v3.5.0.2
Stock-Based Compensation - Additional Information (Detail)
3 Months Ended 9 Months Ended
Sep. 30, 2016
USD ($)
shares
Sep. 30, 2015
USD ($)
Sep. 30, 2016
USD ($)
Plan
shares
Sep. 30, 2015
USD ($)
shares
Dec. 31, 2015
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of equity incentive plans | Plan     2    
Shares outstanding under equity incentive plans 1,091,000   1,091,000   1,257,000
Shares available for grant under equity incentive plans 0   0    
Expense related to options granted under equity incentive plan | $ $ 70,000 $ 54,000 $ 225,000 $ 156,000  
Unrecognized compensation expense related to non-vested stock options | $ $ 176,000   $ 176,000    
Recognition of unrecognized compensation expense, weighted-average period (in years)     1 year 22 days    
Stock options granted under equity incentive plans       20,000  
Fair value assumption, risk-free interest rates     1.86%    
Fair value assumption, expected dividend yields     0.00%    
Fair value assumption, expected term (years)     6 years    
Fair value assumption, expected volatility     96.60%    
Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock option exercisable period     7 years    
2006 Equity Incentive Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares outstanding under equity incentive plans 814,000   814,000    
Shares available for grant under equity incentive plans 0   0    
2015 Equity Incentive Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares outstanding under equity incentive plans 277,000   277,000    
Shares available for grant under equity incentive plans 1,064,000   1,064,000