Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenue	$ 5,021	$ 7,053
Cost of revenue	2,586	3,285
Gross profit	2,435	3,768
Operating expenses
Research and development	1,476	2,211
Selling, general and administrative	1,669	1,621
Total operating expenses	3,145	3,832
Loss from operations	(710)	(64)
Other income (expense)	(13)	389
Income (loss) before income taxes	(723)	325
Benefit from income taxes	(105)	(148)
Net income (loss)	$ (618)	$ 473
Net income (loss) per share:
Basic	$ (0.04)	$ 0.03
Diluted	$ (0.04)	$ 0.03
Weighted average shares outstanding in computing net income (loss) per share
Basic	17,172,699	16,823,851
Diluted	17,172,699	18,177,605