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Investment Securities - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Debt Securities, Available-for-sale [Line Items] |  |  |  |
Proceeds from sale of available-for-sale investment securities | $ 25,600 | $ 0 | $ 25,573 | $ 0
Loss on debt securities, available-for-sale | $ 2,900 |  | $ 2,900 |
Investment securities: |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |
Average percent of amortized cost for securities in unrealized loss positions for more than 12 months | 98.60% |  | 98.60% |

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