Note 2 - Investment Securities - Amortized Cost and Fair Value of Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Due In One Year or Less, amortized cost	$ 361
Due In One Year or Less, fair value	360
Due After One Year Through Five Years, amortized cost	4,148
Due After One Year Through Five Years, fair value	4,110
Due After Five Years Through Ten Years, amortized cost	1,314
Due After Five Years Through Ten Years, fair value	1,310
Due After Ten Years, amortized cost	1,201
Due After Ten Years, fair value	1,162
Amortized cost with single maturity date	7,024
Fair value with single maturity date	6,942
Mortgage-Backed Securities, amortized cost	338,593
Mortgage-Backed Securities, fair value	324,996
Amortized cost	345,617	$ 362,465
Fair Value	$ 331,938	$ 354,247

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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