XML 132 R117.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Intangible Assets - Summary of Intangible Assets (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | ₩ 3,022,803 | ₩ 2,599,751 |
Acquisition and capital expenditure | 386,711 | 1,124,327 |
Disposal and termination | (27,213) | (26,925) |
Amortization | (635,150) | (599,721) | ₩ (609,185)
Impairment | (116,095) | (135,264) |
Inclusion in scope of consolidation | (4,922) | 61,222 |
Others | 6,570 | (587) |
Ending, net | 2,632,704 | 3,022,803 | 2,599,751
Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 6,500,489 | 6,442,500 |
Ending, net | 6,714,014 | 6,500,489 | 6,442,500
Accumulated Depreciation and Amortisation [Member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (3,477,686) | (3,842,749) |
Ending, net | (4,081,310) | (3,477,686) | (3,842,749)
Goodwill [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 253,486 | 342,341 |
Impairment | (84,606) | (131,600) |
Inclusion in scope of consolidation |  | 42,745 |
Ending, net | 168,880 | 253,486 | 342,341
Goodwill [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 492,105 | 449,379 |
Ending, net | 474,908 | 492,105 | 449,379
Goodwill [member] | Accumulated Depreciation and Amortisation [Member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (238,619) | (107,038) |
Ending, net | (306,028) | (238,619) | (107,038)
Development costs [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 334,676 | 461,543 |
Acquisition and capital expenditure | 247,863 | 36,075 |
Disposal and termination | (14,806) | (8,600) |
Amortization | (151,718) | (162,682) |
Inclusion in scope of consolidation | (332) |  |
Others | 2,876 | 8,340 |
Ending, net | 418,559 | 334,676 | 461,543
Development costs [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 1,483,205 | 1,487,420 |
Ending, net | 1,643,886 | 1,483,205 | 1,487,420
Development costs [member] | Accumulated Depreciation and Amortisation [Member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (1,148,529) | (1,025,877) |
Ending, net | (1,225,327) | (1,148,529) | (1,025,877)
Software [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 197,138 | 231,384 |
Acquisition and capital expenditure | 60,475 | 35,631 |
Disposal and termination | (548) | (1,928) |
Amortization | (73,174) | (78,643) |
Impairment | (3) | (46) |
Inclusion in scope of consolidation | (3,216) | 2,462 |
Others | 9,569 | 8,278 |
Ending, net | 190,241 | 197,138 | 231,384
Software [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 838,532 | 805,387 |
Ending, net | 893,500 | 838,532 | 805,387
Software [member] | Accumulated Depreciation and Amortisation [Member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (641,394) | (574,003) |
Ending, net | (703,259) | (641,394) | (574,003)
Frequency usage rights [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 1,677,289 | 972,770 |
Acquisition and capital expenditure |  | 978,309 |
Amortization | (311,146) | (273,790) |
Others | (1,201) |  |
Ending, net | 1,364,942 | 1,677,289 | 972,770
Frequency usage rights [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 2,531,654 | 2,591,229 |
Ending, net | 2,530,341 | 2,531,654 | 2,591,229
Frequency usage rights [member] | Accumulated Depreciation and Amortisation [Member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (854,365) | (1,618,459) |
Ending, net | (1,165,399) | (854,365) | (1,618,459)
Others [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 560,214 | 591,713 |
Acquisition and capital expenditure | 78,373 | 74,312 |
Disposal and termination | (11,859) | (16,397) |
Amortization | (99,112) | (84,606) |
Impairment | (31,486) | (3,618) |
Inclusion in scope of consolidation | (1,374) | 16,015 |
Others | (4,674) | (17,205) |
Ending, net | 490,081 | 560,214 | 591,713
Others [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 1,154,993 | 1,109,085 |
Ending, net | 1,171,378 | 1,154,993 | 1,109,085
Others [member] | Accumulated Depreciation and Amortisation [Member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (594,779) | (517,372) |
Ending, net | ₩ (681,297) | ₩ (594,779) | ₩ (517,372)

X
- Definition The increase in intangible assets and goodwill resulting from acquisitions through business combinations. [Refer: Business combinations [member]; Intangible assets and goodwill] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 38 -IssueDate 2017-01-01 -Paragraph 118 -Subparagraph e -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2017-03-01&anchor=para_118_e_i&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_AcquisitionsThroughBusinessCombinationsIntangibleAssetsAndGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of amortisation of intangible assets other than goodwill. [Refer: Depreciation and amortisation expense; Intangible assets other than goodwill] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 38 -IssueDate 2017-01-01 -Paragraph 118 -Subparagraph e -Clause vi -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2017-03-01&anchor=para_118_e_vi&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_AmortisationIntangibleAssetsOtherThanGoodwill
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_DisclosureOfIntangibleAssetsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The decrease in intangible assets and goodwill resulting from disposals and retirements. [Refer: Intangible assets and goodwill] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 38 -IssueDate 2017-01-01 -Paragraph 118 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2017-03-01&anchor=para_118_e&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_DisposalsAndRetirementsIntangibleAssetsAndGoodwill
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 intangible assets and goodwill. [Refer: Impairment loss recognised in profit or loss; Intangible assets and goodwill] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 38 -IssueDate 2017-01-01 -Paragraph 118 -Subparagraph e -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2017-03-01&anchor=para_118_e_iv&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_ImpairmentLossRecognisedInProfitOrLossIntangibleAssetsAndGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The increase (decrease) in intangible assets and goodwill resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Intangible assets and goodwill] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 38 -IssueDate 2017-01-01 -Paragraph 118 -Subparagraph e -Clause viii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2017-03-01&anchor=para_118_e_viii&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_IncreaseDecreaseThroughOtherChangesIntangibleAssetsAndGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of intangible assets and goodwill held by the entity. [Refer: Goodwill; Intangible assets other than goodwill] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_55&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_IntangibleAssetsAndGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Inclusion of intangible assets and goodwill in scope of consolidation. + References No definition available. + Details
Name: | kt_InclusionOfIntangibleAssetsAndGoodwillInScopeOfConsolidation
Namespace Prefix: | kt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_AccumulatedDepreciationAndAmortisationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsAndGoodwillAxis=ifrs-full_GoodwillMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsAndGoodwillAxis=ifrs-full_IntangibleAssetsUnderDevelopmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsAndGoodwillAxis=ifrs-full_ComputerSoftwareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsAndGoodwillAxis=kt_FrequencyUsageRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsAndGoodwillAxis=ifrs-full_OtherIntangibleAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |