Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Services received from Westlake and included in selling, general and administrative expenses Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party 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] Increase (Decrease) in 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] Income tax provision (benefit) Income Tax Expense (Benefit) Deferred income taxes 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 Address, Postal Zip Code Entity Address, Postal Zip Code Schedule Of Other Assets [Table] Schedule Of Other Assets [Table] Schedule Of Other Assets [Table] Feedstock Purchased Feedstock Purchased [Member] Feedstock Purchased [Member] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Document Fiscal Period Focus Document Fiscal Period Focus Net income per limited partner unit: Earnings Per Share, Basic [Abstract] General Partner General Partner [Member] Cost of sales Cost of Goods and Services Sold Incentive Distribution, Recipient [Domain] Incentive Distribution, Recipient [Domain] Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Incentive Distribution, Marginal Percentage Interest in Distributions Schedule Of Accounts Receivable - Third Parties Schedule Of Accounts And Financing Receivables [Table Text Block] Tabular disclosure of the various categories of receivables, including trade and other receivables, and for each the gross carrying value, allowance (if appropriate), and net carrying value as of the balance sheet date. Schedule Of Inventory Schedule of Inventory, Current [Table Text Block] Distributions per common unit (in usd per share) Distribution Made to Limited Partner, Distributions Paid, Per Unit Debt Instrument [Axis] Debt Instrument [Axis] 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 Schedule of Limited Partners' Capital Account by Class [Table] Schedule of Limited Partners' Capital Account by Class [Table] Accounts Receivable Accounts Receivable [Member] 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 Charges from related parties in cost of sales Related Parties Amount in Cost of Sales Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Basis spread on variable rate, percent Debt Instrument, Basis Spread on Variable Rate Payments for (Proceeds from) Other Investing Activities Payments for (Proceeds from) Other Investing Activities Statistical Measurement [Domain] Statistical Measurement [Domain] Depreciation expense on property, plant and equipment Depreciation Senior Unsecured Revolving Credit Facility Senior Unsecured Revolving Credit Facility [Member] Senior Unsecured Revolving Credit Facility [Member] Distributions Made to Limited Partner [Table] Distributions Made to Limited Partner [Table] Limited Partner Limited Partner [Member] Number of units sold in public offering (in shares) Partners' Capital Account, Units, Sold in Public Offering Above $1.6875 Cash Distribution, Tranche Three [Member] Cash Distribution, Tranche Three [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 Accrued interest included in receivable under IMA Accrued interest included in receivable under IMA Accrued interest included in receivable under IMA Other losses, net Other Noncash Income (Expense) 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] Concentration Risk [Line Items] Concentration Risk [Line Items] Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income Net income attributable to the Partnership Net income Net Income (Loss) Attributable to Parent Capital Expenditures Incurred but Not yet Paid Capital Expenditures Incurred but Not yet Paid Partner Type [Axis] Partner Type [Axis] Distributions declared Distributed Earnings Subsequent Event Type [Axis] Subsequent Event Type [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Site lease agreements, term (in years) Site lease agreements, term (in years) Site lease agreements, term (in years) Trade customers Accounts Receivable, before Allowance for Credit Loss, Current Equity Component [Domain] Equity Component [Domain] Amendment Flag Amendment Flag Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities Subsequent Event Type [Domain] Subsequent Event Type [Domain] Net income in excess of distribution (Distribution in excess of net income) Undistributed Earnings, Basic Ownership [Axis] Ownership [Axis] Accounts payable—Westlake Accounts Payable, Related Parties, Current 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 Distribution declared per unit (in usd per unit) Distribution Made to Limited Partner, Distributions Declared, Per Unit Related Party [Domain] Related Party [Domain] Westlake 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] Entity Current Reporting Status Entity Current Reporting Status Depreciation and amortization Depreciation, Depletion and Amortization 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 Units issued Limited Partners' Capital Account, Units Issued Limited Partners' Capital Account 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 Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Counterparty Name [Axis] Counterparty Name [Axis] Accounts receivable—third parties Increase (Decrease) in Accounts and Other Receivables Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Cash flows from investing activities Net Cash Provided by (Used in) Operating Activities Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Property, plant and equipment, net Property, Plant and Equipment, Net Diluted (in usd per share) 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] Other service charges Other Service Charges [Member] Other Service Charges [Member] Allowance for credit losses Accounts Receivable, Allowance for Credit Loss, Current Legal Entity [Axis] Legal Entity [Axis] Balance Sheet Location [Axis] Balance Sheet Location [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] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Capital Expenditures Payable and Accrued Capital Expenditures Payable and Accrued Capital Expenditures Payable and Accrued Total liabilities Liabilities 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] Total Westlake Chemical Partners LP partners' capital Partners' Capital Maximum Maximum [Member] Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Entity Common Units, Units Outstanding Entity Common Stock, Shares Outstanding Risks and Uncertainties [Abstract] Risks and Uncertainties [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Total current assets Assets, Current Taxes Payable, Current Taxes Payable, Current Document Type Document Type Entity Small Business Entity Small Business SOFR Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Partners' Equity Stockholders' Equity Note Disclosure [Text Block] 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 Entity Shell Company Entity Shell Company Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Accrued and other liabilities Increase (Decrease) in Accrued Liabilities 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 Concentration Risk [Table] Concentration Risk [Table] Other Assets [Line Items] Other Assets [Line Items] Other Assets [Line Items] Accounts receivable, net—Westlake Accounts Receivable, Related Parties, Current Title of 12(b) Security Title of 12(b) Security Affiliated Entity Affiliated Entity [Member] Consolidated Entities [Axis] Consolidated Entities [Axis] Revenue Benchmark Revenue Benchmark [Member] Site lease agreement, number Site lease agreement, number Site lease agreement, number Subsequent Event Subsequent Event [Member] 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 Document Period End Date Document Period End Date Managing Member or General Partner [Axis] Managing Member or General Partner [Axis] Class of Stock [Line Items] Class of Stock [Line Items] Quarterly distribution to unitholders Limited Partners' Capital Account, Distribution Amount 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 Earnings Per Share [Abstract] Earnings Per Share [Abstract] Income Statement Location [Axis] Income Statement Location [Axis] Common units Common units Common Units [Member] Common Units [Member] LIABILITIES Liabilities and Equity [Abstract] 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 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 Accrued maintenance Accrued Maintenance Costs, Current Accrued Maintenance Costs, Current 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] 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 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 Entity Filer Category Entity Filer Category Related Party Transaction [Line Items] Related Party Transaction [Line Items] Summary 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 Commitments and contingencies (Note 12) Commitments and Contingencies Security Exchange Name Security Exchange Name Entity Registrant Name Entity Registrant 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] Net co-products, ethylene and other sales—third parties Revenue from Contract with Customer, Excluding Assessed Tax 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 Cover [Abstract] Minimum Minimum [Member] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company Noncontrolling Interest in OpCo Noncontrolling Interest [Member] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Alternate Base Rate Alternate Base Rate [Member] Alternate Base Rate Fair Value Measurements Fair Value Disclosures [Text Block] Deferred Charges and Other Assets Other Assets Disclosure [Text Block] Total liabilities and equity Liabilities and Equity 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] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Related Party [Axis] Related Party [Axis] Accrued Liabilities [Abstract] Accrued Liabilities [Abstract] Accrued interest on related party debt Interest Payable, Current 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 Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] IDR Holders IDR Holders [Member] Incentive Distribution Rights Holders [Member] Westlake Chemical OpCo LP Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo LP [Member] 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. Westlake Parent Company [Member] Long-term debt payable to Westlake Long-term debt payable to Westlake, carrying value Due to Related Parties, Noncurrent Accounts payable—third parties Increase (Decrease) in Accounts Payable LIBOR London Interbank Offered Rate (LIBOR) [Member] Common units (in usd per share) Basic (in usd per share) Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax Concentration Risk, Percentage Concentration Risk, Percentage Total net sales Revenues Concentration Risk Type [Axis] Concentration Risk Type [Axis] Total current liabilities Liabilities, Current Above $1.2938 up to $1.4063 Cash Distribution, Tranche One [Member] Cash Distribution, Tranche One [Member] Distribution Per Common Unit [Abstract] Distribution Per Common Unit [Abstract] Distribution Per Common Unit [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Net sales—Westlake Revenue from Related Parties Revenue from Related Parties Customer Concentration Risk Customer Concentration Risk [Member] General partner—Westlake General Partners' Capital Account Total equity Total equity Total equity Partners' Capital, Including Portion Attributable to Noncontrolling Interest 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 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] Deferred Charges and Other Assets Other Assets [Member] Majority-Owned Subsidiary, Unconsolidated Majority-Owned Subsidiary, Unconsolidated [Member] Amortization expense Amortization Entity Address, Address Line Two Entity Address, Address Line Two Quarterly distributions to noncontrolling interest retained in OpCo by Westlake Payments to Noncontrolling Interests Entity Address, Address Line One Entity Address, Address Line One Concentration Risk Type [Domain] Concentration Risk Type [Domain] Counterparty Name [Domain] Counterparty Name [Domain] Limited Partners' Capital Account [Line Items] Limited Partners' Capital Account [Line Items] Other Assets, Noncurrent [Abstract] Other Assets, Noncurrent [Abstract] Distribution Type [Axis] Distribution Type [Axis] Site lease agreements, OpCo annual obligation to WLK Site lease agreements, OpCo annual obligation to WLK Site lease agreements, OpCo annual obligation to WLK Ownership [Domain] Ownership [Domain] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Entity Interactive Data Current Entity Interactive Data Current Unit Holders Unit Holders [Member] Unit Holders [Member] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Changes in operating assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Inventories Inventory Disclosure [Text Block] Deferred charges and other assets, net Deferred Costs and Other Assets Equity [Abstract] Equity [Abstract] Other income (expense) Other Nonoperating Income (Expense) [Member] Limited partner interest Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest Distributions Made to Limited Partner, by Distribution Distributions Made to Limited Partner, by Distribution [Table Text Block] Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] Entity Tax Identification Number Entity Tax Identification Number 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 Statement [Table] Statement [Table] Accounts receivable, net—third parties Receivables, Net, Current Document Quarterly Report Document Quarterly Report Consolidated Entities [Domain] Consolidated Entities [Domain] Current assets Assets, Current [Abstract] Cash Distribution Cash Distribution [Member] Statistical Measurement [Axis] Statistical Measurement [Axis] Net increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Supplemental Information Additional Financial Information Disclosure [Text Block] Accrued Liabilities Accrued Liabilities [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Accounts receivable, net—third parties Accounts Receivable, after Allowance for Credit Loss, Current Entity Central Index Key Entity Central Index Key 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] Document Fiscal Year Focus Document Fiscal Year Focus Entity [Domain] Entity [Domain] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] City Area Code City Area Code ASSETS Assets [Abstract] Statement [Line Items] Statement [Line Items] Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Long-term Debt Payable to Westlake Related Party Transactions, Long-term Debt [Text Block] Related Party Transactions, Long-term Debt [Text Block] Other income, net Nonoperating Income (Expense) Variable Rate [Domain] Variable Rate [Domain] Common And Subordinated Units Common And Subordinated Units [Member] Common And Subordinated Units [Member] Selling, general and administrative expenses Selling, General and Administrative Expense Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Related Party Transactions, Long-term Debt Related Party Transactions, Long-term Debt [Table Text Block] Related Party Transactions, Long-term Debt [Table Text Block] OpCo Revolver OpCo Revolver [Member] OpCo Revolver [Member] Limited Liability Company Limited Liability Company [Member] Weighted average interest rate Long-Term Debt, Weighted Average Interest Rate, at Point in Time Net income per limited partner unit attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted) Earnings Per Unit [Abstract] 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 Operating lease expense Operating Lease, Expense Partners units, maximum aggregate offering amount, ATM Partners Units, Maximum Aggregate Offering Amount, ATM Partners Units, Maximum Aggregate Offering Amount, ATM Document Transition Report Document Transition Report Local Phone Number Local Phone Number Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Income from operations Operating Income (Loss) Inventories Increase (Decrease) in Inventories Accrued taxes Accrued Income Taxes Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Increase (Decrease) in Prepaid Expense and Other Assets Increase (Decrease) in Prepaid Expense and Other Assets Description of Business and Basis of Presentation Business Description and Basis of Presentation [Text Block] Goodwill Goodwill Customer [Domain] Customer [Domain]