v3.26.1
Segment information - Differences between segment profit and the amounts included in net income (loss) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Number of reportable segments not disclosed     true  
Net sales $ 43,614 $ 40,366 $ 84,183 $ 80,638
Segment profit 12,353 1,011 18,919 2,310
Corporate expense 2,788 3,519 5,731 6,240
Equity in earnings (losses) of Kronos Worldwide, Inc. 4,644 (2,811) 3,167 2,714
Interest and dividend income 1,144 1,504 2,396 3,542
Marketable equity securities 443 (108) 3,138 (8,659)
Other components of net periodic pension and OPEB cost   (285)   (570)
Interest expense (11) (90) (22) (666)
Income tax benefit (expense) (2,462) 43 (3,934) 66
Net income 9,891 1,054 14,985 2,376
Single reportable segment        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Net sales 43,614 40,366 84,183 80,638
Segment profit 8,921 6,320 15,971 12,189
Corporate expense (2,788) (3,519) (5,731) (6,240)
Equity in earnings (losses) of Kronos Worldwide, Inc. 4,644 (2,811) 3,167 2,714
Interest and dividend income 1,144 1,504 2,396 3,542
Marketable equity securities 443 (108) 3,138 (8,659)
Other components of net periodic pension and OPEB cost   (285)   (570)
Interest expense (11) (90) (22) (666)
Income tax benefit (expense) (2,462) 43 (3,934) 66
Net income $ 9,891 $ 1,054 $ 14,985 $ 2,376