Note 7 - Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating lease cost	$ 389	$ 370	$ 781	$ 736
Short-term lease cost	$ 10	$ 14	$ 22	$ 27
Weighted average remaining lease term (in years) (Year)	5 years 109 days		5 years 109 days
Weighted average discount rate	4.80%		4.80%
Minimum [Member]
Range of remaining lease terms (in years) (Year)			219 days
Maximum [Member]
Range of remaining lease terms (in years) (Year)			7 years 292 days