XML 100 R93.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Recoverable Taxes - Summary of Recoverable Taxes (Detail) - BRL (R$) R$ in Millions | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Disclosure of Recoverable Taxes [Line Items] |  |
Recoverable taxes, current | R$ 174 | R$ 236
Recoverable taxes, non-current | 231 | 178
Recoverable taxes | 405 | 414
ICMS (VAT) [member] |  |
Disclosure of Recoverable Taxes [Line Items] |  |
Recoverable taxes, current | 71 | 155
Recoverable taxes, non-current | 225 | 171
PIS and Pasep taxes [member] |  |
Disclosure of Recoverable Taxes [Line Items] |  |
Recoverable taxes, current | 12 | 12
Recoverable taxes, non-current | 1 | 1
Cofins [member] |  |
Disclosure of Recoverable Taxes [Line Items] |  |
Recoverable taxes, current | 56 | 58
Recoverable taxes, non-current | 3 | 5
Other [member] |  |
Disclosure of Recoverable Taxes [Line Items] |  |
Recoverable taxes, current | 35 | 11
Recoverable taxes, non-current | R$ 2 | R$ 1

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

X
- Definition Disclosure of recoverable taxes. + References No definition available. + Details
Name: | xcmig_DisclosureOfRecoverableTaxesLineItems
Namespace Prefix: | xcmig_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Non-current recoverable taxes. + References No definition available. + Details
Name: | xcmig_NoncurrentRecoverableTaxes
Namespace Prefix: | xcmig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Details
Name: | ifrs-full_ClassesOfAcquiredReceivablesAxis=xcmig_ICMSVATMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfAcquiredReceivablesAxis=xcmig_PISAndPaseptaxesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfAcquiredReceivablesAxis=xcmig_CofinsTaxMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfAcquiredReceivablesAxis=xcmig_OtherTaxRecoverableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |