Note 4 - Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating lease expense	$ 304	$ 296	$ 606	$ 591
Financing lease expense	8	8	16	16
Short Term lease expense	5	37	14	69
Total lease expense	$ 317	$ 341	$ 636	$ 676
Weighted Average Remaining Lease Term (Years) - operating leases (Year)	7 years 10 months 2 days	8 years 7 months 24 days	7 years 10 months 2 days	8 years 7 months 24 days
Weighted Average Remaining Lease Term (Years) - financing leases (Year)	2 years 3 months 29 days	3 years 3 months 29 days	2 years 3 months 29 days	3 years 3 months 29 days
Weighted Average Discount Rate - operating leases	3.23%	3.16%	3.23%	3.16%
Weighted Average Discount Rate - financing leases	5.00%	5.00%	5.00%	5.00%
Operating cash flows from operating leases			$ 653	$ 640
Operating cash flows from financing lease			3	3
Financing cash flows from financing lease			9	8
Right-of-use assets obtained in exchange for new operating lease liabilities			$ 109	$ 261