Term Loan	9 Months Ended
Sep. 30, 2016
Debt Disclosure [Abstract]
Term Loan	Term Loan On August 10, 2016, an indirect subsidiary of the Company, Westlake International Holdings II C.V., a limited partnership organized under the laws of the Netherlands (the "CV Borrower"), entered into a credit agreement with Bank of America, N.A., as agent and lender, providing the CV Borrower with a $150,000 term loan facility. The term loan facility matures on March 31, 2017. The loans thereunder bear interest at a floating interest rate equal to LIBOR plus 2.0% per annum, payable in arrears on the last day of each three-month period following the date of funding and at maturity. The CV Borrower may elect to convert the interest rate to a base rate with a 1.0% spread. The interest rate on the outstanding term loan was 2.82% at September 30, 2016. The facility contains customary covenants and events of default that impose certain operating and financial restrictions on the CV Borrower and certain of its subsidiaries. These restrictions, among other things, provide limitations on the incurrence of additional indebtedness and liens and the ability to engage in certain transactions with affiliates. Pursuant to the credit agreement, all of the non-U.S. subsidiaries of the Company are to remain owned, directly or indirectly, by the CV Borrower and its wholly owned subsidiary, Westlake International II LLC, a Delaware limited liability company ("WII LLC"). The CV Borrower is also required, together with its subsidiaries, to maintain at all times unencumbered cash and cash equivalents in a U.S. dollar equivalent of not less than $150,000, which amount shall be increased by 5% to the extent maintained in non-U.S. currencies. In connection therewith, an amount of cash and cash equivalents for the period (a) from the closing date until the date 30 days thereafter, not less than $50,000, and (b) thereafter, not less than $75,000, shall be maintained by the CV Borrower and its subsidiaries in accounts at Bank of America, N.A., in accordance with existing cash management agreements. Obligations under the term loan facility are secured by a pledge of 65% of the membership interests of WII LLC as well as rights under the partnership agreement of Westlake International Holdings C.V., a limited partnership organized under the laws of the Netherlands, held by WII LLC and the CV Borrower.

Term Loan

On August 10, 2016, an indirect subsidiary of the Company, Westlake International Holdings II C.V., a limited partnership organized under the laws of the Netherlands (the "CV Borrower"), entered into a credit agreement with Bank of America, N.A., as agent and lender, providing the CV Borrower with a $150,000 term loan facility. The term loan facility matures on March 31, 2017. The loans thereunder bear interest at a floating interest rate equal to LIBOR plus 2.0% per annum, payable in arrears on the last day of each three-month period following the date of funding and at maturity. The CV Borrower may elect to convert the interest rate to a base rate with a 1.0% spread. The interest rate on the outstanding term loan was 2.82% at September 30, 2016.

The facility contains customary covenants and events of default that impose certain operating and financial restrictions on the CV Borrower and certain of its subsidiaries. These restrictions, among other things, provide limitations on the incurrence of additional indebtedness and liens and the ability to engage in certain transactions with affiliates.

Pursuant to the credit agreement, all of the non-U.S. subsidiaries of the Company are to remain owned, directly or indirectly, by the CV Borrower and its wholly owned subsidiary, Westlake International II LLC, a Delaware limited liability company ("WII LLC"). The CV Borrower is also required, together with its subsidiaries, to maintain at all times unencumbered cash and cash equivalents in a U.S. dollar equivalent of not less than $150,000, which amount shall be increased by 5% to the extent maintained in non-U.S. currencies. In connection therewith, an amount of cash and cash equivalents for the period (a) from the closing date until the date 30 days thereafter, not less than $50,000, and (b) thereafter, not less than $75,000, shall be maintained by the CV Borrower and its subsidiaries in accounts at Bank of America, N.A., in accordance with existing cash management agreements.

Obligations under the term loan facility are secured by a pledge of 65% of the membership interests of WII LLC as well as rights under the partnership agreement of Westlake International Holdings C.V., a limited partnership organized under the laws of the Netherlands, held by WII LLC and the CV Borrower.