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v3.25.3

Financial Information by Segment & Geographic Area - Other Financial Information by Reportable Segment (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2023
Segment Reporting Information [Line Items] |  |  |
Revenues | $ 3,713 | $ 3,994 | $ 3,931
Depreciation and amortization | 154 | 151 | 144
Equity in earnings of affiliated companies, net of tax | 7 | 6 | 5
Assets | 3,815 | 3,736 | 3,604
Total expenditures for additions to long-lived assets | 303 | 249 | 265
Operating Segments [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 3,591 | 3,860 | 3,788
Depreciation and amortization | 154 | 144 | 142
Equity in earnings of affiliated companies, net of tax | 7 | 6 | 5
Assets | 3,322 | 3,245 | 3,105
Total expenditures for additions to long-lived assets | 300 | 241 | 257
Unallocated and Other [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 122 | 134 | 143
Depreciation and amortization |  | 7 | 2
Equity in earnings of affiliated companies, net of tax | 7 | 6 | 5
Assets | 493 | 491 | 499
Total expenditures for additions to long-lived assets | 3 | 8 | 8
Reinforcement Materials [Member] | Operating Segments [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 2,341 | 2,610 | 2,563
Depreciation and amortization | 70 | 66 | 70
Equity in earnings of affiliated companies, net of tax | 3 | 2 | 2
Assets | 1,822 | 1,751 | 1,632
Total expenditures for additions to long-lived assets | 209 | 165 | 149
Performance Chemicals [Member] | Operating Segments [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 1,250 | 1,250 | 1,225
Depreciation and amortization | 84 | 78 | 72
Equity in earnings of affiliated companies, net of tax | 4 | 4 | 3
Assets | 1,500 | 1,494 | 1,473
Total expenditures for additions to long-lived assets | $ 91 | $ 76 | $ 108

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