v3.26.1
Income taxes and deferred taxes - Additional information (Details) - EUR (€)
6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Income taxes and deferred taxes      
Additional tax accrual for uncertain position € 600,000 € 286,000  
Increase (Decrease) of income tax payable or reimbursed by subsidiaries. 254,000 € 121,000  
Current tax liability 4,020,000   € 3,939,000
Uncertain tax positions € 3,700,000