Investments (Aggregate Carrying And Approximate Market Values Of Available-For-Sale Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	$ 551,103	$ 453,697
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	7,211	5,488
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	7,925	9,102
Securities available-for-sale	550,389	450,083
U.S. Government agencies
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	2	3
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	0	0
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	0	0
Securities available-for-sale	2	3
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	94,552	83,248
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	2,051	594
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	407	1,474
Securities available-for-sale	96,196	82,368
U.S. Government agencies
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	425,559	335,867
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	1,093	1,507
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	7,305	6,560
Securities available-for-sale	419,347	330,814
Private label
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	649	941
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	3	1
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	0	0
Securities available-for-sale	652	942
Trust preferred securities
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	4,764	6,052
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	26	1,164
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	54	554
Securities available-for-sale	4,736	6,662
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	21,916	23,925
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	475	127
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	123	478
Securities available-for-sale	22,268	23,574
Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	547,442	450,036
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	3,648	3,393
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	7,889	9,066
Securities available-for-sale	543,201	444,363
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	2,136	2,136
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	3,563	2,095
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	0	0
Securities available-for-sale	5,699	4,231
Investment funds
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	1,525	1,525
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	0	0
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	36	36
Securities available-for-sale	$ 1,489	$ 1,489