Quarterly report pursuant to Section 13 or 15(d)

Summary of Option Activity (Detail)

v3.10.0.1
Summary of Option Activity (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2018
Dec. 31, 2017
Shares    
Beginning Balance 1,924  
Granted at fair market value 487  
Exercised (1)  
Forfeited, cancelled, or expired (401)  
Ending Balance 2,009 1,924
Options exercisable at September 30, 2018 1,114  
Vested options expired during the quarter ended September 30, 2018 208  
Weighted Average Exercise Price    
Beginning Balance $ 8.62  
Granted at fair market value 1.98  
Exercised 2.10  
Forfeited, cancelled, or expired 11.26  
Ending Balance 6.48 $ 8.62
Options exercisable at September 30, 2018 8.30  
Vested options expired during the quarter ended September 30, 2018 $ 14.28  
Weighted Average Remaining Contractual Term (Years)    
Options outstanding 6 years 29 days 7 years 2 months 15 days
Options exercisable 4 years 9 months 3 days  
Aggregate Intrinsic Value    
Options outstanding [1] $ 57  
[1] The intrinsic value calculation does not include negative values. This can occur when the fair market value on the reporting date is less than the exercise price of the grant.