XML 217 R199.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

Operating Costs and Expenses - Schedule of Operating Costs and Expenses (Details) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | R$ 14,648 | R$ 14,614 | R$ 16,101
Basic network usage charges |  | 2,937 | 2,671 | 3,337
Gas purchased for resale |  | 2,237 | 2,735 | 2,011
Total costs of energy and gas |  | 19,822 | 20,020 | 21,449
Supply from itaipu binacional [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 1,207 | 1,644 | 1,946
Physical guarantee quota contracts [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 918 | 925 | 832
Quotas for Angra I and II nuclear plants [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 364 | 357 | 244
Spot market [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 478 | 530 | 1,224
Proinfa program [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 511 | 598 | 401
Bilateral contracts [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 510 | 493 | 418
Energy acquired in regulated market auctions [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 3,940 | 3,334 | 6,242
Energy acquired in the free market [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale | [1] | 5,612 | 6,003 | 4,976
Distributed generation ('geracao distribuida') [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | 2,331 | 1,977 | 1,268
PIS/pasep and cofins credits [member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Energy purchased for resale |  | (1,223) | (1,247) | (1,450)
Basic network usage charges |  | (337) | (304) | (367)
Transmission Charges Basic Grid [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Basic network usage charges |  | 3,220 | 2,925 | 3,663
Distribution Charges [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Basic network usage charges |  | R$ 54 | R$ 50 | R$ 41
[1] | The energy acquired in the free environment by the Parent Company derives from the contracts transferred by Cemig GT, as a result of the process of partial segregation of the Company's energy trading business.

X
- Definition Basic Network Usage Charges + References No definition available. + Details
Name: | cig_BasicNetworkUsageCharges
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Energy purchased for resale. + References No definition available. + Details
Name: | cig_EnergyPurchasedForResale
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Gas Purchased For Resale + References No definition available. + Details
Name: | cig_GasPurchasedForResale
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total Costs Of Energy And Gas + References No definition available. + Details
Name: | cig_TotalCostsOfEnergyAndGas
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_SupplyFromItaipuBinacionalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_PhysicalGuaranteeQuotaContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_QuotasForAngraIAndIINuclearPlantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_SpotMarketMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_ProinfaProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_BilateralContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_EnergyAcquiredInRegulatedMarketAuctionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_EnergyAcquiredInTheFreeMarketMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_DistributedGenerationGeracaoDistribuidaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_PISPasepAndCofinsCreditsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_TransmissionChargesBasicGridMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=cig_DistributionChargesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |