Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenue:
Product revenue	$ 18,125	$ 16,007
Service revenue	3,050	2,875
Total revenue	21,175	18,882
Cost of Revenue:
Cost of product	9,269	7,595
Cost of services	1,202	1,484
Total cost of revenue	10,471	9,079
Gross profit	10,704	9,803
Operating expenses:
Product development and engineering	4,728	5,344
Selling, general and administrative	6,768	8,017
Total operating expenses	11,496	13,361
Operating loss	(792)	(3,558)
Other expense, net	(203)	(277)
Loss before provision for income taxes	(995)	(3,835)
Provision for income taxes	46	61
Net loss	$ (1,041)	$ (3,896)
Net loss per share — basic (usd per share)	$ (0.15)	$ (0.56)
Net loss per share — diluted (usd per share)	$ (0.15)	$ (0.56)
Weighted average number of shares:
Basic (shares)	6,802	6,981
Diluted (shares)	6,802	6,981