v3.25.4
Fair value of financial assets and liabilities - Reconciliation of Level 3 fair value measurements (Detail) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Fair value of financial assets and liabilities [Line Items]    
Financial assets at beginning of period € 6,992  
Financial liabilities at beginning of period 9,728  
Recognized in profit and loss:    
Financial assets at end of period 7,338 € 6,992
Financial liabilities at end of period 10,257 9,728
Level 3 | Financial liabilities    
Fair value of financial assets and liabilities [Line Items]    
Financial liabilities at beginning of period 113 115
Acquisitions  
Utilizations (1) (9)
Recognized in profit and loss:    
other business income 3 2
financial income and expenses, liabilities 1 3
Recognized in other comprehensive income, liabilities (5) 3
Transfers into Level 3 of fair value hierarchy, liabilities 0
Financial liabilities at end of period 111 113
Level 3 | Financial assets    
Fair value of financial assets and liabilities [Line Items]    
Financial assets at beginning of period 460 503
Purchase 127 86
Sales (44) (48)
Recognized in profit and loss:    
financial income and expenses, assets (17) (23)
Recognized in other comprehensive income, assets (43) (8)
Receivables Held To Collect And Sell (32)
Transfers into Level 3 of fair value hierarchy, assets 74  
Transfers out of Level 3 of fair value hierarchy, assets   (18)
Financial assets at end of period € 556 € 460