Basis of preparation and material accounting policies - Impacts to the financial statements due to the exercise of the extension and termination options (Details)	12 Months Ended
Dec. 31, 2025
Presentation of leases for lessee [abstract]
Information about lessee's exposure arising from extension options and termination options	Lease liabilities and right-of-use-asset increased by 7,373 million Won, reflecting the exercise impact of the extension and termination options during the current term.

Information about the lessee's exposure arising from extension options and termination options.

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Data Type:	xbrli:stringItemType
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Period Type:	duration