v3.26.1
Intangible assets (Details 1) - BRL (R$)
R$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning R$ 44,771,124 R$ 44,012,858
Additions 3,207 2,862,651
Transfer of contract assets 8,117,869 9,033,117
Transfers (139,884) (42,843)
Write-offs and disposals (98,731) (6,864)
Amortization (2,161,112) (2,637,479)
Intangible assets, ending 50,492,473 44,771,124
Transfers to financial assets   (8,450,316)
Concession agreements – new contracts [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 142,656 147,589
Additions
Transfer of contract assets
Transfers
Write-offs and disposals
Amortization (4,933) (4,933)
Intangible assets, ending 137,723 142,656
Transfers to financial assets  
Concession agreements – others [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 59,492
Additions
Transfer of contract assets 24,214 4,090
Transfers (1,627) 57,445
Write-offs and disposals (4)
Amortization (6,987) (2,043)
Intangible assets, ending 75,088 59,492
Transfers to financial assets  
Contract Commitments [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 3,849,759  
Additions  
Transfer of contract assets  
Transfers  
Write-offs and disposals  
Amortization (119,638)  
Intangible assets, ending 3,730,121 3,849,759
Concession agreement – URAE-1 [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 39,956,194
Additions 2,666 20,712
Transfer of contract assets 7,990,514 6,573,841
Transfers (138,257) 42,727,540
Write-offs and disposals (98,727) (4,449)
Amortization (1,765,919) (911,134)
Intangible assets, ending 45,946,471 39,956,194
Transfers to financial assets   (8,450,316)
Software License [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 638,287 513,224
Additions 29,972
Transfer of contract assets 103,141 234,713
Transfers 4,989
Write-offs and disposals
Amortization (190,326) (144,611)
Intangible assets, ending 551,102 638,287
Transfers to financial assets  
Right of use – other assets [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 124,736 118,060
Additions 541 84,048
Transfer of contract assets
Transfers
Write-offs and disposals (46)
Amortization (73,309) (77,326)
Intangible assets, ending 51,968 124,736
Transfers to financial assets  
Concession agreements – equity value [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 506,117
Additions  
Transfer of contract assets   13,216
Transfers   (508,709)
Write-offs and disposals   (22)
Amortization   (10,602)
Intangible assets, ending  
Transfers to financial assets  
Concession agreements – economic value [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 637,760
Additions   (181)
Transfer of contract assets   13,005
Transfers   (576,439)
Write-offs and disposals  
Amortization   (74,145)
Intangible assets, ending  
Transfers to financial assets  
Program contracts [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 20,684,497
Additions  
Transfer of contract assets   1,392,259
Transfers   (21,469,330)
Write-offs and disposals   (1,020)
Amortization   (606,406)
Intangible assets, ending  
Transfers to financial assets  
Program contracts – commitments [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 3,849,759 1,212,026
Additions   2,728,100
Transfer of contract assets  
Transfers  
Write-offs and disposals  
Amortization   (90,367)
Intangible assets, ending   3,849,759
Transfers to financial assets  
Services contracts – Sao Paulo [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning 20,193,585
Additions  
Transfer of contract assets   801,993
Transfers   (20,278,339)
Write-offs and disposals   (1,327)
Amortization   (715,912)
Intangible assets, ending  
Transfers to financial assets