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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Subsequent Events (Westlake Chemical Partners LP) (Details) - $ / shares		6 Months Ended
	Jul. 27, 2018	Jun. 30, 2018
Cash Distribution [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Incentive Distribution, Distribution Per Unit	$ 1.2938
IDR Holders [Member] \| Cash Distribution, Tranche One [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution		15.00%
IDR Holders [Member] \| Cash Distribution, Tranche One [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution	15.00%
IDR Holders [Member] \| Cash Distribution, Tranche Two [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution		25.00%
IDR Holders [Member] \| Cash Distribution, Tranche Two [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution	25.00%
IDR Holders [Member] \| Cash Distribution, Tranche Three [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution		50.00%
IDR Holders [Member] \| Cash Distribution, Tranche Three [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution	50.00%
Unit Holders [Member] \| Cash Distribution, Tranche One [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution		85.00%
Unit Holders [Member] \| Cash Distribution, Tranche One [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution	85.00%
Unit Holders [Member] \| Cash Distribution, Tranche Two [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution		75.00%
Unit Holders [Member] \| Cash Distribution, Tranche Two [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution	75.00%
Unit Holders [Member] \| Cash Distribution, Tranche Three [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution		50.00%
Unit Holders [Member] \| Cash Distribution, Tranche Three [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Maximum Percentage Of Income Distribution	50.00%
IPO [Member] \| Limited Partner [Member] \| Westlake Chemical OpCo LP [Member] \| Subsidiary of Common Parent [Member]
Subsequent Event [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		81.70%
IPO [Member] \| Limited Partner [Member] \| Westlake Chemical Partners LP [Member] \| Subsidiary of Common Parent [Member]
Subsequent Event [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		43.80%