v3.26.1
INVESTMENTS - Assets and Liabilities of joint ventures and associates projects (Details) - BRL (R$)
R$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Disclosure of investments in associates and joint ventures [Line items]        
Current assets R$ 52,090,586 R$ 64,451,102    
Non-current assets 227,595,007 225,420,228    
Total assets 279,685,593 289,871,330    
Current liabilities 30,978,400 31,435,916    
Non-Current liabilities 130,205,536 136,241,184    
Net operating revenue 2,092,596 19,745,698 R$ 11,668,408  
Profit / (Net loss) 6,559,657 10,380,754 4,394,861  
Cash and cash equivalents 16,417,860 26,572,522 13,046,371 R$ 10,739,126
Depreciation and amortization (4,576,919) (3,987,775) (3,621,342)  
Income tax expense R$ 13,539,607 R$ (240,030) R$ 2,998,498  
ISA Energia        
Disclosure of investments in associates and joint ventures [Line items]        
Participation % 21.63% 21.63%    
Current assets R$ 7,087,439 R$ 6,942,987    
Non-current assets 40,113,933 35,058,267    
Total assets 47,201,372 42,001,254    
Current liabilities 1,886,771 3,058,587    
Non-Current liabilities 23,877,590 19,228,086    
Net worth 21,437,011 19,714,581    
Total Liabilities 47,201,372 42,001,254    
Net operating revenue 9,411,153 6,417,562    
Profit / (Net loss) R$ 2,511,015 R$ 3,498,416    
Eletronuclear        
Disclosure of investments in associates and joint ventures [Line items]        
Participation %   67.95%    
Current assets   R$ 3,817,658    
Non-current assets   20,768,853    
Total assets   24,586,511    
Current liabilities   3,008,197    
Non-Current liabilities   9,939,459    
Net worth   11,638,855    
Total Liabilities   24,586,511    
Net operating revenue   4,230,830    
Profit / (Net loss)   R$ 544,787    
Norte Energia S.A. - NESA        
Disclosure of investments in associates and joint ventures [Line items]        
Participation % 49.98% 49.98%    
Current assets R$ 2,564,063 R$ 2,322,930    
Non-current assets 38,497,696 40,441,466    
Total assets 41,061,759 42,764,396    
Current liabilities 2,647,812 2,539,955    
Non-Current liabilities 30,365,532 30,637,340    
Net worth 8,048,415 9,587,101    
Total Liabilities 41,061,759 42,764,396    
Net operating revenue 6,275,455 6,249,120    
Profit / (Net loss) (1,543,674) (1,675,978)    
Cash and cash equivalents 847,695 796,696    
Current financial liabilities 1,278,988 1,156,815    
Non-current financial liabilities 27,008,042 27,456,029    
Depreciation and amortization (1,889,873) (1,767,877)    
Interest income 339,038 165,471    
Interest expense (2,981,496) (2,531,993)    
Income tax expense R$ 9,178 R$ (258,683)    
Jirau Energia S.A.        
Disclosure of investments in associates and joint ventures [Line items]        
Participation % 40.00% 40.00%    
Current assets R$ 1,535,893 R$ 1,890,657    
Non-current assets 17,134,455 17,564,198    
Total assets 18,670,348 19,454,855    
Current liabilities 1,236,790 1,141,624    
Non-Current liabilities 8,623,245 9,141,462    
Net worth 8,810,313 9,171,769    
Total Liabilities 18,670,348 19,454,855    
Net operating revenue 3,625,536 3,582,148    
Profit / (Net loss) (388,540) 218,681    
Cash and cash equivalents 919,023 655,182    
Current financial liabilities 890,672 828,573    
Non-current financial liabilities 8,317,741 8,863,128    
Depreciation and amortization (819,137) (729,033)    
Interest income 246,147 155,489    
Interest expense (1,053,827) (946,475)    
Income tax expense R$ (79,583) R$ (117,962)    
Belo Monte Transmissora - BMTE        
Disclosure of investments in associates and joint ventures [Line items]        
Participation % 49.00% 49.00%    
Current assets R$ 1,270,186 R$ 1,278,940    
Non-current assets 8,568,229 8,374,140    
Total assets 9,838,415 9,653,080    
Current liabilities 724,772 660,683    
Non-Current liabilities 4,160,904 4,224,616    
Net worth 4,952,739 4,767,781    
Total Liabilities 9,838,415 9,653,080    
Net operating revenue 1,083,302 1,159,427    
Profit / (Net loss) 459,950 500,304    
Cash and cash equivalents 68,950 43,100    
Current financial liabilities 707,142 427,470    
Non-current financial liabilities 4,143,081 4,427,363    
Depreciation and amortization (1,553,901) (1,257,382)    
Interest income 54,142 46,015    
Interest expense (308,944) (298,584)    
Income tax expense R$ (230,754) R$ (251,698)    
Interligação Elétrica do Madeira S.A. - IE Madeira        
Disclosure of investments in associates and joint ventures [Line items]        
Participation % 49.00% 49.00%    
Current assets R$ 888,487 R$ 1,228,448    
Non-current assets 6,336,631 6,352,671    
Total assets 7,225,118 7,581,119    
Current liabilities 447,305 760,573    
Non-Current liabilities 2,279,994 2,440,143    
Net worth 4,497,819 4,380,403    
Total Liabilities 7,225,118 7,581,119    
Net operating revenue 768,933 747,614    
Profit / (Net loss) 476,992 478,090    
Cash and cash equivalents 75 41    
Current financial liabilities 419,229 748,397    
Non-current financial liabilities 2,183,511 2,337,740    
Depreciation and amortization (1,331) (964)    
Interest income 45,211 48,829    
Interest expense (103,426) (119,370)    
Income tax expense R$ (107,793) R$ (121,806)    
Transnorte Energia S.A.        
Disclosure of investments in associates and joint ventures [Line items]        
Participation % 64.61%      
Current assets R$ 782,636      
Non-current assets 6,551,413      
Total assets 7,334,049      
Current liabilities 1,702,767      
Non-Current liabilities 3,217,490      
Net worth 2,413,792      
Total Liabilities 7,334,049      
Net operating revenue 3,208,408      
Profit / (Net loss) 892,055      
Cash and cash equivalents 1,510      
Current financial liabilities 1,604,673      
Non-current financial liabilities 3,110,874      
Depreciation and amortization (78,835)      
Interest income 18,132      
Interest expense (108,944)      
Income tax expense R$ (458,980)