Note 4 - Loans and Leases - Loans Individually Evaluated for Impairment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Loans with no related allowance recorded, recorded investment	$ 3,273		$ 2,611
Loans with no related allowance recorded, unpaid principal balance	4,228		3,766
Loans with no related allowance recorded, average recorded investment	2,941	$ 3,948
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment	39		42
Loans with an allowance recorded, unpaid principal balance	39		42
Related allowance	39		42
Loans with an allowance recorded, average recorded investment	41	2,786
Loans with an allowance recorded, interest income recognized	1
Recorded investment	3,312		2,653
Unpaid principal balance	4,267		3,808
Average recorded investment	2,982	6,734
Interest income recognized	1
Commercial and Industrial Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment	193		192
Loans with no related allowance recorded, unpaid principal balance	710		707
Loans with no related allowance recorded, average recorded investment	192	161
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment	25		28
Loans with an allowance recorded, unpaid principal balance	25		28
Related allowance	25		28
Loans with an allowance recorded, average recorded investment	27	1,851
Loans with an allowance recorded, interest income recognized	1
Recorded investment	218		220
Unpaid principal balance	735		735
Average recorded investment	219	2,012
Interest income recognized	1
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment			318
Loans with no related allowance recorded, unpaid principal balance			489
Loans with no related allowance recorded, average recorded investment	159	437
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Loans with an allowance recorded, interest income recognized
Recorded investment			318
Unpaid principal balance			489
Average recorded investment	159	437
Interest income recognized
Undevelopment Land Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment			474
Loans with no related allowance recorded, unpaid principal balance			506
Loans with no related allowance recorded, average recorded investment	237	474
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment		24
Loans with an allowance recorded, interest income recognized
Recorded investment			474
Unpaid principal balance			506
Average recorded investment	237	498
Interest income recognized
Real Estate Mortgage Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment	3,080		1,627
Loans with no related allowance recorded, unpaid principal balance	3,518		2,064
Loans with no related allowance recorded, average recorded investment	2,353	2,853
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment	14		14
Loans with an allowance recorded, unpaid principal balance	14		14
Related allowance	14		14
Loans with an allowance recorded, average recorded investment	14	911
Loans with an allowance recorded, interest income recognized
Recorded investment	3,094		1,641
Unpaid principal balance	3,532		2,078
Average recorded investment	2,367	3,764
Interest income recognized
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans with no related allowance recorded, recorded investment	317		138
Loans with no related allowance recorded, unpaid principal balance	317		138
Loans with no related allowance recorded, average recorded investment	227	35
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Loans with an allowance recorded, interest income recognized
Recorded investment	317		138
Unpaid principal balance	317		138
Average recorded investment	227	35
Interest income recognized
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans with no related allowance recorded, recorded investment	1,466		586
Loans with no related allowance recorded, unpaid principal balance	1,904		1,023
Loans with no related allowance recorded, average recorded investment	1,026	1,503
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment		897
Loans with an allowance recorded, interest income recognized
Recorded investment	1,466		586
Unpaid principal balance	1,904		1,023
Average recorded investment	1,026	2,400
Interest income recognized
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans with no related allowance recorded, recorded investment	843		760
Loans with no related allowance recorded, unpaid principal balance	843		760
Loans with no related allowance recorded, average recorded investment	801	1,242
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment	14		14
Loans with an allowance recorded, unpaid principal balance	14		14
Related allowance	14		14
Loans with an allowance recorded, average recorded investment	14	14
Loans with an allowance recorded, interest income recognized
Recorded investment	857		774
Unpaid principal balance	857		774
Average recorded investment	815	1,256
Interest income recognized
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans with no related allowance recorded, recorded investment
Loans with no related allowance recorded, unpaid principal balance
Loans with no related allowance recorded, average recorded investment
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Loans with an allowance recorded, interest income recognized
Recorded investment
Unpaid principal balance
Average recorded investment
Interest income recognized
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans with no related allowance recorded, recorded investment	454		143
Loans with no related allowance recorded, unpaid principal balance	454		143
Loans with no related allowance recorded, average recorded investment	299	73
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Loans with an allowance recorded, interest income recognized
Recorded investment	454		143
Unpaid principal balance	454		143
Average recorded investment	299	73
Interest income recognized
Consumer Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment
Loans with no related allowance recorded, unpaid principal balance
Loans with no related allowance recorded, average recorded investment		23
Loans with no related allowance recorded, interest income recognized
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Loans with an allowance recorded, interest income recognized
Recorded investment
Unpaid principal balance
Average recorded investment		23
Interest income recognized