v3.26.1
Note 33 - Principal subsidiaries (Details Textual)
 6 Months Ended 12 Months Ended
Jun. 30, 2025
Dec. 31, 2025
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   50.00%
SAUDI STEEL PIPE CO. and subsidiaries [Member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   47.79%
Ternium S.A. [member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   11.46%
Tenaris [member]    
Disclosure of subsidiaries [line items]    
Percent of company voting capital   50.00%
Tubular Technical Services and Pipe Coaters [member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   40.00%
Tubulars Finishing Nigeria Limited [member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   49.00%
Amaja Tubular Services Limited [member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary 49.00%  
Tenaris Baogang Baotou Steel Pipes Ltd [member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   60.00%
Global Pipe Company [Member] | SAUDI STEEL PIPE CO. and subsidiaries [Member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   57.30%
Siderca SAIC [Member] | NKKTUBES [member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   51.00%
EXIROS B.V. and subsidiaries [member] | Ternium S.A. [member]    
Disclosure of subsidiaries [line items]    
Percent of company voting capital   50.00%
DALMINE S.p.A. and subsidiaries [member] | Immobiliare Cultura Industriale S.R.L. [member]    
Disclosure of subsidiaries [line items]    
Proportion of ownership interest in subsidiary   57.00%