v3.26.1
Income taxes (Details) - EUR (€)
€ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Net deferred tax liabilities € 6,076 € 5,848
Royalty certificates    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Deferred tax liabilities 17,383  
Royalty certificates | France    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Deferred tax assets € 11,307