Annual report pursuant to Section 13 and 15(d)

Stock Plans - Schedule of Restricted Stock Award Activity (Detail)

v3.20.4
Stock Plans - Schedule of Restricted Stock Award Activity (Detail) - Restricted Stock Awards [Member]
12 Months Ended
Dec. 31, 2020
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Shares, Unvested, Beginning Balance | shares 22,813
Shares, Granted | shares 6,903
Shares, Vested | shares (29,716)
Shares, Unvested, Ending Balance | shares  
Weighted Average Grant Date Fair Value, Unvested, Beginning Balance | $ / shares $ 7.50
Weighted Average Grant Date Fair Value, Granted | $ / shares 4.47
Weighted Average Grant Date Fair Value, Vested | $ / shares $ 6.80
Weighted Average Grant Date Fair Value, Unvested, Ending Balance | $ / shares