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Investment Securities - Fair Value Measurements (Details) | 9 Months Ended | 12 Months Ended
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Sep. 30, 2020 | Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract] |  |
Percentage of investments recorded at fair value | 62.00% | 71.00%

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- References No definition available. + Details
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- Definition Represents the percentage of the total investment portfolio recorded at fair value based upon quoted market prices or other observable inputs. + References No definition available. + Details
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