Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net sales—Westlake	$ 258,049	$ 193,964	$ 711,968	$ 606,859
Net co-product, ethylene and other sales—third parties	38,726	35,390	152,368	85,940
Total net sales	296,775	229,354	864,336	692,799
Cost of sales	201,372	142,553	571,401	407,203
Gross profit	95,403	86,801	292,935	285,596
Selling, general and administrative expenses	6,805	5,788	21,519	17,733
Income from operations	88,598	81,013	271,416	267,863
Other income (expense)
Interest expense—Westlake	(6,190)	(4,947)	(17,592)	(7,381)
Other income, net	162	(13)	1,844	230
Income before income taxes	82,570	76,053	255,668	260,712
Provision for income taxes	325	194	925	890
Net income	82,245	75,859	254,743	259,822
Less: Net income attributable to noncontrolling interest in OpCo	68,860	67,198	221,619	229,733
Net income attributable to Westlake Chemical Partners LP	$ 13,385	$ 8,661	$ 33,124	$ 30,089
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	27,172,230	27,059,730	27,097,642	27,059,730
Distributions per common unit (usd per share)	$ 0.365	$ 0.3259	$ 1.0649	$ 0.9507
Common units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP	$ 12,887	$ 4,552	$ 23,078	$ 15,909
Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted)
Income per limited partner unit (usd per share)	$ 0.47	$ 0.32	$ 1.23	$ 1.11
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	27,172,230	14,373,615	18,686,701	14,373,615
Common units [Member] | Public [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	13,050,000	12,937,500	12,975,412	12,937,500
Common units [Member] | Westlake [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	14,122,230	1,436,115	5,711,289	1,436,115
Subordinated units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP	$ 0	$ 4,018	$ 8,994	$ 14,041
Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted)
Income per limited partner unit (usd per share)	$ 0.00	$ 0.32	$ 1.07	$ 1.11
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	0	12,686,115	8,410,941	12,686,115
Subordinated units [Member] | Westlake [Member]
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	0	12,686,115	8,410,941	12,686,115