v3.26.1
Net sales by product - Segment information (Details) - BRL (R$)
R$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Disclosure of operating segments [line items]      
Net sales R$ 10,968,416 R$ 11,552,921  
Adjusted EBITDA   4,865,774  
Profit (loss) from operating activities 1,775,136 2,259,035  
Gross profit 3,160,840 3,823,754  
Depreciation, depletion and amortization 2,806,652 2,497,422  
Adjustments to EBITDA R$ (1,643) 109,317  
Pulp      
Disclosure of operating segments [line items]      
Adjusted EBITDA   4,254,146  
Information about major customers 12.35   11.05
Paper      
Disclosure of operating segments [line items]      
Adjusted EBITDA   611,628  
Information about major customers 11.70   12.45
Total of products      
Disclosure of operating segments [line items]      
Net sales R$ 10,968,416 11,552,921  
Market pulp (1)      
Disclosure of operating segments [line items]      
Net sales 8,345,742 8,611,543  
Printing and writing paper (2)      
Disclosure of operating segments [line items]      
Net sales 1,770,639 1,879,301  
Paperboard      
Disclosure of operating segments [line items]      
Net sales 843,550 1,051,768  
Other      
Disclosure of operating segments [line items]      
Net sales R$ 8,485 R$ 10,309  
Fluff pulp      
Disclosure of operating segments [line items]      
Percentage of entity's revenue 0.50% 0.70%  
Tissue      
Disclosure of operating segments [line items]      
Percentage of entity's revenue 6.10% 5.80%