Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue:
Total revenue	$ 6,180	$ 5,438	$ 11,840	$ 11,051
Cost of revenue:
Total cost of revenue	2,185	2,205	4,319	4,390
Gross profit	3,995	3,233	7,521	6,661
Operating expenses:
Sales and marketing	5,087	4,757	10,037	9,644
Research, development and engineering	3,981	4,058	8,019	8,005
General and administrative	2,686	2,416	5,538	5,048
Intellectual property	393	305	751	620
Total operating expenses	12,147	11,536	24,345	23,317
Operating loss	(8,152)	(8,303)	(16,824)	(16,656)
Other income, net	231	274	468	526
Loss before income taxes	(7,921)	(8,029)	(16,356)	(16,130)
Provision for income taxes	(12)	(9)	(40)	(20)
Net loss	$ (7,933)	$ (8,038)	$ (16,396)	$ (16,150)
Earnings (loss) per common share:
Loss per common share — basic	$ (0.68)	$ (0.71)	$ (1.42)	$ (1.43)
Loss per common share — diluted	$ (0.68)	$ (0.71)	$ (1.42)	$ (1.43)
Weighted average common shares outstanding — basic	11,665	11,337	11,576	11,302
Weighted average common shares outstanding — diluted	11,665	11,337	11,576	11,302
Service [Member]
Revenue:
Total revenue	$ 3,529	$ 3,336	$ 7,164	$ 6,843
Cost of revenue:
Total cost of revenue	1,553	1,548	3,084	3,111
Subscription [Member]
Revenue:
Total revenue	2,088	1,444	3,651	3,022
Cost of revenue:
Total cost of revenue	465	508	910	990
License [Member]
Revenue:
Total revenue	563	658	1,025	1,186
Cost of revenue:
Total cost of revenue	$ 167	$ 149	$ 325	$ 289