Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.1
Stock Plans - Schedule of Restricted Stock Award Activity (Detail) - Restricted Stock Awards [Member]
3 Months Ended
Mar. 31, 2019
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Shares, Unvested, Beginning Balance | shares 72,208
Shares, Vested | shares (9,621)
Shares, Unvested, Ending Balance | shares 62,587
Weighted Average Grant Date Fair Value, Unvested, Beginning Balance | $ / shares $ 7.26
Weighted Average Grant Date Fair Value, Vested | $ / shares 3.62
Weighted Average Grant Date Fair Value, Unvested, Ending Balance | $ / shares $ 7.82