Note 1 - Basis of Presentation - Impact of Topic 606 (Details) - USD ($) $ in Thousands	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Total net revenue	$ 5,415		$ 1,851			$ 14,046	$ 6,633
Total cost of revenue	2,323		808			6,108	3,037
Net Income	1,866		1,372			3,817	1,024
Service [Member]
Total net revenue	5,286		1,851			13,757	6,543
Total cost of revenue	2,323		808			5,972	2,950
Product [Member]
Total net revenue	129					289	90
Total cost of revenue						$ 136	$ 87
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Total net revenue
Total cost of revenue
Net Income
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member] | Service [Member]
Total net revenue		166	162	159	149			636
Total cost of revenue		62	51	50	46			209
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member] | Product [Member]
Total net revenue		(166)	(162)	(159)	(149)			(636)
Total cost of revenue		$ (62)	$ (51)	$ (50)	$ (46)			$ (209)