v3.26.1
Results of operation - Research and Development expenses - Additional Information (Details) - EUR (€)
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Research and Development expenses        
Capitalized costs   € (700,000) € (154,000) € (1,600,000)
Increase (Decrease) in research and development expense. € (1,200,000)   € (2,100,000)  
Percentage of increase (decrease) in research and development expense. (11.20%)   (10.20%)  
Research and development expenses before capitalization € 9,500,000 10,800,000 € 18,500,000 20,600,000
Research and development expenses        
Research and Development expenses        
Capitalized costs   € (691,000) € (154,000) € (1,554,000)