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Related Party Transactions (Related Party Leases) (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2025 USD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Aug. 04, 2014
Westlake | Affiliated Entity |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating lease expense | $ 1,705,000 | $ 1,843,000 | $ 1,869,000 |
Westlake Chemical OpCo LP | Westlake | Investee | Site Lease Agreement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Site lease agreement, number | 2 |  |  |
Term of operating lease |  |  |  | 50 years
Site lease expense | $ 1 |  |  |

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