v3.25.4
Earnings Per Common Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Numerator for basic and diluted earnings per common share:    
Net income attributable to L.B. Foster Company $ 7,545 $ 42,946
Denominator:    
Weighted average shares outstanding (in shares) 10,374 10,721
Denominator for basic earnings per common share (in shares) 10,374 10,721
Effect of dilutive securities:    
Stock compensation plans (in shares) 508 327
Dilutive potential common shares (in shares) 508 327
Denominator for diluted earnings per common share - adjusted weighted average shares outstanding and assumed conversions (in shares) 10,882 11,048
Basic earnings per common share (in usd per share) $ 0.73 $ 4.01
Diluted earnings per common share (in usd per share) $ 0.69 $ 3.89