Note 2 - Investment Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Due within one year, AFS, amortized cost	$ 25,215
Due within one year, AFS, fair value	25,144
Due within one year, HTM, carrying value	151,741
Due within one year, HTM, fair value	150,265
Due after one year but within five years, AFS, amortized cost	35,528
Due after one year but within five years, AFS, fair value	34,296
Due after one year but within five years, HTM, carrying value	2,644
Due after one year but within five years, HTM, fair value	2,565
Due after five years but within 10 years, AFS, amortized cost	94,000
Due after five years but within 10 years, AFS, fair value	84,166
Due after five years but within 10 years, HTM, carrying value	24,542
Due after five years but within 10 years, HTM, fair value	23,092
Due after 10 years, AFS, amortized cost	89,325
Due after 10 years, AFS, fair value	85,978
Due after 10 years, HTM, carrying value	491
Due after 10 years, HTM, fair value	479
Mortgage-backed securities – government agencies, AFS, amortized cost	714,538
Mortgage-backed securities – government agencies, AFS, fair value	632,248
Mortgage backed securities - government agencies, HTM, carrying value	195,494
Mortgage backed securities - government agencies, HTM, fair value	176,029
Total available for sale debt securities, amortized cost	958,606	$ 1,154,153
Total available for sale debt securities, fair value	861,832	1,031,179
Total held to maturity debt securities, carrying value	374,912
Total held to maturity debt securities, fair value	$ 352,430	$ 408,519