v3.26.1
Employee benefits - Additional information (Details) - EUR (€)
€ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Employee benefits      
Net balance of post-employee benefits € 11,642 € 17,240 € 17,972
Description of decrease in actuarial assumption leading to changes in defined benefit obligation A 100-basis-point decrease in the discount rate would result in a €1.30 million increase in the amount of the defined-benefit obligation as of December 31, 2025 (December 31, 2024: €1.01 million).    
Actuarial assumption of discount rates      
Employee benefits      
Percentage of reasonably possible decrease in actuarial assumption 1.00%    
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption € 1,300 1,010  
Post-employee benefits defined-benefits plans      
Employee benefits      
Net balance of post-employee benefits € 10,006 € 12,838