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Investments - Additional Information (Details) R$ in Thousands |  |  |  |  |  |  |  |  |  |  |  |  | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 06, 2023 BRL (R$) | Oct. 03, 2023 BRL (R$) | Sep. 20, 2023 BRL (R$) | Sep. 19, 2023 BRL (R$) | Jul. 20, 2023 BRL (R$) PowerPlant | Jun. 28, 2023 BRL (R$) | May 30, 2023 BRL (R$) | Apr. 28, 2023 | Apr. 14, 2023 BRL (R$) MW | Dec. 22, 2022 BRL (R$) | Sep. 12, 2022 BRL (R$) | Jun. 29, 2022 | Dec. 31, 2023 BRL (R$) MW | Dec. 31, 2022 BRL (R$) | Dec. 31, 2021 BRL (R$) | Nov. 22, 2023 BRL (R$) | Oct. 23, 2023 BRL (R$) | Sep. 30, 2023 BRL (R$) | Mar. 20, 2023 BRL (R$)
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Working capital |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 1,249,000 |  |  |  |  |  |
Loss |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,859,000 | R$ 2,972,000 |  |  |  |  |
Dividends received |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 592,000 | 708,000 | R$ 499,000 |  |  |  |
Installed capacity (MW) | MW |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,601.7 |  |  |  |  |  |
Acquisition wholly-owned subsidiary interests |  |  |  |  |  |  |  |  |  |  |  |  |  | 100.00% |  |  |  |  |  |
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$ 578,000 | R$ 494,000 |  |  |  |  |
Melbourne [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Compensation amount paid |  |  |  |  |  |  |  |  |  |  |  | R$ 200,000 |  |  |  |  |  |  |  |
Amount of receivable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 256,000 |
C E M I G Sim [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Acquisition rate |  |  |  |  |  | 100.00% |  |  | 100.00% |  |  |  | 100.00% |  |  |  |  |  |  |
Acquisition wholly-owned subsidiary interests |  |  |  |  |  | 100.00% |  |  |  |  |  |  | 100.00% |  |  |  |  |  |  |
Acquisition interest rate remaining |  |  |  |  |  | 51.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate value of acquisition |  |  |  |  |  | R$ 47,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of photovoltaic generation plants | PowerPlant |  |  |  |  |  | 4 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cemiggt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest rate |  |  |  |  |  |  |  |  |  | 49.90% |  |  |  |  |  |  |  |  |  |
Number of value sold | [1] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 55,000
Capital gain taxes on amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 10,000
Percentage of corporate and tax on net profit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 34.00%
Percentage of corporate income tax |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 25.00%
Percentage of social contribution tax on net profit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 9.00%
Amount of receivable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 257,000 |  |
Total consideration |  |  |  |  |  |  |  |  |  | R$ 200,000 |  |  |  |  |  |  |  |  |  |
Cemiggt [Member] | Furnas Centrais Eletricas S A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7.53%
Cemiggt [Member] | Santo Antnio Energia S.A. [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of value sold |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 55,000
Baguari Energia [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest rate |  | 69.39% |  |  |  |  |  | 49.00% |  | 69.39% |  |  |  |  |  |  |  |  |  |
Percentage of equity interest |  | 34.00% |  |  |  |  |  |  |  | 34.00% |  |  |  |  |  |  |  |  |  |
Acquisition rate |  |  |  |  |  |  |  | 100.00% |  |  |  |  |  |  |  |  |  |  |  |
Amount of receivable |  | R$ 433,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Transaction cost |  | 421,000 |  |  |  |  |  | R$ 454,000 |  |  |  |  |  |  |  |  |  |  |  |
Total consideration |  | 393,000 |  |  |  |  |  |  |  | R$ 393,000 |  |  |  |  |  |  |  |  |  |
Dividends received |  |  | R$ 12,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Installed capacity (MW) | MW |  |  |  |  |  |  |  |  |  | 140 |  |  |  |  |  |  |  |  |  |
Consorcio Uhe Baguari [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest rate |  |  |  |  |  |  |  | 51.00% |  |  |  |  |  |  |  |  |  |  |  |
Axxiom Solucoes Tecnologicas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity interest rate |  |  |  |  |  |  |  |  |  |  | 51.00% |  |  |  |  |  |  |  |  |
Transaction cost |  |  |  |  |  |  |  |  |  |  | R$ 1,000 |  |  |  |  |  |  |  |  |
Percentage of share purchase agreement for the sale |  |  |  |  |  |  |  |  |  |  | 49.00% |  |  |  |  |  |  |  |  |
Retiro Baixo And Baguari [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Installed capacity (MW) | MW |  |  |  |  |  |  |  |  |  | 81.1 |  |  |  |  |  |  |  |  |  |
Retiro Baixo [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100.00% |  |  |
Amount of receivable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 223,000 |  |  |
Transaction cost |  | R$ 218,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total consideration |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | R$ 190,000 |  |  |
Dividends received |  |  |  |  |  |  | R$ 6,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Installed capacity (MW) | MW |  |  |  |  |  |  |  |  |  | 34.8 |  |  |  |  |  |  |  |  |  |
Guanhaes Energia S A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reduce the share capital |  |  |  |  | R$ 235,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Absorption of losses share capital |  |  |  |  | 137,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repaid to stockholders |  |  |  |  | 98,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Correspond of share capital |  |  |  | R$ 48,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Received of share capital |  |  |  | R$ 46,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum [Member] | Guanhaes Energia S A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Decrease in share capital of the jointly controlled subsidiary |  |  |  |  | 313,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum [Member] | Guanhaes Energia S A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Decrease in share capital of the jointly controlled subsidiary |  |  |  |  | R$ 549,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
[1] | The effects of the sale are presented in the results of the Holdings/Holding operating segment in note 5.

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