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Other Financial Assets and Liabilities - Summary of Other Financial Assets and Liabilities (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Other financial assets	₩ 1,747,187	₩ 1,690,046
Korea software financial cooperative [member]
Disclosure of detailed information about financial instruments [line items]
Available-for-sale financial assets investment amount	5,491	1,849
Ustream Inc. [member]
Disclosure of detailed information about financial instruments [line items]
Proceeds from the disposal of Subsidiary	104,442	91,445
Money Market Wrap and Money Market Trust [member]
Disclosure of detailed information about financial instruments [line items]
Other financial assets	₩ 509,068	₩ 406,062

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- 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.

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- Definition

The amount of financial assets that the entity has pledged as collateral for liabilities or contingent liabilities, including amounts that have been reclassified in accordance with paragraph 3.2.23(a) of IFRS 9. [Refer: Contingent liabilities [member]; Financial assets]

+ References

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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
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-IssueDate 2020-01-01
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