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Related Party Transactions Related Party Transactions (Major Customer and Credit Risk) (Details)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenue Benchmark | Westlake | Customer Concentration Risk | Affiliated Entity
Related Party Transaction [Line Items]
Concentration Risk, Percentage	88.60%	83.70%	86.20%

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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