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Other Financial Assets and Liabilities - Summary of Valuation Gains and Losses on Derivatives Contracts (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items] |  |  |
Valuation gain | ₩ 203,961 |  | ₩ 77,275
Valuation loss | 7,206 | ₩ 163,710 | 15,829
Other comprehensive income | 191,570 | (113,742) | 91,521
Interest rate swap [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Valuation loss |  |  | 45
Other comprehensive income | 1 | (567) | (963)
Currency swap [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Valuation gain | 203,961 |  | 72,417
Valuation loss | 7,206 | 161,661 | 15,784
Other comprehensive income | ₩ 191,569 | (113,175) | 87,626
Currency forwards [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Valuation gain |  |  | 4,858
Valuation loss |  | ₩ 2,049 |
Other comprehensive income |  |  | ₩ 4,858

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