Financial Information by Segment - Schedule of Performance Segment (Detail) - Performance Chemicals [Member] - Operating Segments [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 294	$ 245	$ 561	$ 487
Performance Additives [Member]
Segment Reporting Information [Line Items]
Net sales	203	168	387	338
Formulated Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	$ 91	$ 77	$ 174	$ 149