Note 5 - Fair Value Measurements - Assets and Liabilities at Fair Value on Recurring Basis (Details) $ in Thousands		Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Securities available for sale		$ 609,968	$ 618,601
Interest Rate Loan Contract [Member] | Valuation, Market Approach [Member] | Measurement Input, Current Reference Price [Member] | Minimum [Member]
Derivative Asset, Measurement Input	[1]	1.0261
Interest Rate Loan Contract [Member] | Valuation, Market Approach [Member] | Measurement Input, Current Reference Price [Member] | Maximum [Member]
Derivative Asset, Measurement Input	[1]	1.0305
Interest Rate Loan Contract [Member] | Fair Value, Recurring [Member]
Derivative Asset		$ 2	$ 3
Forward Sale Commitment [Member] | Valuation, Market Approach [Member] | Measurement Input, Current Reference Price [Member] | Minimum [Member]
Derivative Liability, Measurement Input	[2]	1.0261	1.016
Forward Sale Commitment [Member] | Valuation, Market Approach [Member] | Measurement Input, Current Reference Price [Member] | Maximum [Member]
Derivative Liability, Measurement Input	[2]	1.0305	1.0264
Forward Sale Commitment [Member] | Fair Value, Recurring [Member]
Derivative Liability		$ (2)	$ (4)
Fair Value, Inputs, Level 1 [Member]
Securities available for sale		0	0
Fair Value, Inputs, Level 2 [Member]
Securities available for sale		609,968	618,601
Fair Value, Inputs, Level 3 [Member]
Securities available for sale		0	0
Fair Value, Inputs, Level 3 [Member] | Interest Rate Loan Contract [Member] | Fair Value, Recurring [Member]
Derivative Asset		2	3
Fair Value, Inputs, Level 3 [Member] | Forward Sale Commitment [Member] | Fair Value, Recurring [Member]
Derivative Liability		(2)	(4)
US Government Agencies Debt Securities [Member]
Securities available for sale		307,989	311,844
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale		0	0
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale		307,989	311,844
US Government Agencies Debt Securities [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		147,999	149,893
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale		0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale		147,999	149,893
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale		0	0
Collateralized Mortgage-Backed Securities [Member]
Securities available for sale		147,323	150,151
Collateralized Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale		0	0
Collateralized Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale		147,323	150,151
Collateralized Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale		0	0
Corporate Debt Securities [Member]
Securities available for sale		5,688	5,750
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale		0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale		5,688	5,750
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale		0	0
US Treasury Securities [Member]
Securities available for sale		969	963
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale		0	0
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale		969	963
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale		$ 0	$ 0

[1] Comprised of only one loan.

[2] Current reference prices were weighted by the relative amount of the loan