Note 3 - Investment Securities - Portfolio of Securities Available-for-sale (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Amortized cost	$ 698,362	$ 721,799
Gross unrealized gains	1,224	289
Gross unrealized losses	(82,424)	(87,204)
Securities available-for-sale	617,162	634,884
US Government Agencies Debt Securities [Member]
Amortized cost	55,898	54,889
Gross unrealized gains	189	0
Gross unrealized losses	(10,761)	(10,439)
Securities available-for-sale	45,326	44,450
Residential Mortgage-Backed Securities [Member]
Amortized cost	462,004	475,263
Gross unrealized gains	620	178
Gross unrealized losses	(51,433)	(57,863)
Securities available-for-sale	411,191	417,578
Commercial Mortgage-Backed Securities [Member]
Amortized cost	25,240	25,485
Gross unrealized gains	0	0
Gross unrealized losses	(3,676)	(4,381)
Securities available-for-sale	21,564	21,104
US States and Political Subdivisions Debt Securities [Member]
Amortized cost	148,795	157,247
Gross unrealized gains	415	111
Gross unrealized losses	(16,505)	(14,462)
Securities available-for-sale	132,705	142,896
Corporate Debt Securities [Member]
Amortized cost	5,000	7,000
Gross unrealized gains	0	0
Gross unrealized losses	(27)	(26)
Securities available-for-sale	4,973	6,974
Asset-Backed Securities [Member]
Amortized cost	1,260	1,673
Gross unrealized gains	0	0
Gross unrealized losses	(22)	(33)
Securities available-for-sale	1,238	1,640
Other Debt Obligations [Member]
Amortized cost	165	242
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Securities available-for-sale	$ 165	$ 242