Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Summary of Stock-Based Compensation Activity) (Details)

v2.4.0.6
Stock-Based Compensation (Summary of Stock-Based Compensation Activity) (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2013
Shares  
Outstanding and expected to vest at December 30, 2012 1,052,861
Granted 130,432
Exercised (310,304)
Forfeited (2,175)
Outstanding and expected to vest at March 31, 2013 870,814
Exercisable at March 31, 2013 589,118
Weighted Average Exercise Price  
Outstanding and expected to vest at December 30, 2012 $ 5.28
Granted $ 28.51
Exercised $ 2.87
Forfeited $ 8.22
Outstanding and expected to vest at March 31, 2013 $ 9.61
Exercisable at March 31, 2013 $ 4.69
Weighted Average Remaining Contractual Term (Year)  
Outstanding and expected to vest at March 31, 2013 5 years 11 months 22 days
Exercisable at March 31, 2013 4 years 7 months 14 days
Aggregate Intrinsic Value  
Outstanding and expected to vest at March 31, 2013 $ 20,003
Exercisable at March 31, 2013 $ 16,433