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Investment Securities (Amortized Cost and Fair Value of Investment Securities) (Details) - USD ($) $ in Thousands | Mar. 31, 2020 | Dec. 31, 2019
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Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | $ 426,550 | $ 415,852
Securities available for sale, Unrealized Gains | 18,761 | 3,696
Securities available for sale, Unrealized Losses | 466 | 1,631
Securities available for sale | 444,845 | 417,917
Securities held to maturity, Amortized Cost | 346,252 | 359,000
Securities held to maturity, Unrealized Gains | 8,322 | 4,882
Securities held to maturity, Unrealized Losses | 3 | 623
Securities held to maturity, fair value | 354,571 | 363,259
Allowance for credit losses, Amortized Cost | (13) |
Held-to-maturity securities, net , Amortized Cost | 346,239 | 359,000
U.S. Government Agency And Government Sponsored Enterprises [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | 9,587 | 26,440
Securities available for sale, Unrealized Gains | 492 | 437
Securities available for sale | 10,079 | 26,877
State And Political Subdivisions [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities held to maturity, Amortized Cost | 187,401 | 192,215
Securities held to maturity, Unrealized Gains | 2,797 | 3,803
Securities held to maturity, Unrealized Losses | 3 |
Securities held to maturity, fair value | 190,195 | 196,018
Collateralized Mortgage Obligations [Member] | Federal National Mortgage Association [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | 23,182 | 23,834
Securities available for sale, Unrealized Gains | 530 |
Securities available for sale, Unrealized Losses | 36 | 57
Securities available for sale | 23,676 | 23,777
Securities held to maturity, Amortized Cost | 39,216 | 41,561
Securities held to maturity, Unrealized Gains | 1,263 | 150
Securities held to maturity, Unrealized Losses |  | 256
Securities held to maturity, fair value | 40,479 | 41,455
Collateralized Mortgage Obligations [Member] | Federal Home Loan Mortgage Corporation [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | 4,808 | 4,907
Securities available for sale, Unrealized Losses | 48 | 18
Securities available for sale | 4,760 | 4,889
Securities held to maturity, Amortized Cost | 46,854 | 49,389
Securities held to maturity, Unrealized Gains | 1,855 | 307
Securities held to maturity, Unrealized Losses |  | 103
Securities held to maturity, fair value | 48,709 | 49,593
Collateralized Mortgage Obligations [Member] | Government National Mortgage Association [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities held to maturity, Amortized Cost | 10,443 | 11,033
Securities held to maturity, Unrealized Gains | 319 | 12
Securities held to maturity, Unrealized Losses |  | 83
Securities held to maturity, fair value | 10,762 | 10,962
Collateralized Mortgage Obligations [Member] | Privately Issued [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Unrealized Gains | 502 | 618
Securities available for sale | 502 | 618
Mortgage-Backed Securities [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | 416,963 | 389,412
Securities available for sale, Unrealized Gains | 18,269 | 3,259
Securities available for sale, Unrealized Losses | 466 | 1,631
Securities available for sale | 434,766 | 391,040
Securities held to maturity, Amortized Cost | 158,851 | 166,785
Securities held to maturity, Unrealized Gains | 5,525 | 1,079
Securities held to maturity, Unrealized Losses |  | 623
Securities held to maturity, fair value | 164,376 | 167,241
Mortgage-Backed Securities [Member] | Federal National Mortgage Association [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | 284,725 | 293,873
Securities available for sale, Unrealized Gains | 14,302 | 2,263
Securities available for sale, Unrealized Losses | 217 | 1,380
Securities available for sale | 298,810 | 294,756
Securities held to maturity, Amortized Cost | 11,908 | 12,049
Securities held to maturity, Unrealized Gains | 530 | 227
Securities held to maturity, Unrealized Losses |  | 6
Securities held to maturity, fair value | 12,438 | 12,270
Mortgage-Backed Securities [Member] | Federal Home Loan Mortgage Corporation [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | 83,977 | 52,733
Securities available for sale, Unrealized Gains | 2,597 | 318
Securities available for sale, Unrealized Losses |  | 172
Securities available for sale | 86,574 | 52,879
Securities held to maturity, Amortized Cost | 6,703 | 6,995
Securities held to maturity, Unrealized Gains | 245 | 77
Securities held to maturity, Unrealized Losses |  | 47
Securities held to maturity, fair value | 6,948 | 7,025
Mortgage-Backed Securities [Member] | Government National Mortgage Association [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | 20,271 | 14,065
Securities available for sale, Unrealized Gains | 338 | 60
Securities available for sale, Unrealized Losses | 165 | 4
Securities available for sale | 20,444 | 14,121
Securities held to maturity, Amortized Cost | 43,727 | 45,758
Securities held to maturity, Unrealized Gains | 1,313 | 306
Securities held to maturity, Unrealized Losses |  | 128
Securities held to maturity, fair value | $ 45,040 | $ 45,936

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