Note 3 - Investment Securities - Summary of Continuous Unrealized Loss Position for Securities Classified as AFS (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Less than 12 Months, Fair Value	$ 8,040	$ 5,526
Less than 12 Months, Unrealized Losses	(73)	(491)
12 Months or More, Fair Value	320,546	329,283
12 Months or More, Unrealized Losses	(62,396)	(57,207)
Fair Value	328,586	334,809
Unrealized Losses	(62,469)	(57,698)
US Government Corporations and Agencies Securities [Member]
Less than 12 Months, Fair Value	345	1,268
Less than 12 Months, Unrealized Losses	(1)	(7)
12 Months or More, Fair Value	9,839	9,284
12 Months or More, Unrealized Losses	(472)	(433)
Fair Value	10,184	10,552
Unrealized Losses	(473)	(440)
US States and Political Subdivisions Debt Securities [Member]
Less than 12 Months, Fair Value	1,260	0
Less than 12 Months, Unrealized Losses	(7)	0
12 Months or More, Fair Value	14,590	15,425
12 Months or More, Unrealized Losses	(1,996)	(2,076)
Fair Value	15,850	15,425
Unrealized Losses	(2,003)	(2,076)
Corporate Debt Securities [Member]
Less than 12 Months, Fair Value	0	468
Less than 12 Months, Unrealized Losses	0	(28)
12 Months or More, Fair Value	26,311	25,888
12 Months or More, Unrealized Losses	(3,440)	(3,713)
Fair Value	26,311	26,356
Unrealized Losses	(3,440)	(3,741)
Residential Mortgage-Backed Securities [Member]
Less than 12 Months, Fair Value	1,356	2,705
Less than 12 Months, Unrealized Losses	(10)	(421)
12 Months or More, Fair Value	221,708	228,415
12 Months or More, Unrealized Losses	(47,507)	(42,498)
Fair Value	223,064	231,120
Unrealized Losses	(47,517)	(42,919)
Commercial Mortgage-Backed Securities [Member]
Less than 12 Months, Fair Value	5,079	1,085
Less than 12 Months, Unrealized Losses	(55)	(35)
12 Months or More, Fair Value	48,098	50,271
12 Months or More, Unrealized Losses	(8,981)	(8,487)
Fair Value	53,177	51,356
Unrealized Losses	$ (9,036)	$ (8,522)