Quarterly report pursuant to Section 13 or 15(d)

Summary of Unvested Stock Option Activity (Detail)

v3.20.1
Summary of Unvested Stock Option Activity (Detail) - $ / shares
shares in Thousands
 3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Weighted Average Grant Date Fair Value    
Granted $ 0.54 $ 1.53
Stock Options    
Shares    
Beginning Balance 254  
Granted 20  
Vested (47)  
Forfeited or cancelled (14)  
Ending Balance 213  
Weighted Average Grant Date Fair Value    
Beginning Balance $ 1.44  
Granted 0.54  
Vested 1.63  
Forfeited or cancelled 2.61  
Ending Balance $ 1.25