XML 179 R158.htm IDEA: XBRL DOCUMENT
v3.25.1

Post-Employment Obligations - Schedule of Consolidated Actuarial Information (Details) - BRL (R$) R$ in Millions | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | --- | ---
IfrsStatementLineItems [Line Items] |  |  |  |
Fair value of plan assets | R$ 8,947 | R$ 9,882 |  |
Net liabilities in the statement of financial position | 4,306 | 5,417 | R$ 5,693 | R$ 6,205
Pension plans and retirement supplement plans [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Fair value of plan assets | 8,947 | 9,882 | 9,198 | 9,378
Health plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 2,560 | 3,007 | 3,314 | 3,469
Dental plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 44 | R$ 53 | R$ 61 | R$ 66
Actuarial assumption of expected rates of pension increases [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 13,105 |  |  |
Fair value of plan assets | (8,947) |  |  |
Net liabilities in the statement of financial position | 4,306 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Initial net liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 4,158 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Effect of asset ceiling [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 148 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Pension plans and retirement supplement plans [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 10,501 |  |  |
Fair value of plan assets | (8,947) |  |  |
Net liabilities in the statement of financial position | 1,702 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Pension plans and retirement supplement plans [member] | Initial net liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 1,554 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Pension plans and retirement supplement plans [member] | Effect of asset ceiling [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 148 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Health plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 2,559 |  |  |
Net liabilities in the statement of financial position | 2,559 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Health plan [member] | Initial net liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 2,559 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Dental plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 45 |  |  |
Net liabilities in the statement of financial position | 45 |  |  |
Actuarial assumption of expected rates of pension increases [member] | Dental plan [member] | Initial net liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | R$ 45 |  |  |

X
- Definition Ifrs Statement Line Items + References No definition available. + Details
Name: | cig_IfrsStatementLineItems
Namespace Prefix: | cig_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 57 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_57_a&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_DefinedBenefitObligationAtPresentValue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 57 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_57_a&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_PlanAssetsAtFairValue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 57 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_57_a&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_SurplusDeficitInPlan
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=cig_PensionPlansAndRetirementSupplementPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=cig_HealthPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=cig_DentalPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ActuarialAssumptionsAxis=ifrs-full_ActuarialAssumptionOfExpectedRatesOfPensionIncreasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_NetDefinedBenefitLiabilityAssetAxis=cig_InitialNetLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_NetDefinedBenefitLiabilityAssetAxis=ifrs-full_EffectOfAssetCeilingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |