v3.26.1
Assets subject to lien and assets acquired through foreclosures - Details of securities loned (Details) - KRW (₩)
₩ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of transferred financial assets that are not derecognised in their entirety [line items]    
Financial assets that entity continues to recognise ₩ 7,000,373 ₩ 1,561,140
Korean treasury and government bonds and others    
Disclosure of transferred financial assets that are not derecognised in their entirety [line items]    
Financial assets that entity continues to recognise ₩ 5,573,299 ₩ 0
Description of nature of transferred financial assets that are not derecognised in their entirety Securities loaned are lending of specific securities to borrowers who agree to return the same amount of the same security at the end of lending period. As the Group does not derecognize these securities. Securities loaned are lending of specific securities to borrowers who agree to return the same amount of the same security at the end of lending period. As the Group does not derecognize these securities.
Loaned to Korea Securities Finance Corporation and others Korea Securities Finance Corporation and others
Korean treasury and government bonds    
Disclosure of transferred financial assets that are not derecognised in their entirety [line items]    
Financial assets that entity continues to recognise ₩ 0 ₩ 12,361
Description of nature of transferred financial assets that are not derecognised in their entirety Securities loaned are lending of specific securities to borrowers who agree to return the same amount of the same security at the end of lending period. As the Group does not derecognize these securities. Securities loaned are lending of specific securities to borrowers who agree to return the same amount of the same security at the end of lending period. As the Group does not derecognize these securities.
Loaned to Korea Securities Finance Corporation Korea Securities Finance Corporation
Foreign currency debt securities    
Disclosure of transferred financial assets that are not derecognised in their entirety [line items]    
Financial assets that entity continues to recognise ₩ 101,439  
Loaned to Nomura Financial Investment (Korea) Co., Ltd. Nomura Financial Investment (Korea) Co., Ltd.