Related Party Transactions (Debt Payable to Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Related Party Transaction [Line Items]
Interest expense—Westlake	$ 5,537	$ 6,581
Affiliated Entity \| Westlake
Related Party Transaction [Line Items]
Interest expense—Westlake	5,537	$ 6,581
Long-term debt payable to Westlake	399,674		$ 399,674
Affiliated Entity \| Westlake \| Accrued Liabilities
Related Party Transaction [Line Items]
Accrued interest on related party debt	$ 5,617		$ 5,848

Amount of interest expense classified as nonoperating.

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