Note 6 - Fair Value Measurements and Fair Value of Financial Instruments - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Securities available-for-sale	$ 581,867	$ 634,884
Fair Value, Recurring [Member]
Securities available-for-sale	581,867	634,884
Equity securities	17,677	15,811
Derivatives - interest rate contracts	61,972	56,797
Total assets	661,516	707,492
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	1,362	242
Equity securities	9,394	9,733
Derivatives - interest rate contracts	0	0
Total assets	10,756	9,975
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	573,488	627,293
Equity securities	8,283	6,078
Derivatives - interest rate contracts	61,972	56,797
Total assets	643,743	690,168
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	7,017	7,349
Equity securities	0	0
Derivatives - interest rate contracts	0	0
Total assets	7,017	7,349
US Government Agencies Debt Securities [Member]
Securities available-for-sale	43,969	44,450
US Government Agencies Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	43,969	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	43,969	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	389,427	417,578
Residential Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	389,427	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	389,427	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	19,927	21,104
Commercial Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	19,927	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	19,927	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	122,899	142,896
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	122,899	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	115,882	135,547
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	7,017	7,349
Corporate Debt Securities [Member]
Securities available-for-sale	2,961	6,974
Corporate Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	2,961	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	2,961	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	1,322	1,640
Asset-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	1,322	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	1,322	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	1,362	242
Other Debt Obligations [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	1,362	242
Other Debt Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	1,362	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