Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue:
Wireless	$ 25,639	$ 27,859	$ 51,499	$ 56,031
Software	16,686	16,776	32,270	33,992
Total revenue	42,325	44,635	83,769	90,023
Operating expenses:
Cost of revenue	7,190	7,513	14,226	15,528
Research and development	4,662	3,212	8,767	6,120
Service, rental and maintenance	7,944	8,187	16,010	16,492
Selling and marketing	5,329	6,429	11,251	12,957
General and administrative	11,939	10,439	23,649	20,946
Depreciation, amortization and accretion	2,851	3,235	6,074	6,558
Total operating expenses	39,915	39,015	79,977	78,601
Operating income	2,410	5,620	3,792	11,422
Interest income	154	61	276	109
Other income	89	104	58	357
Income before income tax expense	2,653	5,785	4,126	11,888
Income tax expense	(1,155)	(2,334)	(1,774)	(4,993)
Net income	$ 1,498	$ 3,451	$ 2,352	$ 6,895
Basic net income per common share (usd per share)	$ 0.07	$ 0.17	$ 0.12	$ 0.33
Diluted net income per common share (usd per share)	$ 0.07	$ 0.17	$ 0.11	$ 0.33
Basic weighted average common shares outstanding (shares)	20,353,801	20,568,058	20,441,781	20,637,070
Diluted weighted average common shares outstanding (shares)	20,366,102	20,568,058	20,508,473	20,637,070
Cash dividends declared per common share (usd per share)	$ 0.125	$ 0.125	$ 0.25	$ 0.25