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Restructuring Activities - Additional Information (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Mar. 31, 2025 | Mar. 31, 2024 | Mar. 31, 2025 | Mar. 31, 2024
Restructuring Cost And Reserve [Line Items] |  |  |  |
Severance income (expenses) | $ (8) | $ (18) | $ (10) | $ (21)
Specialty Additives Facility [Member] |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |
Accelerated depreciation |  | $ 27 |  | $ 49
Life Sciences [Member] |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |
Accelerated depreciation | 13 |  | 13 |
Fiscal 2025 and 2023 Restructuring Severance Costs [Member] | Life Sciences [Member] |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |
Accelerated depreciation | $ 13 |  | $ 13 |

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