v3.26.1
Other disclosures - Disclosure of home purchase loans in Spain (Details) - Property assets from home purchase mortgage loans to households - Spain - EUR (€)
€ in Millions
 6 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Disclosure of credit risk exposure [line items]    
Percentage secured by mortgage 98.47%  
Gross carrying amount    
Disclosure of credit risk exposure [line items]    
Financial assets € 64,030 € 60,002
Gross carrying amount | Without collateral    
Disclosure of credit risk exposure [line items]    
Financial assets 981 215
Gross carrying amount | With collateral    
Disclosure of credit risk exposure [line items]    
Financial assets 63,049 59,787
Credit impaired | Gross carrying amount    
Disclosure of credit risk exposure [line items]    
Financial assets 518 625
Credit impaired | Gross carrying amount | Without collateral    
Disclosure of credit risk exposure [line items]    
Financial assets 26 7
Credit impaired | Gross carrying amount | With collateral    
Disclosure of credit risk exposure [line items]    
Financial assets € 492 € 618