v3.26.1
DEFERRED INCOME TAX (Changes in Deferred Tax Assets and Liabilities) (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance $ 1,105,691 $ 1,542,565  
Translation differences 124,790 (263,349)  
Credits (Charges) directly to OCI (9,579) 57,867  
Recognition of previously unrecognized tax losses 0 25,438  
Write-down of deferred tax assets (427,835) 0 $ 0
Income statement credit (charge) 221,834 (256,830)  
Deferred tax assets, ending balance 1,014,901 1,105,691 1,542,565
Usinas Siderúrgicas de Minas Gerais S.A.      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Unused tax credits for which no deferred tax asset recognised 338,100 8,000  
Unused tax losses for which no deferred tax asset recognised 379,100 287,600  
Unused tax credits for which no deferred tax asset recognised 338,100 8,000  
Unused tax losses for which no deferred tax asset recognised 379,100 287,600  
Ternium Brasil Ltda.      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Unused tax losses for which no deferred tax asset recognised 843,700 688,400  
Unused tax losses for which no deferred tax asset recognised 843,700 688,400  
Ternium Brasil Ltda. And Usinas Siderúrgicas de Minas Gerais S.A.      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets recognized on unused tax losses 322,000 314,100  
Deferred tax assets recognized on unused tax losses 322,000 314,100  
Ternium S.A.      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Unused tax losses for which no deferred tax asset recognised   2,200,000 2,200,000
Estimated tax loss $ 26,400 $ 26,700  
Unused tax losses generated from prior period 0.90 0.92  
Unused tax losses for which no deferred tax asset recognised   $ 2,200,000 2,200,000
Ternium Investments S.à r.l.      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Unused tax losses for which no deferred tax asset recognised   $ 2,500,000 2,600,000
Unused tax losses generated from prior period 0.98 0.98  
Estimated tax result $ 23,400 $ 7,800  
Unused tax losses for which no deferred tax asset recognised   2,500,000 2,600,000
Property, pland and equipment      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance 130,338 323,538  
Translation differences 41,131 (81,642)  
Write-down of deferred tax assets (217,205)    
Income statement credit (charge) 163,092 (111,558)  
Deferred tax assets, ending balance 117,356 130,338 323,538
Inventories      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance   17,831  
Deferred tax liability, beginning balance (37,913)    
Translation differences 3,333 (15,440)  
Write-down of deferred tax assets (7,582)    
Income statement credit (charge) 9,311 (40,304)  
Deferred tax liability, ending balance (32,851) (37,913)  
Deferred tax assets, ending balance     17,831
Intangible assets      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance 152,401 134,328  
Translation differences 19,378 (34,905)  
Write-down of deferred tax assets (10,240)    
Income statement credit (charge) 19,191 52,978  
Deferred tax assets, ending balance 180,730 152,401 134,328
Provisions      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance 267,268 354,097  
Translation differences 25,880 (48,805)  
Write-down of deferred tax assets (123,027)    
Income statement credit (charge) (37,655) (38,024)  
Deferred tax assets, ending balance 132,466 267,268 354,097
Trade receivables      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance 41,308 42,674  
Translation differences 3,337 (5,608)  
Write-down of deferred tax assets (5,818)    
Income statement credit (charge) (7,107) 4,242  
Deferred tax assets, ending balance 31,720 41,308 42,674
Tax losses      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance 314,060 382,971  
Translation differences 27,855 (65,362)  
Recognition of previously unrecognized tax losses   25,438  
Write-down of deferred tax assets (63,963)    
Income statement credit (charge) 43,999 (28,987)  
Deferred tax assets, ending balance 321,951 314,060 382,971
Other      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax assets, beginning balance 238,229 287,126  
Translation differences 3,876 (11,587)  
Credits (Charges) directly to OCI (9,579) 57,867  
Recognition of previously unrecognized tax losses   0  
Write-down of deferred tax assets 0    
Income statement credit (charge) 31,003 (95,177)  
Deferred tax assets, ending balance $ 263,529 $ 238,229 $ 287,126