Note 13 - Leases - Operating Lease Related Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Right-of-use assets- operating leases	$ 30,919	$ 33,990
Lease liabilities - operating leases	$ 33,484	$ 35,873
Weighted-average remaining lease term (in years) (Year)	4 years 8 months 12 days	5 years 4 months 24 days
Weighted-average discount rate	2.77%	3.10%
Operating cash flows from operating leases	$ 9,300	$ 8,400
ROU assets obtained in exchange for lease obligations	$ 5,700	$ 1,800