Securities (Securities held to maturity debt maturities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Amortized Cost
Due in 1 year or less	$ 1,274
Due in 1 to 5 years	31,121
Due in 5 to 10 years	105,183
Due after 10 years	102,330
Amortized Cost	239,908	$ 253,550
Estimated Fair Value
Due in 1 year or less	1,281
Due in 1 to 5 years	31,495
Due in 5 to 10 years	107,052
Due after 10 years	107,566
Estimated Fair Value	$ 247,394	$ 265,494

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

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