Note 8 - Loans and Related Allowance for Loan and Lease Losses - Impaired Loans by Class (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Recorded investment, with no related allowance	$ 6,129	$ 7,344
Unpaid principal balance, with no related allowance	6,923	8,199
Recorded investment, with related allowance	6,757	5,726
Unpaid principal balance, with related allowance	6,818	5,787
Related allowance	1,216	660
Recorded investment	12,886	13,070
Unpaid principal balance	13,741	13,986
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Loan [Member]
Recorded investment, with no related allowance	1,749	1,772
Unpaid principal balance, with no related allowance	1,749	1,772
Recorded investment, with related allowance	1,683	1,702
Unpaid principal balance, with related allowance	1,693	1,713
Related allowance	53	45
Recorded investment	3,432	3,474
Unpaid principal balance	3,442	3,485
Commercial Real Estate Portfolio Segment [Member] | Non-owner occupied Loan [Member]
Recorded investment, with no related allowance	2,773	3,845
Unpaid principal balance, with no related allowance	2,773	3,845
Recorded investment, with related allowance	4,270	3,239
Unpaid principal balance, with related allowance	4,270	3,239
Related allowance	1,095	582
Recorded investment	7,043	7,084
Unpaid principal balance	7,043	7,084
Residential Portfolio Segment [Member]
Recorded investment, with no related allowance	636	759
Unpaid principal balance, with no related allowance	699	829
Recorded investment, with related allowance	516	519
Unpaid principal balance, with related allowance	567	569
Related allowance	25	28
Recorded investment	1,152	1,278
Unpaid principal balance	1,266	1,398
Commercial And Industrial [Member]
Recorded investment, with no related allowance	791	747
Unpaid principal balance, with no related allowance	1,512	1,524
Recorded investment, with related allowance	120	135
Unpaid principal balance, with related allowance	120	135
Related allowance	3	3
Recorded investment	911	882
Unpaid principal balance	1,632	1,659
Home Equity Lines of Credit [Member]
Recorded investment, with no related allowance	179	220
Unpaid principal balance, with no related allowance	189	228
Recorded investment, with related allowance	168	131
Unpaid principal balance, with related allowance	168	131
Related allowance	40	2
Recorded investment	347	351
Unpaid principal balance	357	359
Consumer Portfolio Segment [Member]
Recorded investment, with no related allowance	1	1
Unpaid principal balance, with no related allowance	1	1
Related allowance
Recorded investment	1	1
Unpaid principal balance	$ 1	$ 1