v3.26.1
Intangible assets (Details) - EUR (€)
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Intangible assets    
Intangible assets at beginning € 50,108,000  
Amortization (2,200,000) € (456,000)
Intangible assets at ending 48,016,000 51,407,000
Development cost    
Intangible assets    
Intangible assets at ending 47,657,000 51,005,000
Patents and licenses    
Intangible assets    
Intangible assets at ending 359,000 402,000
Cost    
Intangible assets    
Intangible assets at beginning 55,958,000 54,001,000
Additions 154,000 1,507,000
Other movements   (4,000)
Intangible assets at ending 56,112,000 55,504,000
Cost | Development cost    
Intangible assets    
Intangible assets at beginning 55,367,000 53,410,000
Additions 154,000 1,507,000
Other movements   (4,000)
Intangible assets at ending 55,521,000 54,913,000
Cost | Patents and licenses    
Intangible assets    
Intangible assets at beginning 591,000 591,000
Additions 0 0
Intangible assets at ending 591,000 591,000
Amortization    
Intangible assets    
Intangible assets at beginning (5,850,000) (3,620,000)
Amortization (2,246,000) (477,000)
Intangible assets at ending (8,096,000) (4,097,000)
Amortization | Development cost    
Intangible assets    
Intangible assets at beginning (5,639,000) (3,452,000)
Amortization (2,225,000) (456,000)
Intangible assets at ending (7,864,000) (3,908,000)
Amortization | Patents and licenses    
Intangible assets    
Intangible assets at beginning (211,000) (168,000)
Amortization (21,000) (21,000)
Intangible assets at ending € (232,000) € (189,000)