Borrowings and Debentures - Debentures (Parenthetical) (Detail) ₩ in Millions	Dec. 31, 2018 KRW (₩)
Disclosure of detailed information about borrowings [line items]
Excess carrying amount of financial liabilities designated at fair value through profit or loss over the principal amount	₩ 11,813
3M LIBOR [Member]
Disclosure of detailed information about borrowings [line items]
Annual interest rate (%)	2.80%

The amount by which the carrying amount of a financial liability is more (less) than the amount that the entity would be contractually required to pay at maturity to the holder of the obligation. [Refer: Carrying amount [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2018-01-01
-Paragraph 10
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_10_b&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2018-01-01
-Paragraph 10A
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_10A_b&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_DifferenceBetweenCarryingAmountOfFinancialLiabilityAndAmountContractuallyRequiredToPayAtMaturityToHolderOfObligation
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant