Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenue	$ 8,112	$ 7,628	$ 23,381	$ 21,268
Cost of revenue	3,427	3,388	9,749	9,836
Gross profit	4,685	4,240	13,632	11,432
Operating expenses
Research and development	1,156	1,180	3,817	3,376
Selling, general and administrative	1,541	1,099	4,126	3,561
Total operating expenses	2,697	2,279	7,943	6,937
Income from operations	1,988	1,961	5,689	4,495
Other income (expense)	(59)	(1)	(69)	10
Income before income taxes	1,929	1,960	5,620	4,505
Income taxes	646	630	1,923	1,463
Net income	1,283	1,330	3,697	3,042
Net income allocable to preferred stockholders	778	995	2,559	2,300
Net income allocable to common stockholders	$ 505	$ 335	$ 1,138	$ 742
Net income per share allocable to common stockholders:
Basic	$ 0.09	$ 0.09	$ 0.25	$ 0.21
Diluted	$ 0.08	$ 0.09	$ 0.24	$ 0.19
Weighted average shares outstanding in computing net income per share allocable to common stockholders
Basic	5,827,662	3,621,118	4,515,414	3,465,773
Diluted	6,667,371	4,458,417	5,327,685	5,202,502