Securities (Details 2) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	$ 3,540
Less Than 12 Months
Fair Value	380,739	$ 266,768
Unrealized Losses	(8,521)	(2,112)
More Than 12 Months
Fair Value	207,026	222,763
Unrealized Losses	(11,247)	(7,423)
Total
Fair Value	587,765	489,531
Unrealized Losses	(19,768)	(9,535)
US Government Agencies Debt Securities [Member]
Less Than 12 Months
Fair Value	6,781	9,321
Unrealized Losses	(149)	(86)
More Than 12 Months
Fair Value	5,233	3,538
Unrealized Losses	(323)	(232)
Total
Fair Value	12,014	12,859
Unrealized Losses	(472)	(318)
Mortgage Backed Securities - Residential
Less Than 12 Months
Fair Value	108,401	79,918
Unrealized Losses	(2,903)	(425)
More Than 12 Months
Fair Value	50,247	53,815
Unrealized Losses	(2,488)	(1,387)
Total
Fair Value	158,648	133,733
Unrealized Losses	(5,391)	(1,812)
Collateralized Mortgage Obligations
Less Than 12 Months
Fair Value	199,232	150,182
Unrealized Losses	(4,596)	(1,418)
More Than 12 Months
Fair Value	132,467	146,750
Unrealized Losses	(7,660)	(5,287)
Total
Fair Value	331,699	296,932
Unrealized Losses	(12,256)	(6,705)
State and Municipal Obligations
Less Than 12 Months
Fair Value	66,325	27,347
Unrealized Losses	(873)	(183)
More Than 12 Months
Fair Value	19,079	18,660
Unrealized Losses	(776)	(517)
Total
Fair Value	85,404	46,007
Unrealized Losses	$ (1,649)	$ (700)

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