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Investments (Gross Unrealized Losses and Fair Values of Securities) (Details) $ in Thousands | Mar. 31, 2021 USD ($) item | Dec. 31, 2020 USD ($) item
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Schedule of Investments [Line Items] |  |
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 139,956 | $ 118,172
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses | $ 6,897 | $ 459
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Number of Investments | item | 18 | 14
Available-for-Sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | $ 13,649 | $ 13,260
Available-for-Sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses | $ 4,907 | $ 5,284
Available-for-Sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Investments | item | 9 | 9
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 8,849 | $ 2,973
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses | $ 463 | $ 38
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Number Of Investments | item | 3 | 1
U.S. government agencies [Member] |  |
Schedule of Investments [Line Items] |  |
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 36,765 | $ 39,611
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses | $ 3,155 | $ 322
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Number of Investments | item | 7 | 7
Residential mortgage-backed agencies [Member] |  |
Schedule of Investments [Line Items] |  |
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 21,822 | $ 22,899
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses | $ 784 | $ 100
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Number of Investments | item | 2 | 2
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 8,849 | $ 2,973
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses | $ 463 | $ 38
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Number Of Investments | item | 3 | 1
Commercial mortgage-backed agencies [Member] |  |
Schedule of Investments [Line Items] |  |
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 25,632 | $ 16,034
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses | $ 774 | $ 36
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Number of Investments | item | 3 | 1
Collateralized mortgage obligations [Member] |  |
Schedule of Investments [Line Items] |  |
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 55,737 | $ 39,628
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses | $ 2,184 | $ 1
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Number of Investments | item | 6 | 4
Collateralized debt obligations [Member] |  |
Schedule of Investments [Line Items] |  |
Available-for-Sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | $ 13,649 | $ 13,260
Available-for-Sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses | $ 4,907 | $ 5,284
Available-for-Sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Investments | item | 9 | 9

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