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33. FINANCIAL INSTRUMENTS AND RISK MANAGEMENT (Details 4) - BRL (R$) R$ in Millions | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Jul. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 21, 2019
Derivative Financial Instruments [line items] |  |  |  |  |  |
Cemig's obligation |  | 125.52% of the CDI rate | 150.49% of the CDI |  |  |
Unrealized gain/loss Carrying amount |  |  | R$ 922 | R$ 712 |  |
Unrealized gain/loss fair value |  |  | R$ 1,691 | R$ 813 |  |
Forty Nine Percent of Certificados de Deposito Inter bancario [member] |  |  |  |  |  |
Derivative Financial Instruments [line items] |  |  |  |  |  |
Cemig's right |  |  | US$ exchange variation + Rate (9,25% p.y.) | US$ exchange variation + Rate (9,25% p.y.) | [1] |
Cemig's obligation |  |  | Local currency + R$ 150.49% of CDI | Local currency + R$ 150.49% of CDI | [1] |
Maturity period |  |  | Interest: Half-yearly Principal: Dec. 2024 | Interest: Half-yearly Principal: Dec. 2024 |  |
Notional amount | [2] |  |  |  |  | R$ 1,000
Unrealized gain/loss Carrying amount |  |  | R$ 814 | R$ 1,000 |  |
Unrealized gain/loss fair value |  |  | R$ 1,235 | R$ 627 |  |
Fifty Two Percent of Certificados de Deposito Inter bancario [member] |  |  |  |  |  |
Derivative Financial Instruments [line items] |  |  |  |  |  |
Cemig's right |  |  | US$ exchange variation + Rate (9,25% a.a.) | US$ exchange variation + Rate (9,25% a.a.) | [1] |
Cemig's obligation |  |  | Local currency + R$125.52% of CDI | Local currency + R$125.52% of CDI | [1] |
Maturity period |  |  | Interest: Half-yearly Principal: Dec. 2024 | Interest: Half-yearly Principal: Dec. 2024 |  |
Notional amount | [2] |  | R$ 500 |  |  |
Unrealized gain/loss Carrying amount |  |  | 108 | R$ 33 |  |
Unrealized gain/loss fair value |  |  | R$ 456 | R$ 186 |  |
[1] | For the US$1 billion Eurobond issued on December 2017: (i) for the principal, a call spread was contracted, with floor at R$ 3.25/US$ and ceiling at R$ 5.00/US$; and (ii) a swap was contracted for the total interest, for a coupon of 9.25% p.a. at an average rate equivalent to 150.49% of the CDI. For the additional US$500 issuance of the same Eurobond issued on July 2018: (1) a call spread was contracted for the principal, with floor at R$ 3.85/US$ and ceiling at R$ 5.00/US$; and (2) a swap was contracted for the interest, resulting in a coupon of 9.25% p.a., with an average rate equivalent to 125.52% of the CDI rate.
[2] | In millions of US$.

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