Goodwill and Intangible Assets - Schedule of Goodwill Balances (Detail) $ in Millions	6 Months Ended
	Mar. 31, 2022 USD ($)
Goodwill And Intangible Assets [Line Items]
Beginning balance	$ 140
Foreign currency impact	1
Ending balance	141
Reinforcement Materials [Member]
Goodwill And Intangible Assets [Line Items]
Beginning balance	48
Ending balance	48
Performance Chemicals [Member]
Goodwill And Intangible Assets [Line Items]
Beginning balance	92
Foreign currency impact	1
Ending balance	$ 93