Business and geographic segments - Depreciation and Amortization (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Business and geographic segments | |||
| Depreciation and amortization | $ 66.4 | $ 66.7 | $ 54.1 |
| Operating Segment | |||
| Business and geographic segments | |||
| Depreciation and amortization | 66.4 | 66.7 | 54.1 |
| Chemicals | Operating Segment | |||
| Business and geographic segments | |||
| Depreciation and amortization | 62.7 | 62.9 | 49.9 |
| Component products | Operating Segment | |||
| Business and geographic segments | |||
| Depreciation and amortization | $ 3.7 | 3.7 | 4.0 |
| Real estate management and development | Operating Segment | |||
| Business and geographic segments | |||
| Depreciation and amortization | $ 0.1 | $ 0.2 | |