v3.25.4
Note 25 Sensitivity analysis (Details) - EUR (€)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Actuarial assumption of discount rates [member]      
Sensitivity analysis [Line Items]      
Basis points change sensitivity analysis 0.50%    
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption € (262) € (213) € (265)
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption € 287 232 291
Actuarial assumption of expected rates of salary increases [member]      
Sensitivity analysis [Line Items]      
Basis points change sensitivity analysis 0.50%    
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption € 5 4 4
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption € (5) (4) (4)
Actuarial assumption of expected rates of pension increases [member]      
Sensitivity analysis [Line Items]      
Basis points change sensitivity analysis 0.50%    
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption € 40 27 34
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption € (38) (26) (32)
Actuarial assumption of medical cost trend rates [member]      
Sensitivity analysis [Line Items]      
Basis points change sensitivity analysis 0.50%    
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption € 151 102 141
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption € (137) (93) (126)
Change in obligation from each additional year of longevity [Member]      
Sensitivity analysis [Line Items]      
Basis points change sensitivity analysis    
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption € 154 120 134
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption € 0 € 0 € 0