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INVESTMENTS - Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Mar. 31, 2023 | [1]
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Investments, Debt and Equity Securities [Abstract] |  |
For the remaining three months ending March 31, 2024 | $ 33,918 |
2025 | 100,470 |
2026 | 204,919 |
2027 | 162,746 |
2028 | 38,250 |
Thereafter | 125,394 |
Total contractual repayments | 665,697 |
Investments in equity securities | 202,807 |
Total cost basis of investments held as of December 31, 2023: | $ 868,504 | $ 720,630
[1] | Cumulative gross unrealized appreciation for federal income tax purposes is $150.4 million; cumulative gross unrealized depreciation for federal income tax purposes is $119.3 million. Cumulative net unrealized appreciation is $31.1 million, based on a tax cost of $722.4 million.

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