Financial Instruments - Offsetting of Derivative Assets and Liabilities (Details) - Foreign exchange forward contracts - USD ($) $ in Millions	Mar. 31, 2022	Sep. 30, 2021
Derivative Assets
Gross Amounts Recognized	$ 1	$ 1
Gross Amounts Offset	0	0
Net Amounts Reported	$ 1	$ 1

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant