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Investment Securities (Amortized Cost and Fair Value of Investment Securities) (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Amortized Cost | $ 607,665 | $ 415,852
Securities available for sale, Unrealized Gains | 20,462 | 3,696
Securities available for sale, Unrealized Losses | 68 | 1,631
Securities available for sale | 628,059 | 417,917
Securities held to maturity, Amortized Cost | 271,973 | 359,000
Securities held to maturity, Unrealized Gains | 10,062 | 4,882
Securities held to maturity, Unrealized Losses |  | 623
Securities held to maturity, fair value | 282,035 | 363,259
Allowance for credit losses, Amortized Cost | (7) |
Held-to-maturity securities, net , Amortized Cost | 271,966 | 359,000
U.S. Government Agencies 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 | 6,239 | 26,440
Securities available for sale, Unrealized Gains | 396 | 437
Securities available for sale | 6,635 | 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 | 144,506 | 192,215
Securities held to maturity, Unrealized Gains | 4,478 | 3,803
Securities held to maturity, fair value | 148,984 | 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 | 3,047 | 23,834
Securities available for sale, Unrealized Gains | 97 |
Securities available for sale, Unrealized Losses |  | 57
Securities available for sale | 3,144 | 23,777
Securities held to maturity, Amortized Cost | 29,988 | 41,561
Securities held to maturity, Unrealized Gains | 1,075 | 150
Securities held to maturity, Unrealized Losses |  | 256
Securities held to maturity, fair value | 31,063 | 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 |  | 4,907
Securities available for sale, Unrealized Losses |  | 18
Securities available for sale |  | 4,889
Securities held to maturity, Amortized Cost | 35,897 | 49,389
Securities held to maturity, Unrealized Gains | 1,581 | 307
Securities held to maturity, Unrealized Losses |  | 103
Securities held to maturity, fair value | 37,478 | 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 | 7,864 | 11,033
Securities held to maturity, Unrealized Gains | 265 | 12
Securities held to maturity, Unrealized Losses |  | 83
Securities held to maturity, fair value | 8,129 | 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 | 435 | 618
Securities available for sale | 435 | 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 | 601,426 | 389,412
Securities available for sale, Unrealized Gains | 20,066 | 3,259
Securities available for sale, Unrealized Losses | 68 | 1,631
Securities available for sale | 621,424 | 391,040
Securities held to maturity, Amortized Cost | 127,467 | 166,785
Securities held to maturity, Unrealized Gains | 5,584 | 1,079
Securities held to maturity, Unrealized Losses |  | 623
Securities held to maturity, fair value | 133,051 | 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 | 350,627 | 293,873
Securities available for sale, Unrealized Gains | 15,549 | 2,263
Securities available for sale, Unrealized Losses | 44 | 1,380
Securities available for sale | 366,132 | 294,756
Securities held to maturity, Amortized Cost | 10,776 | 12,049
Securities held to maturity, Unrealized Gains | 703 | 227
Securities held to maturity, Unrealized Losses |  | 6
Securities held to maturity, fair value | 11,479 | 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 | 225,645 | 52,733
Securities available for sale, Unrealized Gains | 3,155 | 318
Securities available for sale, Unrealized Losses | 24 | 172
Securities available for sale | 228,776 | 52,879
Securities held to maturity, Amortized Cost | 5,858 | 6,995
Securities held to maturity, Unrealized Gains | 382 | 77
Securities held to maturity, Unrealized Losses |  | 47
Securities held to maturity, fair value | 6,240 | 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 | 22,107 | 14,065
Securities available for sale, Unrealized Gains | 830 | 60
Securities available for sale, Unrealized Losses |  | 4
Securities available for sale | 22,937 | 14,121
Securities held to maturity, Amortized Cost | 37,084 | 45,758
Securities held to maturity, Unrealized Gains | 1,578 | 306
Securities held to maturity, Unrealized Losses |  | 128
Securities held to maturity, fair value | $ 38,662 | $ 45,936

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