Property, Plant and Equipment - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Property Plant And Equipment [Abstract]
Depreciation expense	$ 148	$ 145	$ 138

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Name:	us-gaap_Depreciation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration