Note 3 - Investment Securities - Amortized Cost and Fair Value of Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Due In One Year or Less, amortized cost	$ 351
Due In One Year or Less, fair value	351
Due After One Year Through Five Years, amortized cost	4,158
Due After One Year Through Five Years, fair value	4,129
Due After Five Years Through Ten Years, amortized cost	1,134
Due After Five Years Through Ten Years, fair value	1,157
Due After Ten Years, amortized cost	1,129
Due After Ten Years, fair value	1,114
Amortized cost with single maturity date	6,772
Fair value with single maturity date	6,751
Mortgage-Backed Securities, amortized cost	357,480
Mortgage-Backed Securities, fair value	351,138
Amortized cost	364,252	$ 363,433
Fair Value	$ 357,889	$ 353,066

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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