v3.26.1
Loans and advances to customers - Schedule of financial assets that are either past due or impaired, with or without collateral (Details) - Financial instruments credit-impaired
€ in Millions
 12 Months Ended
Dec. 31, 2025
EUR (€)
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Estimated collateral value € 11,081
Without collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Estimated collateral value 0
Of which property collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Estimated collateral value 5,657
Of which other collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Estimated collateral value 5,424
Gross carrying amount  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers 31,577
Gross carrying amount | Without collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers 13,846
Gross carrying amount | Of which property collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers 7,777
Gross carrying amount | Of which other collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers 9,954
Accumulated impairment  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers (13,527)
Accumulated impairment | Without collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers (8,133)
Accumulated impairment | Of which property collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers (1,759)
Accumulated impairment | Of which other collateral  
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]  
Loans and advances to customers € (3,635)