Note 8 - Leases - Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating lease cost	$ 1,583	$ 1,476
Short-term lease cost	$ 47	$ 51
Weighted average remaining lease term (in years) (Year)	6 years 146 days
Weighted average discount rate	4.30%
Minimum [Member]
Range of remaining lease terms (in years) (Year)	36 days
Maximum [Member]
Range of remaining lease terms (in years) (Year)	10 years