v3.25.1
FINANCIAL ASSETS AND LIABILITIES - Additional Information (Details) - BRL (R$)
R$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
Investments accounted for using equity method R$ 10,678,566 R$ 17,611,369
Lease liabilities [member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
PIS and COFINS credit included in lease liabilities R$ 30,814 32,244
Bottom of range [member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
Lessee’s incremental borrowing rate applied to the lease liabilities 4.25%  
Restricted cash average maturity period 2 years  
Top of range [member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
Lessee’s incremental borrowing rate applied to the lease liabilities 13.73%  
Restricted cash average maturity period 5 years  
BancoItaú BBA SA [Member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
Weighted Average Rate Use For Calculating Investment In Preferred Shares CDI +1.25  
Cosan Nove Participações S.A. [member] | BancoItaú BBA SA [Member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
PIS and COFINS credit included in lease liabilities R$ 4,115,000  
Investments accounted for using equity method 4,596,631  
Cosan Dez Participações S.A. [member] | Banco Bradesco BBI SA [Member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
PIS and COFINS credit included in lease liabilities 4,000,000  
Investments accounted for using equity method 3,943,883  
Comgas [member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
Receivables in advance from suppliers to financial institutions R$ 132,999 R$ 133,937
Comgas [member] | Top of range [member]    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
Advance receivables payment period 90 days  
CSAN3    
Disclosure of sensitivity analysis of financial instruments changes in foreign exchange rates [line items]    
Borrowings, interest rate 1.31%  
The contracted value of CSAN3 shares with total return swap (in shares) 110,995,312