XML 57 R38.htm IDEA: XBRL DOCUMENT v3.4.0.3
Accounting for Stock-Based Compensation - Valuation Assumptions Used to Calculate Fair Value of Employee Options Awarded (Detail)
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]    
Risk-free interest rate, minimum 1.60% 1.60%
Risk-free interest rate, maximum 1.80% 1.70%
Volatility, minimum 69.00% 68.00%
Volatility, maximum 70.00% 70.00%
Dividends 0.00% 0.00%
Employees [Member]    
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]    
Expected life (years) 6 years 6 years
Officers and Directors [Member]    
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]    
Expected life (years) 7 years 7 years