XML 130 R118.htm IDEA: XBRL DOCUMENT
v3.21.1

Property and Equipment - Summary of Changes in Property and Equipment (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | ₩ 13,785,299 | ₩ 13,068,257
Changes in accounting policy |  | (210,028)
Acquisition and capital expenditure | 3,151,849 | 3,693,428
Disposal and termination | (78,936) | (87,493)
Depreciation | (2,570,775) | (2,502,576)
Impairment | (79,775) | (43,260)
Transfer in (out) | (44,860) | (61,109)
Transfer to investment properties | (2,056) | (41,335)
Transfer assets held-for-sale |  | (90,451)
Changes in scope of consolidation | 818 |
Others | 44,555 | 59,866
Ending, net | 14,206,119 | 13,785,299
Gross carrying amount [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 45,655,456 | 44,289,629
Ending, net | 47,586,332 | 45,655,456
Accumulated depreciation, amortisation and impairment [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | (31,870,157) | (31,221,372)
Ending, net | (33,380,213) | (31,870,157)
Land [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 1,262,181 | 1,281,187
Acquisition and capital expenditure | 25,156 | 338
Disposal and termination | (1,756) | (1,352)
Transfer in (out) | 53,238 | 126,066
Transfer to investment properties | 6,792 | (33,254)
Transfer assets held-for-sale |  | (89,330)
Changes in scope of consolidation | 56 |
Others | (11,040) | (21,474)
Ending, net | 1,334,627 | 1,262,181
Land [member] | Gross carrying amount [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 1,262,313 | 1,281,319
Ending, net | 1,334,759 | 1,262,313
Land [member] | Accumulated depreciation, amortisation and impairment [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | (132) | (132)
Ending, net | (132) | (132)
Buildings and structures [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 2,162,064 | 2,007,685
Changes in accounting policy |  | (149)
Acquisition and capital expenditure | 7,249 | 4,523
Disposal and termination | (3,367) | (4,213)
Depreciation | (135,646) | (134,350)
Impairment | (36) | (32)
Transfer in (out) | 283,937 | 270,980
Transfer to investment properties | (8,848) | (8,081)
Transfer assets held-for-sale |  | (1,121)
Changes in scope of consolidation | 494 |
Others | 2,175 | 26,822
Ending, net | 2,308,022 | 2,162,064
Buildings and structures [member] | Gross carrying amount [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 4,125,229 | 3,873,074
Ending, net | 4,402,691 | 4,125,229
Buildings and structures [member] | Accumulated depreciation, amortisation and impairment [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | (1,963,165) | (1,865,389)
Ending, net | (2,094,669) | (1,963,165)
Machinery and equipment1 [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 9,093,251 | 8,475,016
Changes in accounting policy |  | (12,947)
Acquisition and capital expenditure | 112,085 | 205,359
Disposal and termination | (69,401) | (76,457)
Depreciation | (2,343,965) | (2,278,286)
Impairment | (35,271) | (41,450)
Transfer in (out) | 2,489,138 | 2,742,671
Changes in scope of consolidation | 225 |
Others | 68,921 | 79,345
Ending, net | 9,314,983 | 9,093,251
Machinery and equipment1 [member] | Gross carrying amount [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 37,654,635 | 36,327,007
Ending, net | 39,182,265 | 37,654,635
Machinery and equipment1 [member] | Accumulated depreciation, amortisation and impairment [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | (28,561,384) | (27,851,991)
Ending, net | (29,867,282) | (28,561,384)
Others [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 267,535 | 478,381
Changes in accounting policy |  | (196,932)
Acquisition and capital expenditure | 47,669 | 64,072
Disposal and termination | (3,385) | (4,109)
Depreciation | (91,164) | (89,940)
Impairment | (44,468) | (1,751)
Transfer in (out) | 28,024 | 16,218
Transfer to investment properties |  | 0
Changes in scope of consolidation | 43 |
Others | 1,398 | 1,596
Ending, net | 205,652 | 267,535
Others [member] | Gross carrying amount [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 1,612,108 | 1,981,646
Ending, net | 1,619,822 | 1,612,108
Others [member] | Accumulated depreciation, amortisation and impairment [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | (1,344,573) | (1,503,265)
Ending, net | (1,414,170) | (1,344,573)
Construction-in-progress [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 1,000,268 | 825,988
Acquisition and capital expenditure | 2,959,690 | 3,419,136
Disposal and termination | (1,027) | (1,362)
Impairment | 0 | (27)
Transfer in (out) | (2,899,197) | (3,217,044)
Others | (16,899) | (26,423)
Ending, net | 1,042,835 | 1,000,268
Construction-in-progress [member] | Gross carrying amount [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | 1,001,171 | 826,583
Ending, net | 1,046,795 | 1,001,171
Construction-in-progress [member] | Accumulated depreciation, amortisation and impairment [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Beginning, net | (903) | (595)
Ending, net | ₩ (3,960) | ₩ (903)

X
- Definition The amount of additions to property, plant and equipment other than those acquired through business combinations. [Refer: Business combinations [member]; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_i&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The decrease in property, plant and equipment through classification as held for sale or inclusion in a disposal group classified as held for sale. [Refer: Disposal groups classified as held for sale [member]; Property, plant and equipment; Disposal groups classified as held for sale [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause ii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_ii&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_DecreaseThroughClassifiedAsHeldForSalePropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of depreciation of property, plant and equipment. [Refer: Depreciation and amortisation expense; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause vii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_vii&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 75 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_75_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_DepreciationPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
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 domain members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfPropertyPlantAndEquipmentLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The decrease in property, plant and equipment resulting from disposals and retirements. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_DisposalsAndRetirementsPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of impairment loss recognised in profit or loss for property, plant and equipment. [Refer: Impairment loss recognised in profit or loss; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_v&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 98 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_98_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The increase (decrease) in property, plant and equipment resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause ix -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_ix&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_IncreaseDecreaseThroughOtherChangesPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The increase (decrease) in property, plant and equipment resulting from transfers and changes that the entity does not separately disclose in the same statement or note. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The increase (decrease) in property, plant and equipment resulting from transfers. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_IncreaseDecreaseThroughTransfersPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 54 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_54_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_PropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Change in scope of consolidation. + References No definition available. + Details
Name: | kt_ChangeInScopeOfConsolidation
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Changes in accounting policy property plant and equipment. + References No definition available. + Details
Name: | kt_ChangesInAccountingPolicyPropertyPlantAndEquipment
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

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

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_LandMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_BuildingsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=kt_MachineryAndEquipment1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_OtherPropertyPlantAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_ConstructionInProgressMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |