Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted	35,194,545	35,188,189	35,194,545	33,774,647
Net sales—Westlake	$ 227,431	$ 230,047	$ 442,259	$ 487,087
Total net sales	238,500	270,062	489,049	569,148
Cost of sales	148,470	178,104	295,471	386,536
Gross profit	90,030	91,958	193,578	182,612
Selling, general and administrative expenses	6,139	7,639	12,335	14,612
Income from operations	83,891	84,319	181,243	168,000
Other income (expense)
Interest expense—Westlake	(3,431)	(5,125)	(7,381)	(11,025)
Other income, net	123	1,153	708	1,968
Income before income taxes	80,583	80,347	174,570	158,943
Income tax provision	206	237	423	437
Net income	80,377	80,110	174,147	158,506
Less: Net income attributable to noncontrolling interest in OpCo	65,517	66,377	141,540	129,818
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 14,860	$ 13,733	$ 32,607	$ 28,688
Common units [Member]
Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted	35,194,545	35,188,189	35,194,545	33,774,647
Other income (expense)
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 14,860	$ 13,733	$ 32,607	$ 28,688
Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax	$ 0.43	$ 0.39	$ 0.93	$ 0.85
Common units [Member] | Publicly and Privately Held [Member]
Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted	21,072,315	21,065,959	21,072,315	19,652,417
Common units [Member] | Westlake [Member]
Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted	14,122,230	14,122,230	14,122,230	14,122,230
Product and Service, Other [Member]
Total net sales	$ 11,069	$ 40,015	$ 46,790	$ 82,061