Results of Operations (Tables)
9 Months Ended
Sep. 30, 2012
Results of Operations [Abstract]  
Calculation of basic and diluted net income (loss) per share
                                 
    Three months ended September 30,     Nine months ended September 30,  
    2012     2011     2012     2011  

Numerator:

                               

Net income (loss)

  $ 4,855     $ (4,991 )    $ (5,462 )    $ (9,176 ) 
   

 

 

   

 

 

   

 

 

   

 

 

 

Denominator:

                               

Weighted average shares outstanding

    18,568       13,522       16,523       13,492  

Less: Weighted average shares subject to repurchase

    —         —         —         (1 ) 
   

 

 

   

 

 

   

 

 

   

 

 

 

Weighted average common shares outstanding - basic

    18,568       13,522       16,523       13,491  

Effect of dilutive equity incentive plans

    664       —         —         —    
   

 

 

   

 

 

   

 

 

   

 

 

 

Weighted average common shares outstanding - diluted

    19,232       13,522       16,523       13,491  
   

 

 

   

 

 

   

 

 

   

 

 

 
Antidilutive shares excluded from computation of diluted net income (loss) per share
                                 
    Three months ended September 30,     Nine months ended September 30,  
    2012     2011     2012     2011  

Shares subject to options to purchase common stock

    1,958       2,968       3,147       2,617  

Shares subject to warrants to purchase common stock

    156       156       156       156  
   

 

 

   

 

 

   

 

 

   

 

 

 

Total

    2,114       3,124       3,303       2,773  
   

 

 

   

 

 

   

 

 

   

 

 

 
Computation of total comprehensive income (loss)
                                 
    Three months ended September 30,     Nine months ended September 30,  
    2012     2011     2012     2011  

Net income (loss)

  $ 4,855     $ (4,991 )    $ (5,462 )    $ (9,176 ) 

Changes in unrealized gain (loss) on marketable securities

    7       (5 )      (23 )      34  
   

 

 

   

 

 

   

 

 

   

 

 

 

Comprehensive income (loss)

  $ 4,862     $ (4,996 )    $ (5,485 )    $ (9,142 )