v3.26.1
Risk management - Gross carrying amount per IFRS 9 stage and rating class (Details) - EUR (€)
€ in Millions
Jun. 30, 2026
Dec. 31, 2025
Gross carrying amount | Purchased credit impaired | Stage 3: Lifetime Expected Credit Losses    
Disclosure of credit risk exposure [line items]    
Financial assets € (25) € (29)
Gross carrying amount | IFRS 9    
Disclosure of credit risk exposure [line items]    
Financial assets 1,209,939 1,135,409
Gross carrying amount | IFRS 9 | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 1,109,717 1,044,332
Gross carrying amount | IFRS 9 | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 86,015 77,487
Gross carrying amount | IFRS 9 | Stage 3    
Disclosure of credit risk exposure [line items]    
Financial assets 14,207 13,590
Gross carrying amount | IFRS 9 | 1 (AAA)    
Disclosure of credit risk exposure [line items]    
Financial assets 97,790 80,064
Gross carrying amount | IFRS 9 | 1 (AAA) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 97,210 79,938
Gross carrying amount | IFRS 9 | 1 (AAA) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 580 126
Gross carrying amount | IFRS 9 | 2-4 (AA)    
Disclosure of credit risk exposure [line items]    
Financial assets 148,414 148,315
Gross carrying amount | IFRS 9 | 2-4 (AA) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 147,104 146,878
Gross carrying amount | IFRS 9 | 2-4 (AA) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 1,310 1,437
Gross carrying amount | IFRS 9 | 5-7 (A)    
Disclosure of credit risk exposure [line items]    
Financial assets 341,263 305,093
Gross carrying amount | IFRS 9 | 5-7 (A) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 332,702 299,699
Gross carrying amount | IFRS 9 | 5-7 (A) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 8,561 5,394
Gross carrying amount | IFRS 9 | 8-10 (BBB)    
Disclosure of credit risk exposure [line items]    
Financial assets 368,606 354,012
Gross carrying amount | IFRS 9 | 8-10 (BBB) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 345,826 334,845
Gross carrying amount | IFRS 9 | 8-10 (BBB) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 22,779 19,168
Gross carrying amount | IFRS 9 | 11-13 (BB)    
Disclosure of credit risk exposure [line items]    
Financial assets 176,915 173,589
Gross carrying amount | IFRS 9 | 11-13 (BB) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 158,122 156,373
Gross carrying amount | IFRS 9 | 11-13 (BB) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 18,793 17,217
Gross carrying amount | IFRS 9 | 14-16 (B)    
Disclosure of credit risk exposure [line items]    
Financial assets 52,095 48,855
Gross carrying amount | IFRS 9 | 14-16 (B) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 28,251 26,187
Gross carrying amount | IFRS 9 | 14-16 (B) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 23,844 22,668
Gross carrying amount | IFRS 9 | 17 (CCC)    
Disclosure of credit risk exposure [line items]    
Financial assets 4,929 5,094
Gross carrying amount | IFRS 9 | 17 (CCC) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets 503 412
Gross carrying amount | IFRS 9 | 17 (CCC) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 4,427 4,682
Gross carrying amount | IFRS 9 | 18 (CC)    
Disclosure of credit risk exposure [line items]    
Financial assets 3,802 4,349
Gross carrying amount | IFRS 9 | 18 (CC) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 3,802 4,349
Gross carrying amount | IFRS 9 | 19 (C)    
Disclosure of credit risk exposure [line items]    
Financial assets 1,918 2,447
Gross carrying amount | IFRS 9 | 19 (C) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets 1,918 2,447
Gross carrying amount | IFRS 9 | 20-22 (D)    
Disclosure of credit risk exposure [line items]    
Financial assets 14,207 13,590
Gross carrying amount | IFRS 9 | 20-22 (D) | Stage 3    
Disclosure of credit risk exposure [line items]    
Financial assets 14,207 13,590
Provisions    
Disclosure of credit risk exposure [line items]    
Financial assets (6,214)  
Provisions | IFRS 9    
Disclosure of credit risk exposure [line items]    
Financial assets (6,214) (6,101)
Provisions | IFRS 9 | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (462) (446)
Provisions | IFRS 9 | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (1,184) (1,179)
Provisions | IFRS 9 | Stage 3    
Disclosure of credit risk exposure [line items]    
Financial assets (4,568) (4,476)
Provisions | IFRS 9 | 1 (AAA)    
Disclosure of credit risk exposure [line items]    
Financial assets (2) (2)
Provisions | IFRS 9 | 1 (AAA) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (2) (2)
Provisions | IFRS 9 | 2-4 (AA)    
Disclosure of credit risk exposure [line items]    
Financial assets (13) (13)
Provisions | IFRS 9 | 2-4 (AA) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (12) (11)
Provisions | IFRS 9 | 2-4 (AA) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (1) (1)
Provisions | IFRS 9 | 5-7 (A)    
Disclosure of credit risk exposure [line items]    
Financial assets (54) (45)
Provisions | IFRS 9 | 5-7 (A) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (47) (39)
Provisions | IFRS 9 | 5-7 (A) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (8) (6)
Provisions | IFRS 9 | 8-10 (BBB)    
Disclosure of credit risk exposure [line items]    
Financial assets (138) (119)
Provisions | IFRS 9 | 8-10 (BBB) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (85) (77)
Provisions | IFRS 9 | 8-10 (BBB) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (53) (43)
Provisions | IFRS 9 | 11-13 (BB)    
Disclosure of credit risk exposure [line items]    
Financial assets (268) (254)
Provisions | IFRS 9 | 11-13 (BB) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (170) (165)
Provisions | IFRS 9 | 11-13 (BB) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (99) (89)
Provisions | IFRS 9 | 14-16 (B)    
Disclosure of credit risk exposure [line items]    
Financial assets (545) (504)
Provisions | IFRS 9 | 14-16 (B) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (141) (147)
Provisions | IFRS 9 | 14-16 (B) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (404) (357)
Provisions | IFRS 9 | 17 (CCC)    
Disclosure of credit risk exposure [line items]    
Financial assets (237) (228)
Provisions | IFRS 9 | 17 (CCC) | Stage 1    
Disclosure of credit risk exposure [line items]    
Financial assets (5) (5)
Provisions | IFRS 9 | 17 (CCC) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (232) (224)
Provisions | IFRS 9 | 18 (CC)    
Disclosure of credit risk exposure [line items]    
Financial assets (206) (262)
Provisions | IFRS 9 | 18 (CC) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (206) (262)
Provisions | IFRS 9 | 19 (C)    
Disclosure of credit risk exposure [line items]    
Financial assets (183) (198)
Provisions | IFRS 9 | 19 (C) | Stage 2    
Disclosure of credit risk exposure [line items]    
Financial assets (183) (198)
Provisions | IFRS 9 | 20-22 (D)    
Disclosure of credit risk exposure [line items]    
Financial assets (4,568) (4,476)
Provisions | IFRS 9 | 20-22 (D) | Stage 3    
Disclosure of credit risk exposure [line items]    
Financial assets € (4,568) € (4,476)