XML 82 R58.htm IDEA: XBRL DOCUMENT v3.2.0.727
Stock-Based Compensation - Estimated Fair Values of Employee Stock Options Granted (Detail) - Employee Stock Option [Member]
3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected option life (years)   5 years 11 months 16 days   5 years 11 months 16 days
Risk-free interest rate   1.54%    
Expected volatility   133.00%    
Expected dividend yield 0.00% 0.00% 0.00% 0.00%
Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected option life (years) 1 year 5 months 23 days   1 year 5 months 23 days  
Risk-free interest rate 0.68%   0.68% 1.54%
Expected volatility 65.85%   73.33% 131.00%
Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected option life (years) 6 years 1 month 13 days   6 years 2 months 19 days  
Risk-free interest rate 1.91%   1.91% 1.57%
Expected volatility 73.33%   132.00% 133.00%