XML 107 R94.htm IDEA: XBRL DOCUMENT
v3.25.1

Financial Instruments by Category - Summary of Gains or Losses Arising From Financial Instruments by Category (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | ₩ 303,535 | ₩ 279,607 | ₩ 271,925
Interest expense | (374,665) | (356,345) | (293,854)
Other comprehensive income (loss) for the year | (90,195) | 7,447 | (2,194)
Reclassified to profit or loss from other comprehensive income (loss) for the year | (285,954) | (37,942) |
Interest expense | (47,556) | (52,035) | (41,469)
Total | (215,290) | (92,910) | (353,980)
Financial liabilities at amortized cost [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Gain on foreign currency transaction | (41,959) | (24,054) | (34,574)
Gain (loss) on foreign currency translation | (421,608) | (93,004) | (168,577)
Gain (loss) on disposal | (5,866) | 3,411 |
Interest expense | (387,535) | (358,486) | (275,302)
Financial liabilities designated as at fair value through profit or loss [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Gain on foreign currency transaction |  | (5) | 24
Gain (loss) on disposal |  | 4,788 |
Interest expense |  | (44) | (4,046)
Gain (loss) on valuation | (3,221) | (7,394) | 30,031
Derivatives used for hedging [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Gain (loss) on transactions |  |  | (1,291)
Gain (loss) on valuation | 9,337 | 11,503 | (17,237)
Other comprehensive income (loss) for the year | (871) | 7,557 | (23,957)
Reclassified to profit or loss from other comprehensive income (loss) for the year | (9,386) | (8,764) | 15,195
Lease liabilities [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest expense | (47,556) | (52,035) | (41,469)
Financial assets at amortized cost [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | 379,371 | 360,134 | 144,505
Gain on foreign currency transaction | 27,748 | 22,782 | 23,824
Gain (loss) on foreign currency translation | 9,534 | 5,741 | (2,151)
Gain (loss) on disposal | (2) | (3,409) | (81)
Gain (loss) on valuation | (184,942) | (172,966) | (132,102)
Financial assets at fair value through profit or loss [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | 10,281 | 13,480 | 6,008
Dividend income | 8,411 | 6,918 | 4,600
Gain on foreign currency transaction | 2,469 |  | 1,100
Gain (loss) on foreign currency translation | 29,029 | 3,396 | 13,711
Gain (loss) on disposal | 13,811 | 14,237 | 2,347
Gain (loss) on valuation | (66,133) | (31,965) | (29,282)
Financial assets at fair value through other comprehensive income [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | 19,888 | 18,966 | 190,281
Dividend income | 62,220 | 52,813 | 9,522
Loss on valuation |  |  | (61)
Gain (loss) on disposal | (8,277) | (11,193) | (62,183)
Other comprehensive income (loss) for the year | (7,602) | 121,805 | (158,574)
Derivatives used for hedging [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Gain (loss) on transactions | 38,620 | 10,192 | 27,628
Gain (loss) on valuation | 361,844 | 34,092 | 150,699
Other comprehensive income (loss) for the year | 273,673 | 7,772 | 88,048
Reclassified to profit or loss from other comprehensive income (loss) for the year | ₩ (276,568) | ₩ (29,178) | ₩ (110,616)

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with 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 recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount. [Refer: Carrying amount [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2024-01-01 -Paragraph 130 -Subparagraph d -Clause ii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2024-en-r&anchor=para_130_d_ii&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2024-01-01 -Paragraph 130 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2024-en-r&anchor=para_130_b&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_ImpairmentLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of expense arising from interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2024-01-01 -Paragraph 28 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2024-en-r&anchor=para_28_e&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2024-01-01 -Paragraph B13 -Subparagraph f -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_B13_f&doctype=Appendix&subtype=B -URIDate 2024-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2024-01-01 -Paragraph 23 -Subparagraph d -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2024-en-r&anchor=para_23_d&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_InterestExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of interest expense on lease liabilities. [Refer: Lease liabilities] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 16 -IssueDate 2024-01-01 -Paragraph 53 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2024-en-r&anchor=para_53_b&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_InterestExpenseOnLeaseLiabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of income and expense (including reclassification adjustments) that is not recognised in profit or loss as required or permitted by IFRSs. [Refer: IFRSs [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2024-01-01 -Paragraph B12 -Subparagraph b -Clause viii -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_B12_b_viii&doctype=Appendix&subtype=B -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 91 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_91_a&doctype=Standard -URIDate 2024-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 106 -Subparagraph d -Clause ii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_106_d_ii&doctype=Standard -URIDate 2024-03-27 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 81A -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_81A_b&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_OtherComprehensiveIncome
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of other comprehensive income that will be reclassified to profit or loss, before tax. [Refer: Other comprehensive income] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph IG6 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_IG6&doctype=Implementation%20Guidance -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 82A -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_82A&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossBeforeTax
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of dividends recognised as income. Dividends are distributions of profits to holders of equity investments in proportion to their holdings of a particular class of capital. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 112 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_112_c&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_RevenueFromDividends
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of income arising from interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2024-01-01 -Paragraph 23 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2024-en-r&anchor=para_23_c&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2024-01-01 -Paragraph 28 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2024-en-r&anchor=para_28_e&doctype=Standard -URIDate 2024-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2024-01-01 -Paragraph B13 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_B13_e&doctype=Appendix&subtype=B -URIDate 2024-03-27 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 112 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_112_c&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_RevenueFromInterest
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain loss on derivatives transactions. + References No definition available. + Details
Name: | kt_GainLossOnDerivativesTransactions
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain Loss On Foreign Currency Transaction + References No definition available. + Details
Name: | kt_GainLossOnForeignCurrencyTransaction
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain loss on valuation. + References No definition available. + Details
Name: | kt_GainLossOnValuation
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain on foreign currency translations. + References No definition available. + Details
Name: | kt_GainOnForeignCurrencyTranslations
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gains Losses Arising From Financial Instruments By Category + References No definition available. + Details
Name: | kt_GainsLossesArisingFromFinancialInstrumentsByCategory
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gains (losses) on disposal. + References No definition available. + Details
Name: | kt_GainsLossesOnDisposal
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_CategoriesOfFinancialLiabilitiesAxis=ifrs-full_FinancialLiabilitiesAtAmortisedCostCategoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialLiabilitiesAxis=ifrs-full_FinancialLiabilitiesAtFairValueThroughProfitOrLossCategoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialLiabilitiesAxis=kt_DerivativesLiabilitiesUsedForHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialLiabilitiesAxis=ifrs-full_LeaseLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtAmortisedCostCategoryMember
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_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeCategoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=kt_DerivativeFinancialAssetsForHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |