XML 173 R162.htm IDEA: XBRL DOCUMENT
v3.22.1

Commitments and Contingencies - Summary of Guarantees Provided by the Group for Third Parties (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020
Disclosure of detailed information about borrowings [line items] |  |
Used amount | ₩ 8,437,703 | ₩ 7,316,298
Maturity | Jun. 5, 2025 |
KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Shinhan Bank [member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | Gasan Solar Power Plant Inc. |
Limit | ₩ 4,700 |
Used amount | ₩ 1,035 |
KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Suhyup Bank [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | SPP Inc. |
Limit | ₩ 3,250 |
Used amount | ₩ 624 |
KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Suhyup Bank One [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | Korea Cell Inc. |
Limit | ₩ 3,250 |
Used amount | ₩ 614 |
KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Suhyup Bank Two [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | San-Ya Agricultural Association Corporation |
Limit | ₩ 3,250 |
Used amount | ₩ 624 |
KT Hitel Co., Ltd. [member] | Cash payers [member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | Cash payers |
Limit | ₩ 860 |
Used amount | ₩ 0 |
KT Hitel Co., Ltd. [member] | NongHyup Agribusiness Group Inc And Others [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | Mobile Voucher amount |
Limit | ₩ 30,000 |
Used amount | ₩ 10,400 |
KT Hitel Co., Ltd. [member] | Emart Co., Ltd And Others [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | Mobile Voucher amount |
Limit | ₩ 20,000 |
Used amount | ₩ 300 |
Nasmedia Co Ltd [member] | Korea Securities Finance Corp [Member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Subject to payment guarantees | Stockholders Association Members |
Nasmedia Co Ltd [member] | Korea Securities Finance Corp [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Limit | ₩ 5,654 |
Used amount | ₩ 1,236 |
Bottom of range [member] | Suhyup Bank Two [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Feb. 17, 2014 |
Bottom of range [member] | KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Shinhan Bank [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Jan. 7, 2021 |
Bottom of range [member] | KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Suhyup Bank [Member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Feb. 17, 2014 |
Bottom of range [member] | KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Suhyup Bank One [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Feb. 17, 2014 |
Bottom of range [member] | KT Hitel Co., Ltd. [member] | Cash payers [member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Jul. 21, 2021 |
Bottom of range [member] | KT Hitel Co., Ltd. [member] | NongHyup Agribusiness Group Inc And Others [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Jan. 16, 2021 |
Bottom of range [member] | KT Hitel Co., Ltd. [member] | Emart Co., Ltd And Others [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Jun. 19, 2021 |
Top of range [member] | Suhyup Bank Two [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Feb. 16, 2024 |
Top of range [member] | KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Shinhan Bank [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Jan. 8, 2025 |
Top of range [member] | KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Suhyup Bank [Member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Feb. 16, 2024 |
Top of range [member] | KT Engineering Co Ltd KT ENGCORE Co Ltd [Member] | Suhyup Bank One [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Feb. 16, 2024 |
Top of range [member] | KT Hitel Co., Ltd. [member] | Cash payers [member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Apr. 15, 2022 |
Top of range [member] | KT Hitel Co., Ltd. [member] | NongHyup Agribusiness Group Inc And Others [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Jan. 14, 2022 |
Top of range [member] | KT Hitel Co., Ltd. [member] | Emart Co., Ltd And Others [Member] | Guarantees [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Maturity | Jun. 17, 2022 |

X
- Definition The amount of outstanding funds that the entity is obligated to repay. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_55&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_Borrowings
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The maturity of borrowings. [Refer: Borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 7 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_7&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_BorrowingsMaturity
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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_DisclosureOfDetailedInformationAboutBorrowingsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of contractual undiscounted cash flows for gross commitments to receive a loan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph B11D -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_B11D_e&doctype=Appendix&subtype=B -URIDate 2021-03-24 + Details
Name: | ifrs-full_GrossLoanCommitments
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Description of subject to payment guarantees. + References No definition available. + Details
Name: | kt_DescriptionOfSubjectToPaymentGuarantees
Namespace Prefix: | kt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_SignificantInvestmentsInSubsidiariesAxis=kt_KtEngineeringCoLtdktEngcoreCoLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_ShinhanBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | kt_ContingentLiabilitiesGuaranteeBeneficiaryAxis=ifrs-full_GuaranteesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_SuhyupBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_SuhyupBankOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_SuhyupBankTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInSubsidiariesAxis=kt_KTHitelCoLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_CashPayersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_NonghyupAgribusinessGroupIncAndOthersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_EmartCo.LtdAndOthersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInSubsidiariesAxis=kt_NasmediaCoLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=kt_KoreaSecuritiesFinanceCorpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |