v3.26.1
Debt securities - Debt securities by type and balance sheet lines (Details) - EUR (€)
€ in Millions
Jun. 30, 2026
Dec. 31, 2025
Dec. 31, 2024
Provisions      
Disclosure of financial assets [line items]      
Financial assets € (6,214)    
Debt securities      
Disclosure of financial assets [line items]      
Financial assets 138,233 € 115,903  
Debt securities | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 128,336 107,809  
Debt securities | Provisions      
Disclosure of financial assets [line items]      
Financial assets (32) (26)  
Debt securities | Government bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 67,512 58,163  
Debt securities | Central bank bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 5,415 2,917  
Debt securities | Sub-sovereign, Supranationals and Agencies | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 39,400 30,945  
Debt securities | Covered bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 9,045 9,111  
Debt securities | Corporate bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 250 248  
Debt securities | Financial institutions' bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 1,654 1,300  
Debt securities | ABS portfolio | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 5,061 5,125  
Debt securities | Debt securities portfolio      
Disclosure of financial assets [line items]      
Financial assets 128,304 107,783  
Debt securities at fair value through profit or loss | Debt securities      
Disclosure of financial assets [line items]      
Financial assets 13,484 11,219  
Debt securities at fair value through profit or loss | Debt securities | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 3,554 3,099  
Debt securities at fair value through profit or loss | Debt securities | Provisions      
Disclosure of financial assets [line items]      
Financial assets  
Debt securities at fair value through profit or loss | Debt securities | Government bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 259 288  
Debt securities at fair value through profit or loss | Debt securities | Central bank bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 416 376  
Debt securities at fair value through profit or loss | Debt securities | Sub-sovereign, Supranationals and Agencies | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 391 413  
Debt securities at fair value through profit or loss | Debt securities | Covered bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets  
Debt securities at fair value through profit or loss | Debt securities | Corporate bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 91 89  
Debt securities at fair value through profit or loss | Debt securities | Financial institutions' bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 1,392 1,176  
Debt securities at fair value through profit or loss | Debt securities | ABS portfolio | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 1,006 757  
Debt securities at fair value through profit or loss | Debt securities | Debt securities portfolio      
Disclosure of financial assets [line items]      
Financial assets 3,554 3,099  
Debt securities at fair value through other comprehensive income      
Disclosure of financial assets [line items]      
Financial assets 63,043 56,662 € 46,389
Debt securities at fair value through other comprehensive income | Debt securities      
Disclosure of financial assets [line items]      
Financial assets 56,765 50,817  
Debt securities at fair value through other comprehensive income | Debt securities | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 56,782 50,832  
Debt securities at fair value through other comprehensive income | Debt securities | Provisions      
Disclosure of financial assets [line items]      
Financial assets (17) (15)  
Debt securities at fair value through other comprehensive income | Debt securities | Government bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 33,980 32,578  
Debt securities at fair value through other comprehensive income | Debt securities | Central bank bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets  
Debt securities at fair value through other comprehensive income | Debt securities | Sub-sovereign, Supranationals and Agencies | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 18,428 13,788  
Debt securities at fair value through other comprehensive income | Debt securities | Covered bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 3,628 3,750  
Debt securities at fair value through other comprehensive income | Debt securities | Corporate bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 79 109  
Debt securities at fair value through other comprehensive income | Debt securities | Financial institutions' bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 103 28  
Debt securities at fair value through other comprehensive income | Debt securities | ABS portfolio | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 564 578  
Debt securities at fair value through other comprehensive income | Debt securities | Debt securities portfolio      
Disclosure of financial assets [line items]      
Financial assets 56,765 50,817  
Debt securities at amortised cost | Debt securities      
Disclosure of financial assets [line items]      
Financial assets 67,985 53,867  
Debt securities at amortised cost | Debt securities | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 68,000 53,879  
Debt securities at amortised cost | Debt securities | Provisions      
Disclosure of financial assets [line items]      
Financial assets (15) (11)  
Debt securities at amortised cost | Debt securities | Government bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 33,272 25,297  
Debt securities at amortised cost | Debt securities | Central bank bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 4,998 2,541  
Debt securities at amortised cost | Debt securities | Sub-sovereign, Supranationals and Agencies | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 20,581 16,744  
Debt securities at amortised cost | Debt securities | Covered bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 5,416 5,362  
Debt securities at amortised cost | Debt securities | Corporate bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 81 50  
Debt securities at amortised cost | Debt securities | Financial institutions' bonds | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 159 96  
Debt securities at amortised cost | Debt securities | ABS portfolio | Gross carrying amount      
Disclosure of financial assets [line items]      
Financial assets 3,491 3,790  
Debt securities at amortised cost | Debt securities | Debt securities portfolio      
Disclosure of financial assets [line items]      
Financial assets € 67,985 € 53,867