XML 114 R107.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Concession Financial Assets and Liabilities - Summary of Indemnity Values (Detail) - BRL (R$) R$ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016
Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] |  |
Adjustment of the BRR of Transmission Assets - Aneel Technical Note 183/2017 | R$ 149 |
Cemig GT [member] | Transmission Indemnity receivable [member] |  |
Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] |  |
Adjustment of the BRR of Transmission Assets - Aneel Technical Note 183/2017 | 149 |
Regulatory Remuneration Base (BRR) - Dispatch 2,181 2016 |  | R$ 1,177
Updating per MME | 121 | 913
Monetary adjustment | 103 |
Amounts received | (250) | (285)
Net residual value of the assets to be received |  | 892
Total indemnity | R$ 1,928 | R$ 1,805

X
- Definition Adjustment of BRR of Transmission Assets + References No definition available. + Details
Name: | xcmig_AdjustmentOfBrrOfTransmissionAssets
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of the indemnity received so far. + References No definition available. + Details
Name: | xcmig_AmountOfTheIndemnityReceivedSoFar
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] + References No definition available. + Details
Name: | xcmig_DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionLineItems
Namespace Prefix: | xcmig_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Indeminity. + References No definition available. + Details
Name: | xcmig_Indemnity
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Monetary adjustment. + References No definition available. + Details
Name: | xcmig_MonetaryAdjustment
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Net residual value of assets. + References No definition available. + Details
Name: | xcmig_NetResidualValueOfAssets
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Regulatory remuneration base. + References No definition available. + Details
Name: | xcmig_RegulatoryRemunerationBase
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Updated value by inflation and cost of own capital. + References No definition available. + Details
Name: | xcmig_UpdatedValueByInflationAndCostOfOwnCapital
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | ifrs-full_SignificantInvestmentsInSubsidiariesAxis=xcmig_CemigGTMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ServiceConcessionArrangementsAxis=xcmig_TransmissionIndemnityReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |