v3.26.1
Grupo Santander - Agreement for the sale of the stake in Caceis (Details) - EUR (€)
€ in Millions
12 Months Ended
Dec. 19, 2024
Dec. 31, 2025
Crédit Agricole S.A. | Caceis (Notes 3 and 12)    
Disclosure of detailed information about business combination [line items]    
Ownership interest in subsidiary 100.00%  
Caceis (Notes 3 and 12)    
Disclosure of detailed information about business combination [line items]    
Proportion of ownership interest in associate, sold (in percentage) 30.50%  
Gains (losses) on noncurrent assets held for sale not classified as discontinued operations   € 231