Quarterly report pursuant to Section 13 or 15(d)

Stock Plans - Additional Information (Detail)

v3.20.2
Stock Plans - Additional Information (Detail) - USD ($)
 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Class of Stock [Line Items]      
Accrued employee contributions $ 2,334,000   $ 2,486,000
Employee Stock Purchase Plan [Member]      
Class of Stock [Line Items]      
Common stock were purchased under ESPP 62,469    
Accrued employee contributions $ 99,000    
Timebased Stock Option [Member]      
Class of Stock [Line Items]      
Options granted 551,500    
Restricted Stock [Member]      
Class of Stock [Line Items]      
Unrecognized cost of share-based compensation awards $ 57,000    
Cost of share-based compensation awards, recognition period 3 months 18 days    
Restricted Stock Units [Member]      
Class of Stock [Line Items]      
Unrecognized cost of share-based compensation awards $ 7,574,000    
Cost of share-based compensation awards, recognition period 10 months 24 days    
Performance-based Stock Options [Member]      
Class of Stock [Line Items]      
Cost of share-based compensation awards, recognition period 2 years 10 months 24 days    
Weighted Average Grant Date Fair Value, Granted   $ 2.57  
Total grant date fair value of stock options granted $ 0    
Total grant date fair value of stock options vested 0 $ 0  
Unrecognized compensation expense related to stock options $ 17,259,000    
Stock Options [Member]      
Class of Stock [Line Items]      
Options granted 551,500    
Cost of share-based compensation awards, recognition period 2 years 4 months 24 days    
Weighted Average Grant Date Fair Value, Granted $ 2.06 $ 3.72  
Total grant date fair value of stock options vested $ 4,067,000 $ 5,465,000  
Unrecognized compensation expense related to stock options 5,122,000    
Aggregate intrinsic value of the options exercised $ 177,000 $ 177,000