XML 157 R137.htm IDEA: XBRL DOCUMENT
v3.20.1

Borrowings - Summary of Repayment of Borrowings Including the Current Liabilities (Detail) - KRW (₩) ₩ in Millions | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | ₩ 7,298,867 | ₩ 6,648,293
Debentures [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 5,972,554 | 5,128,649
Long-term borrowings [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 190,780 | 546,090
Gross carrying amount [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 7,319,647 |
Gross carrying amount [member] | Debentures [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 7,045,366 | ₩ 6,029,645
Gross carrying amount [member] | Debentures [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 4,400,000 |
Gross carrying amount [member] | Debentures [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 2,645,366 |
Gross carrying amount [member] | Long-term borrowings [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 274,281 |
Gross carrying amount [member] | Long-term borrowings [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 138,984 |
Gross carrying amount [member] | Long-term borrowings [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 135,297 |
Gross carrying amount [member] | Jan 1, 2020 - Dec 31, 2020 [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,186,833 |
Gross carrying amount [member] | Jan 1, 2020 - Dec 31, 2020 [member] | Debentures [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,053,140 |
Gross carrying amount [member] | Jan 1, 2020 - Dec 31, 2020 [member] | Debentures [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 460,000 |
Gross carrying amount [member] | Jan 1, 2020 - Dec 31, 2020 [member] | Debentures [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 593,140 |
Gross carrying amount [member] | Jan 1, 2020 - Dec 31, 2020 [member] | Long-term borrowings [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 133,693 |
Gross carrying amount [member] | Jan 1, 2020 - Dec 31, 2020 [member] | Long-term borrowings [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 84,968 |
Gross carrying amount [member] | Jan 1, 2020 - Dec 31, 2020 [member] | Long-term borrowings [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 48,725 |
Gross carrying amount [member] | Jan 1, 2021 - Dec 31, 2021 [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,326,925 |
Gross carrying amount [member] | Jan 1, 2021 - Dec 31, 2021 [member] | Debentures [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,230,155 |
Gross carrying amount [member] | Jan 1, 2021 - Dec 31, 2021 [member] | Debentures [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,060,000 |
Gross carrying amount [member] | Jan 1, 2021 - Dec 31, 2021 [member] | Debentures [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 170,155 |
Gross carrying amount [member] | Jan 1, 2021 - Dec 31, 2021 [member] | Long-term borrowings [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 96,770 |
Gross carrying amount [member] | Jan 1, 2021 - Dec 31, 2021 [member] | Long-term borrowings [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 51,518 |
Gross carrying amount [member] | Jan 1, 2021 - Dec 31, 2021 [member] | Long-term borrowings [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 45,252 |
Gross carrying amount [member] | Jan 1, 2022 - Dec 31, 2022 [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,379,745 |
Gross carrying amount [member] | Jan 1, 2022 - Dec 31, 2022 [member] | Debentures [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,337,907 |
Gross carrying amount [member] | Jan 1, 2022 - Dec 31, 2022 [member] | Debentures [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 560,000 |
Gross carrying amount [member] | Jan 1, 2022 - Dec 31, 2022 [member] | Debentures [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 777,907 |
Gross carrying amount [member] | Jan 1, 2022 - Dec 31, 2022 [member] | Long-term borrowings [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 41,838 |
Gross carrying amount [member] | Jan 1, 2022 - Dec 31, 2022 [member] | Long-term borrowings [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 518 |
Gross carrying amount [member] | Jan 1, 2022 - Dec 31, 2022 [member] | Long-term borrowings [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 41,320 |
Gross carrying amount [member] | Jan 1, 2023 - Dec 31, 2023 [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 456,280 |
Gross carrying amount [member] | Jan 1, 2023 - Dec 31, 2023 [member] | Debentures [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 455,780 |
Gross carrying amount [member] | Jan 1, 2023 - Dec 31, 2023 [member] | Debentures [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 340,000 |
Gross carrying amount [member] | Jan 1, 2023 - Dec 31, 2023 [member] | Debentures [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 115,780 |
Gross carrying amount [member] | Jan 1, 2023 - Dec 31, 2023 [member] | Long-term borrowings [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 500 |
Gross carrying amount [member] | Jan 1, 2023 - Dec 31, 2023 [member] | Long-term borrowings [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 500 |
Gross carrying amount [member] | After 2024 [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 2,969,864 |
Gross carrying amount [member] | After 2024 [member] | Debentures [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 2,968,384 |
Gross carrying amount [member] | After 2024 [member] | Debentures [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,980,000 |
Gross carrying amount [member] | After 2024 [member] | Debentures [member] | In foreign currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 988,384 |
Gross carrying amount [member] | After 2024 [member] | Long-term borrowings [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | 1,480 |
Gross carrying amount [member] | After 2024 [member] | Long-term borrowings [member] | In local currency [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Borrowings | ₩ 1,480 |

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 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_Borrowings
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain 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
- Details
Name: | ifrs-full_BorrowingsByNameAxis=kt_DebenturesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_BorrowingsByNameAxis=ifrs-full_LongtermBorrowingsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_CurrencyAxis=kt_LocalCurrenyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=kt_ForeignCurrencyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanOneYearAndNotLaterThanTwoYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanTwoYearsAndNotLaterThanThreeYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanThreeYearsAndNotLaterThanFourYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanFiveYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |