v3.25.4
RELATED-PARTY TRANSACTIONS - Key Management compensation and other information from related parties (Details)
R$ in Thousands
 12 Months Ended
Dec. 31, 2025
BRL (R$)
EquityInstruments
shares
Dec. 31, 2024
BRL (R$)
EquityInstruments
shares
Dec. 31, 2023
BRL (R$)
EquityInstruments
shares
RELATED PARTY TRANSACTIONS      
Cost of Salaries, variable compensation and benefits R$ 37,422 R$ 40,396 R$ 36,964
Cost of contributions to management's defined contribution pension plans 2,017 1,952 1,986
Cost of long-term incentive plans 30,014 32,098 25,352
Total compensation 69,453 74,446 64,302
Cost of social charges R$ 15,344 R$ 16,361 R$ 17,077
Key Management personnel (Board of Directors and executive officers) | Restricted and Performance Shares      
Restricted shares granted to Management      
Balance, beginning of year | EquityInstruments 4,073,931 4,945,852 3,415,166
Granted | EquityInstruments 1,091,796 1,410,887 2,705,702
Exercised | EquityInstruments (803,483) (2,751,812) (938,953)
Cancelled | EquityInstruments   (321,345) (404,922)
Share Bonus | shares   790,349 168,859
Base Adjustment | shares (64,382)    
Balance, end of year | EquityInstruments 4,297,862 4,073,931 4,945,852
Fundacao Gerdau, Instituto Gerdau and Fundacao Ouro Branco      
Restricted shares granted to Management      
Contributions to defined contribution pension plans R$ 160,433 R$ 206,344  
Subsidiaries | Gerdau Aos Longos S.A. and Gerdau Aominas S.A.      
Restricted shares granted to Management      
Investments in debentures 4,815 2,288  
Financial income R$ 110,360 R$ 105,859