v3.26.1
Basis of preparation/impact of changes in accounting principles (Detail: Text Values)
€ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
EUR (€)
Jun. 30, 2025
EUR (€)
Jun. 30, 2026
EUR (€)
Jun. 30, 2025
EUR (€)
Application of the EU carve out version of IAS 39 [Abstract]        
Positive (negative) impact to profit before tax € (688) € (535) € 166 € (144)
Positive (negative) impact to profit after tax € (496) € (383) € 119 € (103)
Positive (negative) impact on CET capital ratio (in bps)     (0.0053) (0.0075)