Employee Benefits - Details of Plan Assets (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of fair value of plan assets [abstract]
Guaranteed deposits in banks	₩ 1,607,253	₩ 1,550,063

The amount cash and cash equivalents contribute to the fair value of defined benefit plan assets. [Refer: Cash and cash equivalents; Plan assets, at fair value; Defined benefit plans [member]]

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 19
-IssueDate 2019-01-01
-Paragraph 142
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2019-en-r&anchor=para_142_a&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_CashAndCashEquivalentsAmountContributedToFairValueOfPlanAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant