Note 4 - Investment and Equity Securities - Amortized Cost and Fair Values of Securities Available for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amortized cost	$ 103,401	$ 98,516
Gross unrealized gains	2,466	855
Gross unrealized losses	(134)	(1,049)
Investment securities available for sale, at fair value	105,733	98,322
Subordinated Debt Securities [Member]
Amortized cost	4,000
Gross unrealized gains	126
Gross unrealized losses
Investment securities available for sale, at fair value	4,126
US Government Agencies Debt Securities [Member]
Amortized cost		7,442
Gross unrealized gains		90
Gross unrealized losses		(61)
Investment securities available for sale, at fair value		7,471
Taxable Municipal Bonds [Member]
Amortized cost	500	502
Gross unrealized gains	1	10
Gross unrealized losses
Investment securities available for sale, at fair value	501	512
Nontaxable Municipal Bonds [Member]
Amortized cost	80,436	72,387
Gross unrealized gains	2,065	667
Gross unrealized losses	(25)	(473)
Investment securities available for sale, at fair value	82,476	72,581
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Amortized cost	18,465	18,185
Gross unrealized gains	274	88
Gross unrealized losses	(109)	(515)
Investment securities available for sale, at fair value	$ 18,630	$ 17,758

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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