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Investments in Associates and Joint Ventures - Summary of Changes in Investments in Associates and Joint Ventures (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning | ₩ 279,431 | ₩ 284,075
Acquisition (Disposal) | 26,912 | (19,018)
Share of net profit from associates and joint ventures | 5,912 | (15,480)
Impairment |  | (3,662)
Others | (39,848) | 33,516
Ending | 272,407 | 279,431
Korea Information & Technology Fund [member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning | 139,534 | 134,969
Share of net profit from associates and joint ventures | 15,037 | 4,275
Others | (6,316) | 290
Ending | 148,255 | 139,534
KT-SB Venture Investment Fund [member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning | 2,942 | 4,736
Acquisition (Disposal) |  | (1,069)
Share of net profit from associates and joint ventures | 1,528 | (725)
Ending | 4,470 | 2,942
Mongolian Telecommunications [member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning |  | 6,244
Share of net profit from associates and joint ventures |  | (348)
Others |  | (5,896)
KT Wibro Infra Co., Ltd. [member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning |  | 52,200
Acquisition (Disposal) |  | (52,200)
KT-CKP New Media Investment Fund [member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning | 2,294 | 4,454
Acquisition (Disposal) | (1,229) | (2,970)
Share of net profit from associates and joint ventures | (784) | 810
Ending | 281 | 2,294
Others [Member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning | 81,728 | 77,851
Acquisition (Disposal) | 2,466 | 3,178
Share of net profit from associates and joint ventures | 8,607 | (1,952)
Impairment |  | (3,662)
Others | (36,016) | 6,313
Ending | 56,785 | 81,728
KT-IBKC future investment fund [member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning | 10,825 | 3,621
Acquisition (Disposal) | (1,050) | 7,500
Share of net profit from associates and joint ventures | 1,028 | (296)
Others | (842) |
Ending | 9,961 | 10,825
K Bank Inc. [member] |  |
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items] |  |
Beginning | 42,108 |
Acquisition (Disposal) | 26,725 | 26,543
Share of net profit from associates and joint ventures | (19,504) | (17,244)
Others | 3,326 | 32,809
Ending | ₩ 52,655 | ₩ 42,108

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- Definition The amount of investments in subsidiaries, joint ventures and associates in an entity's separate financial statements. [Refer: Associates [member]; Joint ventures [member]; Subsidiaries [member]; Investments in subsidiaries] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 27 -IssueDate 2018-01-01 -Paragraph 10 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=27&date=2018-03-01&anchor=para_10&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The entity's share of the profit (loss) from continuing operations of associates and joint ventures accounted for using the equity method. [Refer: Associates [member]; Continuing operations [member]; Investments accounted for using equity method; Joint ventures [member]; Profit (loss) from continuing operations] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2018-01-01 -Paragraph B16 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2018-03-01&anchor=para_B16_a&doctype=Appendix&seq=2 -URIDate 2018-03-16 + Details
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