Operating revenue (Details Narrative) - BRL (R$) R$ in Thousands |
3 Months Ended | 12 Months Ended | |
|---|---|---|---|
Sep. 30, 2025 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| IfrsStatementLineItems [Line Items] | |||
| Revenue | 3.22% | 99.16% | |
| Tariffs revenue | 3.74% | ||
| Revenue from sanitation services | R$ 25,258,543 | ||
| Annual revenue calculated rate | 0.50% | ||
| Programa De Formacao Do Patrimonio Do Servidor Publico [Member] | |||
| IfrsStatementLineItems [Line Items] | |||
| Current taxes | 1.65% | ||
| Pasep for financial revenues rate | 0.65% | ||
| Contribuicao Para O Financiamentoda Seguridade Social [Member] | |||
| IfrsStatementLineItems [Line Items] | |||
| Current taxes | 7.60% | ||
| Cofins for financial revenues rate | 4.00% | ||