XML 210 R189.htm IDEA: XBRL DOCUMENT
v3.21.1

27. REVENUE (Details) - BRL (R$) R$ in Millions |  | 12 Months Ended
--- | --- | ---
Jan. 02, 2019 | [2] | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
RevenueLineItems [Line Items] |  |  |  |  |  |  |
Revenue from supply of energy |  |  | R$ 26,432 | R$ 26,927 |  | R$ 24,872 |
Revenue from use of the electricity distribution systems (TUSD) |  |  | 3,022 |  |  |  |
CVA, and Other financial components |  |  | 455 |  |  |  |
Reimbursement of PIS/Pasep and Cofins over ICMS credits to customers - realization | [1] |  | (266) |  |  |  |
Transmission operation and maintenance revenue |  |  | 280 |  |  |  |
Transmission construction revenue |  |  | 201 |  |  |  |
Interest revenue arising from the financing component in the transmission contract asset |  |  | 438 |  |  |  |
Generation assets - indemnity revenue |  |  |  |  |  |  |
Distribution construction revenue |  |  | 1,436 |  |  |  |
Adjustment to expectation of cash flow from indemnifiable financial assets of distribution concession |  |  | 16 |  |  |  |
Revenue on financial updating of the Concession Grant Fee |  |  | 347 |  |  |  |
Energy transactions on the CCEE |  |  | 154 |  |  |  |
Mechanism for the sale of surplus |  |  | 234 |  |  |  |
Supply of gas |  |  | 2,011 |  |  |  |
Fine for violation of service continuity indicator |  |  | (51) |  |  |  |
Recovery of PIS/Pasep and Cofins (note 10) |  |  |  |  |  |  |
Other operating revenues |  |  | 1,709 | 1,721 |  | 1,585 |
Deductions on revenue |  |  | (11,722) |  |  |  |
NET REVENUE |  |  | R$ 25,228 | 25,487 | [2] | 22,266 |
Restated [member] |  |  |  |  |  |  |
RevenueLineItems [Line Items] |  |  |  |  |  |  |
Revenue from supply of energy |  |  |  | 26,928 |  |  |
Revenue from use of the electricity distribution systems (TUSD) |  |  |  | 2,722 |  | 2,045 |
CVA, and Other financial components |  |  |  | 58 |  | 1,973 |
Reimbursement of PIS/Pasep and Cofins over ICMS credits to customers - realization | [3] |  |  |  |  |  |
Transmission operation and maintenance revenue |  |  |  | 352 |  | 343 |
Transmission construction revenue |  |  |  | 312 |  | 138 |
Interest revenue arising from the financing component in the transmission contract asset |  |  |  | 328 |  | 311 |
Generation assets - indemnity revenue |  |  |  |  |  | 55 |
Distribution construction revenue |  |  |  | 980 |  | 802 |
Adjustment to expectation of cash flow from indemnifiable financial assets of distribution concession |  |  |  | 18 |  |  |
Revenue on financial updating of the Concession Grant Fee |  |  |  | 318 |  | 321 |
Energy transactions on the CCEE |  |  |  | 432 |  | 217 |
Supply of gas |  |  |  | 2,298 |  | 1,995 |
Fine for violation of service continuity indicator |  |  |  | (58) |  | (44) |
Recovery of PIS/Pasep and Cofins (note 10) |  |  |  | 1,428 |  |  |
Other operating revenues |  |  |  | 1,721 |  | 1,585 |
Deductions on revenue |  |  |  | (12,351) |  | (12,314) |
NET REVENUE |  | R$ 22,299 |  | R$ 25,486 | [3],[4] | R$ 22,299 | [3]
[1] | For more information, see note 9 from this financial statements.
[2] | See note 2.8.
[3] | For further details of restatement of comparative balances, see Note 2.8
[4] | Recognition of the profit margin associated to the performance obligation to construct and upgrade the transmission infrastructure, as well as the interest revenue resulting from the financing component;

X
- Definition Deductions from revenues. + References No definition available. + Details
Name: | cig_DeductionsFromRevenues
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fine for violation of service continuity indicator. + References No definition available. + Details
Name: | cig_FineForViolationOfServiceContinuityIndicator
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of generation assets indemnity revenue. + References No definition available. + Details
Name: | cig_GenerationAssetsIndemnityRevenue
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of mechanism for sale of surplus. + References No definition available. + Details
Name: | cig_MechanismForSaleOfSurplus
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represent information about the recovery of p i s pasep and cofins. + References No definition available. + Details
Name: | cig_RecoveryOfPISPasepAndCofins
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount fo PIS/Pasep and Cofins over ICMS credits to customers realization. + References No definition available. + Details
Name: | cig_ReimbursementOfPispasepAndCofinsOverIcmsCreditsToCustomersRealization
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Revenue from CVA and other financial components. + References No definition available. + Details
Name: | cig_RevenueFromCVAAndOtherFinancialComponents
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue from concession grant fee. + References No definition available. + Details
Name: | cig_RevenueFromConcessionGrantFee
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue from distribution concession. + References No definition available. + Details
Name: | cig_RevenueFromDistributionConcession
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue from electricity distribution system. + References No definition available. + Details
Name: | cig_RevenueFromElectricityDistributionSystem
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue from transactions in electricity. + References No definition available. + Details
Name: | cig_RevenueFromTransactionsInElectricity
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue from transmission concession. + References No definition available. + Details
Name: | cig_RevenueFromTransmissionConcession
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue from transmission construction. + References No definition available. + Details
Name: | cig_RevenueFromTransmissionConstruction
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue from transmission indemnity. + References No definition available. + Details
Name: | cig_RevenueFromTransmissionIndemnity
Namespace Prefix: | cig_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | cig_RevenueLineItems
Namespace Prefix: | cig_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of revenue arising from sources that the entity does not separately disclose in the same statement or note. [Refer: Revenue] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_OtherRevenue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 28 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_28_a&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 23 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_23_a&doctype=Standard -URIDate 2020-01-01 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 32 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_32&doctype=Standard -URIDate 2020-01-01 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 33 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_33_a&doctype=Standard -URIDate 2020-01-01 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 34 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_34&doctype=Standard -URIDate 2020-01-01 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 82 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_82_a&doctype=Standard -URIDate 2020-01-01 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 103 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_103&doctype=Standard -URIDate 2020-01-01 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 102 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_102&doctype=Standard -URIDate 2020-01-01 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 5 -IssueDate 2020-01-01 -Paragraph 33 -Subparagraph b -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2020-en-r&anchor=para_33_b_i&doctype=Standard -URIDate 2020-01-01 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2020-01-01 -Paragraph B12 -Subparagraph b -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_B12_b_v&doctype=Appendix&subtype=B -URIDate 2020-01-01 Reference 11: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 12 -IssueDate 2020-01-01 -Paragraph B10 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_B10_b&doctype=Appendix&subtype=B -URIDate 2020-01-01 + Details
Name: | ifrs-full_Revenue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of revenue arising from construction contracts. Construction contracts are contracts specifically negotiated for the construction of an asset or a combination of assets that are closely interrelated or interdependent in terms of their design, technology and function or their ultimate purpose or use. [Refer: Revenue] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_RevenueFromConstructionContracts
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of revenue arising from the sale of electricity. [Refer: Revenue] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_RevenueFromSaleOfElectricity
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of revenue arising from the sale of natural gas. [Refer: Current natural gas; Revenue] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_RevenueFromSaleOfNaturalGas
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_RetrospectiveApplicationAndRetrospectiveRestatementAxis=cig_Restated1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |