Note 5 - Internal Risk Ratings and Payment Activity (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	$ 632,999	$ 615,263
Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	508,680	500,760
Pass [Member] | Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	480,374	473,040
Special Mention [Member] | Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	6,102	395
Substandard [Member] | Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	22,204	27,325
Doubtful [Member] | Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	0
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	110,233	124,397
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	39,268	27,372
Commercial Portfolio Segment [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	255,188	235,171
Commercial Portfolio Segment [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	68,731	63,164
Commercial Portfolio Segment [Member] | Pass [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	102,396	117,246
Commercial Portfolio Segment [Member] | Pass [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	39,259	27,355
Commercial Portfolio Segment [Member] | Pass [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	238,290	218,958
Commercial Portfolio Segment [Member] | Pass [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	65,169	60,286
Commercial Portfolio Segment [Member] | Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	686	0
Commercial Portfolio Segment [Member] | Special Mention [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	0
Commercial Portfolio Segment [Member] | Special Mention [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	5,185	361
Commercial Portfolio Segment [Member] | Special Mention [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	231	34
Commercial Portfolio Segment [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	7,151	7,151
Commercial Portfolio Segment [Member] | Substandard [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	9	17
Commercial Portfolio Segment [Member] | Substandard [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	11,713	15,852
Commercial Portfolio Segment [Member] | Substandard [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	3,331	2,844
Commercial Portfolio Segment [Member] | Doubtful [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	0
Commercial Portfolio Segment [Member] | Doubtful [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	0
Commercial Portfolio Segment [Member] | Doubtful [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	0
Commercial Portfolio Segment [Member] | Doubtful [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	0
State and Political Subdivisions Portfolio Segment [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	35,260	40,285
State and Political Subdivisions Portfolio Segment [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	35,260	39,027
State and Political Subdivisions Portfolio Segment [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	0
State and Political Subdivisions Portfolio Segment [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	0	1,258
State and Political Subdivisions Portfolio Segment [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	$ 0	0
Finance Leases Portfolio Segment [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable		10,371
Finance Leases Portfolio Segment [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable		10,168
Finance Leases Portfolio Segment [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable		0
Finance Leases Portfolio Segment [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable		203
Finance Leases Portfolio Segment [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable		$ 0