Securities (Schedule of Securities with Unrealized Losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	$ 2	$ 94,322
Less than 12 Months Unrealized Loss	0	(887)
12 Months or More Fair Value	372,191	405,289
12 Months or More Unrealized Loss	(7,724)	(13,192)
Total Fair Value	372,193	499,611
Total Unrealized Loss	(7,724)	(14,079)
Obligations of State and Political Subdivisions
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	0	37,936
Less than 12 Months Unrealized Loss	0	(286)
12 Months or More Fair Value	18,574	49,071
12 Months or More Unrealized Loss	(215)	(1,037)
Total Fair Value	18,574	87,007
Total Unrealized Loss	(215)	(1,323)
MBS/CMO - Residential
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	2	56,386
Less than 12 Months Unrealized Loss	0	(601)
12 Months or More Fair Value	353,617	356,218
12 Months or More Unrealized Loss	(7,509)	(12,155)
Total Fair Value	353,619	412,604
Total Unrealized Loss	$ (7,509)	$ (12,756)