Note 4 - Investment Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Due within one year, AFS, amortized cost	$ 38,868
Due within one year, AFS, fair value	38,329
Due within one year, HTM, carrying value	15,029
Due within one year, HTM, fair value	14,796
Due after one year but within five years, AFS, amortized cost	154,801
Due after one year but within five years, AFS, fair value	145,075
Due after one year but within five years, HTM, carrying value	203,384
Due after one year but within five years, HTM, fair value	194,412
Due after five years but within 10 years, AFS, amortized cost	68,137
Due after five years but within 10 years, AFS, fair value	60,473
Due after five years but within 10 years, HTM, carrying value	26,278
Due after five years but within 10 years, HTM, fair value	23,767
Due after 10 years, AFS, amortized cost	161,906
Due after 10 years, AFS, fair value	148,002
Due after 10 years, HTM, carrying value	610
Due after 10 years, HTM, fair value	601
Mortgage-backed securities – government agencies, AFS, amortized cost	874,265
Mortgage-backed securities – government agencies, AFS, fair value	752,738
Mortgage backed securities - government agencies, HTM, carrying value	227,916
Mortgage backed securities - government agencies, HTM, fair value	198,257
Total available for sale debt securities, amortized cost	1,297,977	$ 1,190,379
Total available for sale debt securities, fair value	1,144,617	1,180,298
Total held to maturity debt securities, carrying value	473,217
Total held to maturity debt securities, fair value	$ 431,833	$ 0