Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plan - Stock Options Activity (Details)

v2.4.0.6
Stock Incentive Plan - Stock Options Activity (Details) (USD $)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Number of Options [Roll Forward]      
Beginning balance 5,424,612 8,274,000 9,450,200
Granted 706,644 [1] 257,500 [1] 856,000
Exercised (1,306,145) (2,790,188) (1,801,906)
Forfeited (46,968) (316,700) (230,294)
Ending balance 4,778,143 5,424,612 8,274,000
Options exercisable 3,309,722 3,896,512  
Options expected to vest 1,432,041    
Weighted Average Exercise Price [Roll Forward]      
Beginning Balance, Weighted Average Exercise Price (in usd per share) $ 5.151 $ 4.177 $ 2.680
Granted (in usd per share)   $ 12.520 [1] $ 13.045
Exercised (in usd per share) $ 2.651 $ 2.305 $ 1.484
Forfeited (in usd per share) $ 7.249 $ 10.787 $ 2.074
Ending Balance, Weighted Average Exercise Price (in usd per share) $ 6.794 $ 5.151 $ 4.177
Weighted Average Exercise Price, Options exercisable (in usd per share) $ 4.986 $ 3.773  
Weighted Average Exercise Price, Expected to Vest (in usd per share) $ 10.951    
Stock Options
     
Weighted Average Exercise Price [Roll Forward]      
Ending Balance, Weighted Average Exercise Price (in usd per share) $ 4.03 $ 5.59 $ 7.57
Stock Options | 2010 Plan
     
Weighted Average Exercise Price [Roll Forward]      
Shares available for grant 9,049,574    
[1] Grants are related to the 2010 Plan.