Note 7 - Leases - Lease Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Lease liabilities	$ 4,966		$ 4,966		$ 5,369
Right-of-use assets	$ 4,924		$ 4,924		$ 5,340
Weighted average remaining lease term (years) (Year)	7 years 11 months 1 day		7 years 11 months 1 day		8 years 2 months 1 day
Weighted average discount rate	3.23%		3.23%		3.21%
Operating lease cost	$ 249	$ 283	$ 499	$ 494
Short-term lease cost	1	1	2	2
Total lease cost	250	284	501	496
Cash paid for amounts included in the measurement of lease liabilities	$ 243	$ 274	$ 485	$ 483