Note 14 - Employee Benefit Plans (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Defined Contribution Plan, Discretionary Contribution Percent	2.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 0.5	$ 0.4
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	20.00%
Defined Benefit Plan, Plan Assets, Employer, Related Party, Number of Shares	240,402	312,253
Maximum [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%