Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Sales:
Net sales	$ 39,311	$ 39,312	$ 115,417	$ 113,349
Costs and expenses:
Research and development	4,327	3,789	11,993	11,288
Sales, marketing and support	7,717	7,346	24,700	22,532
General and administrative	6,273	6,134	18,958	18,280
Total costs and expenses	44,169	41,169	133,188	121,618
Loss from operations	(4,858)	(1,857)	(17,771)	(8,269)
Interest income	451	158	1,626	451
Interest expense	73	446	1,016	1,282
Other income, net	680	222	922	459
Loss from continuing operations before income tax (benefit) expense	(3,800)	(1,923)	(16,239)	(8,641)
Income tax (benefit) expense from continuing operations	(492)	8	(3,140)	138
Net loss from continuing operations	(3,308)	(1,931)	(13,099)	(8,779)
(Loss) income from discontinued operations, net of tax	(1,036)	757	49,837	2,369
Net (loss) income	$ (4,344)	$ (1,174)	$ 36,738	$ (6,410)
Net loss from continuing operations per common share
Basic and diluted (in USD per share)	$ (0.19)	$ (0.11)	$ (0.75)	$ (0.52)
Net (loss) income from discontinued operations per common share
Basic and diluted (in USD per share)	(0.06)	0.04	2.86	0.14
Net (loss) income per common share
Basic and diluted (in USD per share)	$ (0.25)	$ (0.07)	$ 2.11	$ (0.38)
Weighted average number of common shares outstanding:
Basic and diluted (in shares)	17,521	17,188	17,429	17,025
Product
Sales:
Net sales	$ 14,808	$ 16,367	$ 43,212	$ 46,521
Costs and expenses:
Costs of sales	10,823	9,767	31,756	28,784
Service
Sales:
Net sales	24,503	22,945	72,205	66,828
Costs and expenses:
Costs of sales	$ 15,029	$ 14,133	$ 45,781	$ 40,734