v3.26.1
Shareholders' equity and share-based payments - Variation of the number of shares composing the share capital (Details) - shares
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Variation of the number of shares composing the share capital        
Common shares issued as of the end of the period 2,206,585,543      
Treasury shares 63,702,529 149,529,818 60,543,213 137,187,667
Common shares issued        
Variation of the number of shares composing the share capital        
Common shares issued as of the beginning of the period 2,397,679,661 2,412,251,835 2,619,131,285  
Capital reduction by cancellation of treasury shares (202,243,171) (25,405,361) (214,881,605)  
Capital increase reserved for employees 11,149,053 10,833,187 8,002,155  
Common shares issued as of the end of the period 2,206,585,543 2,397,679,661 2,412,251,835