Securities (Schedule of Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Securities Available-for-Sale: Amortized cost
Due in one year or less	$ 1,765
Due after one year through five years	21,474
Due after five years through ten years	80,362
Due after ten years	181,390
Amortized Cost	761,243	$ 743,642
Securities Available-for-Sale: Fair Value
Due in one year or less	1,772
Due after one year through five years	21,838
Due after five years through ten years	81,129
Due after ten years	179,300
Fair Value	739,627	740,641
MBS/CMO - Residential
Securities Available-for-Sale: Amortized cost
Amortized cost, MBS/CMO - Residential	476,252
Amortized Cost	476,252	476,205
Securities Available-for-Sale: Fair Value
Fair value, MBS/CMO - Residential	455,588
Fair Value	$ 455,588	$ 467,332

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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