v3.26.1
Events after the reporting period (Details)
 6 Months Ended 12 Months Ended
Jul. 01, 2026
BRL (R$)
Jun. 30, 2026
BRL (R$)
Dec. 31, 2025
BRL (R$)
Jun. 05, 2025
USD ($)
Jun. 05, 2025
BRL (R$)
Disclosure of non-adjusting events after reporting period [line items]          
Acquisition-related costs for transaction recognised separately from acquisition of assets and assumption of liabilities in business combination   R$ 59,211,000 R$ 82,426,000    
FamPro Tissue Holdings B.V.          
Disclosure of non-adjusting events after reporting period [line items]          
Acquired in subsidiary 51.00%        
Revenue of combined entity as if combination occurred at beginning of period   8,468,000      
Profit (loss) of combined entity as if combination occurred at beginning of period   R$ 228,000      
Kimberly Clark Tissue Acquisition          
Disclosure of non-adjusting events after reporting period [line items]          
Purchase price of acquired ownership interest, cash consideration | $       $ 1,734,000,000  
Consideration transferred       $ 1,293,000,000 R$ 6,693,000,000
Non-Adjusting Events After Reporting Period          
Disclosure of non-adjusting events after reporting period [line items]          
Acquisition-related costs for transaction recognised separately from acquisition of assets and assumption of liabilities in business combination R$ 141,637,000        
Non-Adjusting Events After Reporting Period | FamPro Tissue Holdings B.V.          
Disclosure of non-adjusting events after reporting period [line items]          
Acquired in subsidiary 51.00%        
Percentage of ownership not acquired 49.00%