v3.26.1
Related Party Transactions (Cost of Sales from Related Parties) (Details) - Affiliated Entity - Westlake - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Feedstock Purchased    
Related Party Transaction [Line Items]    
Charges from related parties in cost of sales $ 97,061 $ 85,499
Other service charges    
Related Party Transaction [Line Items]    
Charges from related parties in cost of sales $ 38,205 $ 31,477