Note 5 - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating leases	$ 340	$ 446	$ 658	$ 915
Short-term leases	41	82	89	165
Total lease cost	$ 381	$ 528	$ 747	$ 1,080
Weighted-average remaining lease term (in years) (Year)	5 years 2 months 12 days		5 years 2 months 12 days
Weighted-average discount rate	3.30%		3.30%