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27. REVENUE (Details Narrative) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Revenue [abstract] |  |
Average of the implicit rates | 6.86% |
Non-recurring tax provision due | R$ 135 |
Tariff flag revenue | 47 |
Revenue recognized for the tariff subsidies | R$ 1,035 | R$ 1,079

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- Definition Represent information about the average of implicit rates. + References No definition available. + Details
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Namespace Prefix: | cig_
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Balance Type: | na
Period Type: | duration

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- Definition The amount of nonrecurring tax provision due. + References No definition available. + Details
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Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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- Definition The amount of revenue recognized for tariff subsidies. + References No definition available. + Details
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Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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X
- Definition The amount of tariff flag revenue. + References No definition available. + Details
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Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- References No definition available. + Details
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