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Securities (Schedule of Contractual Maturities of Securities) (Details) - USD ($) $ in Thousands | Jun. 30, 2019 | Dec. 31, 2018
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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

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