v3.26.1
Hedging derivatives - Schedule of maturity profile of hedging instruments (Details) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about hedged items [line items]      
Notional amount € 505,992 € 511,727 € 418,294
Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 26,707 33,405 19,038
One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 29,976 31,685 35,624
Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 120,662 145,627 112,546
One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 280,202 257,116 222,777
More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 48,445 43,894 28,309
Fair value hedges      
Disclosure of detailed information about hedged items [line items]      
Notional amount 338,057 308,897 241,792
Fair value hedges | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 17,263 9,791 6,862
Fair value hedges | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 20,353 15,953 14,535
Fair value hedges | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 87,830 88,519 59,170
Fair value hedges | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 176,040 163,086 139,486
Fair value hedges | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 36,571 31,548 21,739
Fair value hedges | Interest rate risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 305,348 290,152 225,377
Fair value hedges | Interest rate risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 15,778 8,725 6,266
Fair value hedges | Interest rate risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 19,042 14,680 13,749
Fair value hedges | Interest rate risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 82,060 85,981 56,860
Fair value hedges | Interest rate risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 160,461 154,440 131,323
Fair value hedges | Interest rate risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 28,007 26,326 17,179
Fair value hedges | Interest rate risk | Interest rate swaps      
Disclosure of detailed information about hedged items [line items]      
Notional amount 285,983 276,715 215,382
Fair value hedges | Interest rate risk | Interest rate swaps | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 15,588 7,910 6,176
Fair value hedges | Interest rate risk | Interest rate swaps | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 18,565 11,913 13,525
Fair value hedges | Interest rate risk | Interest rate swaps | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 78,893 83,890 55,918
Fair value hedges | Interest rate risk | Interest rate swaps | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 146,294 148,913 125,405
Fair value hedges | Interest rate risk | Interest rate swaps | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 26,643 24,089 14,358
Fair value hedges | Interest rate risk | Future interest rate      
Disclosure of detailed information about hedged items [line items]      
Notional amount 19,365    
Fair value hedges | Interest rate risk | Future interest rate | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 190    
Fair value hedges | Interest rate risk | Future interest rate | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 477    
Fair value hedges | Interest rate risk | Future interest rate | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,167    
Fair value hedges | Interest rate risk | Future interest rate | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 14,167    
Fair value hedges | Interest rate risk | Future interest rate | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,364    
Fair value hedges | Interest rate risk | Cap&Floor      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Currency risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,656 4,411 4,331
Fair value hedges | Currency risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 963 1,054 566
Fair value hedges | Currency risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 365 717 678
Fair value hedges | Currency risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,086 469 619
Fair value hedges | Currency risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 112 50
Fair value hedges | Currency risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 242 2,059 2,418
Fair value hedges | Currency risk | Future interest rate      
Disclosure of detailed information about hedged items [line items]      
Notional amount 242 2,059 2,418
Fair value hedges | Currency risk | Future interest rate | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Fair value hedges | Currency risk | Future interest rate | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Fair value hedges | Currency risk | Future interest rate | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Fair value hedges | Currency risk | Future interest rate | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Fair value hedges | Currency risk | Future interest rate | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 242 2,059 2,418
Fair value hedges | Currency risk | Fx forward      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,414 2,240 1,913
Fair value hedges | Currency risk | Fx forward | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 963 1,054 566
Fair value hedges | Currency risk | Fx forward | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 365 717 678
Fair value hedges | Currency risk | Fx forward | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,086 469 619
Fair value hedges | Currency risk | Fx forward | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 50
Fair value hedges | Currency risk | Fx forward | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Fair value hedges | Currency risk | Fx Swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Interest rate and exchange rate risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 27,433 13,739 12,084
Fair value hedges | Interest rate and exchange rate risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 522 12 30
Fair value hedges | Interest rate and exchange rate risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 946 511 108
Fair value hedges | Interest rate and exchange rate risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 4,684 2,019 1,691
Fair value hedges | Interest rate and exchange rate risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 15,079 8,034 8,113
Fair value hedges | Interest rate and exchange rate risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 6,202 3,163 2,142
Fair value hedges | Interest rate and exchange rate risk | Interest rate swaps      
Disclosure of detailed information about hedged items [line items]      
Notional amount 5,452 2,720 2,311
Fair value hedges | Interest rate and exchange rate risk | Interest rate swaps | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 15 0 0
Fair value hedges | Interest rate and exchange rate risk | Interest rate swaps | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 54 149 21
Fair value hedges | Interest rate and exchange rate risk | Interest rate swaps | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 218 104 321
Fair value hedges | Interest rate and exchange rate risk | Interest rate swaps | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,898 1,543 1,508
Fair value hedges | Interest rate and exchange rate risk | Interest rate swaps | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,267 924 461
Fair value hedges | Interest rate and exchange rate risk | Currency swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 21,981 11,019 9,773
Fair value hedges | Interest rate and exchange rate risk | Currency swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 507 12 30
Fair value hedges | Interest rate and exchange rate risk | Currency swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 892 361 87
Fair value hedges | Interest rate and exchange rate risk | Currency swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 4,466 1,915 1,370
Fair value hedges | Interest rate and exchange rate risk | Currency swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 11,181 6,491 6,605
Fair value hedges | Interest rate and exchange rate risk | Currency swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 4,935 2,240 1,681
Fair value hedges | Base risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 500 500  
Fair value hedges | Base risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Base risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Base risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Base risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 500 500  
Fair value hedges | Base risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Base risk | Interest rate swaps      
Disclosure of detailed information about hedged items [line items]      
Notional amount 500 500  
Fair value hedges | Base risk | Interest rate swaps | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Base risk | Interest rate swaps | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Base risk | Interest rate swaps | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Base risk | Interest rate swaps | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 500 500  
Fair value hedges | Base risk | Interest rate swaps | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0  
Fair value hedges | Inflation risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,120    
Fair value hedges | Inflation risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,120    
Fair value hedges | Inflation risk | Inflation swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,120    
Fair value hedges | Inflation risk | Inflation swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | Inflation swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | Inflation swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | Inflation swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Fair value hedges | Inflation risk | Inflation swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,120    
Fair value hedges | Equity risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount   95  
Fair value hedges | Equity risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Fair value hedges | Equity risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount   45  
Fair value hedges | Equity risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount   50  
Fair value hedges | Equity risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Fair value hedges | Equity risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Fair value hedges | Equity risk | Equity swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount   95  
Fair value hedges | Equity risk | Equity swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Fair value hedges | Equity risk | Equity swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount   45  
Fair value hedges | Equity risk | Equity swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount   50  
Fair value hedges | Equity risk | Equity swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Fair value hedges | Equity risk | Equity swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Cash flow hedges      
Disclosure of detailed information about hedged items [line items]      
Notional amount 148,269 179,271 157,796
Cash flow hedges | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 6,499 19,696 7,873
Cash flow hedges | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 4,405 10,088 16,149
Cash flow hedges | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 21,536 43,111 43,913
Cash flow hedges | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 103,955 94,030 83,291
Cash flow hedges | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 11,874 12,346 6,570
Cash flow hedges | Interest rate risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 99,969 134,503 97,780
Cash flow hedges | Interest rate risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,497 14,628 4,467
Cash flow hedges | Interest rate risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,347 7,932 6,859
Cash flow hedges | Interest rate risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 12,090 30,390 30,846
Cash flow hedges | Interest rate risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 76,749 75,459 53,038
Cash flow hedges | Interest rate risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 6,286 6,094 2,570
Cash flow hedges | Interest rate risk | Interest rate swaps      
Disclosure of detailed information about hedged items [line items]      
Notional amount 87,412 106,663 91,569
Cash flow hedges | Interest rate risk | Interest rate swaps | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,497 7,146 4,241
Cash flow hedges | Interest rate risk | Interest rate swaps | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,347 5,856 6,429
Cash flow hedges | Interest rate risk | Interest rate swaps | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 12,077 20,846 29,863
Cash flow hedges | Interest rate risk | Interest rate swaps | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 64,712 67,495 48,735
Cash flow hedges | Interest rate risk | Interest rate swaps | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 5,779 5,320 2,301
Cash flow hedges | Interest rate risk | Future interest rate      
Disclosure of detailed information about hedged items [line items]      
Notional amount 12,357 6,621 3,020
Cash flow hedges | Interest rate risk | Future interest rate | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 6,621 0
Cash flow hedges | Interest rate risk | Future interest rate | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Cash flow hedges | Interest rate risk | Future interest rate | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 13 0 0
Cash flow hedges | Interest rate risk | Future interest rate | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 11,837 0 3,020
Cash flow hedges | Interest rate risk | Future interest rate | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 507 0 0
Cash flow hedges | Interest rate risk | Cap&Floor      
Disclosure of detailed information about hedged items [line items]      
Notional amount 200    
Cash flow hedges | Interest rate risk | Cap&Floor | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Cash flow hedges | Interest rate risk | Cap&Floor | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Cash flow hedges | Interest rate risk | Cap&Floor | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Cash flow hedges | Interest rate risk | Cap&Floor | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 200    
Cash flow hedges | Interest rate risk | Cap&Floor | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Cash flow hedges | Currency risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 24,791 30,653 34,823
Cash flow hedges | Currency risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 981 2,982 2,655
Cash flow hedges | Currency risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,169 1,377 7,087
Cash flow hedges | Currency risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 4,062 8,765 6,607
Cash flow hedges | Currency risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 15,467 14,703 16,711
Cash flow hedges | Currency risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,112 2,826 1,763
Cash flow hedges | Currency risk | Fx forward      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,445 9,286 11,160
Cash flow hedges | Currency risk | Fx forward | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 874 2,594 2,013
Cash flow hedges | Currency risk | Fx forward | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,025 1,310 2,344
Cash flow hedges | Currency risk | Fx forward | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,546 5,382 4,617
Cash flow hedges | Currency risk | Fx forward | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 2,186
Cash flow hedges | Currency risk | Fx forward | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Cash flow hedges | Currency risk | Currency swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 19,740 19,957 20,043
Cash flow hedges | Currency risk | Currency swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 41 133 642
Cash flow hedges | Currency risk | Currency swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 52 66 2,209
Cash flow hedges | Currency risk | Currency swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,024 3,383 1,990
Cash flow hedges | Currency risk | Currency swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 14,511 14,704 14,525
Cash flow hedges | Currency risk | Currency swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,112 1,671 677
Cash flow hedges | Currency risk | Fx Swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,606    
Cash flow hedges | Currency risk | Fx Swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 66    
Cash flow hedges | Currency risk | Fx Swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 92    
Cash flow hedges | Currency risk | Fx Swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 492    
Cash flow hedges | Currency risk | Fx Swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 956    
Cash flow hedges | Currency risk | Fx Swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Cash flow hedges | Interest rate and exchange rate risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 23,445 11,724 12,217
Cash flow hedges | Interest rate and exchange rate risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,021 2,086 407
Cash flow hedges | Interest rate and exchange rate risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,887 778 1,547
Cash flow hedges | Interest rate and exchange rate risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 5,371 3,785 2,270
Cash flow hedges | Interest rate and exchange rate risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 11,690 3,813 7,187
Cash flow hedges | Interest rate and exchange rate risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,476 1,262 806
Cash flow hedges | Interest rate and exchange rate risk | Interest rate swaps      
Disclosure of detailed information about hedged items [line items]      
Notional amount 3,253 3,092 2,847
Cash flow hedges | Interest rate and exchange rate risk | Interest rate swaps | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 761 997 0
Cash flow hedges | Interest rate and exchange rate risk | Interest rate swaps | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 80
Cash flow hedges | Interest rate and exchange rate risk | Interest rate swaps | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 227 395 0
Cash flow hedges | Interest rate and exchange rate risk | Interest rate swaps | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,085 1,260 2,575
Cash flow hedges | Interest rate and exchange rate risk | Interest rate swaps | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 180 440 192
Cash flow hedges | Interest rate and exchange rate risk | Currency swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 20,192 8,632 9,370
Cash flow hedges | Interest rate and exchange rate risk | Currency swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,260 1,090 407
Cash flow hedges | Interest rate and exchange rate risk | Currency swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 1,887 778 1,467
Cash flow hedges | Interest rate and exchange rate risk | Currency swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 5,144 3,389 2,270
Cash flow hedges | Interest rate and exchange rate risk | Currency swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 9,605 2,553 4,612
Cash flow hedges | Interest rate and exchange rate risk | Currency swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,296 822 614
Cash flow hedges | Inflation risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 2,316 12,908
Cash flow hedges | Inflation risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0 344
Cash flow hedges | Inflation risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0 656
Cash flow hedges | Inflation risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount   153 4,182
Cash flow hedges | Inflation risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0 6,296
Cash flow hedges | Inflation risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   2,163 1,430
Cash flow hedges | Inflation risk | Currency swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount     12,495
Cash flow hedges | Inflation risk | Currency swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount     318
Cash flow hedges | Inflation risk | Currency swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount     618
Cash flow hedges | Inflation risk | Currency swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount     3,833
Cash flow hedges | Inflation risk | Currency swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount     6,296
Cash flow hedges | Inflation risk | Currency swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount     1,430
Cash flow hedges | Inflation risk | Inflation swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 2,163  
Cash flow hedges | Inflation risk | Inflation swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Cash flow hedges | Inflation risk | Inflation swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Cash flow hedges | Inflation risk | Inflation swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Cash flow hedges | Inflation risk | Inflation swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   0  
Cash flow hedges | Inflation risk | Inflation swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount   2,163  
Cash flow hedges | Equity risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 64 75 68
Cash flow hedges | Equity risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Cash flow hedges | Equity risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2 1 0
Cash flow hedges | Equity risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 13 18 8
Cash flow hedges | Equity risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 49 55 59
Cash flow hedges | Equity risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 1 1
Cash flow hedges | Equity risk | Equity swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount   75  
Cash flow hedges | Equity risk | Option      
Disclosure of detailed information about hedged items [line items]      
Notional amount 64 75 68
Cash flow hedges | Equity risk | Option | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Cash flow hedges | Equity risk | Option | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2 1 0
Cash flow hedges | Equity risk | Option | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 13 18 8
Cash flow hedges | Equity risk | Option | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 49 55 59
Cash flow hedges | Equity risk | Option | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 1 1
Hedges of net investments in foreign operations      
Disclosure of detailed information about hedged items [line items]      
Notional amount 19,666 23,559 18,706
Hedges of net investments in foreign operations | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,945 3,918 4,303
Hedges of net investments in foreign operations | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 5,218 5,644 4,940
Hedges of net investments in foreign operations | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 11,296 13,997 9,463
Hedges of net investments in foreign operations | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 207 0 0
Hedges of net investments in foreign operations | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Hedges of net investments in foreign operations | Currency risk      
Disclosure of detailed information about hedged items [line items]      
Notional amount 19,666 23,559 18,706
Hedges of net investments in foreign operations | Currency risk | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,945 3,918 4,303
Hedges of net investments in foreign operations | Currency risk | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 5,218 5,644 4,940
Hedges of net investments in foreign operations | Currency risk | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 11,296 13,997 9,463
Hedges of net investments in foreign operations | Currency risk | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 207 0 0
Hedges of net investments in foreign operations | Currency risk | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 0 0
Hedges of net investments in foreign operations | Currency risk | Fx forward      
Disclosure of detailed information about hedged items [line items]      
Notional amount 19,614 23,559 18,706
Hedges of net investments in foreign operations | Currency risk | Fx forward | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 2,893 3,918 4,303
Hedges of net investments in foreign operations | Currency risk | Fx forward | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 5,218 5,644 4,940
Hedges of net investments in foreign operations | Currency risk | Fx forward | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 11,296 13,997 9,463
Hedges of net investments in foreign operations | Currency risk | Fx forward | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 207 0 0
Hedges of net investments in foreign operations | Currency risk | Fx forward | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0 € 0 € 0
Hedges of net investments in foreign operations | Currency risk | Fx Swap      
Disclosure of detailed information about hedged items [line items]      
Notional amount 52    
Hedges of net investments in foreign operations | Currency risk | Fx Swap | Up to one month      
Disclosure of detailed information about hedged items [line items]      
Notional amount 52    
Hedges of net investments in foreign operations | Currency risk | Fx Swap | One to three months      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Hedges of net investments in foreign operations | Currency risk | Fx Swap | Three months to one year      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Hedges of net investments in foreign operations | Currency risk | Fx Swap | One year to five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount 0    
Hedges of net investments in foreign operations | Currency risk | Fx Swap | More than five years      
Disclosure of detailed information about hedged items [line items]      
Notional amount € 0