Changes in Accounting Policies - Additional Information (Detail) - KRW (₩) ₩ in Millions		12 Months Ended
Jan. 01, 2019	Dec. 31, 2018
Disclosure of expected impact of initial application of new standards or interpretations [line items]
Description of practical expedients used for incremental cost of obtaining contract		As a practical expedient, the Group recognizes the incremental costs of obtaining a contracts as an expense when incurred if the amortization period of the asset is one year or less.
Weighted average incremental borrowing rate	3.49%
IFRS 16 [Member]
Disclosure of expected impact of initial application of new standards or interpretations [line items]
Increase (decrease) through changes in accounting policy, property, plant and equipment	₩ 210,028
Increase (decrease) through changes in accounting policy, intangible assets and goodwill	26,207
Increase (decrease) through changes in accounting policy, right of use assets	899,783
Increase (decrease) through changes in accounting policy, investment properties	46,666
Increase (decrease) through changes in accounting policy, lease receivables	14,659
Increase (decrease) through changes in accounting policy, prepayments	8
Increase (decrease) through changes in accounting policy, prepaid expense	84,033
Increase (decrease) through changes in accounting policy, lease liabilities	643,375
Increase (decrease) through changes in accounting policy, lease revenue	757
Increase (decrease) through changes in accounting policy, retained earnings	3,890
Increase (decrease) through changes in accounting policy, other liabilities	₩ 590

Adjustments for increase (decrease) in other liabilities to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Other liabilities; Profit (loss)]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2019-01-01
-Paragraph 20
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&anchor=para_20&doctype=Standard
-URIDate 2019-03-27

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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The description of the practical expedients that have been used when applying IFRS 15 retrospectively.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2019-01-01
-Paragraph C6
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2019-en-r&anchor=para_C6_a&doctype=Appendix&subtype=C
-URIDate 2019-03-27

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The weighted average lessee's incremental borrowing rate applied to lease liabilities recognised in the statement of financial position at the date of initial application of IFRS 16. The incremental borrowing rate is the rate of interest that a lessee would have to pay to borrow over a similar term, and with a similar security, the funds necessary to obtain an asset of a similar value to the right-of-use asset in a similar economic environment.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 16
-IssueDate 2019-01-01
-Paragraph C12
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2019-en-r&anchor=para_C12_a&doctype=Appendix&subtype=C
-URIDate 2019-03-27

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Increase (decrease) through changes in accounting policy, intangible assets and goodwill.

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Increase (decrease) through changes in accounting policy, investment properties.

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Increase (decrease) through changes in accounting policy, lease liabilities.

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Increase (decrease) through changes in accounting policy, lease revenue.

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Increase (decrease) through changes in accounting policy, prepaid expense.

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Increase (decrease) through changes in accounting policy, prepayments.

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Increase (decrease) through changes in accounting policy, property, plant and equipment.

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Increase (decrease) through changes in accounting policy, retained earnings.

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Increase (decrease) through changes in accounting policy, right of use assets.

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