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Supplemental Information (Cash Flow Information) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Related Party Transaction [Line Items] |  |  |
Capital expenditures incurred but not yet paid | $ 3,243 | $ 9,863 | $ 7,809
Interest paid | 23,237 | 26,528 | 24,537
Income taxes paid | 873 | 831 | 827
Right-of-use assets obtained in exchange for operating lease obligations | 920 | 758 | 5,079
Reimbursement to Parent for State Tax | Westlake | Affiliated Entity |  |  |
Related Party Transaction [Line Items] |  |  |
Income taxes paid | 333 | 351 | 347
State and Local Jurisdiction |  |  |
Related Party Transaction [Line Items] |  |  |
Income taxes paid | $ 540 | $ 480 | $ 480

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