Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation (Details 3)

v2.4.0.8
Stock-based Compensation (Details 3) (Employee Stock [Member], USD $)
9 Months Ended
Sep. 30, 2014
item
Sep. 30, 2013
Employee Stock [Member]
   
Weighted-average assumptions relating to options granted    
Risk-free interest rate (as a percent) 2.80% 0.20%
Expected term (in years) 1 year 8 months 12 days 1 year 4 months 24 days
Dividend yield (as a percent) 0.00% 0.00%
Expected volatility (as a percent) 66.00% 64.40%
Additional disclosures    
Shares reserved for future issuance 3,826,858  
Award offering period 24 months  
Number of purchase periods per award offering period 4  
Award purchase period 6 months  
Purchase price expressed as a percentage of fair market value of common stock on the purchase date 85.00%  
Purchase price expressed as a percentage of fair market value of common stock on the first day of the offering period 85.00%  
Total incremental fair value for the Purchase Plan reset $ 577,000