v3.26.1
Share Capital and Premium Related to the Share Capitals - Schedule of Share Capital Information (Detail)
€ / shares in Units, $ in Thousands, € in Millions
6 Months Ended
Jun. 30, 2026
USD ($)
shares
Jun. 30, 2026
EUR (€)
€ / shares
shares
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2025
EUR (€)
€ / shares
shares
Dec. 31, 2025
€ / shares
Dec. 31, 2024
€ / shares
Disclosure of classes of share capital [line items]            
Beginning balance $ 75,901          
Balance at beginning, Number of shares | shares 100,339,441 100,339,441 100,093,873 100,093,873    
Non-cash stock-based compensation expense $ 3,952   $ 2,258      
Exercise of share warrants, employee warrants, stock-options and free-shares vesting, amount $ 204          
Exercise of share warrants, employee warrants, stock-options and free-shares vesting, shares | shares 358,717 [1] 358,717 [1] 231,356 231,356    
Balance at end of year $ 41,067          
Balance at end, Number of shares | shares 100,698,158 100,698,158 100,325,229 100,325,229    
Nominal value | € / shares   € 0.05   € 0.05 € 0.05 € 0.05
Share Capital Issued Capital [member]            
Disclosure of classes of share capital [line items]            
Beginning balance $ 5,903   $ 5,889      
Exercise of share warrants, employee warrants, stock-options and free-shares vesting, amount 21 [1]   13      
Balance at end of year 5,924   5,902      
Premiums Related to Share Capital [member]            
Disclosure of classes of share capital [line items]            
Beginning balance 437,445   494,288      
Allocation of prior period loss (69,800) € 61.8 (63,000) € 58.2    
Non-cash stock-based compensation expense 3,952   2,258      
Exercise of share warrants, employee warrants, stock-options and free-shares vesting, amount 198 [1]   3      
Balance at end of year $ 371,749   $ 433,549      
[1] During the six-month period ended June 30, 2026, 358,717 ordinary shares were issued to the benefit of Cellectis employees related to free share plans which met vesting conditions and exercises of stock-options.