BASIS OF PRESENTATION (Disclosure of interest in subsidiaries) (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Ternium S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Investments S.à.r.l.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Internacional Espana S.L.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Solutions S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Internationaal B.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium USA Inc.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Argentina S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	62.57%	62.49%	62.46%
Prosid Investments S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	62.58%	62.49%	62.46%
Ternium Mexico S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	89.25%	89.22%	89.21%
Las Encinas S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	89.25%	89.22%	89.21%
Ferropak Comercial S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	89.25%	89.22%	89.21%
Transamerica E. & I. Trading Corp.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	89.25%	89.22%	89.21%
Galvacer Chile S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	89.25%	89.22%	89.21%
Ternium Gas México S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	89.25%	89.22%	89.21%
Consorcio Minero Benito Juarez Peña Colorada S.A.de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	44.62%	44.61%	44.61%
Exiros B.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	50.00%	50.00%	50.00%
Servicios Integrales Nova de Monterrey S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	66.49%	66.47%	66.47%
Ternium Internacional Nicaragua S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	99.38%	99.38%	99.38%
Ternium Internacional Honduras S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	99.18%	99.18%	99.18%
Ternium Internacional El Salvador S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	99.92%	99.92%	99.92%
Ternium Internacional Costa Rica S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	99.98%	99.98%	99.98%
Ternium Internacional Guatemala S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	99.98%	99.98%	99.98%
Ternium Colombia S.A.S
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium del Cauca S.A.S.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium del Atlántico S.A.S
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Procurement S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Brasil Ltda.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Tenigal S. de R.L. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	51.00%	51.00%	51.00%
Soluciones Integrales de Gestión S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Participaçoes S.A. em liquidaçao
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Vientos de Olavarría S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	62.57%	0.00%	0.00%
Ternium Siderurgica de Caldas S.A.S.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	0.00%	100.00%	100.00%
Impeco S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	0.00%	62.49%	62.49%
Hylsa S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	0.00%	0.00%	89.21%
Tecnica Industrial S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	0.00%	0.00%	89.21%
Pena Colorada Servicios S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	0.00%	0.00%	44.61%
Ternium Treasury Services S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	0.00%	0.00%	100.00%
Consorcio Minero Benito Juarez Peña Colorada S.A.de C.V. & Exiros B.V. (9)
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	50.00%
Technology & Engineering Services S.A.
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%	100.00%	100.00%
Ternium Investments S.à.r.l. \| Ternium USA Inc.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary		100.00%
Ternium Investments S.à.r.l. \| Ternium Internacional Espana S.L., Ternium Solutions S.A. and Ternium Internationaal B.V.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Internacional Espana S.L. \| Ternium USA Inc.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Internacional Espana S.L. \| Ternium Argentina S.A.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	62.57%
Ternium Internacional Espana S.L. \| Ternium Brasil Ltda.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Internacional Espana S.L. \| Tenigal S. de R.L. de C.V.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	51.00%
Ternium Internacional Espana S.L. \| Ternium Colombia S.A.S., Ternium del Cauca S.A.S., Ternium Siderúrgica de Caldas S.A.S., Ternium del Atlántico S.A.S, Ternium Procurement S.A. , & Technology & Engineering Services S.A.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Argentina S.A. and Ternium Procurement S.A. \| Prosid Investments S.A.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Argentina S.A. and Ternium Internacional Espana S.L.U. \| Ternium Mexico S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Mexico S.A. de C.V. \| Servicios Integrales Nova de Monterrey S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	74.50%
Ternium Mexico S.A. de C.V. \| Las Encinas S.A. de C.V., Ferropak Comercial S.A. de C.V., Transamerica E. & I. Trading Corp. & Galvacer Chile S.A.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Mexico S.A. de C.V and Tenigal S. de R.L. de C.V. \| Ternium Gas Mexico S.A. de C.V.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Internacional España S.L. and Ternium Mexico S.A. de C.V. \| Ternium Internacional Guatemala S.A.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Investments S.a.r.l & Ternium Internacional Espana S.L. \| Soluciones Integrales de Gestión S.A. and Ternium Participaçoes S.A.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%
Ternium Argentina S.A. \| Vientos de Olavarría S.A.
Disclosure of subsidiaries [line items]
Proportion of voting rights held in subsidiary	100.00%