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Financial Instruments by Category - Summary of Gains or Losses Arising From Financial Instruments by Category (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
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Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | ₩ 271,925 | ₩ 273,460 | ₩ 270,571
Interest expense | (293,854) | (263,389) | (263,579)
Total | (353,980) | 215,095 | (38,610)
Other comprehensive income (loss) for the year | (2,194) | 165,567 | 23,255
Reclassified to profit or loss from other comprehensive income (loss) for the year | (95,421) | (136,583) |
Interest expense | (41,469) | (36,651) | (44,091)
Financial liabilities designated as at fair value through profit or loss [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest expense | (4,046) |  |
Gain (loss) foreign currency transaction | 24 | (2) |
Gain (loss) on disposal |  | 2,136 | 799
Gain (loss) on valuation | 30,031 | 42,447 | 119
Derivatives used for hedging [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Gain on transactions | (1,291) | (6,208) | 1,141
Gain (loss) on valuation | (17,237) | (7,206) | (161,003)
Other comprehensive income (loss) for the year | (23,957) | (3,112) | (81,671)
Reclassified to profit or loss from other comprehensive income (loss) for the year | 15,195 | 6,722 | 107,786
Financial liabilities at amortized cost [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest expense | (275,302) | (232,197) | (220,945)
Gain (loss) foreign currency transaction | (34,574) | (3,580) | (10,717)
Gain (loss) on foreign currency translation | (168,577) | (201,623) | 141,849
Lease liabilities [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest expense | (41,469) | (36,650) | (44,091)
Financial assets at amortized cost [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | 144,505 | 74,937 | 55,742
Gain (loss) foreign currency transaction | 23,824 | 12,826 | (19,244)
Gain (loss) on foreign currency translation | (2,151) | 2,911 | (3,895)
Gain (loss) on disposal | (81) | 35 | 138
Gain (loss) on valuation | (132,102) | (110,286) | (140,474)
Financial assets at fair value through profit or loss [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | 6,008 | 3,673 | 6,548
Dividend income | 4,600 | 21,499 | 4,379
Gain (loss) foreign currency transaction | 13,711 | 17,794 |
Gain (loss) on foreign currency translation | 1,100 |  | (38)
Gain (loss) on disposal | 2,347 | 29,974 | (329)
Gain (loss) on valuation | (29,282) | 64,659 | 59,044
Financial assets at fair value through other comprehensive income [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Interest income | 190,281 | 222,290 | 227,736
Dividend income | 9,522 | 1,365 | 56
Gain (loss) on disposal | (62,183) | (22,712) | (8,152)
Gain (loss) on valuation | (61) |  |
Other comprehensive income (loss) for the year | (158,574) | 129,780 | 41,997
Derivatives financial assets for hedging [member] |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |
Gain on transactions | 27,628 |  | 6,050
Gain (loss) on valuation | 150,699 | 203,961 | (2,707)
Other comprehensive income (loss) for the year | 88,048 | 144,967 | (2,373)
Reclassified to profit or loss from other comprehensive income (loss) for the year | ₩ (110,616) | ₩ (143,305) | ₩ 3,645

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