Stock Plans (Details 3) (USD $)
6 Months Ended
Jun. 30, 2012
Share-based award activity under the 2011 plan  
Number of Stock Options, Outstanding - June 30, 2012 2,600,605
Weighted Average Exercise Price, Granted   
Weighted-Average Exercise Price, Outstanding - June 30, 2012 $ 9.33
2011 Plan [Member]
 
Share-based award activity under the 2011 plan  
Shares Available for Grant, Outstanding - January 1, 2012 1,886,296
Additional shares added to the pool grant 919,127
Shares Available for Granted (608,478)
Shares available for Exercised or released   
Shares available for Cancelled or forfeited 128,374
Shares Available for Grant, Outstanding - June 30, 2012 2,325,319
Number of Stock Options, Outstanding - January 1, 2012 2,871,005
Additional shares added to the pool   
Number of Stock Options, Granted 437,981
Number of Stock Options, Exercised (581,457)
Number of stock options outstanding cancelled or forfeited (126,924)
Number of Stock Options, Outstanding - June 30, 2012 2,600,605
Weighted-Average Exercise Price, Outstanding - January 1, 2012 $ 4.15
Weighted Average Exercise Price, Granted $ 32.65
Weighted Average Exercise Price, Exercised or released $ 1.84
Weighted Average Exercise Price Cancelled or forfeited $ 7.11
Weighted-Average Exercise Price, Outstanding - June 30, 2012 $ 9.33
Restricted Stock Units Outstanding Exercised or released   
Weighted Average Grant Date Fair Value, Balances - January 1, 2012   
Weighted Average Grant Date Fair Value, Granted $ 33.19
Weighted Average Grant Date Fair Value Exercised or released   
Weighted Average Grant Date Fair Value, Cancelled or forfeited $ 32.79
Weighted Average Grant Date Fair Value, Balances - June 30, 2012 $ 33.19
Restricted Stock Units [Member] | 2011 Plan [Member]
 
Share-based award activity under the 2011 plan  
Restricted Stock Units Outstanding, Balances - January 1, 2012   
Restricted Stock Units, Granted 170,497
Restricted Stock Units Outstanding Exercised or released   
Restricted Stock Units Outstanding, Cancelled or Forfeited (1,450)
Restricted Stock Units Outstanding, Balances - June 30, 2012 169,047