Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2013

Antidilutive securities excluded from the computation of diluted net loss per common share

The following number of shares outstanding, prior to the application of the treasury stock method, were excluded from the computation of diluted net loss per common share for the periods presented because including them would have had an anti-dilutive effect (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2013		2012		2013		2012
Options to purchase common stock		4,134		3,910		3,799		3,680
Restricted stock units		206		132		168		79
Performance stock units		34		16		34		14
Employee stock purchase plan shares		27		30		60		52
Total		4,401		4,088		4,061		3,825