Note 6 - Fair Value Measurements and Fair Value of Financial Instruments - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Securities available-for-sale	$ 629,001	$ 634,884
Fair Value, Recurring [Member]
Securities available-for-sale	629,001	634,884
Equity securities	18,025	15,811
Derivatives - interest rate contracts	47,620	56,797
Total assets	694,646	707,492
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	132	242
Equity securities	9,892	9,733
Derivatives - interest rate contracts	0	0
Total assets	10,024	9,975
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	621,381	627,293
Equity securities	8,133	6,078
Derivatives - interest rate contracts	47,620	56,797
Total assets	677,134	690,168
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	7,488	7,349
Equity securities	0	0
Derivatives - interest rate contracts	0	0
Total assets	7,488	7,349
US Government Agencies Debt Securities [Member]
Securities available-for-sale	43,515	44,450
US Government Agencies Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	43,515	44,450
US Government Agencies Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
US Government Agencies Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	43,515	44,450
US Government Agencies Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Residential Mortgage-Backed Securities [Member]
Securities available-for-sale	419,667	417,578
Residential Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	419,667	417,578
Residential Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
Residential Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	419,667	417,578
Residential Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Commercial Mortgage-Backed Securities [Member]
Securities available-for-sale	21,960	21,104
Commercial Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	21,960	21,104
Commercial Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
Commercial Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	21,960	21,104
Commercial Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
US States and Political Subdivisions Debt Securities [Member]
Securities available-for-sale	138,296	142,896
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	138,296	142,896
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	130,808	135,547
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	7,488	7,349
Corporate Debt Securities [Member]
Securities available-for-sale	3,977	6,974
Corporate Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	3,977	6,974
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	3,977	6,974
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Asset-Backed Securities [Member]
Securities available-for-sale	1,454	1,640
Asset-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	1,454	1,640
Asset-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
Asset-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	1,454	1,640
Asset-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Other Debt Obligations [Member]
Securities available-for-sale	132	242
Other Debt Obligations [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	132	242
Other Debt Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	132	242
Other Debt Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	0	0
Other Debt Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	$ 0	$ 0