v3.26.1
Hedging derivatives - Schedule of details of hedged exposure/hedged items (Details) - EUR (€)
€ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets € 186,573 € 162,465 € 152,801
Carrying amount of hedged items - Liabilities 107,124 32,642 26,946
Accumulated amount of fair value adjustments on the hedged item - Assets (191) (1,412) (1,798)
Accumulated amount of fair value adjustments on the hedged item - Liabilities 490 (1,200) (1,652)
Change in fair value of hedged item for ineffectiveness assessment (738) (1,445) 1,992
Cash flow hedge/currency translation reserve - Continuing hedges (7,466) (8,480) (9,497)
Cash flow hedge/currency translation reserve- Discontinued hedges 237 50 (173)
Fair value hedges      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 166,907 138,906 134,095
Carrying amount of hedged items - Liabilities 107,124 32,642 26,946
Accumulated amount of fair value adjustments on the hedged item - Assets (191) (1,412) (1,798)
Accumulated amount of fair value adjustments on the hedged item - Liabilities 490 (1,200) (1,652)
Change in fair value of hedged item for ineffectiveness assessment 461 (461) 1,928
Cash flow hedge/currency translation reserve - Continuing hedges 0 0
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0 0
Fair value hedges | Interest rate risk      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 152,380 133,149 130,672
Carrying amount of hedged items - Liabilities 93,395 23,780 19,176
Accumulated amount of fair value adjustments on the hedged item - Assets (201) (1,345) (1,682)
Accumulated amount of fair value adjustments on the hedged item - Liabilities 364 (1,176) (1,546)
Change in fair value of hedged item for ineffectiveness assessment 400 (343) 1,757
Cash flow hedge/currency translation reserve - Continuing hedges 0 0 0
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0 0
Fair value hedges | Currency risk      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 2,154 2,017 637
Carrying amount of hedged items - Liabilities 242 1,562 1,365
Accumulated amount of fair value adjustments on the hedged item - Assets (6) 1 (1)
Accumulated amount of fair value adjustments on the hedged item - Liabilities 0 3 (3)
Change in fair value of hedged item for ineffectiveness assessment (43) (118) 60
Cash flow hedge/currency translation reserve - Continuing hedges 0 0 0
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0 0
Fair value hedges | Interest rate and exchange rate risk      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 9,619 3,238 2,786
Carrying amount of hedged items - Liabilities 13,487 7,205 6,405
Accumulated amount of fair value adjustments on the hedged item - Assets 3 (68) (115)
Accumulated amount of fair value adjustments on the hedged item - Liabilities 126 (27) (103)
Change in fair value of hedged item for ineffectiveness assessment 66 1 111
Cash flow hedge/currency translation reserve - Continuing hedges 0 0 0
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0 0
Fair value hedges | Inflation risk      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 2,253 0 0
Carrying amount of hedged items - Liabilities 0 0 0
Accumulated amount of fair value adjustments on the hedged item - Assets 13 0 0
Accumulated amount of fair value adjustments on the hedged item - Liabilities 0 0 0
Change in fair value of hedged item for ineffectiveness assessment 38 0 0
Cash flow hedge/currency translation reserve - Continuing hedges 0 0 0
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0 0
Fair value hedges | Credit risk      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 0 0 0
Carrying amount of hedged items - Liabilities 0 0 0
Accumulated amount of fair value adjustments on the hedged item - Assets 0 0 0
Accumulated amount of fair value adjustments on the hedged item - Liabilities 0 0 0
Change in fair value of hedged item for ineffectiveness assessment 0 0 0
Cash flow hedge/currency translation reserve - Continuing hedges 0 0 0
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0 0
Fair value hedges | Base risk      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 501 502  
Carrying amount of hedged items - Liabilities 0 0  
Accumulated amount of fair value adjustments on the hedged item - Assets 0 0  
Accumulated amount of fair value adjustments on the hedged item - Liabilities 0 0  
Change in fair value of hedged item for ineffectiveness assessment 0 0  
Cash flow hedge/currency translation reserve - Continuing hedges 0 0  
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0  
Fair value hedges | Equities      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 0 0  
Carrying amount of hedged items - Liabilities 0 95  
Accumulated amount of fair value adjustments on the hedged item - Assets 0 0  
Accumulated amount of fair value adjustments on the hedged item - Liabilities 0 0  
Change in fair value of hedged item for ineffectiveness assessment 0 (1)  
Cash flow hedge/currency translation reserve - Continuing hedges 0 0  
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0  
Cash flow hedges      
Disclosure of detailed information about hedged items [line items]      
Change in fair value of hedged item for ineffectiveness assessment (1,063) (564) (1,824)
Cash flow hedge/currency translation reserve - Continuing hedges 401 (478) (813)
Cash flow hedge/currency translation reserve- Discontinued hedges 235 50 (173)
Cash flow hedges | Interest rate risk      
Disclosure of detailed information about hedged items [line items]      
Change in fair value of hedged item for ineffectiveness assessment (1,174) (156) (2,182)
Cash flow hedge/currency translation reserve - Continuing hedges 381 (794) (797)
Cash flow hedge/currency translation reserve- Discontinued hedges 86 83 (77)
Cash flow hedges | Currency risk      
Disclosure of detailed information about hedged items [line items]      
Change in fair value of hedged item for ineffectiveness assessment 240 (439) 500
Cash flow hedge/currency translation reserve - Continuing hedges (8) 213 (80)
Cash flow hedge/currency translation reserve- Discontinued hedges 0 19 0
Cash flow hedges | Interest rate and exchange rate risk      
Disclosure of detailed information about hedged items [line items]      
Change in fair value of hedged item for ineffectiveness assessment (8) (40) 100
Cash flow hedge/currency translation reserve - Continuing hedges 28 11 (144)
Cash flow hedge/currency translation reserve- Discontinued hedges (13) 0 0
Cash flow hedges | Inflation risk      
Disclosure of detailed information about hedged items [line items]      
Change in fair value of hedged item for ineffectiveness assessment (131) 69 (233)
Cash flow hedge/currency translation reserve - Continuing hedges 0 82 196
Cash flow hedge/currency translation reserve- Discontinued hedges 162 (52) (96)
Cash flow hedges | Equity risk      
Disclosure of detailed information about hedged items [line items]      
Change in fair value of hedged item for ineffectiveness assessment 10 2 (9)
Cash flow hedge/currency translation reserve - Continuing hedges 10 12
Cash flow hedge/currency translation reserve- Discontinued hedges 0 0 0
Cash flow hedges | Other risks      
Disclosure of detailed information about hedged items [line items]      
Change in fair value of hedged item for ineffectiveness assessment 0    
Cash flow hedge/currency translation reserve - Continuing hedges 0    
Cash flow hedge/currency translation reserve- Discontinued hedges 0    
Net foreign investments hedges      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 19,666 23,559 18,706
Carrying amount of hedged items - Liabilities 0 0 0
Change in fair value of hedged item for ineffectiveness assessment (136) (420) 1,888
Cash flow hedge/currency translation reserve - Continuing hedges (7,867) (8,002) (8,684)
Cash flow hedge/currency translation reserve- Discontinued hedges 2 0 0
Net foreign investments hedges | Currency risk      
Disclosure of detailed information about hedged items [line items]      
Carrying amount of hedged items - Assets 19,666 23,559 18,706
Carrying amount of hedged items - Liabilities 0 0 0
Change in fair value of hedged item for ineffectiveness assessment (136) (420) 1,888
Cash flow hedge/currency translation reserve - Continuing hedges (7,867) (8,002) (8,684)
Cash flow hedge/currency translation reserve- Discontinued hedges € 2 € 0 € 0