Accounts and other receivables, net - Components of Accounts and Other Receivables (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Trade accounts receivable: | ||
| VAT and other receivables | $ 36.8 | $ 32.7 |
| Refundable income taxes | 1.3 | 1.9 |
| Allowance for doubtful accounts | (3.7) | (3.9) |
| Total | 434.2 | 318.9 |
| Income taxes | Contran | ||
| Trade accounts receivable: | ||
| Receivables from affiliates | 5.0 | 2.4 |
| Trade items | Contran | ||
| Trade accounts receivable: | ||
| Receivables from affiliates | 0.1 | 0.1 |
| Trade items | Other | ||
| Trade accounts receivable: | ||
| Receivables from affiliates | 0.6 | 0.6 |
| Kronos | Trade accounts receivable | ||
| Trade accounts receivable: | ||
| Trade Accounts receivable | 373.4 | 270.7 |
| CompX | Trade accounts receivable | ||
| Trade accounts receivable: | ||
| Trade Accounts receivable | 19.6 | 13.8 |
| BMI/LandWell | Trade accounts receivable | ||
| Trade accounts receivable: | ||
| Trade Accounts receivable | $ 1.1 | $ 0.6 |