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Investment Securities - Unrealized Loss Positions (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
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Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | $ 137,582 | $ 9,918
Available-for-sale, greater than 12 continuous months, fair value | 1,699 | 1,790
Available-for-sale, total securities in a loss position, fair value | 139,281 | 11,708
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | (3,468) | (25)
Available-for-sale, greater than 12 continuous months, unrealized loss | (53) | (55)
Available-for-sale, total securities in a loss position, unrealized loss | (3,521) | (80)
Marketable Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Marketable securities, less than 12 continuous months, fair value | 141,817 | 9,918
Marketable securities, greater than 12 continuous months, fair value | 1,699 | 1,790
Marketable securities, total securities in a loss position, fair value | 143,516 | 11,708
Marketable Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Marketable securities, less than 12 continuous months, unrealized loss | (3,657) | (25)
Marketable securities, greater than 12 continuous months, unrealized loss | (53) | (55)
Marketable securities, total securities in a loss position, unrealized loss | (3,710) | (80)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Less than 12 continuous months | 4,235 |
Greater than or equal to 12 continuous months | 0 |
Total Securities in a loss position | 4,235 |
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Less than 12 continuous months | (189) |
Greater than or equal to 12 continuous months | 0 |
Held-to-maturity, gross unrealized losses | (189) |
MBS pass-through securities issued by FHLMC and FNMA |  |
Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | 10,013 |
Available-for-sale, greater than 12 continuous months, fair value | 0 |
Available-for-sale, total securities in a loss position, fair value | 10,013 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | (56) |
Available-for-sale, greater than 12 continuous months, unrealized loss | 0 |
Available-for-sale, total securities in a loss position, unrealized loss | (56) |
SBA-backed securities |  |
Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | 0 | 0
Available-for-sale, greater than 12 continuous months, fair value | 1,699 | 1,790
Available-for-sale, total securities in a loss position, fair value | 1,699 | 1,790
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | 0 | 0
Available-for-sale, greater than 12 continuous months, unrealized loss | (53) | (55)
Available-for-sale, total securities in a loss position, unrealized loss | (53) | (55)
CMOs issued by FNMA |  |
Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | 7,304 |
Available-for-sale, greater than 12 continuous months, fair value | 0 |
Available-for-sale, total securities in a loss position, fair value | 7,304 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | (31) |
Available-for-sale, greater than 12 continuous months, unrealized loss | 0 |
Available-for-sale, total securities in a loss position, unrealized loss | (31) |
CMOs issued by FHLMC |  |
Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | 32,658 | 5,975
Available-for-sale, greater than 12 continuous months, fair value | 0 | 0
Available-for-sale, total securities in a loss position, fair value | 32,658 | 5,975
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | (948) | (1)
Available-for-sale, greater than 12 continuous months, unrealized loss | 0 | 0
Available-for-sale, total securities in a loss position, unrealized loss | (948) | (1)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Less than 12 continuous months | 4,235 |
Greater than or equal to 12 continuous months | 0 |
Total Securities in a loss position | 4,235 |
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Less than 12 continuous months | (189) |
Greater than or equal to 12 continuous months | 0 |
Held-to-maturity, gross unrealized losses | (189) |
Debentures of government- sponsored agencies |  |
Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | 53,289 | 3,943
Available-for-sale, greater than 12 continuous months, fair value | 0 | 0
Available-for-sale, total securities in a loss position, fair value | 53,289 | 3,943
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | (2,041) | (24)
Available-for-sale, greater than 12 continuous months, unrealized loss | 0 | 0
Available-for-sale, total securities in a loss position, unrealized loss | (2,041) | $ (24)
Obligations of state and political subdivisions |  |
Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | 28,529 |
Available-for-sale, greater than 12 continuous months, fair value | 0 |
Available-for-sale, total securities in a loss position, fair value | 28,529 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | (195) |
Available-for-sale, greater than 12 continuous months, unrealized loss | 0 |
Available-for-sale, total securities in a loss position, unrealized loss | (195) |
Corporate bonds |  |
Debt Securities, Available-For-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Available-for-sale, less than 12 continuous months, fair value | 5,789 |
Available-for-sale, greater than 12 continuous months, fair value | 0 |
Available-for-sale, total securities in a loss position, fair value | 5,789 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] |  |
Available-for-sale, less than 12 continuous months, unrealized loss | (197) |
Available-for-sale, greater than 12 continuous months, unrealized loss | 0 |
Available-for-sale, total securities in a loss position, unrealized loss | $ (197) |

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