Lease - Summary of Details of Future Minimum Lease Payments under Operating Lease Contracts (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2018	Dec. 31, 2017
Disclosure of finance lease and operating lease by lessee [Line Items]
Net amount of minimum lease payments	₩ 373,573	₩ 377,327
Less than 1 year [member]
Disclosure of finance lease and operating lease by lessee [Line Items]
Net amount of minimum lease payments	109,025	109,258
1-5 years [member]
Disclosure of finance lease and operating lease by lessee [Line Items]
Net amount of minimum lease payments	263,395	266,434
More than 5 years [member]
Disclosure of finance lease and operating lease by lessee [Line Items]
Net amount of minimum lease payments	₩ 1,153	₩ 1,635

The amount of future minimum lease payments payable under non-cancellable operating leases. Minimum lease payments are payments over the lease term that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with: (a) for a lessee, any amounts guaranteed by the lessee or by a party related to the lessee; or (b) for a lessor, any residual value guaranteed to the lessor by: (i) the lessee; (ii) a party related to the lessee; or (iii) a third party unrelated to the lessor that is financially capable of discharging the obligations under the guarantee.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 17
-IssueDate 2018-01-01
-Paragraph 35
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=17&date=2018-03-02&anchor=para_35_a&doctype=Standard&book=b
-URIDate 2018-03-16

Name:	ifrs-full_MinimumLeasePaymentsPayableUnderNoncancellableOperatingLease
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant