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v3.21.1

Deferred Income Tax and Income Tax Expense - Summary of Movement in Deferred Income Tax Assets and Liabilities (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | ₩ (612) | ₩ 260,584 |
Consolidated statements of operations | (72,124) | (199,527) | ₩ 15,016
Other comprehensive income | 77,103 | (61,669) |
Ending | 4,367 | (612) | 260,584
Deferred tax liabilities derivative assets [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (10,898) |  |
Consolidated statements of operations | 10,055 | (10,250) |
Other comprehensive income |  | (648) |
Ending | (843) | (10,898) |
Deferred tax liabilities investment in subsidiaries associates and joint ventures [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (108,191) | (93,604) |
Consolidated statements of operations | (64,553) | (14,622) |
Other comprehensive income | (8,820) | 35 |
Ending | (181,564) | (108,191) | (93,604)
Deferred tax liabilities depreciation [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (11,606) | (424) |
Consolidated statements of operations | 7,431 | (11,182) |
Ending | (4,175) | (11,606) | (424)
Deferred tax liabilities advanced depreciation provision [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (313,121) | (313,184) |
Consolidated statements of operations | 1,203 | 63 |
Ending | (311,918) | (313,121) | (313,184)
Deferred tax liabilities deposits for severance benefits [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (496,853) | (398,982) |
Consolidated statements of operations | (26,419) | (99,126) |
Other comprehensive income | 2,015 | 1,255 |
Ending | (521,257) | (496,853) | (398,982)
Deferred tax liabilities accrued income [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (1,541) | (1,558) |
Consolidated statements of operations | (212) | 17 |
Ending | (1,753) | (1,541) | (1,558)
Deferred tax liabilities reserve for technology and human resource development [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (204) | (204) |
Ending | (204) | (204) | (204)
Other deferred tax liabilities [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (523,150) | (284,255) |
Consolidated statements of operations | 53,797 | (238,725) |
Other comprehensive income | 0 | (170) |
Ending | (469,353) | (523,150) | (284,255)
Deferred tax derivative assets [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning |  | 8,341 |
Consolidated statements of operations |  | (850) |
Other comprehensive income |  | (7,491) |
Ending |  |  | 8,341
Deferred tax assets provision for impairment or trade receivables [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 84,071 | 99,887 |
Consolidated statements of operations | 4,994 | (15,816) |
Ending | 89,065 | 84,071 | 99,887
Deferred tax assets inventory valuation [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 23 | 121 |
Consolidated statements of operations | (259) | (98) |
Ending | (236) | 23 | 121
Deferred tax assets contribution for construction [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 16,154 | 16,800 |
Consolidated statements of operations | 246 | (646) |
Ending | 16,400 | 16,154 | 16,800
Deferred Tax Assets Provisions [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 32,824 | 36,178 |
Consolidated statements of operations | 1,198 | (3,354) |
Ending | 34,022 | 32,824 | 36,178
Deferred tax assets property, plant and equipment [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 228,655 | 230,278 |
Consolidated statements of operations | (1,695) | (1,623) |
Ending | 226,960 | 228,655 | 230,278
Deferred Tax assets assets retirement obligation [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 29,016 | 24,532 |
Consolidated statements of operations | (883) | 4,484 |
Ending | 28,133 | 29,016 | 24,532
Deferred tax assets withholding of facilities expenses [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 6,183 | 6,609 |
Consolidated statements of operations | (436) | (426) |
Ending | 5,747 | 6,183 | 6,609
Deferred tax assets deduction of installment receivables [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 48 | 42 |
Consolidated statements of operations | (20) | 6 |
Ending | 28 | 48 | 42
Deferred tax assets gain or loss foreign currency translation [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 20,677 | 10,672 |
Consolidated statements of operations | (20,539) | 10,005 |
Ending | 138 | 20,677 | 10,672
Deferred tax assets deferred revenue [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 35,800 | 39,641 |
Consolidated statements of operations | 7,230 | (3,841) |
Ending | 43,030 | 35,800 | 39,641
Deferred tax assets real-estate sales [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 13,685 | 21,728 |
Consolidated statements of operations | (13,685) | (8,043) |
Ending |  | 13,685 | 21,728
Other deferred tax assets [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 708,437 | 537,209 |
Consolidated statements of operations | (123,798) | 174,177 |
Other comprehensive income | 948 | (2,949) |
Ending | 585,587 | 708,437 | 537,209
Deferred tax assets [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 1,905,480 | 1,673,777 |
Consolidated statements of operations | (20,492) | 235,361 |
Other comprehensive income | 6,274 | (3,658) |
Ending | 1,891,262 | 1,905,480 | 1,673,777
Deferred tax assets defined benefit liabilities [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 569,471 | 513,842 |
Consolidated statements of operations | 13,707 | 48,847 |
Other comprehensive income | 15,186 | 6,782 |
Ending | 598,364 | 569,471 | 513,842
Deferred tax assets tax credit carry forwards [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 128,245 | 102,898 |
Consolidated statements of operations | 16,686 | 25,347 |
Ending | 144,931 | 128,245 | 102,898
Deferred tax liabilities contract assets [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (53,750) | (11,505) |
Consolidated statements of operations | (112,794) | (42,245) |
Ending | (166,544) | (53,750) | (11,505)
Deferred tax liabilities financial assets at fair value through profit or loss [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (323) | (661) |
Consolidated statements of operations | (304) | 338 |
Ending | (627) | (323) | (661)
Deferred tax liabilities Financial assets at fair value through other comprehensive income [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (103,837) | (41,798) |
Consolidated statements of operations | (4,420) | (3,556) |
Other comprehensive income | 77,634 | (58,483) |
Ending | (30,623) | (103,837) | (41,798)
Deferred tax assets unsettled expenses [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | 160,436 | 127,897 |
Consolidated statements of operations | (24,358) | 32,539 |
Ending | 136,078 | 160,436 | 127,897
Temporary differences [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (128,857) | 157,686 |
Consolidated statements of operations | (88,810) | (224,874) |
Other comprehensive income | 77,103 | (61,669) |
Ending | (140,564) | (128,857) | 157,686
Deferred tax liabilities [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (2,034,337) | (1,516,091) |
Consolidated statements of operations | (68,318) | (460,235) |
Other comprehensive income | 70,829 | (58,011) |
Ending | (2,031,826) | (2,034,337) | (1,516,091)
Deferred Tax Liabilities Contract Cost [Member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Beginning | (410,863) | (369,916) |
Consolidated statements of operations | 67,898 | (40,947) |
Ending | (342,965) | ₩ (410,863) | ₩ (369,916)
Deferred Tax Assets Derivative instrument [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Consolidated statements of operations | 40,342 |  |
Other comprehensive income | (9,860) |  |
Ending | 30,482 |  |
Deferred Tax Assets Contract Assets [member] |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items] |  |  |
Consolidated statements of operations | 97,464 |  |
Ending | ₩ 97,464 |  |

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