Note 4 - Loans and Allowance for Loan Losses - Allowance for Loan Losses and the Recorded Investment of Loans Based on Impairment Method (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Individually evaluated for impairment	$ 854	$ 807
Collectively evaluated for impairment	7,875	5,465
Total ending allowance balance	8,729	6,272	$ 8,013	$ 6,728
Loans individually evaluated for impairment	11,126	17,135
Loans collectively evaluated for impairment	763,960	755,639
Total ending loans balance	775,086	772,774
Residential Portfolio Segment [Member]
Individually evaluated for impairment
Collectively evaluated for impairment	2,002	1,250
Total ending allowance balance	2,002	1,250	2,079	1,583
Loans individually evaluated for impairment	428	438
Loans collectively evaluated for impairment	307,451	309,815
Total ending loans balance	307,879	310,253
Commercial Real Estate Portfolio Segment [Member]
Individually evaluated for impairment	409	385
Collectively evaluated for impairment	2,619	1,543
Total ending allowance balance	3,028	1,928	2,452	2,186
Loans individually evaluated for impairment	5,088	11,300
Loans collectively evaluated for impairment	222,460	210,836
Total ending loans balance	227,548	222,136
Commercial and Industrial Portfolio Segment [Member]
Individually evaluated for impairment	445	303
Collectively evaluated for impairment	1,600	1,144
Total ending allowance balance	2,045	1,447	1,315	1,063
Loans individually evaluated for impairment	5,207	4,910
Loans collectively evaluated for impairment	97,363	95,113
Total ending loans balance	102,570	100,023
Consumer Portfolio Segment [Member]
Individually evaluated for impairment		119
Collectively evaluated for impairment	1,654	1,528
Total ending allowance balance	1,654	1,647	$ 2,167	$ 1,896
Loans individually evaluated for impairment	403	487
Loans collectively evaluated for impairment	136,686	139,875
Total ending loans balance	$ 137,089	$ 140,362

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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

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