XML 49 R36.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended
Feb. 28, 2018
Feb. 28, 2017
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of options exercised     0   0  
Proceeds from exercise of stock options     $ 0   $ 0  
Issuance of common stock for services (Shares)     75,183 46,858 75,183 46,858
Issuance of common stock for services, amount     $ 300 $ 200 $ 300 $ 200
Options to Purchase Common Stock [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unrecognized stock based compensation expense     14,500   $ 14,500  
Unrecognized stock based compensation expense, weighted-average remaining recognition period         2 years 8 months 12 days  
Number of options exercised       9,025   28,326
Restricted Stock Units (RSUs) [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unrecognized stock based compensation expense     $ 1,600   $ 1,600  
Unrecognized stock based compensation expense, weighted-average remaining recognition period         1 year  
Number of shares issued upon vesting of restricted stock units     0 0 0 15,188
Performance-Based Restricted Stock Units (PRSUs) [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of vested shares     0 0 0 0
Recognized stock-based compensation related expense in connection with vesting of award granted     $ 300   $ 400  
Unrecognized stock based compensation expense     300   $ 300  
Unrecognized stock based compensation expense, weighted-average remaining recognition period         3 months 18 days  
Employee Stock Purchase Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unrecognized stock based compensation expense     $ 100   $ 100  
Unrecognized stock based compensation expense, weighted-average remaining recognition period         2 months 12 days  
Number of shares issued under ESPP 68,589 42,845        
Purchase price $ 4.38 $ 8.77        
Proceeds $ 300 $ 400