XML 185 R139.htm IDEA: XBRL DOCUMENT
v3.20.1

19. PROPERTY, PLANT AND EQUIPMENT (Details Narrative) | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure of detailed information about property, plant and equipment [abstract] |  |  |
Average annual depreciation rate | 3.13% | 3.72% | 3.14%

X
- Definition Average annual depreciation rate property, plant and equipment. + References No definition available. + Details
Name: | cig_AverageAnnualDepreciationRatePropertyPlantAndEquipment
Namespace Prefix: | cig_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | ifrs-full_DisclosureOfPropertyPlantAndEquipmentAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration