v3.26.3
Accounting principles - Going concern (Details) - EUR (€)
€ in Thousands
Oct. 14, 2024
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
Going Concern          
Cash and cash equivalents   € 166,127 € 99,312 € 122,076 € 96,564
Short-term deposits   67,765 € 131,558    
Minimum cash covenant under Debt Financing Transaction   € 30,000      
Maximum | Lenders' Tranche C          
Going Concern          
Potential gross proceeds € 55,000        
Maximum | T3 Warrants          
Going Concern          
Additional proceeds receivable upon exercise of warrants € 116,000