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Basis of Presentation and Significant Accounting Policies - Investment Securities (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020
Accounting Policies [Abstract] |  |
Percentage of investments recorded at fair value | 68.00% | 73.00%
Variance threshold for outliers | $ 0.5 |
Variance threshold for outliers (as a percent) | 5.00% |

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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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