Annual report pursuant to Section 13 and 15(d)

Stock Plans - Schedule of Restricted Stock Unit (Detail)

v3.20.1
Stock Plans - Schedule of Restricted Stock Unit (Detail) - 2014 Plan Stock Options/Stock Issuance Plan and 2017 Stock Incentive Plan [Member] - Restricted Stock Units [Member] - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Shares, Unvested, Beginning Balance 49,143  
Shares, Granted 162,211  
Shares, Forfeited (19,200)  
Shares, Vested (50,009)  
Shares, Unvested, Ending Balance 142,145 49,143
Weighted Average Grant Date Fair Value, Unvested, Beginning Balance $ 12.57  
Weighted Average Grant Date Fair Value, Granted 6.97 $ 13.46
Weighted Average Grant Date Fair Value, Forfeited 8.81  
Weighted Average Grant Date Fair Value, Vested 12.51  
Weighted Average Grant Date Fair Value, Unvested, Ending Balance $ 6.71 $ 12.57