v3.25.4
SCOPE OF CONSOLIDATION - Associates Narrative (Details) - Vallourec
€ / shares in Units, € in Millions, tonne in Millions, $ in Millions
12 Months Ended
Aug. 06, 2024
EUR (€)
board_member
€ / shares
shares
Aug. 06, 2024
USD ($)
Dec. 31, 2025
USD ($)
tonne
Disclosure of associates [line items]      
Shares acquired in associate held by entity (in shares) | shares 65,243,206    
Percentage of voting equity interests acquired 28.40%   27.85%
Par value per share (in eur per share) | € / shares € 14.64    
Purchase of interests in associates € 960 $ 1,048  
Number of board members | board_member 11    
ArcelorMittal appointed board members | board_member 2    
Percentage of rolling capacity     0.85
Capacity of rolled products | tonne     2.2
Fair value of investments in associates for which there are quoted market prices | $     $ 1,203
Forward contract      
Disclosure of associates [line items]      
Increase (decrease) in fair value measurement, assets | $   $ 83