v3.25.4
Taxation - Summary of changes in deferred tax (Details) - EUR (€)
€ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) € (208) € (362)  
Change through equity (137) (103)  
Change through net result (739) 251 € 1,059
Exchange rate differences (23) 6  
Changes in the composition of the group and other changes  
Deferred tax liability (asset) (1,108) (208) (362)
–  Deferred tax liabilities      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) (1,209) (1,447)  
Deferred tax liability (asset) (1,896) (1,209) (1,447)
–  Deferred tax assets      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) 1,001 1,085  
Deferred tax liability (asset) 788 1,001 1,085
Net deferred tax      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) (208) (362)  
Deferred tax liability (asset)   (208) (362)
Unused tax losses carried forward      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) 85 209  
Change through equity  
Change through net result (47) (128)  
Exchange rate differences (4) 3  
Changes in the composition of the group and other changes  
Deferred tax liability (asset) 35 85 209
Other provisions      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) 62 48  
Change through equity  
Change through net result (1) 12  
Exchange rate differences 1  
Changes in the composition of the group and other changes 1  
Deferred tax liability (asset) 61 62 48
Pension and post-employment benefits      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) (32) (33)  
Change through equity 4 6  
Change through net result (1) 1  
Exchange rate differences 1 (5)  
Changes in the composition of the group and other changes (1)  
Deferred tax liability (asset) (28) (32) (33)
Loans and advances      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) 427 475  
Change through equity 1  
Change through net result (42) (49)  
Exchange rate differences (9)  
Changes in the composition of the group and other changes  
Deferred tax liability (asset) 376 427 475
Cash flow hedges      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) 363 502  
Change through equity (43) (138)  
Change through net result  
Exchange rate differences 2 (1)  
Changes in the composition of the group and other changes  
Deferred tax liability (asset) 322 363 502
Depreciation      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) (22) (13)  
Change through equity  
Change through net result 18 (9)  
Exchange rate differences 6  
Changes in the composition of the group and other changes  
Deferred tax liability (asset) 2 (22) (13)
Other      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) (208) (154)  
Change through equity 57 (41)  
Change through net result 21 (9)  
Exchange rate differences (8) (5)  
Changes in the composition of the group and other changes 1  
Deferred tax liability (asset) (139) (208) (154)
Financial assets at FVOCI      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) 126 64  
Change through equity (155) 70  
Change through net result 5 (8)  
Exchange rate differences 2  
Changes in the composition of the group and other changes  
Deferred tax liability (asset) (22) 126 64
Financial assets and liabilities at FVPL      
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]      
Deferred tax liability (asset) (1,008) (1,461)  
Change through equity  
Change through net result (694) 441  
Exchange rate differences (13) 12  
Changes in the composition of the group and other changes  
Deferred tax liability (asset) € (1,715) € (1,008) € (1,461)