XML 213 R177.htm IDEA: XBRL DOCUMENT
v3.22.1

Schedule of construction cost (Details) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Operating Costs And Expenses |  |  |
Personnel and managers | R$ 100 | R$ 83 | R$ 85
Materials | 1,150 | 775 | 595
Outsourced services | 682 | 598 | 421
Others | 104 | 125 | 99
Construction cost | R$ 2,036 | R$ 1,581 | R$ 1,200

X
- References No definition available. + Details
Name: | cig_ConstructionContractsCosts
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition Material construction cost. + References No definition available. + Details
Name: | cig_MaterialConstructionCost
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Other construction cost. + References No definition available. + Details
Name: | cig_OtherConstructionCost
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Outsourced service cost. + References No definition available. + Details
Name: | cig_OutsourcedServiceCost
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Personnel and managers cost. + References No definition available. + Details
Name: | cig_PersonnelAndManagersCost
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration