Note 7 - Internal Risk Ratings and Payment Activity (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	$ 658,905	$ 632,999
Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	532,843	508,680
Pass [Member] | Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	504,618	480,374
Special Mention [Member] | Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	9,958	6,102
Substandard [Member] | Excluding Retail Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	18,267	22,204
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	120,344	110,233
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	40,244	39,268
Commercial Portfolio Segment [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	268,051	255,188
Commercial Portfolio Segment [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	68,681	68,731
Commercial Portfolio Segment [Member] | Pass [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	110,818	102,396
Commercial Portfolio Segment [Member] | Pass [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	40,237	39,259
Commercial Portfolio Segment [Member] | Pass [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	252,137	238,290
Commercial Portfolio Segment [Member] | Pass [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	65,903	65,169
Commercial Portfolio Segment [Member] | Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	4,598	686
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	5,131	5,185
Commercial Portfolio Segment [Member] | Special Mention [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	229	231
Commercial Portfolio Segment [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	4,928	7,151
Commercial Portfolio Segment [Member] | Substandard [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	7	9
Commercial Portfolio Segment [Member] | Substandard [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	10,783	11,713
Commercial Portfolio Segment [Member] | Substandard [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	2,549	3,331
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	35,523	35,260
State and Political Subdivisions Portfolio Segment [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	35,523	35,260
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	0
State and Political Subdivisions Portfolio Segment [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases receivable	$ 0	$ 0