Taxable/Distributable Income and Dividend Distributions - Components of Accumulated Overdistributed Earnings (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Undistributed ordinary income, net		$ 33,525
Net realized capital losses		(509,832)
Unrealized losses, net		(175,031)
Accumulated overdistributed earnings	$ (725,078)	$ (651,338)

Investment Company, Distributable Earnings (Loss), Accumulated Unrealized Gains (Losses)

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Amount of accumulated undistributed earnings (deficit) from long-term capital gain (loss) of investment company.

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Amount of accumulated undistributed earnings (deficit) from ordinary income (loss) of investment company.

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Amount of accumulated undistributed earnings (deficit).

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