Taxable/Distributable Income - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Sep. 30, 2025
Tax Credit Carryforward [Line Items]
Deferred income tax expense (benefit)	$ 87	$ 45
Income tax expense (benefit)		100
Cost of investments			$ 6,736,200
Unrealized appreciation			169,400
Unrealized depreciation			170,600
Unrealized appreciation (depreciation)			$ 1,200
Investment Income
Tax Credit Carryforward [Line Items]
Current income tax expense (benefit)	300	300
Realized and Unrealized Gains (Losses)
Tax Credit Carryforward [Line Items]
Current income tax expense (benefit)		100
Deferred income tax expense (benefit)	$ 100	$ 100