Net Loss per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Components of basic and diluted net loss per share
Net loss	$ (1,547)	$ (1,908)	$ (8,649)	$ (5,803)
Weighted average common shares outstanding	21,925	21,603	21,875	21,574
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.07)	$ (0.09)	$ (0.40)	$ (0.27)
Anti-dilutive securities excluded from the computation of diluted net loss per share
Anti-dilutive securities (in shares)			11,109	3,254
Employee And Non Employee Stock Option [Member]
Anti-dilutive securities excluded from the computation of diluted net loss per share
Anti-dilutive securities (in shares)			3,210	2,763
Restricted Stock Units R S U [Member]
Anti-dilutive securities excluded from the computation of diluted net loss per share
Anti-dilutive securities (in shares)			517	491
Warrant [Member]
Anti-dilutive securities excluded from the computation of diluted net loss per share
Anti-dilutive securities (in shares)			7,382