Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net sales—Westlake	$ 235,031	$ 212,930
Net co-product, ethylene and other sales—third parties	49,241	64,518
Total net sales	284,272	277,448
Cost of sales	191,767	179,487
Gross profit	92,505	97,961
Selling, general and administrative expenses	7,133	7,828
Income from operations	85,372	90,133
Other income (expense)
Interest expense—Westlake	(4,866)	(5,460)
Other income, net	491	1,658
Income before income taxes	80,997	86,331
Provision for income taxes	283	303
Net income	80,714	86,028
Less: Net income attributable to noncontrolling interest in OpCo	68,419	76,264
Net income attributable to Westlake Chemical Partners LP	$ 12,295	$ 9,764
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	32,236,449	27,059,730
Distributions per common unit (usd per share)	$ 0.3864	$ 0.345
Common units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP	$ 11,562	$ 5,064
Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted)
Income per limited partner unit (usd per share)	$ 0.36	$ 0.35
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)	32,236,449	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)	18,115,036	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
Subordinated units [Member]
Other income (expense)
Net income attributable to Westlake Chemical Partners LP		$ 4,469
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	$ 0.35
Weighted average limited partner units outstanding (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in shares)		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