Note 5 - Loans Disaggregated by Impairment Method (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	$ 7,394	$ 7,554	$ 8,001	$ 8,925
Allowance for loan losses - individually evaluated for impairment	1,198	974
Allowance for loan losses - collectively evaluated for impairment	6,034	6,296
Loans and leases receivable	632,999	615,263
Loans - individually evaluated for impairment	15,006	14,941
Loans - collectively evaluated for impairment	617,993	600,322
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	1,459	1,521	1,892	2,044
Allowance for loan losses - individually evaluated for impairment	696	712
Allowance for loan losses - collectively evaluated for impairment	763	809
Loans and leases receivable	110,233	124,397
Loans - individually evaluated for impairment	5,134	4,586
Loans - collectively evaluated for impairment	105,099	119,811
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	449	286	297	439
Allowance for loan losses - individually evaluated for impairment	0	0
Allowance for loan losses - collectively evaluated for impairment	449	286
Loans and leases receivable	39,268	27,372
Loans - individually evaluated for impairment	224	364
Loans - collectively evaluated for impairment	39,044	27,008
Commercial Portfolio Segment [Member] \| Secured by Commercial Real Estate [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	2,646	2,411	2,700	2,898
Allowance for loan losses - individually evaluated for impairment	0	14
Allowance for loan losses - collectively evaluated for impairment	2,646	2,397
Loans and leases receivable	255,188	235,171
Loans - individually evaluated for impairment	6,383	6,998
Loans - collectively evaluated for impairment	248,805	228,173
Commercial Portfolio Segment [Member] \| Secured by Residential Real Estate [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	1,760	1,812	1,630	1,632
Allowance for loan losses - individually evaluated for impairment	494	203
Allowance for loan losses - collectively evaluated for impairment	1,266	1,609
Loans and leases receivable	68,731	63,164
Loans - individually evaluated for impairment	2,313	2,113
Loans - collectively evaluated for impairment	66,418	61,051
State and Political Subdivisions Portfolio Segment [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	123	222	221	186
Allowance for loan losses - individually evaluated for impairment	0	0
Allowance for loan losses - collectively evaluated for impairment	123	222
Loans and leases receivable	35,260	40,285
Loans - individually evaluated for impairment	0	0
Loans - collectively evaluated for impairment	35,260	40,285
Retail Portfolio Segment [Member] \| Consumer Loans [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	76	76	85	64
Allowance for loan losses - individually evaluated for impairment	0	0
Allowance for loan losses - collectively evaluated for impairment	76	76
Loans and leases receivable	5,670	4,286
Loans - individually evaluated for impairment	93	0
Loans - collectively evaluated for impairment	5,577	4,286
Retail Portfolio Segment [Member] \| Family Residential Mortgages [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	366	350	312	303
Allowance for loan losses - individually evaluated for impairment	8	25
Allowance for loan losses - collectively evaluated for impairment	358	325
Loans and leases receivable	47,124	42,833
Loans - individually evaluated for impairment	748	583
Loans - collectively evaluated for impairment	46,376	42,250
Retail Portfolio Segment [Member] \| Home Equity Loans and Lines [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	353	428	453	583
Allowance for loan losses - individually evaluated for impairment	0	0
Allowance for loan losses - collectively evaluated for impairment	353	428
Loans and leases receivable	71,525	67,384
Loans - individually evaluated for impairment	111	151
Loans - collectively evaluated for impairment	71,414	67,233
Unallocated Financing Receivables [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	162	284	318	669
Finance Leases Portfolio Segment [Member]
Credit Losses Related To Financing Receivables Current And Noncurrent [Line Items]
Allowance for loan losses	$ 0	164	$ 93	$ 103
Allowance for loan losses - individually evaluated for impairment		20
Allowance for loan losses - collectively evaluated for impairment		144
Loans and leases receivable		10,371
Loans - individually evaluated for impairment		146
Loans - collectively evaluated for impairment		$ 10,225

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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