v3.26.3
EARNINGS PER SHARE (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended 9 Months Ended
Sep. 17, 2026
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Numerator:          
Net income attributable to equity holders of Constellium SE   $ 117 $ 88 $ 462 $ 161
Denominator:          
Basic - weighted-average ordinary shares outstanding (in shares)   134,874,759 138,668,972 135,377,676 140,655,433
Dilutive effect of non-vested restricted stock units and performance-based restricted stock units (in shares)   4,112,443 1,855,669 4,363,335 1,624,424
Diluted - weighted-average ordinary shares, of restricted stock units and performance-based restricted stock units (in shares)   138,987,202 140,524,641 139,741,011 142,279,857
Basic earnings per share (in USD per share)   $ 0.87 $ 0.63 $ 3.41 $ 1.14
Diluted earnings per share (in USD per share)   $ 0.84 $ 0.62 $ 3.31 $ 1.13
Antidilutive securities excluded from computation of earnings per share (in shares)   0 0 0 0
Treasury share cancelled (in shares) 6,000,000