Note 8 - Commitments and Contingencies - Additional Lease Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating lease cost	$ 1,912	$ 1,756
Short-term lease cost	192	291
Total lease cost	2,104	2,047
Cash paid for amounts included in the measurement of operating lease liabilities	2,404	1,858
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 2,770	$ 10,571
Weighted average remaining lease term - operating leases (years) (Year)	7 years 9 months 18 days	8 years 3 months 18 days
Weighted average discount rate - operating leases	5.02%	5.25%