Note 3 - Available-for-sale Securities - Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Available-for-sale securities, amortized cost	$ 49,960	$ 48,860
Available-for-sale securities, gross unrealized gains	491	405
Available-for-sale securities, gross unrealized losses	(1,189)	(948)
Available-for-sale securities	49,262	48,317
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale securities, amortized cost	16,719	16,663
Available-for-sale securities, gross unrealized gains	131	90
Available-for-sale securities, gross unrealized losses	(17)	(68)
Available-for-sale securities	16,833	16,685
Corporate Debt Securities [Member]
Available-for-sale securities, amortized cost	18,014	18,018
Available-for-sale securities, gross unrealized gains	260	133
Available-for-sale securities, gross unrealized losses	(984)	(838)
Available-for-sale securities	17,290	17,313
Subordinated Notes [Member]
Available-for-sale securities, amortized cost	9,036	9,022
Available-for-sale securities, gross unrealized gains	97	182
Available-for-sale securities, gross unrealized losses	(128)
Available-for-sale securities	9,005	9,204
SBA Loan Pools [Member]
Available-for-sale securities, amortized cost	5,627	5,157
Available-for-sale securities, gross unrealized gains
Available-for-sale securities, gross unrealized losses	(60)	(42)
Available-for-sale securities	5,567	$ 5,115
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities, amortized cost	564
Available-for-sale securities, gross unrealized gains	3
Available-for-sale securities, gross unrealized losses
Available-for-sale securities	$ 567

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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