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v3.25.1

Loans and Debentures - Additional Information (Details) shares in Thousands, $ in Millions |  |  |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Dec. 27, 2024 BRL (R$) shares | Dec. 05, 2024 BRL (R$) | Dec. 05, 2024 USD ($) | Sep. 27, 2024 BRL (R$) Number shares | Jul. 31, 2018 USD ($) Number | Dec. 31, 2017 USD ($) Number | Dec. 31, 2024 BRL (R$) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 BRL (R$)
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Principal amount | R$ 200,000,000 |  |  | R$ 2,436,000,000 |  |  |  |  |
Average foreign currencies exchange rate |  |  |  |  |  |  | 7.92 |  |
Debenture | R$ 200,000,000 |  |  |  |  |  |  |  |
Debenture rate | 0.47% |  |  |  |  |  |  |  |
Maturity term | 5 years |  |  |  |  |  |  |  |
Threshold amount of early maturity clauses for cross default |  |  |  |  |  |  | R$ 50,000,000 |  |
Debt average repayment period |  |  |  |  |  |  | 2 years 9 months 18 days | 2 years 9 months 18 days |
Nominal Cost Of Entitys Debt |  |  |  |  |  |  | 12.64% | 12.64% | 11.98%
Real Cost Of Entitys Debt |  |  |  |  |  |  | 7.66% | 7.66% | 6.65%
Restricted Cash and Cash Equivalents |  |  |  |  |  |  | R$ 235,000,000 |  | R$ 31,000,000
Cemig D [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Fiduciary guarantee |  |  |  |  |  |  | 185,000,000 |  |
Eurobonds [member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Number Of Monthly Payments Of Interest | Number |  |  |  |  | 6 | 6 |  |  |
Debentures - 7th Issue - Single series [Member] | Cemig D [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Fiduciary guarantee |  |  |  |  |  |  | R$ 181,000,000 |  |
Debentures - 9th Issue - Single series [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Principal amount | R$ 200,000,000 |  |  |  |  |  |  |  |
Debentures shares issued | shares | 200 |  |  |  |  |  |  |  |
Debentures - 9th Issue - Single series [Member] | Gasmig [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Nominal Unit Value | 1,000 |  |  |  |  |  |  |  |
11th Debentures Issuance CEMIG D [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Principal amount |  |  |  | R$ 2,500,000,000 |  |  |  |  |
Debentures shares issued | shares |  |  |  | 2,500 |  |  |  |  |
11th Debentures Issuance CEMIG D [Member] | Cemig D [Member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Number Of Series Of Unsecured Non Convertible Debentures Issue | Number |  |  |  | 2 |  |  |  |  |
Cemiggt [Member] | Eurobonds [member] |  |  |  |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |  |  |  |
Principal amount | $ |  |  |  |  | $ 500 | $ 1,000 |  |  |
Repayments of borrowings, classified as financing activities |  | R$ 2,309,000,000 | $ 381 |  |  |  |  | $ 1,119 |
Average foreign currencies exchange rate |  | 6.0585 | 6.0585 |  |  |  |  |  |
Gain (loss) on hedge ineffectiveness |  | R$ 443,000,000 |  |  |  |  |  |  |
Net effect on cash position |  | R$ 1,866,000,000 |  |  |  |  |  |  |

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