v3.26.1
Financial Assets and Liabilities - Summary of Fair Value Hierarchy (Detail) - EUR (€)
€ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
Disclosure of detailed information about financial instruments [line items]        
Royalty funding liabilities € 301,800      
Derivative liabilities 0 € 256,231    
Level 3 [member]        
Disclosure of detailed information about financial instruments [line items]        
Derivative liabilities 0 256,231 € 186,579 € 150,670
Carrying amount [member]        
Disclosure of detailed information about financial instruments [line items]        
Financial liabilities measured at amortized cost 301,789 720,262    
Financial liabilities measured at fair value through profit or loss 0 256,231    
Carrying amount [member] | Level 3 [member]        
Disclosure of detailed information about financial instruments [line items]        
Convertible senior notes 0 429,391    
Royalty funding liabilities 301,789 290,871    
Derivative liabilities 0 256,231    
Fair value [member]        
Disclosure of detailed information about financial instruments [line items]        
Financial liabilities measured at amortized cost 303,011 723,328    
Financial liabilities measured at fair value through profit or loss 0 256,231    
Fair value [member] | Level 3 [member]        
Disclosure of detailed information about financial instruments [line items]        
Convertible senior notes 0 426,429    
Royalty funding liabilities 303,011 296,899    
Derivative liabilities € 0 € 256,231