Note 2 - New Accounting Standards (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total	$ 1,866,000	$ 1,372,000	$ 3,817,000	$ 1,024,000
Cost of Revenue, Total	2,323,000	808,000	6,108,000	3,037,000
Operating Leases, Future Minimum Payments Due, Total	$ 1,346,000		$ 1,346,000
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Cumulative Effect on Retained Earnings, Net of Tax, Total		13,000		99,000
Accounting Standards Update 2014-09 [Member] | Restatement Adjustment [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total		17,000		123,000
Cost of Revenue, Total		$ 4,000		$ 24,000