Note 15 - Employee Benefit Plan (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 276	$ 263
Employee First 3 Percent [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	100.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	3.00%
Employee Next 3 Percent [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	50.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	3.00%