Securities (Schedule of Contractual Maturities of Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Available for Sale, Fair Value
Debt Securities, Available-for-sale, Amortized Cost	$ 387,641	$ 450,548
Debt Securities, Available-for-sale	393,148	442,752
Held to Maturity, Amortized Cost
Held to maturity Securities, Amortized Cost	797,359	611,490
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Total	808,656	603,640
Available for Sale Securities and Held to Maturity Securities Amortized Cost	1,185,000	1,062,038
Debt Securities, Available-for-sale and Held-to-maturity	1,201,804	1,046,392
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	10,004
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	9,998
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	93,837
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	94,490
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	116,936
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	119,138
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Ten Years, Amortized Cost	964,223
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Ten Years, Fair Value	978,178
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	10,004
Available for Sale, Amortized Cost, Due after one year to five years	10,003
Available for Sale, Amortized Cost, Due after five to ten years	12,469
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	9,998
Available for Sale, Fair Value, Due after one year to five years	10,148
Available for Sale, Fair Value, Due after five to ten years	12,777
Available for Sale, Fair Value, Due after ten years	0
Debt Securities, Available-for-sale, Amortized Cost	32,476	32,477
Debt Securities, Available-for-sale	32,923	32,038
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	12,833
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	12,833	0
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	12,963
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	12,963
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	59,099
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	60,181
Debt Securities, Available-for-sale, Amortized Cost	59,099	53,317
Debt Securities, Available-for-sale	60,181	51,927
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	33,757
Held to maturity Securities, Amortized Cost	33,757	23,727
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	34,194
Held to Maturity, Fair Value, Total	34,194	23,483
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	10,004
Available for Sale, Amortized Cost, Due after one year to five years	68,545
Available for Sale, Amortized Cost, Due after five to ten years	77,667
Available for Sale, Amortized Cost, Due after ten years	231,425
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	9,998
Available for Sale, Fair Value, Due after one year to five years	69,024
Available for Sale, Fair Value, Due after five to ten years	79,427
Available for Sale, Fair Value, Due after ten years	234,699
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	25,292
Held to Maturity, Amortized Cost, Due after five to ten years	39,269
Held to Maturity, Amortized Cost, Due after ten years	732,798
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	25,466
Held to Maturity, Fair Value, Due after five to ten years	39,711
Held to Maturity, Fair Value, Due after ten years	743,479
Held to Maturity, Fair Value, Total	808,656
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	1,653
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	1,281
Debt Securities, Available-for-sale, Amortized Cost	1,653	1,678
Debt Securities, Available-for-sale	1,281	1,329
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	717
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	717
Debt Securities, Available-for-sale, Amortized Cost	717	717
Debt Securities, Available-for-sale	717	707
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	1,490
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	693
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	1,026
Available for Sale, Fair Value, Due after five to ten years	712
Available for Sale, Fair Value, Due after ten years	0
Debt Securities, Available-for-sale, Amortized Cost	1,715	1,719
Debt Securities, Available-for-sale	1,738	1,735
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	97,299
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	98,643
Debt Securities, Available-for-sale, Amortized Cost	97,299	138,149
Debt Securities, Available-for-sale	98,643	134,911
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	335
Held to Maturity, Amortized Cost, Due after ten years	324,106
Held to maturity Securities, Amortized Cost	324,441	332,775
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	334
Held to Maturity, Fair Value, Due after ten years	327,384
Held to Maturity, Fair Value, Total	327,718	326,724
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	0
Available for Sale, Amortized Cost, Due after one year to five years	57,520
Available for Sale, Amortized Cost, Due after five to ten years	64,505
Available for Sale, Amortized Cost, Due after ten years	72,657
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	57,850
Available for Sale, Fair Value, Due after five to ten years	65,938
Available for Sale, Fair Value, Due after ten years	73,877
Debt Securities, Available-for-sale, Amortized Cost	194,682	222,491
Debt Securities, Available-for-sale	197,665	220,105
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	11,456
Held to Maturity, Amortized Cost, Due after five to ten years	37,434
Held to Maturity, Amortized Cost, Due after ten years	374,935
Held to maturity Securities, Amortized Cost	423,825	252,484
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	11,479
Held to Maturity, Fair Value, Due after five to ten years	37,887
Held to Maturity, Fair Value, Due after ten years	381,901
Held to Maturity, Fair Value, Total	431,267	250,928
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	1,003
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	1,003	1,004
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	1,024
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	$ 1,024	$ 1,015