Note 4 - Securities - Available-for-sale Debt Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale debt securities, amortized cost	$ 268,971	$ 301,779
Available-for-sale debt securities, gross unrealized holding gains	4,374	288
Available-for-sale debt securities, gross unrealized holding losses	506	6,035
Available-for-sale debt securities, at fair value	272,839	296,032
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale debt securities, amortized cost	115,428	154,268
Available-for-sale debt securities, gross unrealized holding gains	2,694	214
Available-for-sale debt securities, gross unrealized holding losses	359	2,295
Available-for-sale debt securities, at fair value	117,763	152,187
Residential Mortgage Backed Securities [Member]
Available-for-sale debt securities, amortized cost	79,606	35,147
Available-for-sale debt securities, gross unrealized holding gains	780	6
Available-for-sale debt securities, gross unrealized holding losses	92	946
Available-for-sale debt securities, at fair value	80,294	34,207
Commercial Mortgage Backed Securities [Member]
Available-for-sale debt securities, amortized cost	17,414	76,038
Available-for-sale debt securities, gross unrealized holding gains	320
Available-for-sale debt securities, gross unrealized holding losses	11	2,398
Available-for-sale debt securities, at fair value	17,723	73,640
Collateralized Mortgage Backed Securities [Member]
Available-for-sale debt securities, amortized cost	18,142	24,165
Available-for-sale debt securities, gross unrealized holding gains	343	47
Available-for-sale debt securities, gross unrealized holding losses		278
Available-for-sale debt securities, at fair value	18,485	23,934
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Available-for-sale debt securities, amortized cost	25,069	2,908
Available-for-sale debt securities, gross unrealized holding gains	49	7
Available-for-sale debt securities, gross unrealized holding losses	43	2
Available-for-sale debt securities, at fair value	25,075	2,913
Corporate Debt Securities [Member]
Available-for-sale debt securities, amortized cost	7,000	5,000
Available-for-sale debt securities, gross unrealized holding gains	182	14
Available-for-sale debt securities, gross unrealized holding losses		78
Available-for-sale debt securities, at fair value	7,182	4,936
Asset-backed Securities [Member]
Available-for-sale debt securities, amortized cost	5,618	1,825
Available-for-sale debt securities, gross unrealized holding gains	4
Available-for-sale debt securities, gross unrealized holding losses	1	23
Available-for-sale debt securities, at fair value	5,621	1,802
Negotiable Certificates of Deposit [Member]
Available-for-sale debt securities, amortized cost	694	2,428
Available-for-sale debt securities, gross unrealized holding gains	2	0
Available-for-sale debt securities, gross unrealized holding losses		15
Available-for-sale debt securities, at fair value	$ 696	$ 2,413

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).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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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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