v3.25.4
Financial result - Additional Information (Detail)
€ / shares in Units, € in Millions
12 Months Ended
Dec. 31, 2025
EUR (€)
Dec. 31, 2024
EUR (€)
€ / shares
Dec. 31, 2023
EUR (€)
€ / shares
Jun. 30, 2025
€ / shares
Jun. 30, 2025
$ / shares
Dec. 31, 2024
$ / shares
Dec. 31, 2023
$ / shares
Dec. 31, 2022
€ / shares
Dec. 31, 2022
$ / shares
Statements [Line Items]                  
Change in fair value of warrant liabilities € 1.7 € 17.3 € 2.1            
Bottom of range [member]                  
Statements [Line Items]                  
Exercise price of warrants or rights | (per share)   € 0.24 € 2.64     $ 0.25 $ 2.92 € 2.35 $ 2.51
Top of range [member]                  
Statements [Line Items]                  
Exercise price of warrants or rights | (per share)   € 0.24 € 2.64 € 0 $ 0 $ 0.25 $ 2.92