v3.26.1
Provisions - Schedule of status and changes of the defined benefit obligations, United Kingdom (Details) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of net defined benefit liability (asset) [line items]      
Benefits paid by settlements € 133 € 20 € 2
United Kingdom      
Disclosure of net defined benefit liability (asset) [line items]      
Financial actuarial (gains)/losses 117    
United Kingdom | Present value of defined benefit obligation      
Disclosure of net defined benefit liability (asset) [line items]      
Net defined benefit liability (asset) at beginning of period 8,898 9,451 8,982
Net incorporation of companies into the Group 0 0 (28)
Current service cost 9 13 14
Interest cost 465 438 436
Benefits paid (469) (465) (428)
Benefits paid by settlements 0 0 9
Contributions made by employees 3 7 6
Past service cost 0 0 0
Actuarial (gains)/losses (304) (965) 281
Demographic actuarial (gains)/losses (91) (133) (59)
Financial actuarial (gains)/losses (213) (832) 340
Exchange differences and other items (438) 419 197
Net defined benefit liability (asset) at end of period € 8,164 € 8,898 € 9,451