Income tax benefit from tax loss related to divestiture.

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- Definition

Income taxes.

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No definition available.

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- Definition

Non cash income tax expense(benefit).

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No definition available.

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- Definition

Unrecognized tax benefits included in consolidated financial statement.

+ References

No definition available.

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- Definition

Unrecognized tax benefits offset against deferred tax assets.

+ References

No definition available.

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- Definition

The potential impact on the consolidated tax provision if unrecognized tax benefits were recognized at a given point in time.

+ References

No definition available.

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- Definition

The sum of the amounts of estimated penalties and interest recognized in the period arising from income tax examinations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (c)
-Publisher FASB
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- Definition

Tax year that remains open to examination under enacted tax laws, in YYYY format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
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- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

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- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

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- Definition

Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile.

+ References

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- Definition

Amount of unrecognized tax benefits.

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- Definition

Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

+ References

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- Definition

Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

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Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Income Taxes [Line Items]
Increased/(decreased) valuation in allowance	$ 31
Other tax credit carryforwards	140
Undistributed earnings	2,000
Unrecognized tax benefits	29	$ 22	$ 20	$ 159
Unrecognized tax benefits, offset against deferred tax assets	11	13
Non cash income tax expense (benefit)		24
Accruals for penalties and interest	13	10
Total penalties and interest	5	5	2
Favorable impact on tax provision	29
Purification Solutions [Member]
Income Taxes [Line Items]
Income tax benefit from tax loss related to divestiture			$ 137	$ 137
Other Liabilities [Member]
Income Taxes [Line Items]
Unrecognized tax benefits, recorded	9	9
Accounts payable and accrued liabilities [Member]
Income Taxes [Line Items]
Unrecognized tax benefits, recorded	9
Maximum [Member]
Income Taxes [Line Items]
Other tax credit carryforwards	$ 1
Maximum [Member] \| United States Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Tax years remain subject to examination	2024
Minimum [Member] \| United States Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Tax years remain subject to examination	2022
Foreign Jurisdictions [Member]
Income Taxes [Line Items]
NOLs	$ 30
Foreign Jurisdictions [Member] \| Maximum [Member]
Income Taxes [Line Items]
Tax years remain subject to examination	2024
Foreign Jurisdictions [Member] \| Minimum [Member]
Income Taxes [Line Items]
Tax years remain subject to examination	2006
State Tax Authorities [Member] \| Maximum [Member]
Income Taxes [Line Items]
Tax years remain subject to examination	2024
State Tax Authorities [Member] \| Minimum [Member]
Income Taxes [Line Items]
Tax years remain subject to examination	2019
U.S. Defined Benefit Plans [Member]
Income Taxes [Line Items]
Increased/(decreased) valuation in allowance	$ 516
U.S. Defined Benefit Plans [Member] \| Maximum [Member]
Income Taxes [Line Items]
Increased/(decreased) valuation in allowance		494
U.S. Defined Benefit Plans [Member] \| Minimum [Member]
Income Taxes [Line Items]
Increased/(decreased) valuation in allowance		$ 22