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FAIR VALUE MEASUREMENTS - Changes in Fair Value of Investments Measured Using Level 3 Inputs (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024
First lien loans |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | $ 1,309,449 | $ 1,000,984
Realized & Unrealized Gains (Losses) | (61,142) | (25,020)
Purchases of Investments | 616,629 | 520,239
Repayments | (244,854) | (176,763)
PIK Interest Capitalized | 12,843 | 10,845
Divestitures | (31,584) | (13,875)
Conversion/Exchange of Security | (14,719) | (6,961)
Fair value. ending balance | 1,586,622 | 1,309,449
YTD Unrealized Appreciation (Depreciation) on Investments held at period end | (21,908) | (19,824)
Second lien loans |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 33,774 | 35,820
Realized & Unrealized Gains (Losses) | (6,960) | 342
Purchases of Investments | 37 | 169
Repayments | (3,840) | (2,913)
PIK Interest Capitalized | 70 | 356
Divestitures | 0 | 0
Conversion/Exchange of Security | (5,015) | 0
Fair value. ending balance | 18,066 | 33,774
YTD Unrealized Appreciation (Depreciation) on Investments held at period end | (5,062) | 339
Subordinated debt |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 1,336 | 791
Realized & Unrealized Gains (Losses) | 36 | (31)
Purchases of Investments | 57 | 562
Repayments | (75) | (19)
PIK Interest Capitalized | 17 | 33
Divestitures | 0 | 0
Conversion/Exchange of Security | (153) | 0
Fair value. ending balance | 1,218 | 1,336
YTD Unrealized Appreciation (Depreciation) on Investments held at period end | 28 | (31)
Preferred equity |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 71,127 | 63,393
Realized & Unrealized Gains (Losses) | 25,094 | (5,442)
Purchases of Investments | 9,767 | 10,279
Repayments | 0 | 0
PIK Interest Capitalized | 0 | 0
Divestitures | (16,920) | (273)
Conversion/Exchange of Security | 13,850 | 3,170
Fair value. ending balance | 102,918 | 71,127
YTD Unrealized Appreciation (Depreciation) on Investments held at period end | 18,671 | (5,340)
Common equity & warrants |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 60,875 | 54,144
Realized & Unrealized Gains (Losses) | 3,593 | 517
Purchases of Investments | 7,036 | 6,281
Repayments | 0 | 0
PIK Interest Capitalized | 0 | 0
Divestitures | (1,066) | (3,858)
Conversion/Exchange of Security | 6,037 | 3,791
Fair value. ending balance | 76,475 | 60,875
YTD Unrealized Appreciation (Depreciation) on Investments held at period end | 4,388 | 285
Total Investments |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 1,476,561 | 1,155,132
Realized & Unrealized Gains (Losses) | (39,379) | (29,634)
Purchases of Investments | 633,526 | 537,530
Repayments | (248,769) | (179,695)
PIK Interest Capitalized | 12,930 | 11,234
Divestitures | (49,570) | (18,006)
Conversion/Exchange of Security | 0 | 0
Fair value. ending balance | 1,785,299 | 1,476,561
YTD Unrealized Appreciation (Depreciation) on Investments held at period end | (3,883) | $ (24,571)
Cost basis allocated from first lien debt to warrants |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Conversion/Exchange of Security | $ 3,800 |

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