XML 157 R145.htm IDEA: XBRL DOCUMENT v3.21.1

Borrowings - Summary of Long-term Borrowings (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2020
Inter-Korean Cooperation Fund [member]
Disclosure of detailed information about borrowings [line items]
Long term debt repayment	The above Inter-Korean Cooperation Fund is repayable in installments over 13 years after a seven-year grace period.
Vessel facility loans [member] | Shinhan Bank [member]
Disclosure of detailed information about borrowings [line items]
LIBOR rate	0.238%
Vessel facility loans [member] | Kookmin Bank [member]
Disclosure of detailed information about borrowings [line items]
LIBOR rate	0.238%

X

- Definition

The adjustment to the basis (reference rate) used for calculation of the interest rate on borrowings. [Refer: Borrowings]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 7
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_7&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_BorrowingsAdjustmentToInterestRateBasis
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
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

- Definition

Long term debt repayment description.

+ References

No definition available.

+ Details

Name:	kt_LongTermDebtRepaymentDescription
Namespace Prefix:	kt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=kt_InterKoreanCooperationFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=kt_VesselFacilityLoansMember
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:	ifrs-full_CounterpartiesAxis=kt_KookminBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: