Income Taxes - Components of Deferred Income Taxes (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Components Of Deferred Tax Assets [Abstract]
Deferred expenses	$ 14	$ 19
Intangible assets	38	37
Inventory	13	13
Operating lease liability	21	20
Other	42	51
Pension and other benefits	32	35
Net operating loss carryforwards	257	254
Foreign tax credit carryforwards	48	58
R&D credit carryforwards	46	44
Other business credit carryforwards	24	23
Subtotal	535	554
Valuation allowance	(470)	(481)
Total deferred tax assets	65	73
Property, plant and equipment	(47)	(40)
Right of use asset	(20)	(20)
Unremitted earnings of non-U.S. subsidiaries	(18)	(18)
Total deferred tax liabilities	$ (85)	$ (78)