Note 3 - Securities - Available-for-sale Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Available-for-sale debt securities, amortized cost	$ 275,365	$ 301,779
Available-for-sale debt securities, gross unrealized holding gains	1,088	288
Available-for-sale debt securities, gross unrealized holding losses	2,339	6,035
Available-for-sale debt securities	274,114	296,032
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale debt securities, amortized cost	132,165	154,268
Available-for-sale debt securities, gross unrealized holding gains	807	214
Available-for-sale debt securities, gross unrealized holding losses	848	2,295
Available-for-sale debt securities	132,124	152,187
Residential Mortgage Backed Securities [Member]
Available-for-sale debt securities, amortized cost	34,365	35,147
Available-for-sale debt securities, gross unrealized holding gains	83	6
Available-for-sale debt securities, gross unrealized holding losses	496	946
Available-for-sale debt securities	33,952	34,207
Commercial Mortgage Backed Securities [Member]
Available-for-sale debt securities, amortized cost	75,948	76,038
Available-for-sale debt securities, gross unrealized holding gains	8
Available-for-sale debt securities, gross unrealized holding losses	813	2,398
Available-for-sale debt securities	75,143	73,640
Collateralized Mortgage Backed Securities [Member]
Available-for-sale debt securities, amortized cost	21,104	24,165
Available-for-sale debt securities, gross unrealized holding gains	113	47
Available-for-sale debt securities, gross unrealized holding losses	105	278
Available-for-sale debt securities	21,112	23,934
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Available-for-sale debt securities, amortized cost	2,782	2,908
Available-for-sale debt securities, gross unrealized holding gains	28	7
Available-for-sale debt securities, gross unrealized holding losses	3	2
Available-for-sale debt securities	2,807	2,913
Corporate Debt Securities [Member]
Available-for-sale debt securities, amortized cost	5,000	5,000
Available-for-sale debt securities, gross unrealized holding gains	49	14
Available-for-sale debt securities, gross unrealized holding losses	56	78
Available-for-sale debt securities	4,993	4,936
Asset-backed Securities [Member]
Available-for-sale debt securities, amortized cost	1,573	1,825
Available-for-sale debt securities, gross unrealized holding gains	0
Available-for-sale debt securities, gross unrealized holding losses	13	23
Available-for-sale debt securities	1,560	1,802
Negotiable Certificates of Deposit [Member]
Available-for-sale debt securities, amortized cost	2,428	2,428
Available-for-sale debt securities, gross unrealized holding gains	0	0
Available-for-sale debt securities, gross unrealized holding losses	5	15
Available-for-sale debt securities	$ 2,423	$ 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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-Publisher FASB
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