Securities (Schedule of Securities Available-for-Sale) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 702,500	$ 631,800
Gross Unrealized Gains	18,183	10,400
Gross Unrealized Losses	(767)	(4,360)
Total Fair Value	719,916	637,840
U.S. Treasury and Agency Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,000	10,000
Gross Unrealized Gains	54	0
Gross Unrealized Losses	0	(102)
Total Fair Value	10,054	9,898
Obligations of State and Political Subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	231,306	195,360
Gross Unrealized Gains	12,908	8,286
Gross Unrealized Losses	(6)	(18)
Total Fair Value	244,208	203,628
Mortgage-backed Securities - Residential
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	460,841	426,087
Gross Unrealized Gains	5,221	2,114
Gross Unrealized Losses	(761)	(4,240)
Total Fair Value	465,301	423,961
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	353	353
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Total Fair Value	$ 353	$ 353