Note 4 - Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating lease expense	$ 299	$ 287	$ 890	$ 929
Financing lease expense	8	0	24	0
Short Term lease expense	35	20	104	100
Total lease expense	$ 342	$ 307	$ 1,018	$ 1,029
Weighted Average Remaining Lease Term (Years) - operating leases (Year)	8 years 4 months 28 days	9 years 5 months 15 days	8 years 4 months 28 days	9 years 5 months 15 days
Weighted Average Remaining Lease Term (Years) - financing leases (Year)	3 years 29 days		3 years 29 days
Weighted Average Discount Rate - operating leases	3.23%	3.13%	3.23%	3.13%
Weighted Average Discount Rate - financing leases	5.00%		5.00%
Operating cash flows from operating leases			$ 983	$ 1,002
Operating cash flows from financing lease			4	0
Financing cash flows from financing lease			13	0
Right-of-use assets obtained in exchange for new operating lease liabilities			$ 699	$ 39