Goodwill and Intangible Assets - Schedule of Goodwill Balances (Detail) $ in Millions	12 Months Ended
	Sep. 30, 2022 USD ($)
Goodwill And Intangible Assets [Line Items]
Beginning balance	$ 140	[1]
Foreign currency impact	(11)
Ending balance	129
Reinforcement Materials [Member]
Goodwill And Intangible Assets [Line Items]
Beginning balance	48	[1]
Foreign currency impact	(2)
Ending balance	46
Performance Chemicals [Member]
Goodwill And Intangible Assets [Line Items]
Beginning balance	92	[1]
Foreign currency impact	(9)
Ending balance	$ 83

[1] The balance as of September 30, 2021 included $444 million of accumulated impairment losses associated with the goodwill of Purification Solutions segment. There were no accumulated impairment losses associated with the goodwill of the Reinforcement Materials or Performance Chemicals segments.