Earnings Per Share - Details of Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Earnings per share [abstract] | ||||
| Net loss attributable to shareholders of Cellectis ($ in thousands) | $ (21,819) | $ (23,736) | $ (39,584) | $ (41,863) |
| Weighted average number of outstanding shares, used to calculate basic net result per share | 100,647,451 | 100,305,204 | 100,587,696 | 100,231,292 |
| Weighted average number of outstanding shares, used to calculate diluted net result per share | 100,647,451 | 100,305,204 | 100,587,696 | 100,231,292 |
| Basic net loss per share attributable to shareholders of Cellectis ($ /share) | $ (0.22) | $ (0.24) | $ (0.39) | $ (0.42) |
| Diluted net loss per share attributable to shareholders of Cellectis ($ /share) | $ (0.22) | $ (0.24) | $ (0.39) | $ (0.42) |