Note 11 - Fair Values - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale	$ 609,153	$ 617,092
Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	0	0
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-Sale	385,709	390,496
Collateralized Mortgage-Backed Securities [Member]
Debt Securities, Available-for-Sale	27,782	29,473
Municipal General Obligation Bonds [Member]
Debt Securities, Available-for-Sale	166,632	167,860
Municipal Revenue Bonds [Member]
Debt Securities, Available-for-Sale	28,530	28,763
Other Debt and Equity Securities [Member]
Debt Securities, Available-for-Sale	500	500
Fair Value, Recurring [Member]
Total assets	638,814	644,597
Total liabilities	30,036	27,964
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Total assets	0	0
Total liabilities	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Total assets	638,308	644,084
Total liabilities	30,036	27,964
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Total assets	506	513
Total liabilities	0	0
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-Sale	385,709	390,496
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	385,709	390,496
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member]
Debt Securities, Available-for-Sale	27,782	29,473
Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	27,782	29,473
Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Municipal General Obligation Bonds [Member]
Debt Securities, Available-for-Sale	166,632	167,860
Fair Value, Recurring [Member] | Municipal General Obligation Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Municipal General Obligation Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	166,126	167,347
Fair Value, Recurring [Member] | Municipal General Obligation Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-Sale	506	513
Fair Value, Recurring [Member] | Municipal Revenue Bonds [Member]
Debt Securities, Available-for-Sale	28,530	28,763
Fair Value, Recurring [Member] | Municipal Revenue Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Municipal Revenue Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	28,530	28,763
Fair Value, Recurring [Member] | Municipal Revenue Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Other Debt and Equity Securities [Member]
Debt Securities, Available-for-Sale	500	500
Fair Value, Recurring [Member] | Other Debt and Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Other Debt and Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	500	500
Fair Value, Recurring [Member] | Other Debt and Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-Sale	0	0
Fair Value, Recurring [Member] | Interest Rate Swap [Member]
Interest rate swaps	29,661	27,505
Interest rate swaps	30,036	27,964
Fair Value, Recurring [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Interest rate swaps	0	0
Interest rate swaps	0	0
Fair Value, Recurring [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Interest rate swaps	29,661	27,505
Interest rate swaps	30,036	27,964
Fair Value, Recurring [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Interest rate swaps	0	0
Interest rate swaps	$ 0	$ 0