Securities (Schedule of Contractual Maturities of Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Available for Sale, Fair Value
Debt Securities, Available-for-sale, Amortized Cost	$ 450,495	$ 448,219
Held to Maturity, Amortized Cost
Held to maturity Securities, Amortized Cost	553,705	497,688
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Total	534,622	494,194
U.S. Government agency securities
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	20,012
Available for Sale, Amortized Cost, Due after five to ten years	12,467
Available for Sale, Amortized Cost, Due after ten years	0
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	19,728
Available for Sale, Fair Value, Due after five to ten years	11,844
Available for Sale, Fair Value, Due after ten years	0
Debt Securities, Available-for-sale, Amortized Cost	32,479	35,475
Available for sale Securities, Fair Value, Total	31,572
Small Business Administration Pooled Securities [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	55,961
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	54,336
Debt Securities, Available-for-sale, Amortized Cost	55,961	47,852
Available for sale Securities, Fair Value, Total	54,336
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	0
Held to Maturity, Amortized Cost, Due after five to ten years	0
Held to Maturity, Amortized Cost, Due after ten years	25,376
Held to maturity Securities, Amortized Cost	25,376	27,416
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	0
Held to Maturity, Fair Value, Due after five to ten years	0
Held to Maturity, Fair Value, Due after ten years	24,522
Held to Maturity, Fair Value, Total	24,522	27,399
Debt Securities [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	278
Available for Sale, Amortized Cost, Due after one year to five years	65,948
Available for Sale, Amortized Cost, Due after five to ten years	112,857
Available for Sale, Amortized Cost, Due after ten years	271,412
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	281
Available for Sale, Fair Value, Due after one year to five years	64,448
Available for Sale, Fair Value, Due after five to ten years	109,469
Available for Sale, Fair Value, Due after ten years	261,663
Available for sale Securities, Fair Value, Total	435,861
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	13,446
Held to Maturity, Amortized Cost, Due after five to ten years	39,914
Held to Maturity, Amortized Cost, Due after ten years	500,345
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	13,197
Held to Maturity, Fair Value, Due after five to ten years	38,907
Held to Maturity, Fair Value, Due after ten years	482,518
Held to Maturity, Fair Value, Total	534,622
Pooled trust preferred securities issued by banks and insurers
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	2,159
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	1,800
Debt Securities, Available-for-sale, Amortized Cost	2,159	2,179
Available for sale Securities, Fair Value, Total	1,800
Single Issuer Trust Preferred Securities Issued by Banks and Insurers [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	1,000
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	1,004
Debt Securities, Available-for-sale, Amortized Cost	1,000	2,012
Available for sale Securities, Fair Value, Total	1,004
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	0
Held to Maturity, Amortized Cost, Due after five to ten years	1,500
Held to Maturity, Amortized Cost, Due after ten years	0
Held to maturity Securities, Amortized Cost	1,500	1,500
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	0
Held to Maturity, Fair Value, Due after five to ten years	1,490
Held to Maturity, Fair Value, Due after ten years	0
Held to Maturity, Fair Value, Total	1,490	1,529
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	1,022
Available for Sale, Amortized Cost, Due after five to ten years	951
Available for Sale, Amortized Cost, Due after ten years	0
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	1,023
Available for Sale, Fair Value, Due after five to ten years	958
Available for Sale, Fair Value, Due after ten years	0
Debt Securities, Available-for-sale, Amortized Cost	1,973	2,237
Available for sale Securities, Fair Value, Total	1,981
Agency Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	143,764
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	137,645
Debt Securities, Available-for-sale, Amortized Cost	143,764	124,098
Available for sale Securities, Fair Value, Total	137,645
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	0
Held to Maturity, Amortized Cost, Due after five to ten years	941
Held to Maturity, Amortized Cost, Due after ten years	335,405
Held to maturity Securities, Amortized Cost	336,346	262,998
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	0
Held to Maturity, Fair Value, Due after five to ten years	936
Held to Maturity, Fair Value, Due after ten years	322,580
Held to Maturity, Fair Value, Total	323,516	258,408
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	278
Available for Sale, Amortized Cost, Due after one year to five years	44,914
Available for Sale, Amortized Cost, Due after five to ten years	99,439
Available for Sale, Amortized Cost, Due after ten years	68,528
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	281
Available for Sale, Fair Value, Due after one year to five years	43,697
Available for Sale, Fair Value, Due after five to ten years	96,667
Available for Sale, Fair Value, Due after ten years	66,878
Debt Securities, Available-for-sale, Amortized Cost	213,159	214,934
Available for sale Securities, Fair Value, Total	207,523
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	12,442
Held to Maturity, Amortized Cost, Due after five to ten years	37,473
Held to Maturity, Amortized Cost, Due after ten years	139,564
Held to maturity Securities, Amortized Cost	189,479	204,768
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	12,191
Held to Maturity, Fair Value, Due after five to ten years	36,481
Held to Maturity, Fair Value, Due after ten years	135,416
Held to Maturity, Fair Value, Total	184,088	205,823
US Treasury Securities [Member]
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	1,004
Held to Maturity, Amortized Cost, Due after five to ten years	0
Held to Maturity, Amortized Cost, Due after ten years	0
Held to maturity Securities, Amortized Cost	1,004	1,006
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	1,006
Held to Maturity, Fair Value, Due after five to ten years	0
Held to Maturity, Fair Value, Due after ten years	0
Held to Maturity, Fair Value, Total	1,006	1,035
Equity Securities [Member]
Available for Sale, Fair Value
Debt Securities, Available-for-sale, Amortized Cost	$ 0	$ 19,432