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Intangible Assets - Summary of Intangible Assets (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | ₩ 2,632,704 | ₩ 3,022,803 |
Acquisition and capital expenditure | 1,331,172 | 386,711 |
Disposal and termination | (15,417) | (27,213) |
Amortization | (629,526) | (635,150) | ₩ (599,721)
Impairment | (12,996) | (116,095) |
Inclusion in scope of consolidation | 93,719 |  |
Exclusion in scope of consolidation |  | (4,922) |
Others | 7,468 | 6,570 |
Ending, net | 3,407,123 | 2,632,704 | 3,022,803
Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 6,714,014 | 6,500,489 |
Ending, net | 8,064,270 | 6,714,014 | 6,500,489
Accumulated depreciation and amortisation [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (4,081,310) | (3,477,686) |
Ending, net | (4,657,147) | (4,081,310) | (3,477,686)
Goodwill [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 168,880 | 253,486 |
Impairment | (518) | (84,606) |
Inclusion in scope of consolidation | 67,696 |  |
Ending, net | 236,058 | 168,880 | 253,486
Goodwill [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 474,908 | 492,105 |
Ending, net | 542,074 | 474,908 | 492,105
Goodwill [member] | Accumulated depreciation and amortisation [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (306,028) | (238,619) |
Ending, net | (306,016) | (306,028) | (238,619)
Development costs [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 418,559 | 334,676 |
Acquisition and capital expenditure | 56,670 | 247,863 |
Disposal and termination | (3,436) | (14,806) |
Amortization | (147,304) | (151,718) |
Exclusion in scope of consolidation |  | (332) |
Others | 10,621 | 2,876 |
Ending, net | 335,110 | 418,559 | 334,676
Development costs [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 1,643,886 | 1,483,205 |
Ending, net | 1,680,372 | 1,643,886 | 1,483,205
Development costs [member] | Accumulated depreciation and amortisation [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (1,225,327) | (1,148,529) |
Ending, net | (1,345,262) | (1,225,327) | (1,148,529)
Software [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 190,241 | 197,138 |
Acquisition and capital expenditure | 29,800 | 60,475 |
Disposal and termination | (736) | (548) |
Amortization | (72,185) | (73,174) |
Impairment | (222) | (3) |
Inclusion in scope of consolidation | 2,073 |  |
Exclusion in scope of consolidation |  | (3,216) |
Others | 16,973 | 9,569 |
Ending, net | 165,944 | 190,241 | 197,138
Software [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 893,500 | 838,532 |
Ending, net | 947,312 | 893,500 | 838,532
Software [member] | Accumulated depreciation and amortisation [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (703,259) | (641,394) |
Ending, net | (781,368) | (703,259) | (641,394)
Frequency usage rights [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 1,364,942 | 1,677,289 |
Acquisition and capital expenditure | 1,110,865 |  |
Disposal and termination | (558) |  |
Amortization | (318,815) | (311,146) |
Others | 66 | (1,201) |
Ending, net | 2,156,500 | 1,364,942 | 1,677,289
Frequency usage rights [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 2,530,341 | 2,531,654 |
Ending, net | 3,641,231 | 2,530,341 | 2,531,654
Frequency usage rights [member] | Accumulated depreciation and amortisation [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (1,165,399) | (854,365) |
Ending, net | (1,484,731) | (1,165,399) | (854,365)
Others [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 490,081 | 560,214 |
Acquisition and capital expenditure | 133,837 | 78,373 |
Disposal and termination | (10,687) | (11,859) |
Amortization | (91,222) | (99,112) |
Impairment | (12,256) | (31,486) |
Inclusion in scope of consolidation | 23,950 |  |
Exclusion in scope of consolidation |  | (1,374) |
Others | (20,192) | (4,674) |
Ending, net | 513,511 | 490,081 | 560,214
Others [member] | Gross carrying amount [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | 1,171,378 | 1,154,993 |
Ending, net | 1,253,281 | 1,171,378 | 1,154,993
Others [member] | Accumulated depreciation and amortisation [member] |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |
Beginning, net | (681,297) | (594,779) |
Ending, net | ₩ (739,770) | ₩ (681,297) | ₩ (594,779)

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