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, 2024	Dec. 31, 2023
Securities available-for-sale	$ 619,397	$ 617,162
Fair Value, Recurring [Member]
Securities available-for-sale	619,397	617,162
Equity securities	19,457	18,564
Derivatives - interest rate contracts	50,508	43,805
Total assets	689,362	679,531
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	127	165
Equity securities	9,743	9,867
Derivatives - interest rate contracts	0	0
Total assets	9,870	10,032
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	612,380	609,875
Equity securities	9,714	8,697
Derivatives - interest rate contracts	50,508	43,805
Total assets	672,602	662,377
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	6,890	7,122
Equity securities	0	0
Derivatives - interest rate contracts	0	0
Total assets	6,890	7,122
US Government Agencies Debt Securities [Member]
Securities available-for-sale	65,732	45,326
US Government Agencies Debt Securities [Member] \| Fair Value, Recurring [Member]
Securities available-for-sale	65,732	45,326
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	65,732	45,326
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	396,421	411,191
Residential Mortgage-Backed Securities [Member] \| Fair Value, Recurring [Member]
Securities available-for-sale	396,421	411,191
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	396,421	411,191
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	21,438	21,564
Commercial Mortgage-Backed Securities [Member] \| Fair Value, Recurring [Member]
Securities available-for-sale	21,438	21,564
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	21,438	21,564
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	129,556	132,705
US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Recurring [Member]
Securities available-for-sale	129,556	132,705
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	122,666	125,583
US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	6,890	7,122
Corporate Debt Securities [Member]
Securities available-for-sale	4,971	4,973
Corporate Debt Securities [Member] \| Fair Value, Recurring [Member]
Securities available-for-sale	4,971	4,973
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	4,971	4,973
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	1,152	1,238
Asset-Backed Securities [Member] \| Fair Value, Recurring [Member]
Securities available-for-sale	1,152	1,238
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	1,152	1,238
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	127	165
Other Debt Obligations [Member] \| Fair Value, Recurring [Member]
Securities available-for-sale	127	165
Other Debt Obligations [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	127	165
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