v3.26.1
Note 6 Wholesale financing operations carried out by group entities (Details) - Jun. 30, 2026
€ in Millions, S/ in Millions, $ in Millions, $ in Millions, $ in Millions
USD ($)
EUR (€)
MXN ($)
ARS ($)
PEN (S/)
Jan-26 [Member] | 3.750% [Member] | Equivalent in euros [Member] | Jan-36 [Member]          
Type of issue [Line Items]          
Senior non-preferred [1]   € 1,250      
Jan-26 [Member] | 2.754% [Member] | Equivalent in euros [Member] | Jan-29 [Member]          
Type of issue [Line Items]          
Senior non-preferred [1]   750      
Jan-26 [Member] | Issued in euros [Member] | 3.750% [Member] | Jan-36 [Member]          
Type of issue [Line Items]          
Senior non-preferred | $ $ 1,250        
Jan-26 [Member] | Issued in euros [Member] | 2.754% [Member] | Jan-29 [Member]          
Type of issue [Line Items]          
Senior non-preferred | $ 750        
Mar-26 [Member] | 4.150% [Member] | Equivalent in euros [Member] | Mar-29 [Member]          
Type of issue [Line Items]          
Senior non-preferred [1]   878      
Mar-26 [Member] | 5.127% [Member] | Equivalent in euros [Member] | Mar-36 [Member]          
Type of issue [Line Items]          
Senior non-preferred [1]   878      
Mar-26 [Member] | 4.532% [Member] | Equivalent in euros [Member] | Mar-29 [Member]          
Type of issue [Line Items]          
Senior non-preferred [1]   439      
Mar-26 [Member] | TAMAR+350 Basis Points [Member] | Equivalent in euros [Member] | Mar-27 [Member]          
Type of issue [Line Items]          
Senior debt [1]   27      
Mar-26 [Member] | 6.750% [Member] | Equivalent in euros [Member] | Mar-38 [Member]          
Type of issue [Line Items]          
Tier 2 [1],[2]   77      
Mar-26 [Member] | United States of America, Dollars | 4.150% [Member] | Mar-29 [Member]          
Type of issue [Line Items]          
Senior non-preferred | $ 1,000        
Mar-26 [Member] | United States of America, Dollars | 5.127% [Member] | Mar-36 [Member]          
Type of issue [Line Items]          
Senior non-preferred | $ 1,000        
Mar-26 [Member] | United States of America, Dollars | 4.532% [Member] | Mar-29 [Member]          
Type of issue [Line Items]          
Senior non-preferred | $ 500        
Mar-26 [Member] | Argentina, Pesos | TAMAR+350 Basis Points [Member] | Mar-27 [Member]          
Type of issue [Line Items]          
Senior debt | $       $ 45,457  
Mar-26 [Member] | Peru, Nuevos Soles | 6.750% [Member] | Mar-38 [Member]          
Type of issue [Line Items]          
Tier 2 | S/ [2]         S/ 300
May-26 [Member] | 7.1250% [Member] | Equivalent in euros [Member] | Perpetual [Member]          
Type of issue [Line Items]          
AT 1 [1],[3]   878      
May-26 [Member] | 4.968% [Member] | Equivalent in euros [Member] | May-31 [Member]          
Type of issue [Line Items]          
Senior non-preferred [1]   1,097      
May-26 [Member] | 5.000% [Member] | Equivalent in euros [Member] | May-28 [Member]          
Type of issue [Line Items]          
Senior debt [1]   42      
May-26 [Member] | 3.250% [Member] | Equivalent in euros [Member] | May-27 [Member]          
Type of issue [Line Items]          
Senior debt [1]   22      
May-26 [Member] | TAMAR+325 Basis Points [Member] | Equivalent in euros [Member] | May-27 [Member]          
Type of issue [Line Items]          
Senior debt [1]   50      
May-26 [Member] | United States of America, Dollars | 7.1250% [Member] | Perpetual [Member]          
Type of issue [Line Items]          
AT 1 | $ [3] 1,000        
May-26 [Member] | United States of America, Dollars | 4.968% [Member] | May-31 [Member]          
Type of issue [Line Items]          
Senior non-preferred | $ 1,250        
May-26 [Member] | United States of America, Dollars | 5.000% [Member] | May-28 [Member]          
Type of issue [Line Items]          
Senior debt | $ 48        
May-26 [Member] | United States of America, Dollars | 3.250% [Member] | May-27 [Member]          
Type of issue [Line Items]          
Senior debt | $ 25        
May-26 [Member] | Argentina, Pesos | TAMAR+325 Basis Points [Member] | May-27 [Member]          
Type of issue [Line Items]          
Senior debt | $       83,914  
Jun-26 [Member] | 3.125% [Member] | Equivalent in euros [Member] | Jun-33 [Member]          
Type of issue [Line Items]          
covered bonds [1]   1,000      
Jun-26 [Member] | 2.875% [Member] | Equivalent in euros [Member] | jun-29 [Member]          
Type of issue [Line Items]          
covered bonds [1]   1,250      
Jun-26 [Member] | 3.375% [Member] | Equivalent in euros [Member] | Jun-31 [Member]          
Type of issue [Line Items]          
Senior non-preferred [1]   1,250      
Jun-26 [Member] | 5.400% [Member] | Equivalent in euros [Member] | Jun-31 [Member]          
Type of issue [Line Items]          
Senior USD [1]   878      
Jun-26 [Member] | SOFR+125 Basis Points [Member] | Equivalent in euros [Member] | Jun-27 [Member]          
Type of issue [Line Items]          
Syndicated Loans [1]   29      
Jun-26 [Member] | EUR+110 Basis Points [Member] | Equivalent in euros [Member] | Jun-27 [Member]          
Type of issue [Line Items]          
Syndicated Loans [1]   24      
Jun-26 [Member] | SOFR+175 Basis Points [Member] | Equivalent in euros [Member] | Jun-28 [Member]          
Type of issue [Line Items]          
Syndicated Loans [1]   92      
Jun-26 [Member] | EUR+160 Basis Points [Member] | Equivalent in euros [Member] | Jun-28 [Member]          
Type of issue [Line Items]          
Syndicated Loans [1]   40      
Jun-26 [Member] | SOFR+200 Basis Points [Member] | Equivalent in euros [Member] | jun-29 [Member]          
Type of issue [Line Items]          
Syndicated Loans [1]   77      
Jun-26 [Member] | TAMAR+325 Basis Points [Member] | Equivalent in euros [Member] | Jun-27 [Member]          
Type of issue [Line Items]          
Senior debt [1]   96      
Jun-26 [Member] | Issued in euros [Member] | 3.125% [Member] | Jun-33 [Member]          
Type of issue [Line Items]          
covered bonds   1,000      
Jun-26 [Member] | Issued in euros [Member] | 2.875% [Member] | jun-29 [Member]          
Type of issue [Line Items]          
covered bonds   1,250      
Jun-26 [Member] | Issued in euros [Member] | 3.375% [Member] | Jun-31 [Member]          
Type of issue [Line Items]          
Senior non-preferred | $ 1,250        
Jun-26 [Member] | Issued in euros [Member] | EUR+110 Basis Points [Member] | Jun-27 [Member]          
Type of issue [Line Items]          
Syndicated Loans   24      
Jun-26 [Member] | Issued in euros [Member] | EUR+160 Basis Points [Member] | Jun-28 [Member]          
Type of issue [Line Items]          
Syndicated Loans | $ 40        
Jun-26 [Member] | United States of America, Dollars | 5.400% [Member] | Jun-31 [Member]          
Type of issue [Line Items]          
Senior USD | $ 1,000        
Jun-26 [Member] | United States of America, Dollars | SOFR+125 Basis Points [Member] | Jun-27 [Member]          
Type of issue [Line Items]          
Syndicated Loans | $ 33        
Jun-26 [Member] | United States of America, Dollars | SOFR+175 Basis Points [Member] | Jun-28 [Member]          
Type of issue [Line Items]          
Syndicated Loans | $ 105        
Jun-26 [Member] | United States of America, Dollars | SOFR+200 Basis Points [Member] | jun-29 [Member]          
Type of issue [Line Items]          
Syndicated Loans   88      
Jun-26 [Member] | Argentina, Pesos | TAMAR+325 Basis Points [Member] | Jun-27 [Member]          
Type of issue [Line Items]          
Senior debt | $       $ 161,298  
Feb-26 [Member] | 9.260% [Member] | Equivalent in euros [Member] | Jan-36 [Member]          
Type of issue [Line Items]          
senior [1]   446      
Feb-26 [Member] | TIIEF+32 Basis Points [Member] | Equivalent in euros [Member] | Jul-29 [Member]          
Type of issue [Line Items]          
senior [1]   308      
Feb-26 [Member] | 4.190% [Member] | Equivalent in euros [Member] | Sep-28 [Member]          
Type of issue [Line Items]          
Senior USD [1]   14      
Feb-26 [Member] | 5.000% [Member] | Equivalent in euros [Member] | Aug-27 [Member]          
Type of issue [Line Items]          
Senior debt [1]   32      
Feb-26 [Member] | United States of America, Dollars | 4.190% [Member] | Sep-28 [Member]          
Type of issue [Line Items]          
Senior USD | $ 16        
Feb-26 [Member] | United States of America, Dollars | 5.000% [Member] | Aug-27 [Member]          
Type of issue [Line Items]          
Senior debt | $ $ 37        
Feb-26 [Member] | Mexico, Pesos | 9.260% [Member] | Jan-36 [Member]          
Type of issue [Line Items]          
senior | $     $ 8,876    
Feb-26 [Member] | Mexico, Pesos | TIIEF+32 Basis Points [Member] | Jul-29 [Member]          
Type of issue [Line Items]          
senior | $     $ 6,124    
Several [Member] | Several [Member] | Equivalent in euros [Member] | Several [Member]          
Type of issue [Line Items]          
Senior Debt MTNs (Medium Term Notes) [1]   1,382      
Several [Member] | Issued in euros [Member] | Several [Member] | Several [Member]          
Type of issue [Line Items]          
Senior Debt MTNs (Medium Term Notes)   € 1,382      
[1] (1) Equivalent in euros at the closing exchange rate of the period
[2]
(3) First Reset Date in March 2033.
[3]
(2) First Reset Date in May 2033.