Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Details)

v2.4.0.6
Stock-Based Compensation (Details) (USD $)
In Millions, except Share data in Thousands, unless otherwise specified
 6 Months Ended 12 Months Ended
Jun. 30, 2012
Dec. 31, 2011
Stock option activity    
Number of Shares Underlying Options, Outstanding at beginning of period 3,805  
Number of Shares Underlying Options, Granted 1,024  
Number of Shares Underlying Options, Exercised (727)  
Number of Shares Underlying Options, Forfeited (5)  
Number of Shares Underlying Options, Exercisable at end of period 3,185  
Number of Shares Underlying Options, Outstanding at end of period 4,097 3,805
Weighted Average Exercise Price Per Share, Outstanding at beginning of period $ 5.10  
Weighted Average Exercise Price Per Share, Granted $ 8.81  
Weighted Average Exercise Price Per Share, Exercised $ 4.63  
Weighted Average Exercise Price Per Share, Forfeited $ 8.33  
Weighted Average Exercise Price Per Share, Outstanding at end of period $ 6.10 $ 5.10
Weighted Average Exercise Price Per Share, Exercisable at end of period $ 5.52  
Weighted Average Remaining Contractual Term, Outstanding at beginning of period 3 years 1 month 24 days 2 years 11 months 9 days
Weighted Average Remaining Contractual Term, Granted 4 years 8 months 16 days  
Weighted Average Remaining Contractual Term, Exercised 1 year 7 months 17 days  
Weighted Average Remaining Contractual Term, Forfeited 4 years 5 months 12 days  
Weighted Average Remaining Contractual Term, Outstanding at end of period 3 years 1 month 24 days 2 years 11 months 9 days
Weighted Average Remaining Contractual Term, Exercisable at end of period 2 years 9 months 22 days  
Aggregate Intrinsic Value, Outstanding at end of period $ 8.42  
Aggregate Intrinsic Value, Exercisable at end of period $ 8.10