Note 3 - Investment Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Due within one year, AFS, amortized cost	$ 38,238
Due within one year, AFS, fair value	37,810
Due within one year, HTM, carrying value	65,167
Due within one year, HTM, fair value	63,709
Due after one year but within five years, AFS, amortized cost	154,856
Due after one year but within five years, AFS, fair value	146,932
Due after one year but within five years, HTM, carrying value	153,365
Due after one year but within five years, HTM, fair value	147,726
Due after five years but within 10 years, AFS, amortized cost	67,697
Due after five years but within 10 years, AFS, fair value	60,871
Due after five years but within 10 years, HTM, carrying value	26,014
Due after five years but within 10 years, HTM, fair value	24,170
Due after 10 years, AFS, amortized cost	153,686
Due after 10 years, AFS, fair value	142,784
Due after 10 years, HTM, carrying value	589
Due after 10 years, HTM, fair value	581
Mortgage-backed securities – government agencies, AFS, amortized cost	851,879
Mortgage-backed securities – government agencies, AFS, fair value	743,455
Mortgage backed securities - government agencies, HTM, carrying value	223,616
Mortgage backed securities - government agencies, HTM, fair value	197,714
Total available for sale debt securities, amortized cost	1,266,356	$ 1,297,977
Total available for sale debt securities, fair value	1,131,852	1,144,617
Total held to maturity debt securities, carrying value	468,751
Total held to maturity debt securities, fair value	$ 433,900	$ 431,833