XML 24 R28.htm IDEA: XBRL DOCUMENT v2.4.0.6
Summary of Significant Accounting Policies (Details 1)
9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Valuation assumptions used in computation of stock option expense    
Expected volatility, minimum 75.80% 71.70%
Expected volatility, maximum 115.40% 84.70%
Weighted-average volatility 76.60% 81.00%
Risk-free interest rate, minimum 0.40% 0.40%
Risk-free interest rate, maximum 0.90% 2.20%
Expected dividend 0.00% 0.00%
Maximum [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected life in years 8 years 7 months 6 days 8 years 7 months 6 days
Minimum [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected life in years 3 years 6 months 3 years 6 months