v3.26.1
Net sales by product - Segment information (Details) - BRL (R$)
R$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disclosure of operating segments [line items]          
Net sales R$ 11,590,133   R$ 13,295,895 R$ 22,558,549 R$ 24,848,816
Adjusted EBITDA       9,284,751 10,953,192
Profit (loss) from operating activities 2,788,631   2,875,144 4,563,767 5,134,179
Gross profit R$ 2,828,668   R$ 4,687,771 5,989,508 8,511,525
Depreciation, depletion and amortization       5,939,254 5,336,686
Adjustments to EBITDA       (1,218,270) 482,327
Pulp          
Disclosure of operating segments [line items]          
Adjusted EBITDA       8,240,312 9,632,109
Information about major customers 12.25 11.05      
Paper          
Disclosure of operating segments [line items]          
Adjusted EBITDA       1,044,439 1,321,083
Information about major customers 12.36 12.45      
Total of products          
Disclosure of operating segments [line items]          
Net sales       22,558,549 24,848,816
Market pulp (1)          
Disclosure of operating segments [line items]          
Net sales       17,101,601 18,899,505
Printing and writing paper (2)          
Disclosure of operating segments [line items]          
Net sales       3,691,432 3,912,113
Paperboard          
Disclosure of operating segments [line items]          
Net sales       1,748,983 2,017,848
Other          
Disclosure of operating segments [line items]          
Net sales       R$ 16,533 R$ 19,350
Fluff pulp          
Disclosure of operating segments [line items]          
Percentage of entity's revenue       0.60% 0.70%
Tissue          
Disclosure of operating segments [line items]          
Percentage of entity's revenue       6.30% 5.60%