Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Details 2)

v2.4.0.8
Stock-Based Compensation (Details 2) (USD $)
3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Summary of weighted average assumptions used to value options granted      
Grant date fair value of options (in dollars per share) $ 4.97 $ 6.11 $ 4.91
Volatility (as a percent) 39.70% 40.40% 39.70%
Risk-free interest rate (as a percent) 1.20% 1.00% 1.20%
Dividend yield (as a percent) 0.00% 0.00% 0.00%
Expected term 6 years 6 years 6 years