v3.26.1
Fair value of financial instruments - Schedule of financial instruments at fair value whose measurement was based on internal models (Levels 2 and 3) (Details) (Details) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Level 2        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value € 163,796 € 163,941 € 133,874  
Financial liabilities, at fair value 198,377 179,766 166,542  
Level 2 | Financial assets and liabilities | Financial assets held for trading        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 139,293 138,176 106,993  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Central banks        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 14,191 12,966 17,717  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Credit institutions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 25,815 26,546 14,061  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 27,986 24,602 11,418  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Debt and equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 14,470 11,115 8,683  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 56,831 62,947 55,114  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 39,716 47,519 44,987  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Exchange rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 1,332 1,583 836  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 1,490 1,879 2,210  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Index and securities options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 439 465 126  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Interest rate forwards        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 177 1,445 33  
Level 2 | Financial assets and liabilities | Financial assets held for trading | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 13,677 10,056 6,922  
Level 2 | Financial assets and liabilities | Hedging derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 3,924 5,652 5,297  
Level 2 | Financial assets and liabilities | Hedging derivatives | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 3,690 5,390 4,665  
Level 2 | Financial assets and liabilities | Hedging derivatives | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 91 2 2  
Level 2 | Financial assets and liabilities | Hedging derivatives | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 143 260 630  
Level 2 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 2,465 1,505 2,050  
Level 2 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 899 763 815  
Level 2 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 54 205 539  
Level 2 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss | Loans and advances        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 1,512 537 696  
Level 2 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 5,152 5,065 6,846  
Level 2 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Central banks        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 0      
Level 2 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Credit institutions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 413 408 459  
Level 2 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 4,725 4,590 6,189  
Level 2 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 14 67 198  
Level 2 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 12,962 13,543 12,688  
Level 2 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income | Equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 19 5 5  
Level 2 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 6,819 9,644 9,638  
Level 2 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income | Loans and advances        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 6,124 3,894 3,045  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 133,490 121,243 101,103  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Central banks        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 12,385 13,300 7,808  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Credit institutions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 27,058 26,284 17,862  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 36,120 18,984 19,837  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 50,248 56,205 49,380  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 33,597 41,283 39,395  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 121 2,295 2,207  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Exchange rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 903 1,057 549  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Index and securities options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 1,094 1,160 466  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Forwards on interest rate and variable income        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 1,951 1,276 101  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 12,582 9,134 6,662  
Level 2 | Financial assets and liabilities | Financial liabilities held for trading | Short positions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 7,679 6,470 6,216  
Level 2 | Financial assets and liabilities | Hedging derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 4,229 4,740 7,650  
Level 2 | Financial assets and liabilities | Hedging derivatives | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 4,191 4,618 6,866  
Level 2 | Financial assets and liabilities | Hedging derivatives | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 3 1  
Level 2 | Financial assets and liabilities | Hedging derivatives | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 38 119 783  
Level 2 | Financial assets and liabilities | FINANCIAL LIABILITIES DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 42,148 36,200 40,313  
Level 2 | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 18,510 17,583 17,476  
Level 3        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 18,487 15,319 10,351 € 8,290
Financial liabilities, at fair value 1,110 1,352 1,227 925
Level 3 | Financial assets held for trading        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 6,496 3,930 2,086 383
Level 3 | Financial assets held for trading | Central banks        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 441 0    
Level 3 | Financial assets held for trading | Credit institutions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 152 769 0  
Level 3 | Financial assets held for trading | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 4,592 1,801 24 0
Level 3 | Financial assets held for trading | Derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 971 947 1,147 340
Level 3 | Financial assets held for trading | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 551 556 577 139
Level 3 | Financial assets held for trading | Exchange rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 39 2 9 4
Level 3 | Financial assets held for trading | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 39 30 153 39
Level 3 | Financial assets held for trading | Index and securities options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 120 241 235 48
Level 3 | Financial assets held for trading | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 222 118 173 110
Level 3 | Financial assets held for trading | Equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value   0 1 1
Level 3 | Financial assets held for trading | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 340 413 914 42
Level 3 | Non-trading financial assets mandatorily at fair value through profit or loss        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 2,889 2,588 2,095 1,833
Level 3 | Non-trading financial assets mandatorily at fair value through profit or loss | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 171 505 287 239
Level 3 | Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 2,543 1,841 1,495 1,269
Level 3 | Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 175 242 313 325
Level 3 | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 34 106 181 427
Level 3 | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 14 20 31 5
Level 3 | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 20 86 150 422
Level 3 | Financial assets at fair value through other comprehensive income        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 9,061 8,675 5,989 5,647
Level 3 | Financial assets at fair value through other comprehensive income | Equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 272 375 492 700
Level 3 | Financial assets at fair value through other comprehensive income | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 887 1,047 559 229
Level 3 | Financial assets at fair value through other comprehensive income | Loans and advances        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 7,902 7,253 4,938 4,718
Level 3 | Financial liabilities held for trading        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 864 934 869 415
Level 3 | Financial liabilities held for trading | Derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 864 934 869 415
Level 3 | Financial liabilities held for trading | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 418 479 388 235
Level 3 | Financial liabilities held for trading | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 95 79 139 19
Level 3 | Financial liabilities held for trading | Exchange rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 34 0 8 0
Level 3 | Financial liabilities held for trading | Index and securities options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 151 294 187 42
Level 3 | Financial liabilities held for trading | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 166 82 147 119
Level 3 | FINANCIAL LIABILITIES DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 160 29 € 151
Level 3 | Financial assets and liabilities | Financial assets held for trading        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 6,496 3,930 2,086  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Central banks        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 441 0 0  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Credit institutions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 152 769 0  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 4,592 1,801 24  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Debt and equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 340 413 915  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 971 947 1,147  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 551 556 577  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Exchange rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 39 2 9  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 39 30 153  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Index and securities options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 120 241 235  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Interest rate forwards        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Financial assets held for trading | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 222 118 173  
Level 3 | Financial assets and liabilities | Hedging derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 7 20 0  
Level 3 | Financial assets and liabilities | Hedging derivatives | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 7 20 0  
Level 3 | Financial assets and liabilities | Hedging derivatives | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Hedging derivatives | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 2,889 2,588 2,095  
Level 3 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 2,543 1,841 1,495  
Level 3 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 175 242 313  
Level 3 | Financial assets and liabilities | Non-trading financial assets mandatorily at fair value through profit or loss | Loans and advances        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 171 505 287  
Level 3 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 34 106 181  
Level 3 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Central banks        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 0      
Level 3 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Credit institutions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 14 20 31  
Level 3 | Financial assets and liabilities | FINANCIAL ASSETS DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 20 86 150  
Level 3 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 9,061 8,675 5,989  
Level 3 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income | Equity instruments        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 272 375 492  
Level 3 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income | Debt securities        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 887 1,047 559  
Level 3 | Financial assets and liabilities | Financial assets at fair value through other comprehensive income | Loans and advances        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial assets, at fair value 7,902 7,253 4,938  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 864 934 869  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Central banks        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Credit institutions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Customers        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 864 934 869  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 418 479 388  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 79 139  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Exchange rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 34 0 8  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Index and securities options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 151 294 187  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Forwards on interest rate and variable income        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 95 0 0  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 166 82 147  
Level 3 | Financial assets and liabilities | Financial liabilities held for trading | Short positions        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Hedging derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 19 12 6  
Level 3 | Financial assets and liabilities | Hedging derivatives | Swaps        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 19 12 6  
Level 3 | Financial assets and liabilities | Hedging derivatives | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | Hedging derivatives | Other derivatives        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 0 0  
Level 3 | Financial assets and liabilities | FINANCIAL LIABILITIES DESIGNATED AT FAIR VALUE THROUGH PROFIT OR LOSS        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value 0 160 29  
Level 3 | Interest rate options        
Measurement of financial assets and liabilities and recognition of fair value changes        
Financial liabilities, at fair value € 227 € 246 € 323