v3.20.1
Stock-Based Compensation - Summary of Restricted Stock Activity (Detail) - Restricted Stock [Member]
12 Months Ended
Dec. 31, 2018
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Shares, Nonvested beginning balance | shares 91,576
Shares, Granted | shares 60,000
Shares, Vested | shares (149,243)
Shares, Forfeited | shares (2,333)
Weighted Average Grant Date Fair Value, Nonvested beginning balance | $ / shares $ 2.12
Weighted Average Grant Date Fair Value, Granted | $ / shares 4.75
Weighted Average Grant Date Fair Value, Vested | $ / shares 3.18
Weighted Average Grant Date Fair Value, Forfeited | $ / shares $ 2.25