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Earnings per Share - Summary of Basic and Diluted Earnings per Share from Operations (Detail) - KRW (₩) ₩ / shares in Units, ₩ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Basic earnings per share [abstract] |  |  |
Profit (loss) attributable to ordinary shares | ₩ 700,889 | ₩ 645,703 | ₩ 645,571
Weighted average number of ordinary shares outstanding | 245,207,307 | 245,171,283 | 245,049,466
Basic earnings per share (In Korean won) | ₩ 2,858 | ₩ 2,634 | ₩ 2,634
Profit attributable to ordinary shares (In millions of Korean won) | ₩ 700,889 | ₩ 645,703 | ₩ 645,571
Adjustment to net income attributable to ordinary shares (In millions of Korean won) |  | (157) |
Diluted profit attributable to ordinary shares (In millions of Korean won) | ₩ 700,889 | ₩ 645,546 | ₩ 645,571
Number of dilutive potential ordinary shares outstanding | 69,598 | 70,267 | 1,163
Weighted average number of ordinary shares outstanding | 245,276,905 | 245,241,550 | 245,050,629
Diluted earnings per share (In Korean won) | ₩ 2,858 | ₩ 2,632 | ₩ 2,634

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- Definition The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 33 -IssueDate 2020-01-01 -Paragraph 70 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2020-en-r&anchor=para_70_b&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 33 -IssueDate 2020-01-01 -Paragraph 66 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2020-en-r&anchor=para_66&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The profit (loss) attributable to ordinary equity holders of the parent entity. [Refer: Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 33 -IssueDate 2020-01-01 -Paragraph 70 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2020-en-r&anchor=para_70_a&doctype=Standard -URIDate 2020-01-01 + Details
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