v3.26.1
Other Intangible Assets and Goodwill - Summary of Goodwill Recognized (Details) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Disclosure of detailed information about intangible assets [line items]    
Goodwill € 367.9 € 380.6
Intangible assets with indefinite useful life 474.3 486.5
Total 842.2 867.1
CGU Immunotherapies    
Disclosure of detailed information about intangible assets [line items]    
Goodwill 358.3 369.8
Intangible assets with indefinite useful life 474.3 486.5
Total 832.6 856.3
CGU External Product Sales of JPT    
Disclosure of detailed information about intangible assets [line items]    
Goodwill 0.0 0.5
Intangible assets with indefinite useful life 0.0 0.0
Total 0.0 0.5
CGU External Business of InstaDeep    
Disclosure of detailed information about intangible assets [line items]    
Goodwill 9.6 10.3
Intangible assets with indefinite useful life 0.0 0.0
Total € 9.6 € 10.3