v3.25.4
EQUITY - Ownership of shares (Details) - shares
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
EQUITY      
Shares subscribed and paid up 2,000,879,949 2,078,805,560 1,757,067,050
Ownership of shares, as a percentage of total issued shares 100.00% 100.00% 100.00%
Common      
EQUITY      
Shares subscribed and paid up 717,782,619 719,956,830 600,526,442
Ownership of shares, as a percentage of total issued shares 100.00% 100.00% 100.00%
Preferred      
EQUITY      
Shares subscribed and paid up 1,283,097,330 1,358,848,730 1,156,540,608
Ownership of shares, as a percentage of total issued shares 100.00% 100.00% 100.00%
Treasury stock      
EQUITY      
Shares subscribed and paid up 25,736,058 37,512,079 7,544,641
Ownership of shares, as a percentage of total issued shares 1.30% 1.80% 0.40%
Treasury stock | Common      
EQUITY      
Shares subscribed and paid up 418,800 1,093,011  
Ownership of shares, as a percentage of total issued shares 0.10% 0.20% 0.00%
Treasury stock | Preferred      
EQUITY      
Shares subscribed and paid up 25,317,258 36,419,068 7,544,641
Ownership of shares, as a percentage of total issued shares 2.00% 2.70% 0.70%
Metalurgica Gerdau S.A.      
EQUITY      
Shares subscribed and paid up 702,952,615 702,952,615 585,793,846
Ownership of shares, as a percentage of total issued shares 35.10% 33.80% 33.30%
Metalurgica Gerdau S.A. | Common      
EQUITY      
Shares subscribed and paid up 702,952,615 702,952,615 585,793,846
Ownership of shares, as a percentage of total issued shares 97.90% 97.60% 97.50%
Metalurgica Gerdau S.A. | Preferred      
EQUITY      
Ownership of shares, as a percentage of total issued shares 0.00% 0.00% 0.00%
Brazilian institutional investors      
EQUITY      
Shares subscribed and paid up 120,297,653 147,312,061 120,232,304
Ownership of shares, as a percentage of total issued shares 6.00% 7.10% 6.80%
Brazilian institutional investors | Common      
EQUITY      
Shares subscribed and paid up 649,134 229,736 2,442,108
Ownership of shares, as a percentage of total issued shares 0.10% 0.00% 0.40%
Brazilian institutional investors | Preferred      
EQUITY      
Shares subscribed and paid up 119,648,519 147,082,325 117,790,196
Ownership of shares, as a percentage of total issued shares 9.30% 10.80% 10.20%
Foreign institutional investors      
EQUITY      
Shares subscribed and paid up 598,847,817 1,055,646,584 547,646,333
Ownership of shares, as a percentage of total issued shares 29.90% 50.80% 31.20%
Foreign institutional investors | Common      
EQUITY      
Shares subscribed and paid up 1,024,037 1,279,113 1,425,937
Ownership of shares, as a percentage of total issued shares 0.10% 0.20% 0.20%
Foreign institutional investors | Preferred      
EQUITY      
Shares subscribed and paid up 597,823,780 1,054,367,471 546,220,396
Ownership of shares, as a percentage of total issued shares 46.60% 77.60% 47.20%
Other shareholders      
EQUITY      
Shares subscribed and paid up 553,045,806 135,382,221 495,849,926
Ownership of shares, as a percentage of total issued shares 27.70% 6.50% 28.30%
Other shareholders | Common      
EQUITY      
Shares subscribed and paid up 12,738,033 14,402,355 10,864,551
Ownership of shares, as a percentage of total issued shares 1.80% 2.00% 1.90%
Other shareholders | Preferred      
EQUITY      
Shares subscribed and paid up 540,307,773 120,979,866 484,985,375
Ownership of shares, as a percentage of total issued shares 42.10% 8.90% 41.90%