Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted	35,194,545	32,345,398
Net sales—Westlake	$ 214,828	$ 257,040
Total net sales	250,549	299,086
Cost of sales	147,001	208,432
Gross profit	103,548	90,654
Selling, general and administrative expenses	6,196	6,973
Income from operations	97,352	83,681
Other income (expense)
Interest expense—Westlake	(3,950)	(5,900)
Other income, net	585	815
Income before income taxes	93,987	78,596
Income tax provision	217	200
Net income	93,770	78,396
Less: Net income attributable to noncontrolling interest in OpCo	76,023	63,441
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 17,747	$ 14,955
Common units [Member]
Weighted Average Number of Limited Partnership and General Partnership Unit Outstanding, Basic and Diluted	35,194,545	32,345,398
Other income (expense)
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 17,747	$ 14,955
Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax	$ 0.50	$ 0.46
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	18,223,168
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
Product and Service, Other [Member]
Total net sales	$ 35,721	$ 42,046