Related Party Transactions (Tables)

3 Months Ended

Mar. 31, 2018

Related Party Transactions [Abstract]

Schedule of Related Party Transactions

The related party accounts payable balances were as follows:

	March 31, 2018		December 31, 2017
Accounts payable—Westlake	$	14,339	$	14,027

Sales to related parties were as follows:

	Three Months Ended March 31,
	2018		2017
Net sales—Westlake	$	235,031	$	212,930

Debt payable to related parties was as follows:

	March 31, 2018		December 31, 2017
Long-term debt payable to Westlake	$	477,608	$	473,960

The Partnership's receivable under the Investment Management Agreement was as follows:

	March 31, 2018		December 31, 2017
Receivable under the Investment Management Agreement	$	134,712	$	136,510

Charges from related parties included within selling, general and administrative expenses were as follows:

	Three Months Ended March 31,
	2018		2017
Services received from Westlake and included in selling, general and administrative    expenses	$	6,251	$	6,732

The Partnership's accounts receivable from Westlake were as follows:

	March 31, 2018		December 31, 2017
Accounts receivable—Westlake	$	43,257	$	43,884

Charges from related parties for goods and services capitalized as assets were as follows:

	Three Months Ended March 31,
	2018		2017
Goods and services purchased from Westlake and capitalized as assets	$	346	$	1,405

Charges from related parties in cost of sales were as follows:

	Three Months Ended March 31,
	2018		2017
Feedstock purchased from Westlake and included in cost of sales	$	105,415	$	97,113
Other charges from Westlake and included in cost of sales	28,406		25,417
Total	$	133,821	$	122,530