v3.26.1
II. ACCOUNTING POLICIES (Details Textual)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
Subsidiaries
$ / shares
shares
Dec. 31, 2025
USD ($)
Subsidiaries
$ / shares
shares
Dec. 31, 2024
USD ($)
$ / shares
shares
Dec. 31, 2023
USD ($)
$ / shares
shares
Dec. 31, 2017
May 06, 2025
$ / shares
shares
Jul. 03, 2023
shares
Jul. 03, 2023
$ / shares
Jul. 03, 2023
Jul. 03, 2023
Officers
Jul. 03, 2023
Directors
Jul. 03, 2023
d
Disclosure of associates [line items]                        
Minimum applicable tax rate   15.00%                    
Number of subsidiaries acquired | Subsidiaries 2 2                    
Forecast period of revenue projections   3 years                    
Number of major business segments 1 1                    
Total intangible assets and goodwill $ 1,357,116 $ 1,357,116 $ 1,357,749 $ 1,377,110                
Research and development expense   $ 64,200 $ 74,200 $ 60,000                
Number of shares authorised (in shares) | shares 2,500,000,000 2,500,000,000 2,500,000,000 2,500,000,000                
Par value per share (in dollars per share) | $ / shares $ 1 $ 1 $ 1 $ 1   $ 1            
Total number of shares issued (in shares) | shares 1,071,994,930 1,071,994,930 1,162,757,528 1,180,536,830   1,162,757,528            
Number of votes, per share 1 1 1 1                
Employee benefits, unit vesting period (Year)         4 years              
Employee benefits, company redemption period (Year)   7 years     10 years              
Employee benefits, early redemption period (Year)         7 years              
Dilutive effect of share options on number of ordinary shares (in shares) | shares   0                    
Maximum period of lease term of short term leases   12 months                    
Forecast period of cash flow projections   5 years                    
Nominal growth rate 2.00% 2.00%                    
Maximum maturity period of fair value through other comprehensive income instruments for short-term nature   12 months                    
Other current benefits $ 377,088 $ 377,088 $ 585,775                  
Pillar two legislation description Tenaris applies the IAS 12 exception regarding the recognition and disclosure of deferred tax assets and liabilities related to Pillar Two income taxes. Tenaris applies the exception regarding the recognition and disclosure of deferred tax assets and liabilities related to Pillar Two income taxes                    
Employee retention and long-term incentive program (“the Program”) [Member]                        
Disclosure of associates [line items]                        
Carrying value of units granted $ 181,000 $ 181,000 175,000                  
Other current Non-current benefits 154,400 154,400 148,000                  
Other current benefits 50,700 50,700 46,800                  
Information system projects [member]                        
Disclosure of associates [line items]                        
Total intangible assets and goodwill 104,478 104,478 97,106 $ 72,165                
Licenses, patents, trademarks, and proprietary technology [member]                        
Disclosure of associates [line items]                        
Total intangible assets and goodwill 86,700 86,700 86,700 86,700                
Customer-related intangible assets [member]                        
Disclosure of associates [line items]                        
Total intangible assets and goodwill $ 11,328 $ 47,906                
Customer-related intangible assets [member] | Maverick Tube Corporation [member]                        
Disclosure of associates [line items]                        
Intangible assets other than goodwill, useful life (Year)   14 years                    
Customer-related intangible assets [member] | Hydrill Company [member]                        
Disclosure of associates [line items]                        
Intangible assets other than goodwill, useful life (Year)   10 years                    
Customer-related intangible assets [member] | SAUDI STEEL PIPE CO. and subsidiaries [Member]                        
Disclosure of associates [line items]                        
Intangible assets other than goodwill, useful life (Year)   9 years                    
Customer-related intangible assets [member] | Ipsco Tubulars Inc [Member]                        
Disclosure of associates [line items]                        
Intangible assets other than goodwill, useful life (Year)   3 years                    
Customer-related intangible assets [member] | Mattrs Pipe Coating Business Unit [Member]                        
Disclosure of associates [line items]                        
Intangible assets other than goodwill, useful life (Year)   4 months                    
Top of range [member]                        
Disclosure of associates [line items]                        
Percentage of voting rights held in unconsolidated entities 50.00% 50.00%                    
Top of range [member] | Information system projects [member]                        
Disclosure of associates [line items]                        
Intangible assets other than goodwill, useful life (Year)   3 years                    
Top of range [member] | Licenses, patents, trademarks, and proprietary technology [member]                        
Disclosure of associates [line items]                        
Finite-lived intangible asset, residual useful life (Year)   30 years                    
Bottom of range [member]                        
Disclosure of associates [line items]                        
Percentage of voting rights held in unconsolidated entities 20.00% 20.00%                    
Bottom of range [member] | Licenses, patents, trademarks, and proprietary technology [member]                        
Disclosure of associates [line items]                        
Finite-lived intangible asset, residual useful life (Year)   3 years                    
Bottom of range [member] | Customer-related intangible assets [member] | SAUDI STEEL PIPE CO. and subsidiaries [Member]                        
Disclosure of associates [line items]                        
Intangible assets other than goodwill, useful life (Year)   7 years                    
Usiminas [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Shares bound to SHA (in shares) | shares 483,600,000 483,600,000                    
Percent of company voting capital 68.60% 68.60%                    
T/T Group [member]                        
Disclosure of associates [line items]                        
Percent of company voting capital 92.90% 92.90%                    
T/T Group [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Percent of company voting capital 61.30% 61.30%                    
Ternium entitites [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Percent of company voting capital 51.50% 51.50%                    
Confab [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Percent of company voting capital 9.80% 9.80%                    
NSSMC [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Percent of company voting capital 31.70% 31.70%                    
Previdencia Usiminas [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Percent of company voting capital 7.10% 7.10%                    
Tenaris [member]                        
Disclosure of associates [line items]                        
Percent of company voting capital 50.00% 50.00%                    
Preference shares [member] | Usiminas [member]                        
Disclosure of associates [line items]                        
Number of shares subscribed to (in shares) | shares 1,300,000 1,300,000                    
Ordinary shares [member] | Usiminas [member]                        
Disclosure of associates [line items]                        
Number of shares subscribed to (in shares) | shares 47,500,000 47,500,000                    
Usiminas [member]                        
Disclosure of associates [line items]                        
Proportion of voting rights held in associate   6.76% 6.76%                  
Ternium S.A. [member]                        
Disclosure of associates [line items]                        
Proportion of voting rights held in associate   11.70% 11.70%                  
Percentage of Outstanding Shares in Associate 11.70% 11.70%                    
Major purchases of assets [member] | Usiminas [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Majority percentage of control group shares                 55.00%      
Major purchases of assets [member] | Usiminas [member] | T/T Group [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Number of Board members can be appointed through the shareholders agreement | Officers                   4    
Major purchases of assets [member] | Usiminas [member] | Tenaris [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Number of Board members can be appointed through the shareholders agreement                   1 1  
Major purchases of assets [member] | Usiminas [member] | Ordinary shares [member] | T/T Group [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Thresold number of trading days immediately prior to date of exercising option | d                       40
Major purchases of assets [member] | Usiminas [member] | Ordinary shares [member] | T/T Group [member] | The new SHA [member] | From two years anniversary right to buy [Member]                        
Disclosure of associates [line items]                        
Shares subscribed to, price per share (in BRL per share) | $ / shares               $ 2.0584        
Major purchases of assets [member] | Usiminas [member] | Ordinary shares [member] | NSSMC [member] | The new SHA [member]                        
Disclosure of associates [line items]                        
Number of trading days to calculate moving average share price | d                       40
Major purchases of assets [member] | Usiminas [member] | Ordinary shares [member] | NSSMC [member] | The new SHA [member] | From two years anniversary right to buy [Member]                        
Disclosure of associates [line items]                        
Number of shares right purchase under agreement | shares             153,100,000          
Major purchases of assets [member] | Usiminas [member] | Ordinary shares [member] | NSSMC [member] | The new SHA [member] | From two years anniversary right to sell [Member]                        
Disclosure of associates [line items]                        
Shares subscribed to, price per share (in BRL per share) | $ / shares               $ 2.0584