Financial Assets at Amortized Cost - Summary of Financial Assets at Amortized Cost (Details) - KRW (₩) ₩ in Millions	Dec. 31, 2022	Dec. 31, 2021
Financial Assets at Amortized Cost [Line Items]
Current financial assets at amortized costs	₩ 16,762	₩ 15,422
Non-current financial assets at amortized costs	10,236	9,851
Financial assets at amortized costs	26,998	25,273
Gross carrying amount [member]
Financial Assets at Amortized Cost [Line Items]
Current financial assets at amortized costs	16,762	15,422
Non-current financial assets at amortized costs	10,236	9,851
Financial assets at amortized costs	26,998	25,273
Government bonds
Financial Assets at Amortized Cost [Line Items]
Financial assets at amortized costs	1,920	1,308
Government bonds \| Gross carrying amount [member]
Financial Assets at Amortized Cost [Line Items]
Financial assets at amortized costs	1,920	1,308
Others
Financial Assets at Amortized Cost [Line Items]
Financial assets at amortized costs	25,078	23,965
Others \| Gross carrying amount [member]
Financial Assets at Amortized Cost [Line Items]
Financial assets at amortized costs	₩ 25,078	₩ 23,965

The amount of current financial assets measured at amortised cost. [Refer: Financial assets at amortised cost]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 8
-Subparagraph f
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_8_f&doctype=Standard
-URIDate 2022-03-24

+ Details

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

- Definition

The amount of financial assets at amortised cost. The amortised cost is the amount at which financial assets are measured at initial recognition minus principal repayments, plus or minus the cumulative amortisation using the effective interest method of any difference between that initial amount and the maturity amount, and adjusted for any impairment. [Refer: Financial assets]

+ References

+ Details

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

- Definition

The amount of non-current financial assets measured at amortised cost. [Refer: Financial assets at amortised cost]

+ References

+ Details

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

- References

No definition available.

+ Details

Name:	kep_FinancialAssetsAtAmortizedCostLineItems
Namespace Prefix:	kep_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis=ifrs-full_GrossCarryingAmountMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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