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Borrowings - General, Narrative (Details) - USD ($) | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jun. 09, 2018 | Jun. 08, 2018 | Nov. 05, 2014
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Debt Disclosure [Abstract] |  |  |  |  |  |  |  |
Minimum asset coverage ratio |  |  |  |  |  | 150.00% | 200.00% | 150.00%
Borrowings allowable per dollar of equity |  |  |  |  |  | $ 2 |  |
Debt to equity ratio, maximum |  |  |  |  |  |  |  | 1.65
Maximum secured debt ratio |  |  |  |  |  |  |  | 0.70
Asset coverage ratio | 177.42% | 181.21% | 180.68% | 173.98% | 181.37% |  |  |

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