Note 3 - Investment Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Due within one year, AFS, amortized cost	$ 34,464
Due within one year, AFS, fair value	34,211
Due within one year, HTM, carrying value	14,078
Due within one year, HTM, fair value	13,804
Due after one year but within five years, AFS, amortized cost	157,245
Due after one year but within five years, AFS, fair value	147,011
Due after one year but within five years, HTM, carrying value	203,124
Due after one year but within five years, HTM, fair value	193,712
Due after five years but within 10 years, AFS, amortized cost	69,127
Due after five years but within 10 years, AFS, fair value	59,766
Due after five years but within 10 years, HTM, carrying value	26,333
Due after five years but within 10 years, HTM, fair value	23,887
Due after 10 years, AFS, amortized cost	172,941
Due after 10 years, AFS, fair value	157,596
Due after 10 years, HTM, carrying value	1,815
Due after 10 years, HTM, fair value	1,778
Mortgage-backed securities – government agencies, AFS, amortized cost	883,386
Mortgage-backed securities – government agencies, AFS, fair value	750,589
Mortgage backed securities - government agencies, HTM, carrying value	232,775
Mortgage backed securities - government agencies, HTM, fair value	200,190
Total available for sale debt securities, amortized cost	1,317,163	$ 1,190,379
Total available for sale debt securities, fair value	1,149,173	1,180,298
Total held to maturity debt securities, carrying value	478,125
Total held to maturity debt securities, fair value	$ 433,371	$ 0