Supplemental Information [Abstract]
Supplemental Information [Abstract]
Supplemental Information
Additional Financial Information Disclosure [Text Block]
Debt Disclosure [Abstract]
Long-Term Debt
Debt Disclosure [Text Block]
Partners' Capital [Abstract]
Schedule of Related Party Transactions, by Related Party [Table]
Schedule of Related Party Transactions, by Related Party [Table]
Related Party [Axis]
Related Party [Axis]
Related Party [Domain]
Related Party [Domain]
Principal Stockholder [Member]
Principal Owner [Member]
Subsidiary of Common Parent [Member]
Subsidiary of Common Parent [Member]
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]
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]
TTWF LP [Member]
TTWF LP [Member]
TTWF LP [Member]
Westlake Chemical Partners LP [Member]
Westlake Chemical Partners LP [Member]
Westlake Chemical Partners LP [Member]
Related Party Transaction [Line Items]
Related Party Transaction [Line Items]
Partners' Capital Account, Units, Sold in Public Offering
Partners' Capital Account, Units, Sold in Public Offering
Limited Partnership Ownership Percentage Increase
Limited Partnership Ownership Percentage Increase
Limited Partnership Ownership Percentage Increase
Sale of Unit Price Per Unit
Sale of Unit Price Per Unit
Per unit amount received by subsidiary or equity investee for each unit issued or sold in the unit transaction.
Proceeds from issuance of Westlake Chemical Partners LP common units
Payments to Acquire Limited Partnership Interests
Partners' Capital Account, Units, Sold in Private Placement
Partners' Capital Account, Units, Sold in Private Placement
Proceeds from Issuance of Private Placement
Proceeds from Issuance of Private Placement
Partners' Capital Account, Units, Acquisitions
Partners' Capital Account, Units, Acquisitions
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest
Ownership interest (in units)
Partners' Capital Account, Units
Fair Value Disclosures [Abstract]
Fair Value Measurements
Fair Value Disclosures [Text Block]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial Statements
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
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
Stock-based compensation expense
Share-based Compensation
Disposition and write-off 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)
Other losses (gains), net
Other Operating Activities, Cash Flow Statement
Changes in operating assets and liabilities
Increase (Decrease) in Operating Capital [Abstract]
Accounts receivable
Increase (Decrease) in Accounts and Other Receivables
Inventories
Increase (Decrease) in Inventories
Prepaid expenses and other current assets
Increase (Decrease) in Prepaid Expense and Other 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]
Acquisition of business, net of cash acquired
Payments to Acquire Businesses, Net of Cash Acquired
Additions to property, plant and equipment
Payments to Acquire Property, Plant, and Equipment
Additions to investments in unconsolidated subsidiaries
Payments to Acquire Additional Interest in Subsidiaries
Other, net
Payments for (Proceeds from) Other 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]
Dividends paid
Payments of Ordinary Dividends, Common Stock
Distributions to noncontrolling interests
Payments of Ordinary Dividends, Noncontrolling Interest
Proceeds from notes payable
Proceeds from Notes Payable
Proceeds from issuance of Westlake Chemical Partners LP common units
Proceeds from Issuance of Common Limited Partners Units
Redemption and repayment of notes payable
Repayments of Notes Payable
Other
Proceeds from (Payments for) Other Financing Activities
Net cash provided by (used for) financing activities
Net Cash Provided by (Used in) Financing Activities
Effect of exchange rate changes on cash, cash equivalents and restricted cash
Effect of Exchange Rate on Cash and Cash Equivalents
Net decrease in cash, cash equivalents and restricted cash
Cash and Cash Equivalents, Period Increase (Decrease)
Cash, cash equivalents and restricted cash at beginning of period
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Cash, cash equivalents and restricted cash at end of period
Unamortized Debt Issuance Cost
Unamortized Debt Issuance Expense
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table]
Schedule of Business Acquisitions, by Acquisition [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]
Customer Relationships [Member]
Customer Relationships [Member]
Technology-Based Intangible Assets [Member]
Technology-Based Intangible Assets [Member]
Trade Names [Member]
Trade Names [Member]
Business Acquisition [Line Items]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross
Payments to Acquire Businesses, Gross
Cash
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents
Accounts receivable
Business Combination, Acquired Receivable, Fair Value
Inventories
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory
Prepaid expenses and other current assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets
Property, plant and equipment
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment
Operating lease right-of-use assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease, Right-of-Use-Asset
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease, Right-of-Use-Asset
Intangible assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill
Other assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets
Total assets acquired
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets
Accounts and notes payable
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable
Accrued and other liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Liabilities
Deferred income taxes
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent
Pension and other post-retirement benefits
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Pension and Other Post Retirement Obligations
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Pension and Other Post Retirement Obligations
Operating lease liabilities
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Operating Lease, Liability
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Operating Lease, Liability
Other long-term liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities
Total liabilities assumed
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities
Total identifiable net assets acquired
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net
Goodwill
Goodwill, Acquired During Period
Total purchase consideration
Business Combination, Consideration Transferred
Finite-Lived Intangible Asset, Useful Life
Finite-Lived Intangible Asset, Useful Life
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-term Debt Instruments [Table]
Debt Instrument [Axis]
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Credit Agreement [Member]
Credit Agreement [Member]
Credit Agreement [Member]
Variable Rate [Axis]
Variable Rate [Axis]
Variable Rate [Domain]
Variable Rate [Domain]
Alternate Base Rate [Domain]
Alternate Base Rate [Domain]
Alternate Base Rate [Domain]
London Interbank Offered Rate (LIBOR) [Member]
London Interbank Offered Rate (LIBOR) [Member]
Credit Facility [Axis]
Credit Facility [Axis]
Credit Facility [Domain]
Credit Facility [Domain]
Revolving Credit Facility [Member]
Revolving Credit Facility [Member]
Letter of Credit [Member]
Letter of Credit [Member]
Swingline Loan [Member]
Swingline Loan [Member]
Swingline Loan [Member]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Domain]
Long-term Debt, Type [Domain]
Line of Credit [Member]
Line of Credit [Member]
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Minimum [Member]
Minimum [Member]
Maximum [Member]
Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Maximum borrowing capacity
Line of Credit Facility, Maximum Borrowing Capacity
Spread on variable rate
Debt Instrument, Basis Spread on Variable Rate
Amount outstanding
Long-term Line of Credit
Outstanding letters of credit
Letters of Credit Outstanding, Amount
Remaining borrowing capacity
Line of Credit Facility, Remaining Borrowing Capacity
Line of credit permitted increase
Line Of Credit Facility Permitted Increase
The permitted amount the line of credit facility may be increased by, under certain circumstances if certain lenders agree to commit to such an increase.
Inventory Disclosure [Abstract]
Inventories
Inventory Disclosure [Text Block]
Supplemental Cash Flow Elements [Abstract]
Operating cash flows from operating leases
Operating Lease, Payments
Right-of-use assets obtained in exchange for operating lease obligations
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability
Statement of Financial Position [Abstract]
Statement [Table]
Statement [Table]
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Common Stock [Member]
Common Stock [Member]
Common Stock, Held in Treasury [Member]
Treasury Stock [Member]
Statement [Line Items]
Statement [Line Items]
Preferred stock, par value, in dollars per share
Preferred Stock, Par or Stated Value Per Share
Preferred stock, shares authorized
Preferred Stock, Shares Authorized
Preferred stock, shares issued
Preferred Stock, Shares Issued
Preferred stock, shares outstanding
Preferred Stock, Shares Outstanding
Common stock, par value, in dollars per share
Common Stock, Par or Stated Value Per Share
Common stock, shares authorized
Common Stock, Shares Authorized
Common Stock, Shares, Issued
Common Stock, Shares, Issued
Treasury Stock, Shares
Treasury Stock, Shares
Investments, Debt and Equity Securities [Abstract]
Financial Instruments
Financial Instruments Disclosure [Text Block]
Earnings and Dividends Per Share [Abstract]
Earnings and Dividends Per Share [Abstract]
Schedule Of Net Income Attributable To Common Stockholders
Schedule Of Net Income Loss Attributable To Common Stockholders [Table Text Block]
Schedule of net income (loss) attributable to common stockholders [Table Text Block]
Reconciliation Of Denominator For Basic And Diluted Earnings Per Share
Schedule of Weighted Average Number of Shares [Table Text Block]
Dividends Per Share
Dividends Per Share [Table Text Block]
[Table Text Block] for Dividends Per Share [Table]
Accrued and other liabilities
Accrued Liabilities, Current
Accrued Rebates, Current
Accrued Rebates, Current
Accrued Rebates, Current
Due to Affiliate, Current
Due to Affiliate, Current
Restructuring Charges
Restructuring Charges
Business Acquisition, Transaction Costs
Business Acquisition, Transaction Costs
Income (Loss) from Subsidiaries, Net of Tax
Income (Loss) from Subsidiaries, Net of Tax
Gain on debt redemption
Gain (Loss) on Extinguishment of Debt
Interest Income, Other
Interest Income, Other
Increase (Decrease) in Capital Expenditure Accrual
Increase (Decrease) in Capital Expenditure Accrual
Increase (Decrease) in Capital Expenditure Accrual
Accounts Receivable, Net [Abstract]
Trade customers
Accounts Receivable, Gross, Current
Affiliates
Accounts Receivable, Related Parties, Current
Allowance for doubtful accounts
Allowance for Doubtful Accounts Receivable, Current
Accounts receivable from trade customers, net
Accounts Receivable, Net, Current
Federal and state taxes
Income Taxes Receivable, Current
Other
Other Receivables, Net, Current
Accounts receivable, net
Receivables, Net, Current
Schedule Of Inventory
Schedule of Inventory, Current [Table Text Block]
Accounts and Notes Payable [Abstract]
Accounts and Notes Payable [Abstract]
Schedule of Accounts Payable and Accrued Liabilities
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]
Number of options excluded from computation of diluted earnings per share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Segment Reporting [Abstract]
Number of segments
Number of Operating Segments
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Income Tax Disclosure [Abstract]
Income Taxes
Income Tax Disclosure [Text Block]
Reconciliation of Assets from Segment to Consolidated [Table]
Reconciliation of Assets from Segment to Consolidated [Table]
Consolidation Items [Axis]
Consolidation Items [Axis]
Consolidation Items [Domain]
Consolidation Items [Domain]
Operating Segments [Member]
Operating Segments [Member]
Corporate and other [Member]
Corporate, Non-Segment [Member]
Segments [Axis]
Segments [Axis]
Segments [Domain]
Segments [Domain]
Olefins [Member]
Olefins [Member]
Olefins [Member]
Vinyls [Member]
Vinyls [Member]
Vinyls [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets
Assets
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]
Fair Value [Member]
Estimate of Fair Value Measurement [Member]
3.60% Senior Notes Due 2022 [Member]
Three Point Six Zero Percentage Senior Notes Due Twenty Twenty Two [Member]
Three Point Six Zero Percentage Senior Notes Due Twenty Twenty Two [Member]
3.6% Senior Notes Due 2026 [Member]
Three Point Six Percent Senior Notes Due Twenty Twenty-Six [Member]
Three Point Six Percent Senior Notes Due Twenty Twenty-Six [Member]
Loan related to tax-exempt waste disposal revenue bonds due 2027 [Member]
Waste Disposal Revenue Bonds Due Twenty Twenty Seven [Member]
Waste Disposal Revenue Bonds Due Twenty Twenty-Seven [Member]
6 1/2% GO Zone Senior Notes Due 2029 [Member]
Go Zone Six And One Half Percent Senior Notes Due Twenty Twenty Nine [Member]
GO Zone 6 1/2% Senior Notes Due 2029 [Member]
2035 GO Zone 6 1/2% Notes [Member]
Go Zone Six Point Five Percent Tax Exempt Revenue Bonds Due Twenty Thirty Five [Member]
Go Zone Six Point Five Percent Tax-Exempt Revenue Bonds Due Twenty Thirty Five [Member]
2035 IKE Zone 6 1/2% Notes [Member]
Ike Zone Six Point Five Percent Tax Exempt Revenue Bonds Due Twenty Thirty Five [Member]
IKE Zone six point five percent tax-exempt revenue bonds due twenty thirty five [Member]
5.0% Senior Notes Due 2046 [Member]
Five Percent Senior Notes Due Twenty Forty-Six [Member]
Five Percent Senior Notes Due Twenty Forty-Six [Member]
4.375% Senior Notes Due 2047 [Member]
Four Point Three Seven Five Percent Senior Notes Due Twenty Forty Seven [Member]
Four Point Three Seven Five Percent Senior Notes Due Twenty Forty Seven [Member]
3.50% Senior Notes Due 2032 [Member]
Three Point Five Zero Percent Senior Notes Due Twenty Thirty Two [Member]
Three Point Five Zero Percent Senior Notes Due Twenty Thirty Two [Member]
Senior Notes [Member]
Senior Notes [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
Senior notes
Long-term Debt, Fair Value
Debt Instrument Maturity
Debt Instrument Maturity
Debt Instrument, Maturity
Stated interest rate (percent)
Debt Instrument, Interest Rate, Stated Percentage
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill [Table]
Schedule of Goodwill [Table]
Goodwill [Line Items]
Goodwill [Line Items]
Goodwill [Roll Forward]
Goodwill [Roll Forward]
Beginning Balance
Goodwill
Goodwill acquired during the period
Effects of changes in foreign exchange rates
Goodwill, Foreign Currency Translation Gain (Loss)
Ending Balance
Related Party Transactions [Abstract]
LACC [Member]
LACC [Member]
LACC [Member]
Affiliated Entity [Member]
Affiliated Entity [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Basis of Financial Statements
Basis of Accounting, Policy [Policy Text Block]
Recent Accounting Pronouncements
New Accounting Pronouncements, Policy [Policy Text Block]
Environmental Loss Contingencies [Table]
Loss Contingencies [Table]
Regulatory Agency [Axis]
Regulatory Agency [Axis]
Regulatory Agency [Domain]
Regulatory Agency [Domain]
Environmental Protection Agency [Member]
Environmental Protection Agency [Member]
Environmental Protection Agency [Member]
Environmental Remediation Contingency [Axis]
Environmental Remediation Contingency [Axis]
Environmental Remediation Contingency [Domain]
Environmental Remediation Contingency [Domain]
Operation and Maintenance [Member]
Operation and Maintenance [Member]
Operation and Maintenance [Member]
PolyOne [Member]
PolyOne [Member]
PolyOne [Member]
Litigation Status [Axis]
Litigation Status [Axis]
Litigation Status [Domain]
Litigation Status [Domain]
Pending Litigation [Member]
Pending Litigation [Member]
Environmental Loss Contingencies [Line Items]
Loss Contingencies [Line Items]
Environmental Loss contingency accrual
Loss Contingency Accrual
Environmental Remediation Expense
Environmental Remediation Expense
Environmental Exit Costs, Anticipated Cost
Environmental Exit Costs, Anticipated Cost
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties [Line Items]
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties
Loss Contingency, Damages Sought, Value
Environmental Exit Costs, Reasonably Possible Additional Loss
Environmental Exit Costs, Reasonably Possible Additional Loss
ASSETS
Assets [Abstract]
Current assets
Assets, Current [Abstract]
Cash and cash equivalents
Cash and Cash Equivalents, at Carrying Value
Accounts receivable, net
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
Operating lease right-of-use assets
Operating Lease, Right-of-Use Asset
Goodwill
Customer relationships, net
Finite-Lived Intangible Assets, Net
Other intangible assets, net
Other Intangible Assets, Net
Other assets, net
Deferred Costs and Other Assets
Total assets
LIABILITIES AND EQUITY
Liabilities and Equity [Abstract]
Current liabilities
Liabilities, Current [Abstract]
Accounts and notes payable
Accounts Payable, Current
Total current liabilities
Liabilities, Current
Long-term debt, net
Long-term Debt, Excluding Current Maturities
Deferred income taxes
Deferred Tax Liabilities, Net, Noncurrent
Pension and other post-retirement benefits
Liability, Defined Benefit Plan, Noncurrent
Operating lease liabilities
Operating Lease, Liability, Noncurrent
Other liabilities
Other Liabilities, Noncurrent
Total liabilities
Liabilities
Stockholders' equity
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, $0.01 par value, 50,000,000 shares authorized; no shares issued and outstanding
Preferred Stock, Value, Issued
Common stock, $0.01 par value, 300,000,000 shares authorized; 134,651,380 and 134,651,380 shares issued at March 31, 2019 and December 31, 2018, respectively
Common Stock, Value, Issued
Common stock, held in treasury, at cost; 6,059,073 and 6,183,125 shares at March 31, 2019 and December 31, 2018, respectively
Treasury Stock, Value
Additional paid-in capital
Additional Paid in Capital, Common Stock
Retained earnings
Retained Earnings (Accumulated Deficit)
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss), Net of Tax
Total Westlake Chemical Corporation stockholders' equity
Stockholders' Equity Attributable to Parent
Noncontrolling interests
Stockholders' Equity Attributable to Noncontrolling Interest
Total equity
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest
Total liabilities and equity
Liabilities and Equity
Principal Amount
Long-term Debt, Gross
Unamortized Premium (Discount) and Debt Issuance Costs
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net
Net, Long-term Debt
Westlake Chemical Partners LP
Partners' Capital Notes Disclosure [Text Block]
OCI Parenthetical [Abstract]
OCI Parenthetical [Abstract]
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest
Weighted average common shares—basic
Weighted Average Number of Shares Outstanding, Basic
Weighted Average Number Diluted Shares Outstanding Adjustment
Weighted Average Number Diluted Shares Outstanding Adjustment
Incremental Shares From Assumed exercise of options
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants
Weighted average common shares-diluted
Weighted Average Number of Shares Outstanding, Diluted
Earnings per share attributable to Westlake Chemical Corporation: Basic
Earnings Per Share, Basic
Earnings per share attributable to Westlake Chemical Corporation: Diluted
Earnings Per Share, Diluted
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]
Cash and Cash Equivalents [Abstract]
Debt Securities, Held-to-maturity
Debt Securities, Held-to-maturity
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
Schedule of Goodwill
Schedule of Goodwill [Table Text Block]
Segment Information
Segment Reporting Disclosure [Text Block]
Document And Entity Information [Abstract]
Document And Entity Information (Abstract)
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 Emerging Growth Company
Entity Emerging Growth Company
Entity Small Business
Entity Small Business
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Dividends per common share (in usd per share)
Common Stock, Dividends, Per Share, Declared
Goodwill
Goodwill Disclosure [Text Block]
Acquisition
Business Combination Disclosure [Text Block]
Leases [Abstract]
Lease related asset and liability
Lease related asset and liability [Table Text Block]
[Table Text Block] for Lease related asset and liability [Table]
Lease, Cost
Lease, Cost [Table Text Block]
Maturities of Operating Lease Liabilities
Lessee, Operating Lease, Liability, Maturity [Table Text Block]
Schedule of Future Lease Commitments for Operating Leases
Schedule of Property Subject to or Available for Operating Lease [Table Text Block]
Schedule Of Long-Term Debt
Schedule of Long-term Debt Instruments [Table Text Block]
Schedule of Operating Lease Supplemental Cash Flow
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]
Summary Of Carrying And Fair Values Of Long-Term Debt
Fair Value, by Balance Sheet Grouping [Table Text Block]
New Accounting Pronouncements or Change in Accounting Principle [Table]
New Accounting Pronouncements or Change in Accounting Principle [Table]
Adjustments for New Accounting Pronouncements [Axis]
Adjustments for New Accounting Pronouncements [Axis]
Type of Adoption [Domain]
Type of Adoption [Domain]
Accounting Standards Update 2016-02 [Member]
Accounting Standards Update 2016-02 [Member]
Balance Sheet Location [Axis]
Balance Sheet Location [Axis]
Balance Sheet Location [Domain]
Balance Sheet Location [Domain]
Accrued and Other Liabilities [Member]
Accrued and Other Liabilities [Member]
Accrued and Other Liabilities [Member]
Other Liabilities [Member]
Other Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accrued and other liabilities
Operating Lease, Liability, Current
Leases
Leases of Lessee Disclosure [Text Block]
Income from operations
Operating Income (Loss)
Interest expense
Interest Expense
Other income (expense), net
Nonoperating Income (Expense)
Accounts Receivable
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]
Earnings per Share
Earnings and Dividends Per Share [Text Block]
Earnings and Dividends Per Share [Text Block]
Segment Reporting Information
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]
Total Assets
Reconciliation of Assets from Segment to Consolidated [Table Text Block]
Accounts and Notes Payable
Accounts Payable and Accrued Liabilities Disclosure [Text Block]
Finished products
Inventory, Finished Goods, Net of Reserves
Feedstock, additives, chemicals and other raw materials
Inventory, Work in Process and Raw Materials, Net of Reserves
Materials and supplies
Inventory, Supplies, Net of Reserves
Inventories
Assets and Liabilities, Lessee [Abstract]
Assets and Liabilities, Lessee [Abstract]
Operating lease liabilities
Operating Lease, Liability
Weighted Average Remaining Term (in years)
Operating Lease, Weighted Average Remaining Lease Term
Weighted Average Lease Discount Rate
Operating Lease, Weighted Average Discount Rate, Percent
Lease, Cost [Abstract]
Lease, Cost [Abstract]
Operating lease cost
Operating Lease, Cost
Short-term lease cost
Short-term Lease, Cost
Total operating lease cost
Lease, Cost
Operating Lease Liabilities, Payments Due [Abstract]
Operating Lease Liabilities, Payments Due [Abstract]
2019 (excluding the three months ended March 31, 2019)
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year
2020
Lessee, Operating Lease, Liability, Payments, Due Year Two
2021
Lessee, Operating Lease, Liability, Payments, Due Year Three
2022
Lessee, Operating Lease, Liability, Payments, Due Year Four
2023
Lessee, Operating Lease, Liability, Payments, Due Year Five
Thereafter
Lessee, Operating Lease, Liability, Payments, Due after Year Five
Total lease payments
Lessee, Operating Lease, Liability, Payments, Due
Less: imputed interest
Lessee, Operating Lease, Liability, Undiscounted Excess Amount
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019
Operating Leases, Future Minimum Payments Due, Next Twelve Months
2020
Operating Leases, Future Minimum Payments, Due in Two Years
2021
Operating Leases, Future Minimum Payments, Due in Three Years
2022
Operating Leases, Future Minimum Payments, Due in Four Years
2023
Operating Leases, Future Minimum Payments, Due in Five Years
Thereafter
Operating Leases, Future Minimum Payments, Due Thereafter
Total lease payments
Operating Leases, Future Minimum Payments Due
Accumulated Other Comprehensive Income (Loss)
Comprehensive Income (Loss) Note [Text Block]
Schedule Of Accounts Receivable
Schedule Of Accounts And Financing Receivables [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.
Statement of Comprehensive Income [Abstract]
Other comprehensive loss, net of income taxes
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Foreign Currency Translation Adjustment, by Component [Abstract]
Foreign Currency Translation Adjustment, by Component [Abstract]
Foreign currency translation
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax
Income tax benefit (provision) on foreign currency translation
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax
Other comprehensive loss, net of income taxes
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 interests, net of tax of $1 and $1 for the three months ended March 31, 2019 and 2018, respectively
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest
Comprehensive income attributable to Westlake Chemical Corporation
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Accounts payable—third parties
Accounts Payable, Trade, Current
Accounts payable to affiliates
Accounts Payable, Related Parties
Notes payable
Notes Payable, Current
Accounts and notes payable
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance
Other comprehensive income (loss) before reclassifications
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax
Net other comprehensive income (loss) attributable to Westlake Chemical Corporation
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Ending balance
Net income attributable to Westlake Chemical Corporation
Net Income (Loss) Attributable to Parent
Net income attributable to participating securities
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted
Net income attributable to common shareholders
Net Income Loss Available To Common Stockholders
Net income available to common stockholders after adjustments for net income attributable to participating securities.
Statement of Stockholders' Equity [Abstract]
Additional Paid-in Capital [Member]
Additional Paid-in Capital [Member]
Retained Earnings [Member]
Retained Earnings [Member]
Noncontrolling Interests [Member]
Noncontrolling Interest [Member]
Beginning balances
Beginning balance, shares issued
Beginning balance, Treasury shares
Cumulative effect of accounting change
Cumulative Effect of New Accounting Principle in Period of Adoption
Net income attributable to noncontrolling interests
Net Income (Loss) Attributable to Noncontrolling Interest
Other comprehensive loss
Shares issued—stock- based compensation (in shares)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures
Shares issued—stock-based compensation
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures
Stock-based compensation
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition
Dividends declared
Dividends, Common Stock, Cash
Distributions to noncontrolling interests
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders
Issuance of Westlake Chemical Partners LP common units
Noncontrolling Interest, Increase from Subsidiary Equity Issuance
Ending balances
Ending balance, shares issued
Ending balance, Treasury shares
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Intersegment sales [Member]
Intersegment Eliminations [Member]
Product and Service [Axis]
Product and Service [Axis]
Product and Service [Domain]
Product and Service [Domain]
Polyethylene [Member]
Polyethylene [Member]
Polyethylene [Member]
Styrene, Feedstock And Other [Member]
Styrene, Feedstock And Other [Member]
Styrene, Feedstock And Other [Member]
PVC, Caustic Soda And Other [Member]
Pvc Caustic Soda And Other [Member]
PVC, caustic soda and other [Member]
Building Products [Member]
Building Products [Member]
Building Products [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Net sales
Revenues
Income (loss) from operations
Provision for (benefit from) income taxes
Income Tax Expense (Benefit)
Additions to property, plant and equipment
Income Statement [Abstract]
Cost of sales
Cost of Goods and Services Sold
Gross profit
Gross Profit
Selling, general and administrative expenses
Selling, General and Administrative Expense
Amortization of intangibles
Amortization of Intangible Assets
Restructuring, Transaction and Integration Cost
Restructuring, Transaction and Integration Cost
Costs incurred could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.
Income from operations
Other income (expense)
Nonoperating Income (Expense) [Abstract]
Other income, net
Provision for income taxes
Net income attributable to Westlake Chemical Corporation
Earnings per common share attributable to Westlake Chemical Corporation:
Earnings Per Share [Abstract]
Basic (in dollars per share)
Diluted (in dollars per share)
Weighted average common shares outstanding:
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Basic (in shares)
Diluted (in shares)
Restricted Cash and Cash Equivalents
Restricted Cash and Cash Equivalents