Note 10 - Leases - Operating Lease Related Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Right-of-use assets - operating leases	$ 29,179	$ 30,919
Lease liabilities - operating leases	$ 32,028	$ 33,484
Weighted-average remaining lease term (in years) (Year)	4 years 6 months	4 years 8 months 12 days
Weighted-average discount rate	2.62%	2.77%