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Information About Non-controlling Interests - Summary of Changes in Ownership Interest on the Equity Attributable to Owners (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of subsidiaries [abstract] |  |  |
Carrying amount of non-controlling interests acquired | ₩ 1,750 | ₩ (9,566) | ₩ (194)
Consideration paid to non-controlling interests | 9,878 | 484 | 11,312
Excess of consideration paid recognized in parent's equity | ₩ 11,628 | ₩ (9,082) | ₩ 11,118

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