Note 6 - Operating Leases (Details Textual) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Operating Lease, Right-of-Use Asset	$ 3,782	$ 3,782	$ 4,286
Operating Lease, Liability, Total	$ 4,209	$ 4,209
Operating Lease, Weighted Average Discount Rate, Percent	3.90%	3.90%
Operating Lease, Weighted Average Remaining Lease Term (Year)	4 years 3 months 18 days	4 years 3 months 18 days
Operating Lease, Expense	$ 269	$ 807