Finance Income and Costs - Details of Interest Expenses Included in Finance Costs (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Analysis of income and expense [abstract]
Interest expense on borrowings	₩ 26,300	₩ 31,718	₩ 29,917
Interest expense on debentures	277,937	272,846	247,105
Others	78,968	98,565	112,791
Interest expense	₩ 383,205	₩ 403,129	₩ 389,813

The amount of expense arising from interest.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-IssueDate 2025-01-01
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2025-01-01
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