v3.26.1
Intangible assets (Details) - BRL (R$)
R$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance R$ 14,854,960  
Intangible assets, ending balance 14,592,523 R$ 14,854,960
Licences [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 2,336,003 2,382,138
Additions/(Amortization) (983,061) (936,731)
Write-offs
Transfers 1,575,776 890,596
Intangible assets, ending balance 2,928,718 2,336,003
Authorizations [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 8,630,978 9,416,332
Additions/(Amortization) (855,087) (830,657)
Write-offs
Transfers 35,340 45,303
Intangible assets, ending balance 7,811,231 8,630,978
Goodwill [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 3,112,169 3,112,169
Additions/(Amortization)
Write-offs
Transfers
Intangible assets, ending balance 3,112,169 3,112,169
Right To Use Infrastructure Of Lt Amazonas [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 104,433 110,415
Additions/(Amortization) (11,996) (11,096)
Write-offs
Transfers 7,544 5,114
Intangible assets, ending balance 99,981 104,433
List Of Customers [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 165,410 198,492
Additions/(Amortization) (33,082) (33,082)
Write-offs
Transfers  
Intangible assets, ending balance 132,328 165,410
Other intangible assets [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 169,547 201,629
Additions/(Amortization) (41,630) (41,192)
Write-offs
Transfers 3,336 9,110
Intangible assets, ending balance 131,253 169,547
Intangible assets under development [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 336,420 203,866
Additions/(Amortization) 1,662,419 1,082,832
Write-offs (155)
Transfers (1,621,996) (950,123)
Intangible assets, ending balance 376,843 336,420
Gross carrying amount [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 47,460,121 46,313,583
Additions/(Amortization) 1,706,746 1,146,747
Write-offs (1,132) (209)
Transfers
Intangible assets, ending balance 49,165,735 47,460,121
Gross carrying amount [member] | Licences [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 24,058,388 23,167,846
Additions/(Amortization)
Write-offs (1,132) (54)
Transfers 1,575,776 890,596
Intangible assets, ending balance 25,633,032 24,058,388
Gross carrying amount [member] | Authorizations [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 18,903,457 18,794,239
Additions/(Amortization) 44,327 63,915
Write-offs
Transfers 35,340 45,303
Intangible assets, ending balance 18,983,124 18,903,457
Gross carrying amount [member] | Goodwill [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 3,112,169 3,112,169
Additions/(Amortization)
Write-offs
Transfers
Intangible assets, ending balance 3,112,169 3,112,169
Gross carrying amount [member] | Right To Use Infrastructure Of Lt Amazonas [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 212,703 207,589
Additions/(Amortization)
Write-offs
Transfers 7,544 5,114
Intangible assets, ending balance 220,247 212,703
Gross carrying amount [member] | List Of Customers [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 253,629 253,629
Additions/(Amortization)
Write-offs
Transfers
Intangible assets, ending balance 253,629 253,629
Gross carrying amount [member] | Other intangible assets [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 583,355 574,245
Additions/(Amortization)
Write-offs
Transfers 3,336 9,110
Intangible assets, ending balance 586,691 583,355
Gross carrying amount [member] | Intangible assets under development [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 336,420 203,866
Additions/(Amortization) 1,662,419 1,082,832
Write-offs (155)
Transfers (1,621,996) (950,123)
Intangible assets, ending balance 376,843 336,420
Accumulated depreciation and amortisation [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance (32,605,161) (30,688,542)
Additions/(Amortization) (1,969,183) (1,916,673)
Write-offs 1,132 54
Transfers
Intangible assets, ending balance (34,573,212) (32,605,161)
Accumulated depreciation and amortisation [member] | Licences [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance (21,722,385) (20,785,708)
Additions/(Amortization) (983,061) (936,731)
Write-offs 1,132 54
Transfers
Intangible assets, ending balance (22,704,314) (21,722,385)
Accumulated depreciation and amortisation [member] | Authorizations [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance (10,272,479) (9,377,907)
Additions/(Amortization) (899,414) (894,572)
Write-offs
Transfers
Intangible assets, ending balance (11,171,893) (10,272,479)
Accumulated depreciation and amortisation [member] | Right To Use Infrastructure Of Lt Amazonas [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance (108,270) (97,174)
Additions/(Amortization) (11,996) (11,096)
Write-offs
Transfers
Intangible assets, ending balance (120,266) (108,270)
Accumulated depreciation and amortisation [member] | List Of Customers [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance (88,219) (55,137)
Additions/(Amortization) (33,082) (33,082)
Write-offs
Transfers
Intangible assets, ending balance (121,301) (88,219)
Accumulated depreciation and amortisation [member] | Other intangible assets [member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance (413,808) (372,616)
Additions/(Amortization) (41,630) (41,192)
Write-offs
Transfers
Intangible assets, ending balance (455,438) (413,808)
Total Intangible Assets Net [Member]    
IfrsStatementLineItems [Line Items]    
Intangible assets, beginning balance 14,854,960 15,625,041
Additions/(Amortization) (262,437) (769,926)
Write-offs (155)
Transfers
Intangible assets, ending balance R$ 14,592,523 R$ 14,854,960