XML 106 R80.htm IDEA: XBRL DOCUMENT v2.4.1.9
Employee Benefits (Narrative Defined Contribution Plans) (Details) (USD $)
In Thousands, unless otherwise specified
5 Months Ended 12 Months Ended
Dec. 31, 2014
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Non-U. S. Plans [Member]        
Defined Contribution Plan [Line Items]        
Defined contribution savings plan expense $ 416us-gaap_DefinedContributionPlanCostRecognized
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_ForeignPostretirementBenefitPlansDefinedBenefitMember
     
Defined Contribution Savings Plan [Member] | U. S. Plans [Member]        
Defined Contribution Plan [Line Items]        
Maximum employee contribution as a percentage of annual compensation   100.00%wlk_MaximumEmployeeContributionAsPercentageOfAnnualCompensation
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionSavingsPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
   
Matching percentage by company of first 4% of employee contribution   100.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionSavingsPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
   
Percentage of employee contribution fully matched by company   4.00%wlk_PercentageOfEmployeeContributionFullyMatchedByCompany
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionSavingsPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
   
Employer contributions to plans   6,856us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionSavingsPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
6,022us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionSavingsPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
5,180us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionSavingsPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
Defined Contribution Retirement Plan [Member] | U. S. Plans [Member]        
Defined Contribution Plan [Line Items]        
Employer contributions to plans   $ 8,309us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionRetirementPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
$ 6,227us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionRetirementPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
$ 6,310us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ wlk_DefinedContributionPlanNameAxis
= wlk_DefinedContributionRetirementPlanMember
/ wlk_DefinedContributionPlanTypeAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
Length of service required to be eligible for annual retirement contributions (in years)   1 year