XML 147 R126.htm IDEA: XBRL DOCUMENT v3.21.1

16. INVESTMENTS (Details 5)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Amazonia [member]
Disclosure of detailed information about investment property [line items]
Direct interest %	[1]	74.50%	74.50%
Indirect interest %	[1]	5.76%	5.76%
Lightger [member]
Disclosure of detailed information about investment property [line items]
Direct interest %	[1]	49.00%	49.00%
Indirect interest %	[1]	11.52%	11.52%
Guanhaes [member]
Disclosure of detailed information about investment property [line items]
Direct interest %	[1]	49.00%	49.00%
Indirect interest %	[1]	11.52%	11.52%
Axxion [member]
Disclosure of detailed information about investment property [line items]
Direct interest %	[1]	49.00%	49.00%
Indirect interest %	[1]	11.52%	11.52%
UHE Itaocara [member]
Disclosure of detailed information about investment property [line items]
Direct interest %	[1]	49.00%	49.00%
Indirect interest %	[1]	11.52%	11.52%
[1] After selling the shares held in Light, on January 22, 2021, the Company no longer holds the indirect interest above.

X

- Definition

The percentage represents of direct stake.

+ References

No definition available.

+ Details

Name:	cig_PercentageOfDirectStake
Namespace Prefix:	cig_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The percentage represents of indirect stake.

+ References

No definition available.

+ Details

Name:	cig_PercentageOfIndirectStake
Namespace Prefix:	cig_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfInvestmentPropertyLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=cig_AmazoniaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=cig_LightgerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=cig_GuanhaesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=cig_AxxionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=cig_UHELtaocaraMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: