v3.26.1
Significant Developments In The Current Reporting Period - Additional Information (Detail) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Jan. 23, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Significant Developments In The Current Reporting Period [Abstract]          
Debt Securities Repurchased Principal Amount   € 63      
Debt Securities Issued Principal Amount   625      
Cash Outflow On Repurchase Of Debt Securities   59      
Gain On Repurchase Recorded In Other Reserves   € 4      
Outstanding Principal Amount Of Debt Securities € 525   € 525    
Insurance Claims Received Recognised In Other Income € 164     € 3
Revenue recognized in IRIS 2 contract     147  
Termination fees for contractual commitments     € 8