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

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]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 35H
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_35H&doctype=Standard
-URIDate 2022-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 35M
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_35M&doctype=Standard
-URIDate 2022-03-24

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 35N
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_35N&doctype=Standard
-URIDate 2022-03-24

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 35I
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_35I&doctype=Standard
-URIDate 2022-03-24

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 25
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_25&doctype=Standard
-URIDate 2022-03-24

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

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]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 25
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_25&doctype=Standard
-URIDate 2022-03-24

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

The gains (losses) including exchange differences recognised in other comprehensive income on the fair value measurement of assets. [Refer: At fair value [member]; Other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2022-03-24
-Paragraph 93
-Subparagraph e
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_e_ii&doctype=Standard
-URIDate 2022-03-24

Name:	ifrs-full_GainsLossesRecognisedInOtherComprehensiveIncomeFairValueMeasurementAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

The gains (losses) including exchange differences recognised in other comprehensive income on the fair value measurement of liabilities. [Refer: At fair value [member]; Other comprehensive income]

Name:	ifrs-full_GainsLossesRecognisedInOtherComprehensiveIncomeFairValueMeasurementLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

The gains (losses) including exchange differences recognised in profit or loss on the fair value measurement of assets. [Refer: At fair value [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2022-03-24
-Paragraph 93
-Subparagraph e
-Clause i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_e_i&doctype=Standard
-URIDate 2022-03-24

Name:	ifrs-full_GainsLossesRecognisedInProfitOrLossFairValueMeasurementAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

The gains (losses) including exchange differences recognised in profit or loss on the fair value measurement of liabilities. [Refer: At fair value [member]]

Name:	ifrs-full_GainsLossesRecognisedInProfitOrLossFairValueMeasurementLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

The increase in the fair value measurement of assets resulting from purchases of those assets. [Refer: At fair value [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2022-03-24
-Paragraph 93
-Subparagraph e
-Clause iii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_e_iii&doctype=Standard
-URIDate 2022-03-24

Name:	ifrs-full_PurchasesFairValueMeasurementAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The increase in the fair value measurement of liabilities resulting from purchases of those liabilities. [Refer: At fair value [member]]

Name:	ifrs-full_PurchasesFairValueMeasurementLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The decrease in the fair value measurement of assets resulting from sales. [Refer: At fair value [member]]

Name:	ifrs-full_SalesFairValueMeasurementAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The decrease in the fair value measurement of liabilities resulting from sales. [Refer: At fair value [member]]

Name:	ifrs-full_SalesFairValueMeasurementLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Changes in scope of consolidation fair value measurement assets.

No definition available.

Name:	kt_ChangesInScopeOfConsolidationFairValueMeasurementAssets
Namespace Prefix:	kt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Changes in scope of consolidation fair value measurement liabilities.

No definition available.

Name:	kt_ChangesInScopeOfConsolidationFairValueMeasurementLiabilities
Namespace Prefix:	kt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Reclassification Fair Value Measurement Assets

No definition available.

Name:	kt_ReclassificationFairValueMeasurementAssets
Namespace Prefix:	kt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Reclassification fair value measurement, liabilities.

No definition available.

Name:	kt_ReclassificationFairValueMeasurementLiabilities
Namespace Prefix:	kt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

Name:	ifrs-full_MeasurementAxis=ifrs-full_RecurringFairValueMeasurementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

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

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