Quarterly report pursuant to Section 13 or 15(d)

Stock Plans - Additional Information (Detail)

v3.20.1
Stock Plans - Additional Information (Detail) - USD ($)
 3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Class of Stock [Line Items]      
Accrued employee contributions $ 1,957,000   $ 2,486,000
Employee Stock Purchase Plan [Member]      
Class of Stock [Line Items]      
Common stock were purchased under ESPP 62,469    
Accrued employee contributions $ 52,000    
Timebased Stock Option [Member]      
Class of Stock [Line Items]      
Options granted 487,500    
Restricted Stock [Member]      
Class of Stock [Line Items]      
Unrecognized cost of share-based compensation awards $ 104,000    
Cost of share-based compensation awards, recognition period 7 months 6 days    
Restricted Stock Units [Member]      
Class of Stock [Line Items]      
Unrecognized cost of share-based compensation awards $ 217,000    
Cost of share-based compensation awards, recognition period 8 months 12 days    
Performance-based Stock Options [Member]      
Class of Stock [Line Items]      
Cost of share-based compensation awards, recognition period 3 years 1 month 6 days    
Weighted Average Grant Date Fair Value, Granted $ 2.54    
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 $ 19,319,000    
Stock Options [Member]      
Class of Stock [Line Items]      
Options granted 487,500    
Cost of share-based compensation awards, recognition period 2 years 2 months 12 days    
Weighted Average Grant Date Fair Value, Granted $ 1.64 $ 3.55  
Total grant date fair value of stock options vested $ 2,371,000 $ 2,718,000  
Unrecognized compensation expense related to stock options 6,283,000    
Aggregate intrinsic value of the options exercised $ 0 $ 74,000