Related Party and Affiliate Transactions	12 Months Ended
Related Party and Affiliate Transactions	Dec. 31, 2025
Related Party Transactions [Abstract]
Related Party And Affiliate Transactions	Related Party and Affiliate Transactions The Company and Lotte have a joint venture, LACC, to operate an ethylene facility with 2.2 billion pounds per year of ethylene production capacity. See Note 8 for details of the Company's transactions with LACC. The Company leases two office spaces for management and administrative services from an affiliate of the Company's principal stockholder. For the year ended December 31, 2025, 2024 and 2023, the Company incurred lease payments of approximately $4, $4 and $3, respectively. Cypress Interstate Pipeline L.L.C., a natural gas liquids pipeline joint venture in which the Company owns a 50% equity interest, transports natural gas liquid feedstocks to the Company's Lake Charles complex through its pipeline. The Company accounts for its investments in Cypress Interstate Pipeline L.L.C. under the equity method of accounting. The investment in Cypress Interstate Pipeline L.L.C. at December 31, 2025 and 2024 was $10 and $8, respectively. For the years ended December 31, 2025, 2024 and 2023, the Company incurred pipeline lease service fees of approximately $20, $20 and $20, respectively, payable to this joint venture for usage of the pipeline. The amounts due to this joint venture were $2 and $1 at December 31, 2025 and 2024. The Company owns an approximately 20% equity interest in both YNCORIS GmbH & Co. KG (formerly known as InfraServ Knapsack GmbH & Co. KG) and InfraServ Gendorf GmbH & Co. KG (collectively "Infraserv"). The Company accounts for its investments in Infraserv under the equity method of accounting. The Company has service agreements with these entities, including contracts to provide electricity, technical and leasing services to certain of the Company's production facilities in Germany. The investment in Infraserv was $56 and $52 at December 31, 2025 and 2024, respectively. For the years ended December 31, 2025, 2024 and 2023, the Company incurred charges aggregating approximately $160, $146 and $176, respectively, for these services. The amounts accrued for these related parties were approximately $26 and $23 at December 31, 2025 and 2024, respectively. In conjunction with the Westlake Epoxy acquisition, the Company acquired 49.99% equity interest in Westlake UV Coatings (Shanghai) Co., Ltd. (formerly known as Hexion UV Coatings Co., LTD). The investment in Westlake UV Coatings (Shanghai) Co., Ltd. was $4 and $4 at December 31, 2025 and 2024, respectively. The Company accounts for its investments in Westlake UV Coatings (Shanghai) Co., Ltd. under the equity method of accounting. Dividends received from equity method investments were $16, $20 and $18 for the years ended December 31, 2025, 2024 and 2023, respectively.

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

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WESTLAKE CORP 10-K