XML 114 R99.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Other Financial Assets and Liabilities - Summary of Other Financial Assets and Liabilities (Parenthetical) (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Disclosure of detailed information about financial instruments [Line Items] |  |
Other financial assets | ₩ 754,992 | ₩ 664,726
Ustream Inc. [member] |  |
Disclosure of detailed information about financial instruments [Line Items] |  |
Proceeds from the disposal of Subsidiary | 59,660 | ₩ 49,721
Money Market Wrap and Money Market Trust [member] | Ustream Inc. [member] |  |
Disclosure of detailed information about financial instruments [Line Items] |  |
Other financial assets | ₩ 870,453 |

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

X
- Definition The amount of non-current financial assets that the entity does not separately disclose in the same statement or note. [Refer: Other financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 54 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_54_d&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_OtherNoncurrentFinancialAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Proceeds from partial disposal of a subsidiary. + References No definition available. + Details
Name: | kt_ProceedsFromPartialDisposalOfSubsidiary
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

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