Quarterly report pursuant to Section 13 or 15(d)

Stock Incentive Plan - Schedule of Stock Option Activity (Detail)

v3.19.2
Stock Incentive Plan - Schedule of Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2018
Jun. 30, 2019
Dec. 31, 2018
Shares      
Ending Balance 2,011,087 1,826,147  
Employee Stock Option [Member]      
Shares      
Beginning Balance   1,980,972  
Granted   5,000  
Exercised   (200)  
Forfeited or expired   (159,625)  
Ending Balance   1,826,147 1,980,972
Exercisable at end of period   1,289,269  
Expected to Vest   509,766  
Weighted Average Exercise Price      
Beginning Balance   $ 4.63  
Granted   2.82  
Exercised   2.38  
Forfeited or expired   6.39  
Ending Balance   4.49 $ 4.63
Exercisable at end of period   4.88  
Expected to Vest   4.51  
Weighted Average Grant Date Fair value      
Beginning Balance   2.61  
Granted   1.43  
Exercised   2.05  
Forfeited or expired   4.50  
Ending Balance   2.46 $ 2.61
Exercisable at end of period   2.77  
Expected to Vest   $ 2.47  
Weighted Average Remaining Contractual Term      
Contractual term   3 years 10 months 24 days 4 years 1 month 6 days
Exercisable at end of period   2 years 9 months 18 days  
Expected to Vest   3 years 10 months 24 days  
Aggregate Intrinsic Value      
Exercised   $ 0  
Forfeited or expired   2  
Ending Balance   3  
Exercisable at end of period   3  
Expected to Vest   $ 3