v2.4.0.8
Stockholders' Equity , ESPP Information (Details) (Employee Stock Purchase Plan [Member], USD $)
In Thousands, except Per Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Employee Stock Purchase Plan [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term in years 6 months 6 months 6 months
Volatility (%) 44.00% 53.70% 59.90%
Risk-free interest rate (%) 0.12% 0.12% 0.07%
Dividend rate (%) 0.00% 0.00% 0.00%
Weighted-average fair value per share granted (in dollars per share) $ 6.11 $ 7.06 $ 6.56
Shares issued under the ESPP (in shares) 672 577 0
Weighted-average price per share issued (in dollars per share) $ 18.88 $ 18.90 $ 0