Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2013

Stock-based Compensation [Abstract]

Allocation Of Stock-Based Compensation To Expense Catagories

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	(unaudited)				(unaudited)
	2013		2012		2013		2012
Cost of revenue	$	72	$	72	$	151	$	136
Research and development		137		146		292		287
Selling, general and administrative		250		433		635		977
Total stock compensation expense	$	459	$	651	$	1,078	$	1,400

Key Assumptions Used For Black-Scholes Option Pricing Model

	For the Six Months Ended
	June 30,
	2013		2012
Dividend yield	0	%	0	%
Risk free interest rates	0.35 – 1.48	%	0.36 - 0.87	%
Expected  volatility	70.9 to 73.8	%	71.8 to 81.2	%
Expected term (in years)	3.5 to 5.0		3.0 to 5.5

Stock Option Activity

	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (In Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2012		4,685,434	$	3.82
Options granted		236,411		3.50
Options exercised		(163,615)		1.57
Options forfeited		(64,949)		4.35
Options cancelled or expired		(87,568)		6.61
Outstanding at June 30, 2013		4,605,713	$	3.83		4.85	$	3,901,599
Vested or expected to vest at June 30, 2013 (1)		4,569,281	$	3.82		4.85	$	3,896,971
Exercisable at June 30, 2013		3,694,946	$	3.52		5.03	$	3,785,907

(1) The expected to vest options are the result of applying the pre-vesting forfeiture rate assumptions to total unvested options.