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Securities (Schedule of Contractual Maturities of Securities) (Details) - USD ($) $ in Thousands | Sep. 30, 2020 | Dec. 31, 2019
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Available for Sale, Fair Value |  |
Debt Securities, Available-for-sale, Amortized Cost | $ 404,159 | $ 420,703
Debt Securities, Available-for-sale | 423,478 | 426,424
Held to Maturity, Fair Value |  |
Debt Securities, Held-to-maturity | 659,573 | 740,806
Held to Maturity, Fair Value, Total | 690,467 | 753,263
Available for Sale Securities and Held to Maturity Securities Amortized Cost | 1,063,732 |
Debt Securities, Available-for-sale and Held-to-maturity | 1,113,945 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost | 10,026 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value | 10,109 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost | 86,523 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value | 89,073 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost | 106,650 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value | 113,935 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Ten Years, Amortized Cost | 860,533 |
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Ten Years, Fair Value | 900,828 |
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 | 10,001 |
Available for Sale, Amortized Cost, Due after five to ten years | 12,474 |
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 | 10,288 |
Available for Sale, Fair Value, Due after five to ten years | 13,985 |
Available for Sale, Fair Value, Due after ten years | 0 |
Debt Securities, Available-for-sale, Amortized Cost | 22,475 | 32,473
Debt Securities, Available-for-sale | 24,273 | 33,115
Held to Maturity, Fair Value |  |
Debt Securities, Held-to-maturity | 0 | 12,874
Held to Maturity, Fair Value, Total | 0 | 12,997
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 | 59,830 |
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 | 63,873 |
Debt Securities, Available-for-sale, Amortized Cost | 59,830 | 54,024
Debt Securities, Available-for-sale | 63,873 | 54,795
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 | 28,566 |
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 | 30,139 |
Debt Securities, Held-to-maturity | 28,566 | 31,324
Held to Maturity, Fair Value, Total | 30,139 | 31,607
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 | 515 |
Available for Sale, Amortized Cost, Due after one year to five years | 82,045 |
Available for Sale, Amortized Cost, Due after five to ten years | 51,620 |
Available for Sale, Amortized Cost, Due after ten years | 269,979 |
Available for Sale, Fair Value |  |
Available for Sale, Fair Value, Due in one year or less | 516 |
Available for Sale, Fair Value, Due after one year to five years | 84,483 |
Available for Sale, Fair Value, Due after five to ten years | 56,148 |
Available for Sale, Fair Value, Due after ten years | 282,331 |
Held to Maturity, Amortized Cost |  |
Held to Maturity, Amortized Cost, Due in one year or less | 9,511 |
Held to Maturity, Amortized Cost, Due after one year to five years | 4,478 |
Held to Maturity, Amortized Cost, Due after five to ten years | 55,030 |
Held to Maturity, Amortized Cost, Due after ten years | 590,554 |
Held to Maturity, Fair Value |  |
Held to Maturity, Fair Value, Due in one year or less | 9,593 |
Held to Maturity, Fair Value, Due after one year to five years | 4,590 |
Held to Maturity, Fair Value, Due after five to ten years | 57,787 |
Held to Maturity, Fair Value, Due after ten years | 618,497 |
Held to Maturity, Fair Value, Total | 690,467 |
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 | 1,433 |
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 | 1,021 |
Debt Securities, Available-for-sale, Amortized Cost | 1,433 | 1,488
Debt Securities, Available-for-sale | 1,021 | 1,114
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 | 489 |
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 | 469 |
Debt Securities, Available-for-sale, Amortized Cost | 489 | 488
Debt Securities, Available-for-sale | 469 | 493
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, 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 | 1,498 |
Held to Maturity, Fair Value, Due after ten years | 0 |
Debt Securities, Held-to-maturity | 1,500 | 1,500
Held to Maturity, Fair Value, Total | 1,498 | 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 | 515 |
Available for Sale, Amortized Cost, Due after one year to five years | 420 |
Available for Sale, Amortized Cost, Due after five to ten years | 190 |
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 | 516 |
Available for Sale, Fair Value, Due after one year to five years | 422 |
Available for Sale, Fair Value, Due after five to ten years | 207 |
Available for Sale, Fair Value, Due after ten years | 0 |
Debt Securities, Available-for-sale, Amortized Cost | 1,125 | 1,377
Debt Securities, Available-for-sale | 1,145 | 1,396
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 | 98,657 |
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 | 0 |
Available for Sale, Fair Value, Due after five to ten years | 0 |
Available for Sale, Fair Value, Due after ten years | 102,077 |
Debt Securities, Available-for-sale, Amortized Cost | 98,657 | 87,305
Debt Securities, Available-for-sale | 102,077 | 88,511
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 | 237,380 |
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 | 246,937 |
Debt Securities, Held-to-maturity | 237,380 | 293,662
Held to Maturity, Fair Value, Total | 246,937 | 297,314
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 | 71,624 |
Available for Sale, Amortized Cost, Due after five to ten years | 38,956 |
Available for Sale, Amortized Cost, Due after ten years | 109,570 |
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 | 73,773 |
Available for Sale, Fair Value, Due after five to ten years | 41,956 |
Available for Sale, Fair Value, Due after ten years | 114,891 |
Debt Securities, Available-for-sale, Amortized Cost | 220,150 | 243,548
Debt Securities, Available-for-sale | 230,620 | 247,000
Held to Maturity, Amortized Cost |  |
Held to Maturity, Amortized Cost, Due in one year or less | 8,510 |
Held to Maturity, Amortized Cost, Due after one year to five years | 1,458 |
Held to Maturity, Amortized Cost, Due after five to ten years | 53,530 |
Held to Maturity, Amortized Cost, Due after ten years | 324,608 |
Held to Maturity, Fair Value |  |
Held to Maturity, Fair Value, Due in one year or less | 8,574 |
Held to Maturity, Fair Value, Due after one year to five years | 1,509 |
Held to Maturity, Fair Value, Due after five to ten years | 56,289 |
Held to Maturity, Fair Value, Due after ten years | 341,421 |
Debt Securities, Held-to-maturity | 388,106 | 397,414
Held to Maturity, Fair Value, Total | 407,793 | 405,802
US Treasury Securities [Member] |  |
Held to Maturity, Amortized Cost |  |
Held to Maturity, Amortized Cost, Due in one year or less | 1,001 |
Held to Maturity, Amortized Cost, Due after one year to five years | 3,020 |
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, Fair Value |  |
Held to Maturity, Fair Value, Due in one year or less | 1,019 |
Held to Maturity, Fair Value, Due after one year to five years | 3,081 |
Held to Maturity, Fair Value, Due after five to ten years | 0 |
Held to Maturity, Fair Value, Due after ten years | 0 |
Debt Securities, Held-to-maturity | 4,021 | 4,032
Held to Maturity, Fair Value, Total | $ 4,100 | $ 4,053

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