Note 10 - Leases - Operating Lease Related Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Right-of-use assets - operating leases	$ 32,591	$ 33,990
Lease liabilities - operating leases	$ 35,116	$ 35,873
Weighted-average remaining lease term (in years) (Year)	4 years 10 months 24 days	5 years 4 months 24 days
Weighted-average discount rate	2.79%	3.10%