Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net sales - Westlake	$ 937,625	$ 1,074,957	$ 973,081
Total net sales	1,091,871	1,285,622	1,172,981
Cost of sales	712,443	908,463	769,314
Gross profit	379,428	377,159	403,667
Selling, general and administrative expenses	29,278	27,590	29,260
Income from operations	350,150	349,569	374,407
Other income (expense)
Interest expense—Westlake	(19,623)	(21,433)	(21,861)
Other income, net	3,096	2,457	1,792
Income before income taxes	333,623	330,593	354,338
Provision for income taxes	728	22	1,280
Net income	332,895	330,571	353,058
Less: Net income attributable to noncontrolling interest in OpCo	271,914	281,224	304,388
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 60,981	$ 49,347	$ 48,670
Weighted average limited partner units outstanding (basic and diluted)
Weighted Average Number of Shares Outstanding, Basic and Diluted	34,488,058	32,240,858	28,392,470
Common units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 60,981	$ 48,614	$ 38,010
Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax	$ 1.77	$ 1.51	$ 1.72
Weighted average limited partner units outstanding (basic and diluted)
Weighted Average Number of Shares Outstanding, Basic and Diluted	34,488,058	32,240,858	22,101,547
Subordinated units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income			$ 8,994
Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax	$ 0	$ 0	$ 1.43
Weighted average limited partner units outstanding (basic and diluted)
Weighted Average Number of Shares Outstanding, Basic and Diluted			6,290,923
Public [Member] | Common units [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted Average Number of Shares Outstanding, Basic and Diluted	20,365,828	18,118,628	14,270,240
Westlake [Member] | Common units [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted Average Number of Shares Outstanding, Basic and Diluted	14,122,230	14,122,230	7,831,307
Westlake [Member] | Subordinated units [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted Average Number of Shares Outstanding, Basic and Diluted	0	0	6,290,923
Product and Service, Other [Member]
Total net sales	$ 154,246	$ 210,665	$ 199,900