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Financial Risk Management - Summary of Gearing Ratios (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure of detailed information about financial instruments [abstract] |  |  |  |
Total borrowings | ₩ 7,316,298 | ₩ 7,298,867 |  |
Less: cash and cash equivalents | (2,634,624) | (2,305,894) | ₩ (2,703,422) | ₩ (1,928,182)
Net debt | 4,681,674 | 4,992,973 |  |
Total equity | 15,551,433 | 15,140,684 | ₩ 14,658,490 | ₩ 13,183,354
Total capital | ₩ 20,233,107 | ₩ 20,133,657 |  |
Gearing ratio | 23.00% | 25.00% |  |

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- Definition The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 7 -IssueDate 2020-01-01 -Paragraph 45 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2020-en-r&anchor=para_45&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2020-01-01 -Paragraph B13 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_B13_a&doctype=Appendix&subtype=B -URIDate 2020-01-01 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 54 -Subparagraph i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_54_i&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of residual interest in the assets of the entity after deducting all its liabilities. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 1 -IssueDate 2020-01-01 -Paragraph 24 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2020-en-r&anchor=para_24_a&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 1 -IssueDate 2020-01-01 -Paragraph 32 -Subparagraph a -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2020-en-r&anchor=para_32_a_i&doctype=Standard -URIDate 2020-01-01 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2020-01-01 -Paragraph 93 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2020-en-r&anchor=para_93_a&doctype=Standard -URIDate 2020-01-01 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2020-01-01 -Paragraph 93 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2020-en-r&anchor=para_93_b&doctype=Standard -URIDate 2020-01-01 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2020-01-01 -Paragraph 93 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2020-en-r&anchor=para_93_e&doctype=Standard -URIDate 2020-01-01 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_55&doctype=Standard -URIDate 2020-01-01 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 78 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_78_e&doctype=Standard -URIDate 2020-01-01 + Details
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