Financial Highlights - Summary of Financial Highlights (Details) (Parenthetical) $ in Thousands	Sep. 30, 2025 USD ($) shares	Sep. 30, 2024 shares	Sep. 30, 2019 $ / shares
Investment Company Financial Highlights [Line Items]
Amount used to multiply asset coverage ratio to determine the asset coverage per unit | $	$ 1,000
Capital outstanding | shares	0	0
2024 Notes
Investment Company Financial Highlights [Line Items]
Increment in issued price per unit | $ / shares			25