v3.25.1
Discontinued operations and assets held for sale - Net cash inflow/outflow on disposal of the Jyseleca business (Details) - EUR (€)
 12 Months Ended
Jun. 21, 2022
Dec. 31, 2024
Dec. 31, 2022
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]      
Cash out from disposals of subsidiaries, net of cash disposed of   € (8,949,000)  
Other Liabilities Relate To The Disposal Of Subsidiaries [line items]      
Cash used for other liabilities related to the disposal of subsidiaries € (28,164,000) (3,598,000) € (28,164,000)
Escrow Account   41,163,000  
Jyseleca Business [member]      
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]      
Upfront Payment Received   50,000,000  
Settlement for net cash and working capital   9,835,000  
Transfer to escrow account   (40,000,000)  
Contribution for R&D costs paid by us to Alfasigma   (15,000,000)  
Earn-out paid by Alfasigma   2,053,000  
Less: Cash and cash equivalents balances disposed of   (19,523,000)  
Less: settlement of pre-existing relationships   3,686,000  
Cash out from disposals of subsidiaries, net of cash disposed of   (8,949,000)  
Other Liabilities Relate To The Disposal Of Subsidiaries [line items]      
Costs associated to the sale taken into result in 2023   (3,072,000)  
Costs associated to the sale taken into result in 2024   (526,000)  
Cash used for other liabilities related to the disposal of subsidiaries   (3,598,000)  
Escrow Account   40,000,000  
Jyseleca Business [member] | Alfasigma [member]      
Other Liabilities Relate To The Disposal Of Subsidiaries [line items]      
Upfront Payment Received Discontinued Operations   50,000,000  
Cash Related To Disposal Transfered To Escrow Account   € 40,000,000