Post-Employment Benefits - Details of Remeasurements of Net Defined Benefit Liabilities (Assets) Included in Other Comprehensive Income (Loss) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Disclosure of net defined benefit liability (asset) [Line Items]
Group's share of associates regarding remeasurements	₩ 0	₩ (85)	₩ 170
Related income tax	(7,065)	22,368	(14,818)
Remeasurements of net defined benefit liabilities (assets) [member]
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	(84,833)	47,087	(2,900)
Actuarial profit or loss arising from: Experience adjustment	(5,600)	(21,525)	66,461
Actuarial profit or loss arising from: Demographic assumptions	(12,692)	7,487	(85)
Actuarial profit or loss arising from: Financial assumptions	100,363	(128,384)	(871)
Return on plan assets	(894)	(11,781)	(870)
Group's share of associates regarding remeasurements	0	(85)	170
Subtotal	81,177	(154,288)	64,805
Related income tax	(7,065)	22,368	(14,818)
Ending balance	₩ (10,721)	₩ (84,833)	₩ 47,087

The decrease (increase) in a net defined benefit liability (asset) resulting from actuarial gains (losses) arising from changes in demographic assumptions that result in remeasurements of the net defined benefit liability (asset). Demographic assumptions deal with matters such as: (a) mortality; (b) rates of employee turnover, disability and early retirement; (c) the proportion of plan members with dependants who will be eligible for benefits; (d) the proportion of plan members who will select each form of payment option available under the plan terms; and (e) claim rates under medical plans. [Refer: Net defined benefit liability (asset)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The decrease (increase) in a net defined benefit liability (asset) resulting from actuarial gains (losses) arising from changes in financial assumptions that result in remeasurements of the net defined benefit liability (asset). Financial assumptions deal with items such as: (a) the discount rate; (b) benefit levels, excluding any cost of the benefits to be met by employees, and future salary; (c) in the case of medical benefits, future medical costs, including claim handling costs (ie the costs that will be incurred in processing and resolving claims, including legal and adjuster's fees); and (d) taxes payable by the plan on contributions relating to service before the reporting date or on benefits resulting from that service. [Refer: Net defined benefit liability (asset)]

+ References

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-Name IAS
-Number 19
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- Definition

The decrease (increase) in a net defined benefit liability (asset) resulting from actuarial gains (losses) arising from experience adjustments that result in remeasurements of the net defined benefit liability (asset). Experience adjustments deal with the effects of differences between the previous actuarial assumptions and what has actually occurred. [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

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No definition available.

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to remeasurements of defined benefit plans. [Refer: Other comprehensive income; Reserve of remeasurements of defined benefit plans; Defined benefit plans [domain]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The amount of other comprehensive income that will not be reclassified to profit or loss, before tax. [Refer: Other comprehensive income]

+ References

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- Definition

A component of equity representing the accumulated remeasurements of defined benefit plans. [Refer: Defined benefit plans [domain]]

+ References

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-Note Expiry date 2027-01-01
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- Definition

The decrease (increase) in the net defined benefit liability (asset) resulting from the return on plan assets, excluding amounts included in interest income or expense. The return on plan assets is interest, dividends and other revenue derived from the plan assets, together with realised and unrealised gains or losses on the plan assets, less any costs of managing plan assets and less any tax payable by the plan itself, other than tax included in the actuarial assumptions used to measure the present value of the defined benefit obligation. [Refer: Plan assets [member]; Net defined benefit liability (asset); Actuarial assumptions [domain]; Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)]

+ References

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Share of the other comprehensive income of associates and joint ventures accounted for using the equity method that will not be reclassified to profit or loss, before tax.

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