Note 3 - Investment Securities - Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Securities available for sale, amortized cost, due in one year or less	$ 28,204
Securities available for sale, fair value, due in one year or less	28,078
Securities available for sale, amortized cost, due after one year through five years	58,319
Securities available for sale, fair value, due after one year through five years	57,485
Securities available for sale, amortized cost, due after five years through ten years	34,062
Securities available for sale, fair value, due after five years through ten years	33,890
Securities available for sale, amortized cost, due after ten years	17,884
Securities available for sale, fair value, due after ten years	18,139
Securities available for sale, amortized cost, single maturity	138,469
Securities available for sale, fair value, single maturity	137,592
Securities available for sale, amortized cost, Mortgage-backed securities and CMO	127,968
Securities available for sale, fair value, Mortgage-backed securities and CMO	124,249
Securities available for sale, fair value	261,841	$ 271,172
Debt Securities [Member]
Securities available for sale, amortized cost	266,437
Securities available for sale, fair value	$ 261,841

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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