v3.26.1
Loans and other financial assets at amortized cost - Changes in the loss allowance and gross carrying amount of due from banks (Details) - KRW (₩)
₩ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]      
Beginning balance ₩ 486,850,601    
Increase (decrease) in impairment loss due from financial institutions [Abstract]      
Ending balance 549,165,419 ₩ 486,850,601  
Due from bank | Allowance for credit losses      
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]      
Beginning balance (6,327) (15,846) ₩ (12,317)
Increase (decrease) in impairment loss due from financial institutions [Abstract]      
Transfer to 12-month expected credit losses 0 0 0
Transfer to lifetime expected credit losses 0 0 0
Transfer to credit impaired financial assets 0 0 0
Net provision of allowance for credit losses     (5,254)
Net reversal of allowance for credit losses 1,697 9,874  
Others [1] (50) (355) 1,725
Ending balance (4,680) (6,327) (15,846)
Due from bank | Stage 1 | Allowance for credit losses      
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]      
Beginning balance (6,327) (15,846) (12,317)
Increase (decrease) in impairment loss due from financial institutions [Abstract]      
Transfer to 12-month expected credit losses 0 0 0
Transfer to lifetime expected credit losses 0 0 0
Transfer to credit impaired financial assets 0 0 0
Net provision of allowance for credit losses     (5,254)
Net reversal of allowance for credit losses 1,697 9,874  
Others [1] (50) (355) 1,725
Ending balance (4,680) (6,327) (15,846)
Due from bank | Lifetime expected credit losses | Allowance for credit losses | Stage 2      
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]      
Beginning balance 0 0 0
Increase (decrease) in impairment loss due from financial institutions [Abstract]      
Transfer to 12-month expected credit losses 0 0 0
Transfer to lifetime expected credit losses 0 0 0
Transfer to credit impaired financial assets 0 0 0
Net provision of allowance for credit losses     0
Net reversal of allowance for credit losses 0 0  
Others [1] 0 0 0
Ending balance 0 0 0
Due from bank | Lifetime expected credit losses | Allowance for credit losses | Stage 3      
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]      
Beginning balance 0 0 0
Increase (decrease) in impairment loss due from financial institutions [Abstract]      
Transfer to 12-month expected credit losses 0 0 0
Transfer to lifetime expected credit losses 0 0 0
Transfer to credit impaired financial assets 0 0 0
Net provision of allowance for credit losses     0
Net reversal of allowance for credit losses 0 0  
Others [1] 0 0 0
Ending balance ₩ 0 ₩ 0 ₩ 0
[1] Changes due to foreign currencies translation, etc