Other Financial Assets and Liabilities - Additional Information (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about financial instruments [Line Items]
Ineffective portion recognized in profit or loss cash flow hedge valuation gain	₩ 1,961	₩ 1,637	₩ 2,663
Korea Software Financial Cooperative [Member]
Disclosure of detailed information about financial instruments [Line Items]
Available-for-sale financial assets investment amount	₩ 1,000

The gains (losses) on the ineffective portion of cash flow hedges recognised in profit or loss. [Refer: Cash flow hedges [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2018-01-01
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 24
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_24_b&doctype=Standard&book=B
-URIDate 2017-03-09

Name:	ifrs-full_GainsLossesOnIneffectivenessOfCashFlowHedgesRecognisedInProfitOrLoss
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration