v3.26.3
Financial Assets and Financial Liabilities - Summary Of Movement In The Derivative Warrant Liabilities (Detail) - EUR (€)
€ in Thousands
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Disclosure in tabular form of movement in warrant liabilities [line items]    
Exchange differences [1] € (3,524) € 11,654
Public warrants [member]    
Disclosure in tabular form of movement in warrant liabilities [line items]    
Euros, Beginning balance € 0  
Number of warrants, Beginning balance (Shares) 262,956  
Euros, Ending balance € 0  
Number of warrants, Ending balance (Shares) 262,956  
Private warrants [member]    
Disclosure in tabular form of movement in warrant liabilities [line items]    
Euros, Beginning balance € 0  
Number of warrants, Beginning balance (Shares) 444,167  
Euros, Ending balance € 0  
Number of warrants, Ending balance (Shares) 444,167  
BBVA warrant [Member]    
Disclosure in tabular form of movement in warrant liabilities [line items]    
Euros, Beginning balance € 19  
Number of warrants, Beginning balance (Shares) 50,394  
Change in fair value of derivative warrant liabilities € (6)  
Exchange differences 1  
Euros, Ending balance € 14  
Number of warrants, Ending balance (Shares) 50,394  
Generac warrant [member]    
Disclosure in tabular form of movement in warrant liabilities [line items]    
Euros, Beginning balance € 51  
Number of warrants, Beginning balance (Shares) 655,147  
Change in fair value of derivative warrant liabilities € 22  
Number of warrants issued during the period 229,938  
Value of warrants issued during the period € 2  
Euros, Ending balance € 75  
Number of warrants, Ending balance (Shares) 885,085  
Other warrant [member]    
Disclosure in tabular form of movement in warrant liabilities [line items]    
Euros, Beginning balance € 0  
Number of warrants, Beginning balance (Shares) 0  
Number of warrants issued during the period 3,301,758  
Value of warrants issued during the period € 7,216  
Euros, Ending balance € 7,216  
Number of warrants, Ending balance (Shares) 3,301,758  
Public warrant, Private warrant, Bbva warrant, Generac warrant and Other warrant [member]    
Disclosure in tabular form of movement in warrant liabilities [line items]    
Euros, Beginning balance € 70  
Number of warrants, Beginning balance (Shares) 1,412,664  
Change in fair value of derivative warrant liabilities € 16  
Number of warrants issued during the period 3,531,696  
Value of warrants issued during the period € 7,218  
Exchange differences 1  
Euros, Ending balance € 7,305  
Number of warrants, Ending balance (Shares) 4,944,360  
[1] Unaudited