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Significant Accounting Policies - Additional Information (Detail) - KRW (₩) ₩ in Millions |  | 12 Months Ended |  |
--- | --- | --- | --- | ---
Jan. 01, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Disclosure of significant accounting policies [line items] |  |  |  |
Short-term lease description |  | A lease term of 12 months or less at the commencement date |  |
Low value assets description |  | Underlying assets below $ 5,000 |  |
Loans and receivables |  | ₩ 9,653,443 |  |
Financial assets available-for-sales |  | 380,953 | ₩ 404,774 | ₩ 360,037
Debt instruments held with entity |  | 9,653,594 |  |
Loss allowance recognized for credit losses of financial assets |  | 523,799 |  |
Hedging instrument, assets |  | 7,389 |  |
Hedging instrument, liabilities |  | ₩ 93,770 |  |
Useful lives of investment property, excluding land depreciated cost model |  | 10 to 40 Years |  |
Minimum [member] | Increase (decrease) due to changes in accounting policy required by IFRSs [member] |  |  |  |
Disclosure of significant accounting policies [line items] |  |  |  |
Cumulative effect of change in operating income and expenses under modified retrospective method | ₩ 900,000 |  |  |
Maximum [member] | Increase (decrease) due to changes in accounting policy required by IFRSs [member] |  |  |  |
Disclosure of significant accounting policies [line items] |  |  |  |
Cumulative effect of change in operating income and expenses under modified retrospective method | ₩ 1,100,000 |  |  |
Available-for-sale [member] |  |  |  |
Disclosure of significant accounting policies [line items] |  |  |  |
Equity instruments held with entity |  | ₩ 371,054 |  |
Loans and receivables [member] |  |  |  |
Disclosure of significant accounting policies [line items] |  |  |  |
Debt instruments held with entity |  | 9,653,443 |  |
Held-to-maturity financial assets [member] |  |  |  |
Disclosure of significant accounting policies [line items] |  |  |  |
Debt instruments held with entity |  | ₩ 151 |  |

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- Definition The amount of additional allowance for credit losses of financial assets recognised in profit or loss. [Refer: Allowance account for credit losses of financial assets] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Note Expiry date 2018-01-01 -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_16&doctype=Standard&book=B -URIDate 2017-03-09 + Details
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- Definition The amount of instruments representing indebtedness held by the entity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_55&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The amount of instruments held by the entity that provide evidence of a residual interest in the assets of another entity after deducting all of its liabilities. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_55&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The amount of non-derivative financial assets that are designated as available for sale or are not classified as (a) loans and receivables; (b) held-to-maturity investments; or (c) financial assets at fair value through profit or loss. [Refer: Derivative financial assets; Financial assets at fair value through profit or loss; Held-to-maturity investments] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Expiry date 2018-01-01 -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph 8 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_8_d&doctype=Standard&book=B -URIDate 2017-03-09 + Details
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- Definition The amount of a hedging instrument, recognised as an asset. [Refer: Hedging instruments [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Effective 2018-01-01 -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph 24A -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_24A_a&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The amount of non-derivative financial assets with fixed or determinable payments that are not quoted in an active market, other than: (a) those that the entity intends to sell immediately or in the near term, which shall be classified as held for trading, and those that the entity, upon initial recognition, designates as at fair value through profit or loss; (b) those that the entity, upon initial recognition, designates as available for sale; or (c) those for which the holder may not recover substantially all of its initial investment, other than because of credit deterioration, which shall be classified as available for sale. An interest acquired in a pool of assets that are not loans or receivables (for example, an interest in a mutual fund or a similar fund) is not a loan or receivable. [Refer: Derivative financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Expiry date 2018-01-01 -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph 8 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_8_c&doctype=Standard&book=B -URIDate 2017-03-09 + Details
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- Definition The statement that the lessee accounts for leases of low-value assets using the recognition exemption in paragraph 6 of IFRS 16. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Effective 2019-01-01 -Name IFRS -Number 16 -IssueDate 2017-01-01 -Paragraph 60 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=16&date=2017-03-01&anchor=para_60&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The statement that the lessee accounts for short-term leases using the recognition exemption in paragraph 6 of IFRS 16. Short-term lease is a lease that, at the commencement date, has a lease term of 12 months or less. A lease that contains a purchase option is not a short-term lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Effective 2019-01-01 -Name IFRS -Number 16 -IssueDate 2017-01-01 -Paragraph 60 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=16&date=2017-03-01&anchor=para_60&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The useful lives or depreciation rates used for investment property. [Refer: Investment property] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 40 -IssueDate 2017-01-01 -Paragraph 79 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=40&date=2017-03-01&anchor=para_79_b&doctype=Standard -URIDate 2017-03-09 + Details
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