v3.26.1
Note 11 - Property, plant and equipment, net (Details Textual) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment, capitalized interest $ 25.6 $ 27.2  
Percentage of ownership interest in subsidiary 50.00%    
CONFAB INDUSTRIAL S.A. and subsidiaries [member] | Companhia Siderúrgica Nacional [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment, pledged as security $ 33.4    
Saudi Arabia | Global Pipe Company [Member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment, pledged as security $ 49.7 $ 147.9  
Saudi Arabia | SAUDI STEEL PIPE CO. and subsidiaries [Member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Percentage of ownership interest in subsidiary [1] 47.79% 48.00% 48.00%
Saudi Arabia | SAUDI STEEL PIPE CO. and subsidiaries [Member] | Global Pipe Company [Member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Proportion of ownership interest in joint venture 57.30%    
[1] All percentages rounded.