Note 9 - Allowance for Credit Losses and Credit Quality Information - Summary of Collateral Dependent Loans (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Related allowance		$ 419	$ 428
Recorded investment		3,260	4,284
Unpaid principal balance		3,594	4,618
Residential Portfolio Segment [Member]
Recorded investment, with no related allowance		744	758
Unpaid principal balance, with no related allowance		744	758
Recorded investment, with related allowance		214	221
Unpaid principal balance, with related allowance		214	221
Related allowance		26	28
Recorded investment		958	979
Unpaid principal balance		958	979
Commercial Real Estate Portfolio Segment [Member]
Related allowance	[1]	0	0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Recorded investment, with no related allowance		636	668
Unpaid principal balance, with no related allowance		636	668
Recorded investment	[1]	636	668
Unpaid principal balance	[1]	636	668
Consumer Portfolio Segment [Member]
Recorded investment, with no related allowance		269	306
Unpaid principal balance, with no related allowance		269	306
Recorded investment, with related allowance		113	119
Unpaid principal balance, with related allowance		113	119
Related allowance	[2]	97	103
Recorded investment	[2]	382	425
Unpaid principal balance	[2]	382	425
Commercial Portfolio Segment [Member]
Recorded investment, with no related allowance		22	0
Unpaid principal balance, with no related allowance		22	0
Recorded investment, with related allowance		1,262	2,212
Unpaid principal balance, with related allowance		1,596	2,546
Related allowance	[3]	296	297
Recorded investment	[3]	1,284	2,212
Unpaid principal balance	[3]	$ 1,618	$ 2,546

[1] Secured by commercial land.

[2] Secured by second mortgages on single family housing and autos.

[3] Secured by business equipment.