Note 3 - Securities - Securities Held-to-maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Securities held to maturity, amortized cost	$ 11,808	$ 12,033
Securities held to maturity, gross unrecognized gains	308	372
Securities held to maturity, gross unrecognized losses	(1)	(1)
Securities held to maturity	12,115	12,404
US States and Political Subdivisions Debt Securities [Member]
Securities held to maturity, amortized cost	11,806	12,031
Securities held to maturity, gross unrecognized gains	308	372
Securities held to maturity, gross unrecognized losses	(1)	(1)
Securities held to maturity	12,113	12,402
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities held to maturity, amortized cost	2	2
Securities held to maturity, gross unrecognized gains
Securities held to maturity, gross unrecognized losses
Securities held to maturity	$ 2	$ 2

Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

+ References

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- Definition

Amount, before other-than-temporary impairment (OTTI) accretion, of investment in debt securities measured at amortized cost (held-to-maturity).

+ References

No definition available.

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- Definition

Fair value of investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563

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