Securities (Schedule of Securities Available-for-Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 761,243	$ 743,642
Gross Unrealized Gains	2,511	7,149
Gross Unrealized Losses	(24,127)	(10,150)
Fair Value	739,627	740,641
Obligations of State and Political Subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	284,991	267,437
Gross Unrealized Gains	2,473	6,733
Gross Unrealized Losses	(3,425)	(861)
Fair Value	284,039	273,309
MBS/CMO - Residential
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	476,252	476,205
Gross Unrealized Gains	38	416
Gross Unrealized Losses	(20,702)	(9,289)
Fair Value	$ 455,588	$ 467,332

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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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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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Amount 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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-Publisher FASB
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