Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Summary of Stock-Based Compensation Granted as Deemed Dividends (Detail)

v3.20.2
Stock-Based Compensation - Summary of Stock-Based Compensation Granted as Deemed Dividends (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Nonemployee Restricted Stock Units [Member] | Cellectis [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Deemed dividends from grants to Cellectis employees $ 198 $ 366 $ 422 $ 777