Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Sales:
Net sales	$ 157,893	$ 153,029
Costs and expenses:
Research and development	15,926	14,951
Sales, marketing and support	33,434	30,571
General and administrative	25,486	23,201
Total costs and expenses	178,989	163,675
Loss from operations	(21,096)	(10,646)
Interest income	2,003	622
Interest expense	1,020	1,784
Other income, net	101	710
Loss from continuing operations before income tax (benefit) expense	(20,012)	(11,098)
Income tax (benefit) expense from continuing operations	(4,003)	346
Net loss from continuing operations	(16,009)	(11,444)
Income from discontinued operations, net of tax	49,264	3,212
Net income (loss)	$ 33,255	$ (8,232)
Net loss from continuing operations per common share
Basic and diluted (in dollars per share)	$ (0.92)	$ (0.67)
Net income from discontinued operations per common share
Basic and diluted (in dollars per share)	2.82	0.19
Net income (loss) per common share
Basic and diluted (in dollars per share)	$ 1.90	$ (0.48)
Number of shares used in per share calculation:
Basic and diluted (in shares)	17,459	17,072
Product
Sales:
Net sales	$ 61,925	$ 63,277
Costs and expenses:
Cost of product and service sales	42,887	39,510
Service
Sales:
Net sales	95,968	89,752
Costs and expenses:
Cost of product and service sales	$ 61,256	$ 55,442