XML 136 R115.htm IDEA: XBRL DOCUMENT
v3.21.1

14. CONCESSION FINANCIAL AND SECTOR ASSETS AND LIABILITIES (Details 5) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure Of Financial Assets And Financial Liabilities With The Tariff Adjustments [abstract] |  |  |  |
Beginning balance |  | R$ 882 | R$ 1,080 | R$ (46)
Additions |  | 611 | 724 | 1,638
Amortization |  | (156) | (666) | 335
Others - R&D Reimbursement |  |  |  | (115)
Payments from the Flag Tariff Centralizing Account |  | (63) | (361) | (794)
Receipt funds of ''Covid-account'' | [1] | (1,404) |  |
Updating - Selic rate (Note 31) |  | 32 | 105 | 62
Ending balance |  | R$ (98) | R$ 882 | R$ 1,080
[1] | The amount received via 'Covid-account' will be reversed in a negative financial component in the 2021 or 2022 tariff processes, as detailed in note 1.

X
- Definition Additions financial assets (liabilities). + References No definition available. + Details
Name: | cig_AdditionsFinancialAssetsLiabilities
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amortization + References No definition available. + Details
Name: | cig_Amortization
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Disclosure Of Financial Assets And Financial Liabilities With The Tariff Adjustments [abstract] + References No definition available. + Details
Name: | cig_DisclosureOfFinancialAssetsAndFinancialLiabilitiesWithTheTariffAdjustmentsAbstract
Namespace Prefix: | cig_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financial assets (liabilities), net. + References No definition available. + Details
Name: | cig_FinancialAssetsLiabilitiesNet
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Others research and development reimbursement. + References No definition available. + Details
Name: | cig_OthersResearchAndDevelopmentReimbursement
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Payments From The Tariff Flag + References No definition available. + Details
Name: | cig_PaymentsFromTheTariffFlag
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Receipt funds of ''covid-account''. + References No definition available. + Details
Name: | cig_ReceiptFundsOfCovidaccount
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Updating - Selic rate + References No definition available. + Details
Name: | cig_UpdatingSelicRate
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration