Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans and Allowance for Loan Losses by Evaluation Method (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Allowance for loan losses, individually evaluated for impairment	$ 156	$ 177
Allowance for loan losses, collectively evaluated for impairment	7,557	7,748
Allowance for loan losses	7,713	7,925	$ 8,473	$ 8,300
Loans, individually evaluated for impairment	11,934	11,924
Loans, collectively evaluated for impairment	690,502	656,758
Loans	702,436	668,682
Real Estate Construction Portfolio Segment[Member]
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	474	337
Allowance for loan losses	474	337	298	438
Loans, individually evaluated for impairment	2,470	2,882
Loans, collectively evaluated for impairment	40,078	31,812
Loans	42,548	34,694
Consumer Real Estate Portfolio Segment [Member]
Allowance for loan losses, individually evaluated for impairment	14	16
Allowance for loan losses, collectively evaluated for impairment	2,164	2,011
Allowance for loan losses	2,178	2,027	2,022	1,830
Loans, individually evaluated for impairment	1,688	1,267
Loans, collectively evaluated for impairment	169,991	165,698
Loans	171,679	166,965
Commercial Real Estate Portfolio Segment [Member]
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	3,039	3,044
Allowance for loan losses	3,039	3,044	3,693	3,738
Loans, individually evaluated for impairment	6,610	6,516
Loans, collectively evaluated for impairment	340,146	333,898
Loans	346,756	340,414
Commercial Non Real Estate Segment [Member]
Allowance for loan losses, individually evaluated for impairment	142	160
Allowance for loan losses, collectively evaluated for impairment	540	912
Allowance for loan losses	682	1,072	1,115	1,063
Loans, individually evaluated for impairment	1,149	1,229
Loans, collectively evaluated for impairment	43,348	39,289
Loans	44,497	40,518
Public Sector and IDA Portfolio Segment[Member]
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	570	419
Allowance for loan losses	570	419	385	330
Loans, individually evaluated for impairment	0	0
Loans, collectively evaluated for impairment	59,369	51,443
Loans	59,369	51,443
Consumer Non Real Estate Portfolio Segment [Member]
Allowance for loan losses, individually evaluated for impairment		1
Allowance for loan losses, collectively evaluated for impairment	724	706
Allowance for loan losses	724	707	732	644
Loans, individually evaluated for impairment	17	30
Loans, collectively evaluated for impairment	37,570	34,618
Loans	37,587	34,648
Unallocated Financing Receivables [Member]
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	46	319
Allowance for loan losses	46	319	$ 228	$ 257
Loans, individually evaluated for impairment	0	0
Loans, collectively evaluated for impairment		0
Loans		$ 0

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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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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