Goodwill and Other Intangibles - Summary of Goodwill by Reportable Segment (Parenthetical) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Personal Care [Member]
Goodwill [Line Items]
Accumulated impairment	$ 356	$ 356
Specialty Additives [Member]
Goodwill [Line Items]
Accumulated impairment	174	174
Intermediates [Member]
Goodwill [Line Items]
Accumulated impairment	$ 90	$ 90