Derivative and Hedging Instruments - Schedule of Aggregate Notional Amount of the Derivative Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Derivative [Line Items]
Notional amount	$ 11,896	$ 13,649
Designated as Hedging Instruments:
Derivative [Line Items]
Notional amount	9,399	11,736
Not Designated as Hedging Instruments:
Derivative [Line Items]
Notional amount	$ 2,497	$ 1,913