Adjustment to fair value of options.

No definition available.

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- Definition

Basel ratio percentage required above minimum set by regulating bank.

+ References

No definition available.

+ Details

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- Definition

The period of projection for daily liquidity.

+ References

No definition available.

+ Details

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- Definition

Period of distribution service concession minimum parameters for economic and financial sustainability.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Definition

Period of distribution service concession quality criteria.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Definition

Estimated contract credits in arrears receivable.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financial instruments and risk management.

+ References

No definition available.

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- Definition

Gain on cashflow hedge dismantled.

+ References

No definition available.

+ Details

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Namespace Prefix:	cig_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Hedge Dismantled on Cash Inflow

+ References

No definition available.

+ Details

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Namespace Prefix:	cig_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Interest on swap settled in cash flow.

+ References

No definition available.

+ Details

Name:	cig_InterestOnSwapSettledInCashFlow
Namespace Prefix:	cig_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Minimum equity required for concession of credit.

+ References

No definition available.

+ Details

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Namespace Prefix:	cig_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of estimated general market prices index inflation index.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
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- Definition

Percentage of estimated national consumer price index inflation index.

+ References

No definition available.

+ Details

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- Definition

Percentage of reasonably possible unobservable input, assets and liabilities.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
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- Definition

Percentage of fair value of loans and debentures based on expanded national consumer price index rate.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Percentage of fair value of loans and debentures based on interbank deposit certificates rate.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of maximum portfolio limit per bank entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	cig_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of minimum fedreal risk concentrate.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
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- Definition

Percentage of regulatory agent limits for consumer exposure.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of regulatory agent margin distributor supply.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The average exchange rate used by the entity. Exchange rate is the ratio of exchange for two currencies.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 112
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-URIDate 2024-03-27

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

- Definition

The net gain arising from exchange differences recognised in profit or loss, excluding those arising on financial instruments measured at fair value through profit or loss in accordance with IFRS 9. [Refer: Foreign exchange gain (loss)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 21
-IssueDate 2024-01-01
-Paragraph 52
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=21&code=ifrs-tx-2024-en-r&anchor=para_52_a&doctype=Standard
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Balance Type:	credit
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Financial Instruments and Risk Management - Additional Information (Details) - BRL (R$)		12 Months Ended
	Dec. 05, 2024	Dec. 31, 2024	Dec. 31, 2021	Dec. 31, 2023
Financial instruments and risk management [line items]
Interest on swap settled in cash flow		R$ (7,000,000)
Percentage of fair value of loans and debentures on CDI rates		111.43%
Adjustment to fair value	R$ 381,110,000,000
Gain on cash flow hedge dismantled	521,000,000
Hedge dismantled on cash inflow	R$ 443,000,000
Appreciation to excahange of foreign currencies, amount		R$ 5,700,000
Average foreign currencies exchange rate		7.92
Estimated contract credits in arrears receivable		R$ 850,000,000		R$ 868,000,000
Minimum equity required for concession of credit		R$ 800,000,000
Basel ratio percentage required above minimum set by regulating bank		1.00%
Percentage of estimated IPCA inflation index		4.50%
Percentage of estimated IGPM inflation index		3.76%
Percentage of maximum portfolio limit per bank entity		30.00%
Percentage of minimum fedreal risk concentrate		50.00%
Percentage of regulatory agent limits for consumer exposure		100.00%
Distribution service concession quality criteria period			three consecutive years
Distribution service concession minimum parameters for economic and financial sustainability			two consecutive years
Daily liquidity projection period		180 days
Minimum [Member]
Financial instruments and risk management [line items]
Percentage of fair value of loans and debentures on CDI rates		0.47%
Percentage of fair value of loans and debentures on IPCA		4.10%
Percentage of regulatory agent margin distributor supply		95.00%
Maximum [Member]
Financial instruments and risk management [line items]
Percentage of fair value of loans and debentures on CDI rates		2.05%
Percentage of fair value of loans and debentures on IPCA		7.62%
Percentage of regulatory agent margin distributor supply		105.00%
Probable Scenario [Member]
Financial instruments and risk management [line items]
Percentage of estimated IPCA inflation index		4.50%
Percentage of estimated IGPM inflation index		3.76%
Selic interest rate [Member] \| Minimum [Member]
Financial instruments and risk management [line items]
Significant interest rate risk		6.006%
Selic interest rate [Member] \| Maximum [Member]
Financial instruments and risk management [line items]
Significant interest rate risk		9.009%
Selic interest rate [Member] \| Probable Scenario [Member]
Financial instruments and risk management [line items]
Significant interest rate risk		15.00%
TJLP interest rate [member] \| Probable Scenario [Member]
Financial instruments and risk management [line items]
Significant interest rate risk		7.94%