Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Restricted Stock Units - Additional Information (Detail)

v3.19.2
Stock-Based Compensation - Restricted Stock Units - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense $ 2,304 $ 2,292 $ 3,860 $ 2,224
Unrecognized stock-based compensation expense related to to non-vested stock options and restricted stock units 22,400   $ 22,400  
2017 Omnibus Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period     6 years  
Stock-based compensation expense 1,500 1,400 $ 2,300 1,000
Restricted Stock Units [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total fair value vested 1,300 1,500 1,400 1,500
Stock-based compensation expense 800 900 $ 1,600 1,200
Unrecognized stock-based compensation expense, expected recognition weighted-average period     42 months  
Restricted Stock Units [Member] | 2017 Omnibus Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period     5 years  
Nonemployee Restricted Stock Units [Member] | Cellectis [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Dividends $ 400 $ 700 $ 800 $ 1,400
Employee Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized stock-based compensation expense, expected recognition weighted-average period     61 months