Net Income (Loss) Per Share (Tables)
 6 Months Ended
Jun. 30, 2015
Earnings Per Share [Abstract]  
Schedule of Computation of Earnings Per Share, Basic and Diluted
The following table presents the computation of basic and diluted net loss per share:    
 
Three Months Ended June 30,
 
Six Months Ended June 30,
 
2015
 
2014
 
2015
 
2014
 
(in thousands, except per share amounts)
Net loss per share - basic and diluted
 
 
 
 
 
 
 
Net loss
$
(18,979
)
 
$
(4,574
)
 
$
(29,006
)
 
$
(10,203
)
Weighted average shares used to compute basic and diluted net loss per share
71,426

 
68,292

 
70,961

 
65,882

Net loss per share - basic and diluted
$
(0.27
)
 
$
(0.07
)
 
$
(0.41
)
 
$
(0.15
)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share
The following shares subject to outstanding awards were excluded from the computation of diluted net loss per share for the periods presented as their effect would have been antidilutive:    
 
Three Months Ended June 30,
 
Six Months Ended June 30,
 
2015
 
2014
 
2015
 
2014
 
(in thousands)
Shares subject to outstanding common stock awards
11,326

 
11,430

 
11,326

 
11,430