Annual report pursuant to Section 13 and 15(d)

Organization and Summary of Significant Accounting Policies - Additional Information (Detail)

v3.19.1
Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Significant Accounting Policies [Line Items]      
Place of incorporation Delaware    
Impairment of long-lived assets $ 0    
Assumed dividend yield 0.00%    
Income tax expense (benefit) $ 0 $ 0 $ 0
Accounting Standards Update 2016-09 [Member]      
Significant Accounting Policies [Line Items]      
Income tax expense (benefit) 800,000    
Net impact of adoption $ 0    
Cellectis [Member]      
Significant Accounting Policies [Line Items]      
Percentage of ownership in outstanding common stock 69.50%