v3.26.1
Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt payable to Westlake, fair value $ 409,399 $ 408,780
Westlake | Affiliated Entity    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt payable to Westlake $ 399,674 $ 399,674