Post-Employment Benefits - Details of Net Defined Benefit Liabilities (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2025	Dec. 31, 2024
Disclosure of defined benefit plans [abstract]
Present value of defined benefit obligations	₩ 1,276,310	₩ 1,444,252
Fair value of plan assets	(1,473,736)	(1,603,911)
Total	(197,426)	(159,659)
Defined benefit liabilities, net	1,109	1,093
Defined benefit assets, net	₩ (198,535)	₩ (160,752)

The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2025-01-01
-Paragraph 57
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2025-03-27

+ Details

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

- References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfDefinedBenefitPlansAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of non-current net defined benefit liability. [Refer: Net defined benefit liability]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_55&doctype=Standard
-URIDate 2025-03-27

+ Details

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

- Definition

The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

+ References

+ Details

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

- Definition

The amount of deficit in a defined benefit plan. [Refer: Defined benefit plans [domain]]

+ References

+ Details

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

- Definition

The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]

+ References

+ Details

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