Derivatives - Schedule of Realized and Unrealized Gain (Loss) on Forward Currency Contract (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Open Forward Foreign Currency Contract [Line Items]
Realized gain (loss) on forward currency contracts recognized in income	$ 624	$ 2,021	$ 624	$ 3,192
Foreign exchange
Open Forward Foreign Currency Contract [Line Items]
Realized gain (loss) on forward currency contracts recognized in income	624	2,021	624	3,192
Change in unrealized appreciation (depreciation) on forward currency contracts recognized in income	$ 2,972	$ (5,431)	$ 1,589	$ (22,326)