XML 90 R209.htm IDEA: XBRL DOCUMENT v3.20.1

33. FINANCIAL INSTRUMENTS AND RISK MANAGEMENT (Details) - BRL (R$) R$ in Millions	Dec. 31, 2019		Dec. 31, 2018
Disclosure of detailed information about financial instruments [line items]
Financial assets at fair value	R$ 16,098		R$ 16,183
Financial liabilities	18,764		(18,120)
Financial liabilities at fair value	(18,764)	[1]	(18,120)
Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(18,281)		(17,701)
Financial liabilities at fair value	(18,281)		(17,701)
Financial liabilities at fair value through profit or loss, category [member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(483)		(419)
Financial liabilities at fair value	(483)		(419)
Suppliers [Member] | Level 2 of fair value hierarchy [Member] | Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(2,080)		(1,801)
Financial liabilities at fair value	(2,080)		(1,801)
Debt Agreed With Pension Fund [Member] | Level 2 of fair value hierarchy [Member] | Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(566)		(652)
Financial liabilities at fair value	(566)		(652)
Concessions Payable [Member] | Level 3 of fair value hierarchy [Member] | Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(20)		(19)
Financial liabilities at fair value	(20)		(19)
Advances from clients [Member] | Level 2 of fair value hierarchy [Member] | Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities			(79)
Financial liabilities at fair value			(79)
Solution for deficit of pension fund [Member] | Level 2 of fair value hierarchy [Member] | Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(550)		(378)
Financial liabilities at fair value	(550)		(378)
Loans, financings and debentures [Member] | Level 2 of fair value hierarchy [Member] | Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(14,777)		(14,772)
Financial liabilities at fair value	(14,777)		(14,772)
Derivative financial instrument liabilities, SAAG put options [Member] | Level 3 of fair value hierarchy [Member] | Financial liabilities at fair value through profit or loss, category [member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(483)		(419)
Financial liabilities at fair value	(483)		(419)
Leasing transactions [member] | Level 2 of fair value hierarchy [Member] | Financial liabilities at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial liabilities	(288)
Financial liabilities at fair value	(288)
Financial assets at amortised cost, class [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	12,128		12,675
Financial assets at fair value	12,128		12,675
Financial assets at amortised cost, class [Member] | Securities cash investments one [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	102		117
Financial assets at fair value	102		117
Financial assets at amortised cost, class [Member] | Restricted cash [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	12		91
Financial assets at fair value	12		91
Financial assets at amortised cost, class [Member] | Accounts receivable from the State of Minas Gerais [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	115		246
Financial assets at fair value	115		246
Financial assets at amortised cost, class [Member] | Concession financial assets CVA Account and Other financial components in tariff adjustments [Member] | Level 3 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	882		1,081
Financial assets at fair value	882		1,081
Financial assets at amortised cost, class [Member] | Reimbursement of tariff subsidy payments [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	97		91
Financial assets at fair value	97		91
Financial assets at amortised cost, class [Member] | Low income subsidy [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	30		30
Financial assets at fair value	30		30
Financial assets at amortised cost, class [Member] | Reimbursement for assignment of contract [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets			10
Financial assets at fair value			10
Financial assets at amortised cost, class [Member] | Accounts receivable - Renova [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets			532
Financial assets at fair value			532
Financial assets at amortised cost, class [Member] | Indemnifiable receivable - Transmission [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	1,281		1,296
Financial assets at fair value	1,281		1,296
Financial assets at amortised cost, class [Member] | Customers - Accounts receivable from the State of Minas Gerais [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets			246
Financial assets at fair value			246
Financial assets at amortised cost, class [Member] | Reimbursement for decontracted supply [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets			97
Financial assets at fair value			97
Financial assets at amortised cost, class [Member] | Concession grant fee generation concessions [Member] | Level 3 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	2,468		2,409
Financial assets at fair value	2,468		2,409
Financial assets at amortised cost, class [Member] | Escrow deposits [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	2,540		2,502
Financial assets at fair value	2,540		2,502
Financial assets at amortised cost, class [Member] | Accounts receivable from Customers and traders; Concession holders (transmission service) [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	4,601		4,173
Financial assets at fair value	4,601		4,173
Financial assets at amortised cost, class [Member] | Advances to suppliers [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets			94
Financial assets at fair value			94
Derivative financial instruments [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	3,970		3,508
Financial assets at fair value	3,970		3,508
Derivative financial instruments [Member] | Derivative financial instrument assets, Ativas and Sonda Put options [Member] | Level 3 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	3		4
Financial assets at fair value	3		4
Derivative financial instruments [Member] | Derivative financial instrument assets, Swaps [Member] | Level 3 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	1,691		813
Financial assets at fair value	1,691		813
Derivative financial instruments [Member] | Indemnifiable receivable from generation [Member] | Level 3 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	816		816
Financial assets at fair value	816		816
Derivative financial instruments [Member] | Concession of distribution infrastructure [Member] | Level 3 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	483		396
Financial assets at fair value	483		396
Financial assets at fair value through profit or loss, category [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	977		1,479
Financial assets at fair value	977		1,479
Financial assets at fair value through profit or loss, category [Member] | Cash equivalents investments [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	326		783
Financial assets at fair value	326		783
Financial assets at fair value through profit or loss, category [Member] | Debentures [Member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets			7
Financial assets at fair value			7
Financial assets at fair value through profit or loss, category [Member] | Treasury Financial Notes [Member] | Level 1 of fair value hierarchy [member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	94		254
Financial assets at fair value	94		254
Financial assets at fair value through profit or loss, category [Member] | Bank financial notes [member] | Level 2 of fair value hierarchy [Member]
Disclosure of detailed information about financial instruments [line items]
Financial assets	557		435
Financial assets at fair value	R$ 557		R$ 435
[1] On December 31, 2019 and 2018, the book values of financial instruments reflect their fair values.

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

X

- Definition

The amount of assets that are: (a) cash; (b) an equity instrument of another entity; (c) a contractual right: (i) to receive cash or another financial asset from another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially favourable to the entity; or (d) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to receive a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose the entity’s own equity instruments do not include puttable financial instruments classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. [Refer: Financial instruments, class [member]; Financial liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 25
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_25&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 35H
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_35H&doctype=Standard
-URIDate 2019-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 35I
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_35I&doctype=Standard
-URIDate 2019-03-27

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 35M
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_35M&doctype=Standard
-URIDate 2019-03-27

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 35N
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_35N&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_FinancialAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The fair value of financial assets. [Refer: At fair value [member]; Financial assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 25
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_25&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_FinancialAssetsAtFairValue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity’s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity’s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Financial instruments, class [member]; Financial assets; Derivatives [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 25
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_25&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_FinancialLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The fair value of financial liabilities. [Refer: At fair value [member]; Financial liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 25
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_25&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_FinancialLiabilitiesAtFairValue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=ifrs-full_FinancialLiabilitiesAtAmortisedCostMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=ifrs-full_FinancialLiabilitiesAtFairValueThroughProfitOrLossCategoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_SuppliersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level2OfFairValueHierarchyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_DebtAgreedWithPensionFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ConcessionsPayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level3OfFairValueHierarchyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_AdvancesFromClientsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_SolutionForDeficitOfPensionFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_LoansFinancingsAndDebenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_DerivativeFinancialInstrumentLiabilitiesSAAGPutOptionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_LeasingTransactionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtAmortisedCostMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_SecuritiesCashInvestmentsOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_RestrictedCashMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_AccountsReceivableFromTheStateOfMinasGeraisMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ConcessionFinancialAssetsCVAAccountAndOtherFinancialComponentsInTariffAdjustmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ReimbursementOfTariffSubsidyPaymentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_LowIncomeSubsidyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ReimbursementForAssignmentOfContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_AccountsReceivableRenovaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ReimbursementsReceivableTransmissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_CustomersAccountsReceivableFromTheStateOfMinasGeraisMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ReimbursementForDecontractedSupplyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ConcessionGrantFeeGenerationConcessionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_EscrowDepositsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_CustomersAndTradersConcessionHoldersTransmissionServiceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_AdvancesToSuppliersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_CategoriesOfFinancialAssetsAxis=cig_DerivativeFinancialInstrumentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_DerivativeFinancialInstrumentAssetsAtivasAndSondaPutOptionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_DerivativeFinancialInstrumentAssetsSwapsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ReimbursementsReceivableFromGenerationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_ConcessionOfDistributionInfrastructureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_CashEquivalentsInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_DebenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_TreasuryFinancialNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level1OfFairValueHierarchyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=cig_BankFinancialNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: