Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Predecessor [Member] Predecessor [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Westlake [Member] Parent Company And Subsidiaries, Excluding Reporting Entity And Subsidiaries [Member] Parent Company and Subsidiaries, Excluding Reporting Entity and Subsidiaries [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliated Entity [Member] Affiliated Entity [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] 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 Interest paid, net of interest capitalized Interest Paid, Net Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Limited Partners' Capital Account by Class [Table] Schedule of Limited Partners' Capital Account by Class [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] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo LP [Member] Westlake Chemical OpCo GP LLC [Member] Westlake Chemical OpCo GP LLC [Member] Westlake Chemical OpCo GP LLC [Member] Limited Liability Company [Member] Limited Liability Company [Member] Majority-Owned Subsidiary, Unconsolidated [Member] Majority-Owned Subsidiary, Unconsolidated [Member] Limited Partners' Capital Account [Line Items] Limited Partners' Capital Account [Line Items] Number of units sold in public offering Partners' Capital Account, Units, Sold in Public Offering Limited partner interest Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest Number of ethylene production facilities Number of Production Facilities Number of Production Facilities Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Depreciation expense on property, plant and equipment Depreciation Property, plant and equipment Property, Plant and Equipment, Net Loss Contingencies [Table] Loss Contingencies [Table] Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] Goodrich and PolyOne [Member] Goodrich and PolyOne [Member] Goodrich and PolyOne [Member] Litigation Status [Axis] Litigation Status [Axis] Litigation Status [Domain] Litigation Status [Domain] Settled Litigation [Member] Settled Litigation [Member] Pending Litigation [Member] Pending Litigation [Member] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Unfavorable Regulatory Action [Member] Unfavorable Regulatory Action [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Percentage of costs related to environmental issues to be paid by PolyOne Site Contingency, Third Party Recovery, Percentage Represents environmental costs percentage net of recoveries from third parties, to be paid by a counterparty Minimum number of years between arbitrations Loss Contingency, Arbitration Interval Period Represents the minimum number of years that must pass before another arbitration proceeding may be held to adjust the environmental costs percentage paid by a counterparty. Costs incurred for environmental remediation services Environmental Remediation Expense Reimbursement of remediation costs sought by PolyOne Loss Contingency, Damages Sought, Value Possible amount of claims in settlement for compliance violations Loss Contingency, Estimate of Possible Loss Document Documentand Entity Information [Abstract] Document - 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 Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Earnings Per Share [Abstract] 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] Limited Partners' Common Units [Member] Limited Partners' Subordinated Units [Member] Distribution declared Distributed Earnings Net income in excess of distribution Undistributed Earnings, Basic Net income attributable to Westlake Chemical Partners LP Net Income (Loss) Attributable to Parent Weighted average units outsanding: Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract] Basic and diluted (shares) 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 share) Earnings Per Share, Basic and Diluted Description of Business and Basis of Presentation Business Description and Basis of Presentation [Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] 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 LT Incentive Plan [Member] Westlake Chemical Partners LP LT 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] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of units granted Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Number of units outstanding Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number Compensation Expense Allocated Share-based Compensation Expense Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] 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] Derivatives Not Designated As Hedging Instruments Not Designated as Hedging Instrument [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Forward Contracts [Member] Forward Contracts [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Cost of Sales Cost of Sales [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Gain (Loss) Recognized in Income on Derivative Derivative, Gain (Loss) on Derivative, Net Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Inventory Disclosure [Abstract] Inventories Inventory Disclosure [Text Block] Investments, Debt and Equity Securities [Abstract] Schedule of Cash and 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] Held-to-maturity Securities [Member] Held-to-maturity Securities [Member] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Cash and cash equivalents Cash Equivalents, at Carrying Value Income Statement [Abstract] Statement [Table] Statement [Table] Public [Member] Unidentified Third Parties [Member] Unidentified Third Parties [Member] Statement [Line Items] Statement [Line Items] Net sales - Westlake Revenue from Related Parties Net co-product, ethylene and feedstock sales—third parties Other Revenue, Net Total net sales Revenue, Net Cost of sales Cost of Goods Sold Gross profit Gross Profit Selling, general and administrative expenses Selling, General and Administrative Expense Income from operations Operating Income (Loss) Other income (expense) Nonoperating Income (Expense) [Abstract] Interest expense—Westlake Interest Expense, Related Party Other income, net Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Provision for income taxes Income Tax Expense (Benefit) Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Less: Net income attributable to noncontrolling interest in OpCo Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted) Weighted average limited partner units outstanding (basic and diluted) Weighted average limited partner units outstanding (shares) Accounts Receivable, Net [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Trade customers Accounts Receivable, Gross, Current Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Receivables from trade customers and affiliates, net Trade Customer And Affiliate Receivable Net Current The aggregate of amounts due from customers or clients, within one year of the balance sheet date (or one operating cycle, if longer), for goods or services that have been delivered or sold in the normal course of business, and amounts due from related parties (affiliates) payable within one year of the balance sheet, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Other Other Receivables Current Amount due from other third-parties, or arising from transactions not separately disclosed, within one year of the balance sheet date (or the normal operating cycle, whichever is longer). Accounts receivable, net - third parties Receivables, Net, Current Risks and Uncertainties [Abstract] 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 Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Subsidiary of Common Parent [Member] Subsidiary of Common Parent [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Additional limited partner interest purchased Limited Partnership Ownership Percentage Increase Limited Partnership Ownership Percentage Increase Amount paid to purchase additional limited partner interest Payments to Acquire Limited Partnership Interests Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Distribution declared per unit Distribution Made to Limited Partner, Distributions Declared, Per Unit Distribution declared Distribution Made to Limited Partner, Cash Distributions Declared Statement of Partners' Capital [Abstract] General Partner [Member] General Partner [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Noncontrolling Interest in OpCo [Member] Noncontrolling Interest [Member] Equity, beginning balance Partners' Capital, Including Portion Attributable to Noncontrolling Interest Net distributions to Westlake Partners' Capital Account, Distributions Quarterly distribution for the period from October 1, 2014 to December 31, 2014 to unitholders Limited Partners' Capital Account, Distribution Amount Quarterly distribution for the period from October 1, 2014 to December 31, 2014 to noncontrolling interest retained in OpCo by Westlake Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Equity, ending balance Statement of Financial Position [Abstract] 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, Related Parties, Current Accounts receivable, net—third parties 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 Other assets, net Other Assets [Abstract] Goodwill Goodwill Deferred charges and other assets, net Deferred Costs and Other Assets Total other assets, net Other Assets, Noncurrent Total assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current liabilities Liabilities, Current [Abstract] Accounts payable—Westlake Accounts Payable, Related Parties, Current Accounts payable—third parties Accounts Payable, Current Accrued liabilities Accrued Liabilities, Current Total current liabilities Liabilities, Current Long-term debt payable to Westlake Due to Related Parties, Noncurrent Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Other liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (Notes 9 and 16) Commitments and Contingencies EQUITY Stockholders' Equity Attributable to Parent [Abstract] Limited Partners' Capital Account Limited Partners' Capital Account General Partners' Capital Account General Partners' Capital Account Partners' capital Partners' Capital Noncontrolling interest in Westlake Chemical OpCo LP (OpCo) Noncontrolling Interest in Limited Partnerships Total equity Total liabilities and equity Liabilities and Equity Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] 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] Senior unsecured 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] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Value [Member] Reported Value Measurement [Member] Fair Value [Member] Estimate of Fair Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Senior Notes Senior Notes, Fair Value Disclosure This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents senior notes as of the balance sheet date. Statement of Cash Flows [Abstract] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] 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 Recovery of doubtful accounts Provision for Doubtful Accounts Loss from disposition of fixed assets 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 The increase (decrease) during the reporting period in the aggregate value of 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 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 Quarterly distribution for the period from October 1, 2014 to December 31, 2014 to noncontrolling interest retained in OpCo by Westlake Payments to Noncontrolling Interests Quarterly distribution for the period from October 1, 2014 to December 31, 2014 to unitholders 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 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 Other Assets Investments and Other Noncurrent Assets [Text Block] Long-term debt payable to Westlake Related Party Transactions, Long-term Debt [Text Block] Related Party Transactions, Long-term Debt [Text Block] Income Tax Disclosure [Abstract] Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent U.S. federal statutory income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Basis of Financial Statements Basis of Accounting, Policy [Policy Text Block] Subsequent Events Subsequent Events [Text Block] Income Taxes Income Tax Disclosure [Text Block] Accounts Receivable - Third Parties Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Summary Of Carrying And Fair Values Of Long-Term Debt Fair Value, by Balance Sheet Grouping [Table Text Block] Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party Services received from Westlake and included in selling, general and administrative expenses Supplemental Information Additional Financial Information Disclosure [Text Block] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Accrued Liabilities [Member] Accrued Liabilities [Member] Other Nonoperating Income (Expense) [Member] Other Nonoperating Income (Expense) [Member] Interest Expense, Related Party Interest Costs Capitalized Interest Costs Capitalized Interest Payable, Current Interest Payable, Current Other Assets [Member] Other Assets [Member] Amortization expense Amortization Change in carrying amount of goodwill Goodwill, Period Increase (Decrease) Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] 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 on senior notes Debt Instrument, Unamortized Discount Lessee Leasing Arrangements, Operating Leases, Number Lessee Leasing Arrangements, Operating Leases, Number Lessee Leasing Arrangement, Operating Leases, Number Lessee Leasing Arrangements, Operating Leases, Term of Contract Lessee Leasing Arrangements, Operating Leases, Term of Contract Operating Leases, Rent Expense Operating Leases, Rent Expense Goods and services purchased from Westlake and capitalized as assets RelatedPartyTransactionPurchasesFromRelatedPartyCapitalizedAsAssets Related Party Transaction Purchases From Related Party Capitalized As Assets Net Income Per Limited Partner Unit Earnings Per Share [Text Block] Derivative [Table] Derivative [Table] Designated As Fair Value Hedges Designated as Hedging Instrument [Member] Commodity Forward Contracts [Member] Commodity Forward Contracts [Member] Commodity forward contracts [Member] Derivative [Line Items] Derivative [Line Items] Number of derivatives Derivative, Number of Instruments Held Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule Of Inventory Schedule of Inventory, Current [Table Text Block] Major Customer and Concentration of Credit Risk Concentration Risk Disclosure [Text Block] 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 Total Line of Credit [Member] Line of Credit [Member] Senior Unsecured Revolving Credit Facility [Member] Senior Unsecured Revolving Credit Facility [Member] Senior Unsecured Revolving Credit Facility [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] Long-term debt Basis spread on variable rate, percent Debt Instrument, Basis Spread on Variable Rate Number of intercompany promissory notes Number of Intercompany Promissory Notes Number of Intercompany Promissory Notes 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] Inventory, Current [Table] Inventory, Current [Table] Inventory [Line Items] Inventory [Line Items] Finished products Inventory, Finished Goods, Gross Feedstock, additives and chemicals Inventory, Work in Process and Raw Materials Inventories Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Unit-based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Units issued Limited Partners' Capital Account, Units Issued Units outstanding Limited Partners' Capital Account, Units Outstanding Financial Instruments Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Accounts payable—Westlake 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.