Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Sales:
Net sales	$ 39,972	$ 40,101
Costs and expenses:
Research and development	3,868	3,934
Sales, marketing and support	9,303	8,941
General and administrative	8,080	7,667
Total costs and expenses	45,801	43,281
Loss from operations	(5,829)	(3,180)
Interest income	175	148
Interest expense	385	409
Other expense, net	(106)	(274)
Loss before income tax expense	(6,145)	(3,715)
Income tax expense	34	178
Net loss	$ (6,179)	$ (3,893)
Net loss per common share
Basic and diluted (in USD per share)	$ (0.36)	$ (0.23)
Weighted average number of common shares outstanding:
Basic and diluted (in shares)	17,302	16,742
Product
Sales:
Net sales	$ 12,874	$ 13,992
Costs and expenses:
Cost of goods and services sold	7,853	8,923
Service
Sales:
Net sales	27,098	26,109
Costs and expenses:
Cost of goods and services sold	$ 16,697	$ 13,816