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Investments - Additional Information (Details) R$ in Millions |  |  |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | ---
Oct. 16, 2024 BRL (R$) | Aug. 07, 2024 BRL (R$) MW | Mar. 08, 2024 BRL (R$) | Sep. 19, 2023 BRL (R$) | Dec. 31, 2024 BRL (R$) MW | Dec. 31, 2023 BRL (R$) | Dec. 31, 2022 BRL (R$) | Dec. 27, 2024 BRL (R$) | Sep. 27, 2024 BRL (R$)
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Working capital |  |  |  |  | R$ (1,914) | R$ (1,224) |  |  |
Loss |  |  |  |  | 3,053 | 2,859 |  |  |
Principal amount |  |  |  |  |  |  |  | R$ 200 | R$ 2,436
Dividends received |  |  |  |  | R$ 349 | 592 | R$ 708 |  |
Installed capacity (MW) | MW |  |  |  |  | 3,601.7 |  |  |  |
Acquisition wholly-owned subsidiary interests |  |  |  |  | 100.00% |  |  |  |
Impairment |  |  |  |  | R$ 46 |  |  |  |
The Jequitiba I Solar Plant [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Installed generation capacity | MW |  | 6.55 |  |  |  |  |  |  |
Alianca Norte Energia [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Percentage of equity interest |  |  |  |  | 11.69% |  |  |  |
Amazonia Energia S A And Alianca Norte Energia S A [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Working capital |  |  |  |  | R$ 217 | R$ 578 |  |  |
C E M I G Sim [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Acquisition rate |  | 100.00% | 100.00% |  |  |  |  |  |
Aggregate value of acquisition |  | R$ 43 | R$ 40 |  |  |  |  |  |
Cemiggt [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Installed capacity (MW) | MW |  |  |  |  | 14.8 |  |  |  |
Percentage of Impairment |  |  |  |  | 100.00% |  |  |  |
Impairment |  |  |  |  | R$ 41 |  |  |  |
Guanhaes Energia S A [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Reduce the share capital |  |  |  | R$ 235 |  |  |  |  |
Absorption of losses share capital |  |  |  | 137 |  |  |  |  |
Repaid to stockholders |  |  |  | R$ 98 |  |  |  |  |
Correspond of share capital |  |  |  |  | 48 |  |  |  |
Paracambi Energetica S A [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Reduce the share capital | R$ 18 |  |  |  |  |  |  |  |
Correspond of share capital |  |  |  |  | R$ 9 |  |  |  |

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