Portion of the carrying amount as of the balance sheet date of obligations due all related parties that is payable after one year or beyond the normal operating cycle if longer.

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Related Party Transactions (Debt Payable to Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Interest on related party debt payable	$ 3,431	$ 5,125	$ 7,381	$ 11,025
Accrued interest on related party debt	3,431		3,431		$ 4,187
Long-term debt payable to Westlake	399,674		399,674		399,674
Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Interest capitalized	0
Other income (expense) [Member] \| Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Interest on related party debt payable	3,431	$ 5,125
Accrued Liabilities [Member] \| Affiliated Entity [Member] \| Westlake [Member]
Related Party Transaction [Line Items]
Accrued interest on related party debt	$ 3,431		$ 3,431		$ 4,187