v3.26.1
Related-Party Balances and Transactions (Details) - BRL (R$)
R$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
IfrsStatementLineItems [Line Items]    
Total current R$ 276,388 R$ 319,546
Accounts receivable, noncurrent 862,782 908,875
Total receivables 1,139,170 1,228,421
Total 1,139,170 1,228,421
Liabilities 61,801,643 44,037,376
Agreement For The Installment Payment Of Sanitation Services [Member]    
IfrsStatementLineItems [Line Items]    
Accounts receivable, noncurrent 1,361 1,361
Reimbursement G E S P 2015 [Member]    
IfrsStatementLineItems [Line Items]    
Accounts receivable, noncurrent 861,421 907,514
Sanitation Services [Member]    
IfrsStatementLineItems [Line Items]    
Total 122,473 123,121
Reimbursement For Retirement And Pension Benefits Paid [Member]    
IfrsStatementLineItems [Line Items]    
Total 1,016,697 1,105,300
Interest On Capital Payable [Member]    
IfrsStatementLineItems [Line Items]    
Liabilities 428,681 458,985
Sanitation Services [Member]    
IfrsStatementLineItems [Line Items]    
Total current 163,865 173,466
Allowance For Loss [Member]    
IfrsStatementLineItems [Line Items]    
Total current (42,753) (51,706)
Monthly Flow Payments [Member]    
IfrsStatementLineItems [Line Items]    
Total current 32,141 84,973
Reimbursement G E S P 2015 [Member]    
IfrsStatementLineItems [Line Items]    
Total current R$ 123,135 R$ 112,813