Quarterly report pursuant to Section 13 or 15(d)

Stock Incentive Plan - Stock Options Activity (Details)

v2.4.0.8
Stock Incentive Plan - Stock Options Activity (Details) (USD $)
9 Months Ended
Sep. 30, 2013
Number of Options [Roll Forward]  
Beginning balance (in shares) 4,778,143
Granted (in shares) 563,360
Exercised (in shares) (507,919)
Forfeited (in shares) (100,206)
Ending balance (in shares) 4,733,378
Options exercisable (in shares) 3,193,796
Expected to vest (in shares) 1,520,676
Options exercisable (in shares) 3,309,722
Weighted Average Exercise Price [Roll Forward]  
Beginning balance (in usd per share) $ 6.794
Granted (in usd per share) $ 9.036
Exercised (in usd per share) $ 3.300
Forfeited (in usd per share) $ 11.810
Ending balance (in usd per share) $ 7.329
Options exercisable (in usd per share) $ 5.847
Expected to vest (in usd per share) $ 10.420
Options exercisable (in usd per share) $ 4.986