v3.26.1
CONTINGENCIES, COMMITMENTS AND RESTRICTIONS ON THE DISTRIBUTION OF PROFITS (Commitments: m-ad) (Details)
m³ in Thousands, T in Thousands, $ in Millions
 1 Months Ended 12 Months Ended 132 Months Ended
Dec. 31, 2023
m³
Jun. 30, 2016
MW
Dec. 31, 2025
USD ($)
letter_of_credit
T
Dec. 31, 2006
distributor
MW
Dec. 31, 2025
USD ($)
letter_of_credit
T
Feb. 13, 2019
USD ($)
Mar. 31, 2017
Oct. 15, 2012
Property, plant and equipment | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 108.9   $ 108.9      
24 Distributos (CCEAR) | Electric Power | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term supply commitment, term       15 years        
Number of distributors | distributor       24        
Long-term supply commitment, electric demand | MW       200        
Vale S.A. | Iron Ore, Pellets and Iron Ore Fines | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, total purchased volume | T     8,000          
Primetals Technologies Brazil Ltda. | Maintenance Services | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 135.3   135.3      
Air Liquide Brasil Ltda., AirSteel Ltda., White Martins Gases Industriais Ltda., White Martins Steel Ltda. and ThyssenKrupp MinEnergy GmbH | Industrial Gas | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     97.2   97.2      
GE Global Parts and Products GMBH, General Electric International Inc. and Alstom Energia Térmica e Indústria Ltda. | Turbine Maintenance | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 165.7   165.7      
Long-term purchase commitment, term             20 years  
Long-term purchase commitment, renewal period     4 years          
Vix Logistica S.A. | Logistics Supply Chain Operations | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 32.2   32.2      
Petrobras S.A. | Petcoke | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     20.1   20.1      
Petrobras S.A. | Petcoke | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 6.0   6.0      
Long-term purchase commitment, minimum volume | T     96          
Petrobras S.A. | Natural Gas | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 110.6   110.6      
Petrobras S.A. | Natural Gas | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 346.7   $ 346.7      
Annual take or pay volume     70.00%   70.00%      
LSI Logistica S.A. | Mobile Equipment Rental | Ternium Brasil Ltda.                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 32.8   $ 32.8      
MBL Materiais Básicos Ltda. | Iron Ore | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     346.6   $ 346.6      
Long-term purchase commitment, term               30 years
Long-term purchase commitment, minimum volume | T         3,600      
Cemig S.A. | Electric Power | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     186.8   $ 186.8      
Cemig S.A. | Electric Power | Usiminas | Bottom of range                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, electrical demand | MW   32            
Cemig S.A. | Electric Power | Usiminas | Top of range                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, electrical demand | MW   65.4            
Engie S.A | Electric Power | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     29.4   29.4      
Jaiba O Energias Renovaveis S.A. | Solar Energy | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     280.9   280.9      
Enel S.A | Electric Power | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     30.3   30.3      
Gasmig S.A. | Natural Gas | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 25.5   $ 25.5      
Long-term purchase commitment, contracted daily capacity | m³ 850              
Capacity deviation 10.00%              
Annual take or pay volume     80.00%   80.00%      
National Operator Of The Electric System (ONS) | Transmission System | Usiminas                
Disclosure of contingent liabilities [line items]                
Long-term purchase commitment, amount     $ 28.0   $ 28.0      
Syndicated Loan | Techgen S.A. de C.V.                
Disclosure of contingent liabilities [line items]                
Original principal amount           $ 640.0    
Borrowings outstanding     44.1   44.1      
Ternium S.A. | Syndicated Loan | Techgen S.A. de C.V.                
Disclosure of contingent liabilities [line items]                
Guarantor obligations, outstanding     $ 21.2   $ 21.2      
Ternium S.A. | Syndicated Loan | Techgen S.A. de C.V.                
Disclosure of contingent liabilities [line items]                
Number of stand-by letters of credit | letter_of_credit     2   2      
Guarantor obligations, percentage     48.00%