Note 8 - Loans and Related Allowance for Loan and Lease Losses - Impaired Loans by Class (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Recorded investment, with no related allowance	$ 3,602	$ 3,501
Unpaid principal balance, with no related allowance	4,216	4,104
Recorded investment, with related allowance	6,018	4,586
Unpaid principal balance, with related allowance	6,796	4,863
Related allowance	959	490
Recorded investment	9,620	8,087
Unpaid principal balance	11,012	8,967
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Loan [Member]
Recorded investment, with no related allowance	981	1,118
Unpaid principal balance, with no related allowance	1,027	1,142
Recorded investment, with related allowance	415	447
Unpaid principal balance, with related allowance	415	447
Related allowance	5	10
Recorded investment	1,396	1,565
Unpaid principal balance	1,442	1,589
Commercial Real Estate Portfolio Segment [Member] | Non-owner occupied Loan [Member]
Recorded investment, with no related allowance	1,624	801
Unpaid principal balance, with no related allowance	1,754	801
Recorded investment, with related allowance	4,520	3,322
Unpaid principal balance, with related allowance	5,194	3,596
Related allowance	739	371
Recorded investment	6,144	4,123
Unpaid principal balance	6,948	4,397
Residential Portfolio Segment [Member]
Recorded investment, with no related allowance	870	941
Unpaid principal balance, with no related allowance	877	1,013
Recorded investment, with related allowance	293	378
Unpaid principal balance, with related allowance	293	378
Related allowance	17	20
Recorded investment	1,163	1,319
Unpaid principal balance	1,170	1,391
Commercial And Industrial [Member]
Recorded investment, with no related allowance	119	561
Unpaid principal balance, with no related allowance	550	1,056
Recorded investment, with related allowance	546	273
Unpaid principal balance, with related allowance	650	276
Related allowance	102	48
Recorded investment	665	834
Unpaid principal balance	1,200	1,332
Home Equity Lines of Credit [Member]
Recorded investment, with no related allowance	8	80
Unpaid principal balance, with no related allowance	8	92
Recorded investment, with related allowance	244	166
Unpaid principal balance, with related allowance	244	166
Related allowance	96	41
Recorded investment	252	246
Unpaid principal balance	$ 252	$ 258