Description of Business and Basis of Presentation (Policies)	6 Months Ended
Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial Statements	Financial information presented for the periods prior to the IPO on August 4, 2014 consists of the Predecessor's combined results of operations, changes in equity and cash flows. Financial information of the Predecessor is derived from the financial statements and accounting records of Westlake. Subsequent to the IPO, the Partnership's financial position, results of operations, changes in equity and cash flows consist of the consolidated activities and balances of the Partnership. The Partnership's consolidated financial statements include the accounts of the Partnership and its consolidated subsidiary, OpCo. In the opinion of the Partnership's management, the accompanying unaudited combined and consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Predecessor's combined financial statements for the three and six months ended June 30, 2014 and the Partnership's consolidated financial statements as of June 30, 2015 and December 31, 2014, and for the three and six months ended June 30, 2015. Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2015 or any other period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates.

Financial information presented for the periods prior to the IPO on August 4, 2014 consists of the Predecessor's combined results of operations, changes in equity and cash flows. Financial information of the Predecessor is derived from the financial statements and accounting records of Westlake. Subsequent to the IPO, the Partnership's financial position, results of operations, changes in equity and cash flows consist of the consolidated activities and balances of the Partnership. The Partnership's consolidated financial statements include the accounts of the Partnership and its consolidated subsidiary, OpCo.

In the opinion of the Partnership's management, the accompanying unaudited combined and consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Predecessor's combined financial statements for the three and six months ended June 30, 2014 and the Partnership's consolidated financial statements as of June 30, 2015 and December 31, 2014, and for the three and six months ended June 30, 2015.

Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2015 or any other period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates.