Note 2 - Investment Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Due within one year, AFS, amortized cost	$ 127,223
Due within one year, AFS, fair value	124,656
Due within one year, HTM, carrying value	151,432
Due within one year, HTM, fair value	147,357
Due after one year but within five years, AFS, amortized cost	37,397
Due after one year but within five years, AFS, fair value	35,288
Due after one year but within five years, HTM, carrying value	2,656
Due after one year but within five years, HTM, fair value	2,511
Due after five years but within 10 years, AFS, amortized cost	79,825
Due after five years but within 10 years, AFS, fair value	69,940
Due after five years but within 10 years, HTM, carrying value	25,539
Due after five years but within 10 years, HTM, fair value	22,941
Due after 10 years, AFS, amortized cost	110,671
Due after 10 years, AFS, fair value	103,304
Due after 10 years, HTM, carrying value	512
Due after 10 years, HTM, fair value	501
Mortgage-backed securities – government agencies, AFS, amortized cost	768,003
Mortgage-backed securities – government agencies, AFS, fair value	660,620
Mortgage backed securities - government agencies, HTM, carrying value	205,265
Mortgage backed securities - government agencies, HTM, fair value	178,559
Total available for sale debt securities, amortized cost	1,123,119	$ 1,154,153
Total available for sale debt securities, fair value	993,808	1,031,179
Total held to maturity debt securities, carrying value	385,404
Total held to maturity debt securities, fair value	$ 351,869	$ 408,519