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Other Financial Assets and Liabilities - Summary of Other Financial Assets and Liabilities (Parenthetical) (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017
Disclosure of detailed information about financial instruments [line items] |  |
Other financial assets | ₩ 1,617,956 | ₩ 1,727,623
Ustream Inc. [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Proceeds from the disposal of Subsidiary | 60,978 | ₩ 59,660
Money Market Wrap and Money Market Trust [member] | Ustream Inc. [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Other financial assets | ₩ 610,862 |

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- Definition The amount of financial assets that the entity does not separately disclose in the same statement or note. [Refer: Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 54 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_54_d&doctype=Standard -URIDate 2018-03-16 + Details
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