Note 4 - Operating Leases (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Lease, Cost	$ 2,997
Operating Lease, Payments	2,432
Total New Lease Liability, Assets Obtained	1,114
Operating Leases, Rent Expense, Total	$ 2,354	$ 2,328	$ 2,308
Minimum [Member]
Lessee, Operating Lease, Remaining Term of Contract	1 year
Maximum [Member]
Lessee, Operating Lease, Remaining Term of Contract	11 years