Condensed Consolidated Statement of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue:
Total revenue	$ 40,628	$ 42,325	$ 83,742	$ 83,769
Operating expenses:
Cost of revenue	7,400	7,190	15,133	14,226
Research and development	6,177	4,662	11,912	8,767
Service, rental and maintenance	7,698	7,944	15,448	16,010
Selling and marketing	6,093	5,329	12,562	11,251
General and administrative	12,741	11,939	24,704	23,649
Depreciation, amortization and accretion	2,669	2,851	5,382	6,074
Total operating expenses	42,778	39,915	85,141	79,977
Operating (loss) income	(2,150)	2,410	(1,399)	3,792
Interest income	342	154	625	276
Other income	102	89	54	58
(Loss) income before income taxes	(1,706)	2,653	(720)	4,126
Benefit from (provision for) income taxes	730	(1,155)	255	(1,774)
Net (loss) income	$ (976)	$ 1,498	$ (465)	$ 2,352
Basic net (loss) income per common share (usd per share)	$ (0.05)	$ 0.07	$ (0.02)	$ 0.12
Diluted net (loss) income per common share (usd per share)	$ (0.05)	$ 0.07	$ (0.02)	$ 0.11
Basic weighted average common shares outstanding (shares)	19,750,941	20,353,801	19,888,606	20,441,781
Diluted weighted average common shares outstanding (shares)	19,750,941	20,366,102	19,888,606	20,508,473
Cash dividends declared per common share (usd per share)	$ 0.125	$ 0.125	$ 0.25	$ 0.250
Wireless
Revenue:
Total revenue	$ 23,658	$ 25,639	$ 47,927	$ 51,499
Software
Revenue:
Total revenue	$ 16,970	$ 16,686	$ 35,815	$ 32,270