Derivatives - Schedule of Derivatives Designated in a Qualifying Hedge Accounting Relationship (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Foreign Currency [Abstract]
Hedging Instruments (Interest rate swaps)	$ 17,717	$ (9,094)	$ (21,225)	$ (5,828)
Hedged items (Unsecured notes)	(17,752)	11,565	16,529	8,600
Fair market value adjustments for hedge accounting recognized in interest expense	$ (35)	$ 2,471	$ (4,696)	$ 2,772