v3.26.1
Investments - Investments in Associates and Joint Ventures (Details)
 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Jun. 30, 2026
BRL (R$)
Jun. 30, 2025
BRL (R$)
Jun. 30, 2026
BRL (R$)
Jun. 30, 2026
BRL (R$)
€ / shares
Jun. 30, 2025
BRL (R$)
Jun. 30, 2025
BRL (R$)
€ / shares
Sep. 30, 2025
Dec. 31, 2025
BRL (R$)
Dec. 31, 2024
BRL (R$)
Disclosure of joint ventures [line items]                  
Equity R$ 49,851,513,000 R$ 43,271,305,000 R$ 49,851,513,000 R$ 49,851,513,000 R$ 43,271,305,000 R$ 43,271,305,000   R$ 43,952,173,000 R$ 32,415,575,000
Income (expenses) of the period 1,807,466,000 5,011,953,000 R$ 6,119,457,000   11,360,131,000        
Proportion of ownership interest in subsidiary     100.00%       100.00%    
In the income (expenses) for the period     R$ (25,589,000)   (189,082,000)        
Goodwill 29,384,000   29,384,000 29,384,000       29,384,000  
Total Investments, including Goodwill and Financial Instruments 1,128,854,000   1,128,854,000 1,128,854,000       1,194,877,000  
Realization of exchange variation on investments abroad (15,636,000)   (15,636,000)        
Impairment loss (reversal of impairment loss) recognised in profit or loss       (76,066,000)     88,871,000  
Other Operating Income (Expense) from Disposal of Property, Plant and Equipment and Biological Assets     (188,297,000)   124,099,000        
Loss from associates and joint ventures (5,224,000) R$ (172,005,000) R$ (25,596,000)   (189,082,000)        
Disclosure of Detailed Information About Investment in Associates and Joint Ventures    
Information of investees as at
Company Participation
06/30/2026Carrying amountIn the income (expenses) for the period
EquityIncome (expenses) of the periodParticipation equity (%)06/30/202612/31/202506/30/202606/30/2025
Associate
Foreign
Ensyn Corporation (1)
 
 
(4,539)
Spinnova Plc (2)
180,554 
(88,585)
18.75 
%
33,854 
54,391 
(16,610)
(9,155)
Simplifyber, Inc.
38,076 
(11,406)
15.52 
%
5,909 
7,973 
(1,770)
(562)
Allotrope Energy Ltd
2,619 
19.72 
%
516 
556 
40,279 
62,920 
(18,380)
(14,256)
Joint ventures
Domestic (Brazil)
Biomas - Serviços Ambientais, Restauração e Carbono Ltda.
20,394 
(16,367)
16.66 
%
3,815 
3,945 
(2,631)
(3,107)
Ibema Companhia Brasileira de Papel
386,501 
(9,174)
49.90 
%
192,864 
197,442 
(4,578)
9,147 
Foreign
Woodspin Oy (3)
 
 
 
(117,232)
196,679 
201,387 
(7,209)
(111,192)
Other investments evaluated at fair value through other comprehensive income
Bem Agro Integração e Desenvolvimento S.A.
4.58 
%
3,368 
3,581 
Celluforce Inc.
8.28 
%
23,553 
25,975 
Nfinite Nanotechnology Inc.
5.40 
%
5,305 
5,639 
Lenzing Aktiengesellschaft
15.00 
%
830,281 
865,986 
862,507 
901,181 
 
 
Goodwill (1)(3)
29,389 
29,389 
(63,634)
29,389 
29,389 
 
(63,634)
1,128,854 
1,194,877 
(25,589)
(189,082)
(1)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 R9,896 related to the reclassification of other comprehensive income.
(2)The average share price quoted on the Nasdaq First North Growth Market (NFNGM) was EUR0.44 on June 30, 2026 and EUR0.46 on December 31, 2025.
(3)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.
            
Associate | Foreign countries                  
Disclosure of joint ventures [line items]                  
Investments Accounted for Using Equity Method, Excluding Goodwill 40,279,000   R$ 40,279,000 40,279,000       62,920,000  
In the income (expenses) for the period     (18,380,000)   (14,256,000)        
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 371,000   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       (4,539,000)        
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               (28,679,000)  
Spinnova Plc | Foreign countries                  
Disclosure of joint ventures [line items]                  
Participation equity (%)     18.75%            
Investments Accounted for Using Equity Method, Excluding Goodwill 33,854,000   R$ 33,854,000 33,854,000       54,391,000  
In the income (expenses) for the period     R$ (16,610,000)   (9,155,000)        
Simplifyber, Inc. (Indirect) | Foreign countries                  
Disclosure of joint ventures [line items]                  
Participation equity (%)     15.52%            
Investments Accounted for Using Equity Method, Excluding Goodwill 5,909,000   R$ 5,909,000 5,909,000       7,973,000  
In the income (expenses) for the period     R$ (1,770,000)   (562,000)        
Allotrope Energy Ltd (Indirect) | Foreign countries                  
Disclosure of joint ventures [line items]                  
Participation equity (%)     19.72%            
Investments Accounted for Using Equity Method, Excluding Goodwill 516,000   R$ 516,000 516,000       556,000  
Joint ventures                  
Disclosure of joint ventures [line items]                  
Investments Accounted for Using Equity Method, Excluding Goodwill 196,679,000   196,679,000 196,679,000       201,387,000  
In the income (expenses) for the period     R$ (7,209,000)   (111,192,000)        
Biomas | Country of domicile                  
Disclosure of joint ventures [line items]                  
Participation equity (%)     16.66%            
Investments Accounted for Using Equity Method, Excluding Goodwill 3,815,000   R$ 3,815,000 3,815,000       3,945,000  
In the income (expenses) for the period     R$ (2,631,000)   (3,107,000)        
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 192,864,000   R$ 192,864,000 192,864,000       197,442,000  
In the income (expenses) for the period     R$ (4,578,000)   9,147,000        
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               15,636,000  
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       (117,232,000)        
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 862,507,000   R$ 862,507,000 862,507,000       901,181,000  
Bem Agro Integração e Desenvolvimento S.A. (Indirect)                  
Disclosure of joint ventures [line items]                  
Proportion of ownership interest in subsidiary     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 3,368,000   R$ 3,368,000 3,368,000       3,581,000  
Celluforce Inc. (Direct)                  
Disclosure of joint ventures [line items]                  
Proportion of ownership interest in subsidiary     8.28%            
Celluforce Inc. (Direct) | Foreign countries                  
Disclosure of joint ventures [line items]                  
Non-current financial assets at fair value through other comprehensive income 23,553,000   R$ 23,553,000 23,553,000       25,975,000  
Nfinite Nanotechnology Inc. (Indirect)                  
Disclosure of joint ventures [line items]                  
Proportion of ownership interest in subsidiary     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 5,305,000   R$ 5,305,000 5,305,000       5,639,000  
Lenzing Aktiengesellschaft (Indirect)                  
Disclosure of joint ventures [line items]                  
Proportion of ownership interest in subsidiary     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 830,281,000   R$ 830,281,000 830,281,000       865,986,000  
Suzano Ventures e Suzano S/A                  
Disclosure of joint ventures [line items]                  
Goodwill 29,389,000   29,389,000 29,389,000       29,389,000  
Impairment loss (reversal of impairment loss) recognised in profit or loss       (63,634,000)        
Total Goodwill                  
Disclosure of joint ventures [line items]                  
Goodwill 29,389,000   29,389,000 29,389,000       R$ 29,389,000  
Impairment loss (reversal of impairment loss) recognised in profit or loss       R$ (63,634,000)        
Ensyn Corporation                  
Disclosure of joint ventures [line items]                  
Equity            
Income (expenses) of the period                
Spinnova Plc                  
Disclosure of joint ventures [line items]                  
Equity 180,554,000   180,554,000 R$ 180,554,000          
Income (expenses) of the period     (88,585,000)            
NASDAQ, Nordic Growth Market, Average Share Price | € / shares       R$ 0.44   R$ 0.46      
Simplifyber, Inc. (Indirect)                  
Disclosure of joint ventures [line items]                  
Equity 38,076,000   38,076,000 R$ 38,076,000          
Income (expenses) of the period     (11,406,000)            
Allotrope Energy Ltd (Indirect)                  
Disclosure of joint ventures [line items]                  
Equity 2,619,000   2,619,000 2,619,000          
Biomas | Country of domicile                  
Disclosure of joint ventures [line items]                  
Equity 20,394,000   20,394,000 20,394,000          
Income (expenses) of the period     (16,367,000)            
Ibema Companhia Brasileira de Papel | Country of domicile                  
Disclosure of joint ventures [line items]                  
Equity 386,501,000   386,501,000 386,501,000          
Income (expenses) of the period     (9,174,000)            
Woodspin Oy | Foreign countries                  
Disclosure of joint ventures [line items]                  
Equity            
Income (expenses) of the period