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Investments - Schedule of Changes in Investments in Subsidiaries Jointly Controlled Entities and Affiliates (Parenthetical) (Details) - BRL (R$) R$ in Millions |  | 12 Months Ended
--- | --- | ---
Dec. 01, 2021 | Dec. 31, 2021
U F V Brasilandia Geracao De Energia Eletrica Distribuida [Member] |  |
IfrsStatementLineItems [Line Items] |  |
Acquisition of jointly controlled subsidiary |  | R$ 2
Itaocara Equity Deficit [Member] |  |
IfrsStatementLineItems [Line Items] |  |
Capital injected | R$ 40 |
Additional capital injected to cover expense | R$ 1 |
Madeira Energia Provisions To Losses [Member] |  |
IfrsStatementLineItems [Line Items] |  |
Loss recognized for extension of contractual obligation |  | R$ 162

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