Note 6 - Fair Value Measurements and Fair Value of Financial Instruments - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Securities available-for-sale	$ 612,819	$ 612,819	$ 634,884
Fair Value, Recurring [Member]
Securities available-for-sale	612,819		634,884
Equity securities	17,950		15,811
Derivatives - interest rate contracts	57,545		56,797
Total assets	688,314		707,492
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	151		242
Equity securities	9,736		9,733
Derivatives - interest rate contracts	0		0
Total assets	9,887		9,975
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	605,431		627,293
Equity securities	8,214		6,078
Derivatives - interest rate contracts	57,545		56,797
Total assets	671,190		690,168
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	7,237		7,349
Equity securities	0		0
Derivatives - interest rate contracts	0		0
Total assets	7,237		7,349
US Government Agencies Debt Securities [Member]
Securities available-for-sale		43,153	44,450
US Government Agencies Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	43,153		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	43,153		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		409,126	417,578
Residential Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	409,126		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	409,126		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		21,210	21,104
Commercial Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	21,210		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	21,210		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		133,839	142,896
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	133,839		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	126,602		135,547
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	7,237		7,349
Corporate Debt Securities [Member]
Securities available-for-sale		3,959	6,974
Corporate Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	3,959		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	3,959		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		1,381	1,640
Asset-Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	1,381		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	1,381		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		$ 151	242
Other Debt Obligations [Member] | Fair Value, Recurring [Member]
Securities available-for-sale	151		242
Other Debt Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	151		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