Note 8 - Loans - Impaired Loans and Related Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Loans with no related allowance, unpaid principal balance	$ 60,198	$ 58,816
Loans with no related allowance, recorded investment	45,293	53,578
Loans with related allowance, unpaid principal balance	23,281	49,842
Loans with related allowance, recorded investment	22,489	41,827
Allowance	5,161	6,429
Unpaid principal balance	83,479	108,658
Recorded investment	67,782	95,405
Commercial Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	26,552	23,784
Loans with no related allowance, recorded investment	14,253	20,698
Loans with related allowance, unpaid principal balance	2,309	13,703
Loans with related allowance, recorded investment	2,080	6,372
Allowance	22	1,030
Real Estate Construction Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	5,776	5,776
Loans with no related allowance, recorded investment	4,116	4,286
Commercial Real Estate Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	20,774	22,877
Loans with no related allowance, recorded investment	20,003	22,287
Loans with related allowance, unpaid principal balance	16,976	31,134
Loans with related allowance, recorded investment	16,881	31,003
Allowance	5,139	5,254
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	7,096	6,379
Loans with no related allowance, recorded investment	6,921	6,307
Loans with related allowance, unpaid principal balance	3,996	5,005
Loans with related allowance, recorded investment	3,528	4,452
Allowance	$ 0	$ 145