Income Taxes - Narrative (Details) - USD ($) |
12 Months Ended | 14 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Aug. 28, 2024 |
Jun. 30, 2025 |
Aug. 31, 2024 |
Jun. 30, 2024 |
Aug. 31, 2023 |
Jun. 30, 2023 |
Aug. 31, 2022 |
Aug. 31, 2024 |
Aug. 31, 2023 |
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| Income Taxes [Line Items] | |||||||||||||
| Ordinary income | $ 227,508,000 | $ 243,085,000 | $ 231,984,000 | ||||||||||
| Return of capital | $ 6,459,000 | $ 10,394,000 | [1] | 71,414,000 | $ 67,479,000 | [1] | $ 44,838,000 | $ 38,379,000 | $ 0 | ||||
| Distributable loss | (497,299,000) | (1,253,880,000) | (436,279,000) | ||||||||||
| Investment company, distributable earnings (loss), accumulated ordinary income (loss) | 0 | $ 0 | |||||||||||
| Investment company, distributable earnings (loss), accumulated long-term capital gain (loss) | 0 | 0 | |||||||||||
| Investment company, distributable earnings (loss), accumulated capital loss carryforward | $ 397,259,000 | 397,259,000 | |||||||||||
| Cost basis of investments for tax purposes | 6,800,692,000 | 7,429,121,000 | |||||||||||
| Unrealized appreciation (depreciation), net | (127,176,000) | 289,122,000 | |||||||||||
| Unrealized gains | 1,308,011,000 | 1,381,820,000 | |||||||||||
| Unrealized loss | 1,435,187,000 | 1,092,698,000 | |||||||||||
| Retained earnings | |||||||||||||
| Income Taxes [Line Items] | |||||||||||||
| Reclassification of distributions from capital, increase (decrease) | 10,394,000 | 63,000 | $ 27,000 | ||||||||||
| Accumulated Realized Losses | |||||||||||||
| Income Taxes [Line Items] | |||||||||||||
| Reclassification of distributions from capital, increase (decrease) | (21,530,000) | (622,000) | |||||||||||
| Paid-in capital in excess of par | |||||||||||||
| Income Taxes [Line Items] | |||||||||||||
| Return of capital | $ 10,394,000 | [1] | 67,479,000 | [1] | $ 38,379,000 | ||||||||
| Reclassification of distributions from capital, increase (decrease) | $ (21,593,000) | $ (595,000) | |||||||||||
| Reclassification, Adjustment | |||||||||||||
| Income Taxes [Line Items] | |||||||||||||
| Distributable loss | $ 61,020,000 | ||||||||||||
| Scenario, Plan | |||||||||||||
| Income Taxes [Line Items] | |||||||||||||
| Ordinary income | $ 389,263,000 | ||||||||||||
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