v3.26.1
Earnings Per Share - Summary of Earnings Per Share (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Numerator (in millions):        
Net income available to Innospec $ 30.8 $ 23.5 $ 61.2 $ 56.3
Denominator (in thousands):        
Weighted average common shares outstanding 24,644 24,937 24,710 24,954
Dilutive effect of stock options and awards 63 105 97 143
Denominator for diluted earnings per share 24,707 25,042 24,807 25,097
Net income per share, basic: $ 1.25 $ 0.94 $ 2.48 $ 2.26
Net income per share, diluted: $ 1.25 $ 0.94 $ 2.47 $ 2.24