XML 185 R178.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Revenues - Summary of Other Operating Revenues (Detail) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Disclosure of revenue [Line Items] |  |  |
Other revenue | R$ 1,484 | R$ 1,421 | R$ 1,440
Charged service [Member] |  |  |
Disclosure of revenue [Line Items] |  |  |
Other revenue | 10 | 6 | 14
Telecoms services [Member] |  |  |
Disclosure of revenue [Line Items] |  |  |
Other revenue | 149 | 137 | 134
Services rendered [Member] |  |  |
Disclosure of revenue [Line Items] |  |  |
Other revenue | 156 | 167 | 131
Subsidies [Member] |  |  |
Disclosure of revenue [Line Items] |  |  |
Other revenue | 1,034 | 1,001 | 996
Rental and leasing [Member] |  |  |
Disclosure of revenue [Line Items] |  |  |
Other revenue | 121 | 105 | 93
Other [Member] |  |  |
Disclosure of revenue [Line Items] |  |  |
Other revenue | R$ 14 | R$ 5 | R$ 72

X
- Definition The amount of revenue arising from sources that the entity does not separately disclose in the same statement or note. [Refer: Revenue] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Expiry date 2018-01-01 -Name IAS -Number 18 -IssueDate 2017-01-01 -Paragraph 35 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=18&date=2017-03-02&anchor=para_35_b&doctype=Standard&book=B -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_112_c&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_OtherRevenue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Disclosure of revenue [line items] + References No definition available. + Details
Name: | xcmig_DisclosureOfRevenueLineItems
Namespace Prefix: | xcmig_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=xcmig_ChargedServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=xcmig_TelecommunicationServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=xcmig_ServicesRenderedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=xcmig_TariffSubsidiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=xcmig_RentalAndLeasingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=xcmig_OtherServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |