Incentive Distribution, Recipient [Domain] Noncontrolling Interest in OpCo Noncontrolling Interest [Member] Income Statement [Abstract] Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Name Forgone Recovery, Individual Name Document Period End Date Document Period End Date Other gains, net Other Noncash Income (Expense) Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Insider Trading Arrangements [Line Items] Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Adjustment to Compensation: Adjustment to Compensation [Axis] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Accounts Receivable Accounts Receivable [Member] Less: Net income attributable to noncontrolling interest in OpCo Net Income (Loss) Attributable to Noncontrolling Interest Document Transition Report Document Transition Report Document Quarterly Report Document Quarterly Report Long-Term Debt Payable to Westlake Related Party Transactions, Long-term Debt [Text Block] Related Party Transactions, Long-term Debt [Text Block] Customer [Domain] Customer [Domain] Entity Current Reporting Status Entity Current Reporting Status Related Party Transactions, Long-term Debt Related Party Transactions, Long-term Debt [Table Text Block] Related Party Transactions, Long-term Debt [Table Text Block] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Long-term debt payable to Westlake OpCo Revolver [Member] OpCo Revolver [Member] Related Party [Axis] Related and Nonrelated Parties [Axis] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Partners units, maximum aggregate offering amount, ATM Partners Units, Maximum Aggregate Offering Amount, ATM Partners Units, Maximum Aggregate Offering Amount, ATM Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Name Awards Close in Time to MNPI Disclosures, Individual Name Revenue Benchmark Revenue Benchmark [Member] Entity Filer Category Entity Filer Category Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Company Selected Measure Name Company Selected Measure Name