XML 166 R214.htm IDEA: XBRL DOCUMENT
v3.20.1

Fair Value - Summary of Valuation Techniques and Inputs (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Jan. 01, 2019 | Dec. 31, 2017
Assets |  |  |  |
Financial assets at fair value through other comprehensive income | ₩ 557,342 | ₩ 326,157 |  |
Other financial assets |  |  |  |
Financial assets at fair value through profit or loss | 632,324 | 777,685 |  |
Derivative financial assets for hedging | 58,576 | 29,843 |  |
Investment properties | 1,387,430 | 1,091,084 | ₩ 46,666 | ₩ 1,189,531
Other financial liabilities |  |  |  |
Financial liabilities at fair value through profit or loss | 38 | 7,758 |  |
Derivative financial liabilities for hedging | 20,096 | 57,308 |  |
Level 2 [Member] |  |  |  |
Other financial assets |  |  |  |
Derivative financial assets for hedging | ₩ 58,576 | ₩ 29,843 |  |
Other financial liabilities |  |  |  |
Valuation techniques | Hull-White model, DCF Model | DCF Model |  |
Level 2 [Member] | Financial assets at fair value through other comprehensive income [member] |  |  |  |
Other financial liabilities |  |  |  |
Valuation techniques | DCF Model | DCF Model |  |
Level 2 [Member] | Financial assets at fair value through other comprehensive income [member] | Trades and other receivables [member] |  |  |  |
Assets |  |  |  |
Financial assets at fair value through other comprehensive income | ₩ 1,256,266 | ₩ 1,097,348 |  |
Level 2, 3 [Member] |  |  |  |
Other financial liabilities |  |  |  |
Derivative financial liabilities for hedging | ₩ 20,096 | ₩ 57,308 |  |
Valuation techniques | Hull-White model, DCF Model | Hull-White model, DCF Model |  |
Level 2, 3 [Member] | Financial assets at fair value through profit or loss [member] |  |  |  |
Other financial assets |  |  |  |
Financial assets at fair value through profit or loss | ₩ 632,092 | ₩ 777,564 |  |
Other financial liabilities |  |  |  |
Valuation techniques | DCF Model, Adjusted net asset model | DCF Model, Adjusted net asset model |  |
Level 2, 3 [Member] | Financial assets at fair value through other comprehensive income [member] |  |  |  |
Assets |  |  |  |
Financial assets at fair value through other comprehensive income | ₩ 550,604 | ₩ 317,296 |  |
Other financial liabilities |  |  |  |
Valuation techniques | DCF Model | DCF Model |  |
Level 3 [Member] |  |  |  |
Other financial assets |  |  |  |
Investment properties | ₩ 2,304,583 | ₩ 1,821,061 |  |
Other financial liabilities |  |  |  |
Valuation techniques | DCF Model | DCF Model |  |
Level 3 [Member] | Financial assets at fair value through profit or loss [member] |  |  |  |
Other financial liabilities |  |  |  |
Financial liabilities at fair value through profit or loss | ₩ 38 | ₩ 7,758 |  |
Valuation techniques | DCF Model, Comparable Company Analysis | DCF Model, Comparable Company Analysis |  |

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

X
- Definition The amount of financial assets classified as derivative instruments. [Refer: Financial assets; Derivatives [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_55&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_DerivativeFinancialAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of financial liabilities classified as derivative instruments. [Refer: Financial assets; Derivatives [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_55&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_DerivativeFinancialLiabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The description of the valuation techniques (for example, the market approach, cost approach and income approach) used for the fair value measurement of assets. [Refer: Valuation techniques [member]; Cost approach [member]; Income approach [member]; Market approach [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2019-01-01 -Paragraph 93 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2019-en-r&anchor=para_93_d&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_DescriptionOfValuationTechniquesUsedInFairValueMeasurementAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The description of the valuation techniques (for example, the market approach, cost approach and income approach) used for the fair value measurement of liabilities. [Refer: Valuation techniques [member]; Cost approach [member]; Income approach [member]; Market approach [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2019-01-01 -Paragraph 93 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2019-en-r&anchor=para_93_d&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_DescriptionOfValuationTechniquesUsedInFairValueMeasurementLiabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of financial assets at fair value through other comprehensive income. [Refer: At fair value [member]; Financial assets; Other comprehensive income] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2019-01-01 -Paragraph 8 -Subparagraph h -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_8_h&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_FinancialAssetsAtFairValueThroughOtherComprehensiveIncome
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of financial assets that are measured at fair value and for which gains (losses) are recognised in profit or loss. A financial asset shall be measured at fair value through profit or loss unless it is measured at amortised cost or at fair value through other comprehensive income. A gain (loss) on a financial asset measured at fair value shall be recognised in profit or loss unless it is part of a hedging relationship, it is an investment in an equity instrument for which the entity has elected to present gains and losses in other comprehensive income or it is a financial asset measured at fair value through other comprehensive income. [Refer: At fair value [member]; Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2019-01-01 -Paragraph 8 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_8_a&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of financial liabilities that meet either of the following conditions: (a) they meet the definition of held for trading; or (b) upon initial recognition they are designated by the entity as at fair value through profit or loss. An entity may use this designation only when permitted by paragraph 4.3.5 of IFRS 9 (embedded derivatives) or when doing so results in more relevant information, because either: (a) it eliminates or significantly reduces a measurement or recognition inconsistency (sometimes referred to as ‘an accounting mismatch’) that would otherwise arise from measuring assets or liabilities or recognising the gains and losses on them on different bases; or (b) a group of financial liabilities or financial assets and financial liabilities is managed and its performance is evaluated on a fair value basis, in accordance with a documented risk management or investment strategy, and information about the group is provided internally on that basis to the entity’s key management personnel (as defined in IAS 24). [Refer: At fair value [member]; Key management personnel of entity or parent [member]; Derivatives [member]; Financial assets; Financial liabilities] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2019-01-01 -Paragraph 8 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_8_e&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_FinancialLiabilitiesAtFairValueThroughProfitOrLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of property (land or a building - or part of a building - or both) held (by the owner or by the lessee as a right-of-use asset) to earn rentals or for capital appreciation or both, rather than for: (a) use in the production or supply of goods or services or for administrative purposes; or (b) sale in the ordinary course of business. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 40 -IssueDate 2019-01-01 -Paragraph 76 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2019-en-r&anchor=para_76&doctype=Standard -URIDate 2019-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 40 -IssueDate 2019-01-01 -Paragraph 79 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2019-en-r&anchor=para_79_d&doctype=Standard -URIDate 2019-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 54 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_54_b&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_InvestmentProperty
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Other financial assets. + References No definition available. + Details
Name: | kt_OtherFinancialAssetsAbstract
Namespace Prefix: | kt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Other financial liabilities. + References No definition available. + Details
Name: | kt_OtherFinancialLiabilitiesAbstract
Namespace Prefix: | kt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level2OfFairValueHierarchyMember
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_ClassesOfAssetsAxis=kt_TradesAndOtherReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level2And3OfFairValueHierarchyMember
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_LevelsOfFairValueHierarchyAxis=ifrs-full_Level3OfFairValueHierarchyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |