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Investment Securities (Investments Gross Unrealized Losses and Fair Value) (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Less than 12 months, Fair Value | $ 465,673 | $ 29,087
Securities available for sale, Less than 12 months, Unrealized Losses | 10,442 | 68
Securities available for sale, 12 months or longer, Fair Value | 13 | 8
Securities available for sale, Fair Value, Total | 465,686 | 29,095
Securities available for sale, Unrealized Losses, Total | 10,442 | 68
Total Securities, Less than 12 months, Fair Value | 465,673 | 29,087
Total Securities, Less than 12 months, Unrealized Losses | 10,442 | 68
Total Securities, 12 months or longer, Fair Value | 13 | 8
Total Securities, Fair Value | 465,686 | 29,095
Total Securities, Unrealized Losses | 10,442 | 68
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, Less than 12 months, Fair Value | 9,941 |
Securities available for sale, Less than 12 months, Unrealized Losses | 59 |
Securities available for sale, Fair Value, Total | 9,941 |
Securities available for sale, Unrealized Losses, Total | 59 |
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, Less than 12 months, Fair Value | 9,665 |
Securities available for sale, Less than 12 months, Unrealized Losses | 43 |
Securities available for sale, 12 months or longer, Fair Value |  | 8
Securities available for sale, Fair Value, Total | 9,665 | 8
Securities available for sale, Unrealized Losses, Total | 43 |
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, Less than 12 months, Fair Value | 6,921 |
Securities available for sale, Less than 12 months, Unrealized Losses | 22 |
Securities available for sale, Fair Value, Total | 6,921 |
Securities available for sale, Unrealized Losses, Total | 22 |
Mortgage-Backed Securities [Member] |  |
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item] |  |
Securities available for sale, Less than 12 months, Fair Value | 455,732 | 29,087
Securities available for sale, Less than 12 months, Unrealized Losses | 10,383 | 68
Securities available for sale, 12 months or longer, Fair Value | 13 | 8
Securities available for sale, Fair Value, Total | 455,745 | 29,095
Securities available for sale, Unrealized Losses, Total | 10,383 | 68
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, Less than 12 months, Fair Value | 224,499 | 18,155
Securities available for sale, Less than 12 months, Unrealized Losses | 4,432 | 44
Securities available for sale, 12 months or longer, Fair Value | 13 |
Securities available for sale, Fair Value, Total | 224,512 | 18,155
Securities available for sale, Unrealized Losses, Total | 4,432 | 44
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, Less than 12 months, Fair Value | 209,482 | 10,932
Securities available for sale, Less than 12 months, Unrealized Losses | 5,760 | 24
Securities available for sale, Fair Value, Total | 209,482 | 10,932
Securities available for sale, Unrealized Losses, Total | 5,760 | $ 24
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, Less than 12 months, Fair Value | 5,165 |
Securities available for sale, Less than 12 months, Unrealized Losses | 126 |
Securities available for sale, Fair Value, Total | 5,165 |
Securities available for sale, Unrealized Losses, Total | $ 126 |

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