v3.26.1
Investments - Investments in Associates and Joint Ventures (Details)
 3 Months Ended 6 Months Ended
Mar. 31, 2026
BRL (R$)
Mar. 31, 2026
BRL (R$)
€ / shares
Mar. 31, 2025
BRL (R$)
Mar. 31, 2025
BRL (R$)
€ / shares
Jun. 30, 2025
Dec. 31, 2025
BRL (R$)
Dec. 31, 2024
BRL (R$)
Disclosure of joint ventures [line items]              
Equity R$ 48,182,731,000 R$ 48,182,731,000 R$ 38,535,646,000 R$ 38,535,646,000   R$ 43,952,173,000 R$ 32,415,575,000
Income (expenses) of the period R$ 4,311,991,000   6,348,178,000        
% 100.00%       100.00%    
In the income (expenses) for the period R$ (20,372,000)   (17,077,000)        
Goodwill 29,384,000 29,384,000       29,384,000  
Total Investments, including Goodwill and Financial Instruments 1,134,258,000 1,134,258,000       1,194,877,000  
Impairment loss (reversal of impairment loss) recognised in profit or loss 88,871,000            
Other Operating Income (Expense) from Disposal of Property, Plant and Equipment and Biological Assets (32,052,000)   46,307,000        
Loss from associates and joint ventures R$ (20,372,000)   (17,077,000)        
Disclosure of Detailed Information About Investment in Associates and Joint Ventures
Information of investees as at
Company Participation
03/31/2026Carrying amountIn the income (expenses) for the period
EquityIncome (expenses) of the periodParticipation equity (%)03/31/202612/31/202503/31/202603/31/2025
Associate
Foreign
Ensyn Corporation (3)
 
(3,091)
Spinnova Plc. (1)
183,627 
(88,538)
18.76 
%
34,449 
54,391 
(16,610)
(9,161)
Simplifyber, Inc.
43,498 
(6,460)
15.52 
%
6,750 
7,973 
(1,004)
Allotrope Energy Ltd
2,636 
19.72 
%
520 
556 
41,719 
62,920 
(17,614)
(12,252)
Joint ventures
Domestic (Brazil)
Biomas - Serviços Ambientais, Restauração e Carbono Ltda.
13,813 
(9,865)
16.66 
%
2,302 
3,945 
(1,644)
(1,449)
Ibema Companhia Brasileira de Papel
393,445 
(2,231)
49.90 
%
196,329 
197,442 
(1,114)
3,551 
Foreign
Woodspin Oy (2)
 
 
 
(6,927)
198,631 
201,387 
(2,758)
(4,825)
Other investments evaluated at fair value through other comprehensive income
Bem Agro Integração e Desenvolvimento S.A.
4.58 
%
3,396 
3,581 
 
Celluforce Inc.
8.28 
%
24,178 
25,975 
Nfinite Nanotechnology Inc.
5.40 
%
5,350 
5,639 
 
Lenzing Aktiengesellschaft
15.00 
%
831,600 
865,986 
 
864,524 
901,181 
 
 
Goodwill (2)(3)
29,384 
29,389 
29,384 
29,389 
 
1,134,258 
1,194,877 
(20,372)
(17,077)
(1)The average share price quoted on the Nasdaq First North Growth Market (NFNGM) was EUR0.42 on March 31, 2026 and EUR0.46 on December 31, 2025.
(2)In August 2025, the Company completed the sale of its entire equity interest in Woodspin Oy and Suzano Finland Oy to Spinnova Plc for the symbolic amount of 1 euro each. For the year ended December 31, 2025, as a result of this transaction, the following accounting effects were recognized, which significantly impacted the equity pickup line: R$ (117,447) related to the impairment of the investment, R$ (28,679) related to the obligation to make an additional capital contribution, and R$ 15,636 related to the realization of other comprehensive income of the joint venture Woodspin Oy; R$ (63,634) related to the write-off of goodwill of the associate Spinnova Plc; and R$ (88,871) related to the impairment of the investment in the subsidiary Suzano Finland Oy.
(3)In November 2025, the Company sold its entire equity interest in Ensyn Corporation, liquidated F&E Technologies LLC, and recognized impairment of the investment in F&E Tecnologia do Brasil S.A., both related to the same technology developed by Ensyn. As of December 31, 2025, as a result of this transaction, the following accounting effects were recognized, which impacted the equity pickup line: (i) R$ (160,462) related to the write-off of Ensyn goodwill; R$ 371 related to the recognition of the provision for losses on investments; and R$$9,896 related to the reclassification of other comprehensive income.
            
Associate | Foreign countries              
Disclosure of joint ventures [line items]              
Investments Accounted for Using Equity Method, Excluding Goodwill R$ 41,719,000 41,719,000       62,920,000  
In the income (expenses) for the period (17,614,000)   (12,252,000)        
Ensyn Corporation              
Disclosure of joint ventures [line items]              
Realization of exchange variation on investments abroad 9,896,000            
Loss from associates and joint ventures (160,462,000)            
Provision for losses on investments R$ 371,000 371,000          
Ensyn Corporation | Foreign countries              
Disclosure of joint ventures [line items]              
Participation equity (%)            
Investments Accounted for Using Equity Method, Excluding Goodwill        
In the income (expenses) for the period   (3,091,000)        
Spinnova Plc              
Disclosure of joint ventures [line items]              
Impairment loss (reversal of impairment loss) recognised in profit or loss (63,634,000)            
Spinnova Plc | Component Of Other Operating Expenses Related To SPA ClosingConditions              
Disclosure of joint ventures [line items]              
Other Operating Income (Expense) from Disposal of Property, Plant and Equipment and Biological Assets R$ (28,679,000)            
Spinnova Plc | Foreign countries              
Disclosure of joint ventures [line items]              
Participation equity (%) 18.76%            
Investments Accounted for Using Equity Method, Excluding Goodwill R$ 34,449,000 34,449,000       54,391,000  
In the income (expenses) for the period R$ (16,610,000)   (9,161,000)        
Simplifyber, Inc. (Indirect) | Foreign countries              
Disclosure of joint ventures [line items]              
Participation equity (%) 15.52%            
Investments Accounted for Using Equity Method, Excluding Goodwill R$ 6,750,000 6,750,000       7,973,000  
In the income (expenses) for the period R$ (1,004,000)          
Allotrope Energy Ltd | Foreign countries              
Disclosure of joint ventures [line items]              
Participation equity (%) 19.72%            
Investments Accounted for Using Equity Method, Excluding Goodwill R$ 520,000 520,000       556,000  
Joint ventures              
Disclosure of joint ventures [line items]              
Investments Accounted for Using Equity Method, Excluding Goodwill 198,631,000 198,631,000       201,387,000  
In the income (expenses) for the period R$ (2,758,000)   (4,825,000)        
Biomas | Country of domicile              
Disclosure of joint ventures [line items]              
Participation equity (%) 16.66%            
Investments Accounted for Using Equity Method, Excluding Goodwill R$ 2,302,000 2,302,000       3,945,000  
In the income (expenses) for the period R$ (1,644,000)   (1,449,000)        
Ibema Companhia Brasileira de Papel | Country of domicile              
Disclosure of joint ventures [line items]              
Participation equity (%) 49.90%            
Investments Accounted for Using Equity Method, Excluding Goodwill R$ 196,329,000 196,329,000       197,442,000  
In the income (expenses) for the period (1,114,000)   3,551,000        
Woodspin Oy              
Disclosure of joint ventures [line items]              
Share Of Profit Loss Of Investments Accounted For Using Equity Method (117,447,000)            
Realization of exchange variation on investments abroad R$ 15,636            
Woodspin Oy | Foreign countries              
Disclosure of joint ventures [line items]              
Participation equity (%)            
Investments Accounted for Using Equity Method, Excluding Goodwill        
In the income (expenses) for the period   (6,927,000)        
Total other investments evaluated at fair value              
Disclosure of joint ventures [line items]              
In the income (expenses) for the period          
Non-current financial assets at fair value through other comprehensive income R$ 864,524,000 864,524,000       901,181,000  
Bem Agro Integração e Desenvolvimento S.A. (Indirect)              
Disclosure of joint ventures [line items]              
% 4.58%            
Bem Agro Integração e Desenvolvimento S.A. (Indirect) | Country of domicile              
Disclosure of joint ventures [line items]              
Non-current financial assets at fair value through other comprehensive income R$ 3,396,000 3,396,000       3,581,000  
Celluforce Inc. (Direct)              
Disclosure of joint ventures [line items]              
% 8.28%            
Celluforce Inc. (Direct) | Foreign countries              
Disclosure of joint ventures [line items]              
Non-current financial assets at fair value through other comprehensive income R$ 24,178,000 24,178,000       25,975,000  
Nfinite Nanotechnology Inc. (Indirect)              
Disclosure of joint ventures [line items]              
% 5.40%            
Nfinite Nanotechnology Inc. (Indirect) | Foreign countries              
Disclosure of joint ventures [line items]              
Non-current financial assets at fair value through other comprehensive income R$ 5,350,000 5,350,000       5,639,000  
Lenzing Aktiengesellschaft (Indirect)              
Disclosure of joint ventures [line items]              
% 15.00%            
Lenzing Aktiengesellschaft (Indirect) | Foreign countries | Level 1              
Disclosure of joint ventures [line items]              
Non-current financial assets at fair value through other comprehensive income R$ 831,600,000 831,600,000       865,986,000  
Suzano Ventures e Suzano S/A              
Disclosure of joint ventures [line items]              
Goodwill 29,384,000 29,384,000       29,389,000  
Impairment loss (reversal of impairment loss) recognised in profit or loss            
Total Goodwill              
Disclosure of joint ventures [line items]              
Goodwill 29,384,000 29,384,000       R$ 29,389,000  
Impairment loss (reversal of impairment loss) recognised in profit or loss            
Ensyn Corporation              
Disclosure of joint ventures [line items]              
Equity          
Income (expenses) of the period            
Spinnova Plc              
Disclosure of joint ventures [line items]              
Equity 183,627,000 R$ 183,627,000          
Income (expenses) of the period (88,538,000)            
NASDAQ, Nordic Growth Market, Average Share Price | € / shares   R$ 0.42   R$ 0.46      
Simplifyber, Inc. (Indirect)              
Disclosure of joint ventures [line items]              
Equity 43,498,000 R$ 43,498,000          
Income (expenses) of the period (6,460,000)            
Allotrope Energy Ltd              
Disclosure of joint ventures [line items]              
Equity 2,636,000 2,636,000          
Biomas | Country of domicile              
Disclosure of joint ventures [line items]              
Equity 13,813,000 13,813,000          
Income (expenses) of the period (9,865,000)            
Ibema Companhia Brasileira de Papel | Country of domicile              
Disclosure of joint ventures [line items]              
Equity 393,445,000 393,445,000          
Income (expenses) of the period (2,231,000)            
Woodspin Oy | Foreign countries              
Disclosure of joint ventures [line items]              
Equity          
Income (expenses) of the period