XML 191 R170.htm IDEA: XBRL DOCUMENT
v3.25.1

Post-Employment Obligations - Additional Information (Details) - BRL (R$) R$ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2022
IfrsStatementLineItems [Line Items] |  |  |  |  |  |
Remuneratory interest applicable on outstanding balance |  |  | 5.51% | 5.70% | 6.00% |
Deficit paid |  |  | R$ 1,207 | R$ 1,207 | R$ 1,207 |
Finance expenses and monetary updating on debt | R$ 3 | R$ 20 |  |  |  |
Expected contributions to pension plan for amortization of deficit | 87 |  |  |  |  |
Expected contributions to defined contribution plan | R$ 93 |  |  |  |  |
Inflation index rate | 6.00% |  |  |  |  |
Net defined benefit liability (asset) | R$ 13,105 | 15,276 | R$ 15,561 |  |  | R$ 14,778
Funded Benefit Plan ('Plan A') [member] |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |
Benefit amount payable | R$ 494 | 545 |  |  |  |
Description of monthly amortizations | The monthly amortizations, calculated by the constant installments system (Price Table), will be paid up to 2031 for the 2015 and 2016 deficits, in the amount of R$323, and up to 2033 for the 2017 deficit, in the amount of R$171. |  |  |  |  |
Remuneratory interest applicable on outstanding balance | 6.00% |  |  |  |  |
Funded Benefit Plan ('Plan A') [member] | Forluz [Member] |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |
Percentage of minimum amount payments into judicial deposit account | 50.00% |  |  |  |  |
Monthly amount of deposits percentage of deficit equalizations |  |  | 50.00% | 50.00% | 50.00% |
Forluz Pension Fund [member] |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |
Inflation index rate | 6.00% |  |  |  |  |
Health plan [member] |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |
Net defined benefit liability (asset) | R$ 2,559 | 3,007 | R$ 3,469 |  |  | 3,314
Dental plan [member] |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |
Net defined benefit liability (asset) | 45 | 53 | R$ 66 |  |  | R$ 60
Life Insurance [Member] |  |  |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |  |  |
Past service cost arising from cancellation of post-retirement obligation | R$ 485 | R$ 591 |  |  |  |

X
- Definition Deficit Paid + References No definition available. + Details
Name: | cig_DeficitPaid
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represent information about the description of monthly amortizations. + References No definition available. + Details
Name: | cig_DescriptionOfMonthlyAmortizations
Namespace Prefix: | cig_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expected contributions to be paid to defined contribution plan. + References No definition available. + Details
Name: | cig_ExpectedContributionsToBePaidToDefinedContributionPlan
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Expected contributions to be paid to plan for amortization of deficit. + References No definition available. + Details
Name: | cig_ExpectedContributionsToBePaidToPlanForAmortizationOfDeficit
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Finance expenses and monetary updating on debt, defined benefit plans. + References No definition available. + Details
Name: | cig_FinanceExpensesAndMonetaryUpdatingOnDebtDefinedBenefitPlans
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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 information represents the inflation index rate. + References No definition available. + Details
Name: | cig_InflationIndexRate
Namespace Prefix: | cig_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The information represents the interest rate on benefit plan. + References No definition available. + Details
Name: | cig_InterestRateOnBenefitPlan
Namespace Prefix: | cig_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage monthly amount of deposits of deficit equalizations. + References No definition available. + Details
Name: | cig_MonthlyAmountOfDepositsPercentageOfDeficitEqualizations
Namespace Prefix: | cig_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of minimum amount payments into judicial deposit account. + References No definition available. + Details
Name: | cig_PercentageOfMinimumAmountPaymentsIntoJudicialDepositAccount
Namespace Prefix: | cig_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of benefits paid or payable for retirement benefit plans. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 26 -IssueDate 2024-01-01 -Paragraph 35 -Subparagraph b -Clause v -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=26&code=ifrs-tx-2024-en-r&anchor=para_35_b_v&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_BenefitsPaidOrPayable
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 140 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_140_a&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_LiabilityAssetOfDefinedBenefitPlans
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of expense (income) resulting from past service cost. Past service cost is the change in the present value of the defined benefit obligation for employee service in prior periods, resulting from a plan amendment (the introduction or withdrawal of, or changes to, a defined benefit plan) or a curtailment (a significant reduction by the entity in the number of employees covered by a plan). [Refer: Post-employment benefit expense in profit or loss, defined benefit plans; Defined benefit plans [domain]] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from past service cost] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 135 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_135_b&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_PastServiceCostDefinedBenefitPlans
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Details
Name: | srt_CounterpartyNameAxis=cig_ForluzMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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