Operating revenue (Details) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
IfrsStatementLineItems [Line Items]
Net operating revenue	R$ 22,055,720	R$ 19,491,061	R$ 17,797,541
Sanitation Sao Paolo [Member]
IfrsStatementLineItems [Line Items]
Net operating revenue	13,318,803	11,529,229	10,722,384
Regional System [Member]
IfrsStatementLineItems [Line Items]
Net operating revenue	5,311,156	4,774,977	4,435,396
Sanitation Services [Member]
IfrsStatementLineItems [Line Items]
Net operating revenue	R$ 18,629,959	R$ 16,304,206	R$ 15,157,780

The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims.

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+ Details