v3.26.1
Segment reporting - Major customers (Details) - USD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of major customers [abstract]      
Sales $ 1,335,121,000 $ 1,643,939,000 $ 1,650,034,000
Top Ten Customers      
Disclosure of major customers [abstract]      
Sales $ 599,501,000 $ 921,029,000 $ 1,322,724,000
Dow Silicones Corporation      
Disclosure of major customers [abstract]      
Percentage of Company's sales 12.30% 16.80% 17.00%
Trade receivables $ 21,663,000 $ 28,109,000