Derivatives - Schedule of Carrying Value of 2028 and 2029 Notes (Details) - Designated as Hedging Instrument - Long-Term Debt - USD ($) $ in Thousands	Mar. 31, 2026	Sep. 30, 2025
2028 Notes
Open Forward Foreign Currency Contract [Line Items]
Carrying Value	$ 712,928	$ 720,521
Cumulative Hedging Adjustment	3,589	9,445
2029 Notes
Open Forward Foreign Currency Contract [Line Items]
Carrying Value	750,156	756,102
Cumulative Hedging Adjustment	$ 3,742	$ 10,232