Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Stock-based Compensation [Abstract]

Schedule of Allocation of Non-Cash Stock-Based Compensation

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2018		2017		2018		2017
		(unaudited)				(unaudited)
Cost of revenues	$	(5)	$	6	$	29	$	18
Research and development		28		25		73		74
Selling, general and administrative		154		159		410		428
Total stock compensation expense	$	177	$	190	$	512	$	520

Schedule of Key Assumptions of Fair Value of Stock Options Granted

	Nine Months Ended
	September 30,
	2018			2017
	(unaudited)
Dividend yield		0	%	0	%
Risk free interest rates		2.16-2.75	%	0.71-1.65	%
Expected  volatility		45.3 to 50.0	%	49.1 to 59.4	%
Expected term (in years)		3.5 to 4.75		3.5 to 5.0

Schedule of Option Activity

		Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (In Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2017			4,768,838	$	3.02
Options granted			587,350		1.70
Options exercised			(99,937)		0.98
Options forfeited			(47,000)		1.78
Options cancelled or expired			(250,131)		4.15
Outstanding at September 30, 2018			4,959,120	$	2.86		4.04	$	146,325
Vested or expected to vest at September 30, 2018	(1)		4,951,630	$	2.86		4.11	$	144,325
Exercisable at September 30, 2018			4,584,666	$	2.92		3.97	$	144,325

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