Goodwill and Other Intangible Assets - Summary of Goodwill by Reportable Segment (Parenthetical) (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Sep. 30, 2025 |
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| Life Sciences [Member] | ||
| Goodwill [Line Items] | ||
| Accumulated impairment | $ 375 | $ 375 |
| Personal Care [Member] | ||
| Goodwill [Line Items] | ||
| Accumulated impairment | 356 | 356 |
| Specialty Additives [Member] | ||
| Goodwill [Line Items] | ||
| Accumulated impairment | 505 | 505 |
| Intermediates [Member] | ||
| Goodwill [Line Items] | ||
| Accumulated impairment | $ 90 | $ 90 |
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- Definition Amount of accumulated impairment loss for asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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