Derivative Financial Instruments - Schedule of Derivative Instruments and Hedging Activities Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Derivative Instruments Gain Loss [Line Items]
Gain (loss) recognized in Other comprehensive income (loss) ("OCI")	$ 6,745	$ (15,014)	$ 6,156	$ 10,226
Foreign Exchange Forward Contract and Options | Not Designated as Hedging Instrument | Other income, net
Derivative Instruments Gain Loss [Line Items]
Net realized and unrealized gain (loss), excluding the underlying foreign currency exposure being hedged	931	(917)	1,143	(360)
Forward Contracts | Designated as Hedging Instrument | Net Investment Hedging
Derivative Instruments Gain Loss [Line Items]
Gain (loss) recognized in Other comprehensive income (loss) ("OCI")	8,942	(19,898)	8,160	13,550
Gain (loss) reclassified from OCI to earnings	0	0	0	0
Gain recognized, excluded portion	$ 1,595	$ 1,254	$ 3,526	$ 2,329