Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2012

Net Loss Per Share [Abstract]

Shares outstanding excluded from the calculation of diluted net loss per share

The shares outstanding at the end of the respective periods presented in the table below were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect (in thousands):

	Three and Six Months Ended June 30,
	2012		2011
Common shares under option		1,718		739
Convertible preferred stock		—		7,245
Total potential dilutive shares		1,718		7,984