Note 3 - Securities - Held-to-maturity Securities (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Held-to-maturity securities	$ 15,097	$ 16,457
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Held-to-maturity securities	15,097	16,457
Held-to-maturity securities, gross unrealized gains	253	327
Held-to-maturity securities, gross unrealized losses	(82)	(55)
Held-to-maturity securities, fair value	$ 15,268	$ 16,729

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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

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