Borrowings - Schedule of Interest Rate and Interest Differential Analysis (Details) - USD ($) $ in Thousands		12 Months Ended
	Nov. 18, 2024	Sep. 30, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Amount Outstanding		$ 4,900,773	$ 4,599,430
2024 Debt Securitization
Debt Instrument [Line Items]
Interest Rate		4.30%
2024 Debt Securitization | AAA/AAA Class A -1R 2024 Notes
Debt Instrument [Line Items]
Interest Rate	1.56%
2024 Debt Securitization | AAA Class A-2RR 2024 Notes
Debt Instrument [Line Items]
Interest Rate	1.75%
2024 Debt Securitization | Senior Notes | AAA/AAA Class A -1R 2024 Notes
Debt Instrument [Line Items]
Amount Outstanding		$ 1,192,400
Interest Rate		1.56%
2024 Debt Securitization | Senior Notes | AAA Class A-2RR 2024 Notes
Debt Instrument [Line Items]
Amount Outstanding		$ 171,600
Interest Rate		1.75%