Nominal or face amount used to calculate payment on derivative.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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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.

+ References

No definition available.

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- Definition

Amount, after tax and reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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- Definition

Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Realized Gain (Loss) on Fair Value Hedges Recognized in Earnings

+ References

No definition available.

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- Definition

Unrealized Gain (Loss) on Fair Value Hedges Recognized in Earnings

+ References

No definition available.

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Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2023
Derivatives, Fair Value [Line Items]
Deferred (losses) gains on derivative financial instruments	$ 0	$ (3)	$ (1)	$ (8)
Interest rate swap
Derivatives, Fair Value [Line Items]
Outstanding hedge contracts					$ 500
Deferred (losses) gains on derivative financial instruments					$ 1
Unrealized pre-tax (losses) gains on derivative financial instruments			(1)	11
Foreign Exchange Contract \| Other Income (Expense)
Derivatives, Fair Value [Line Items]
Realized foreign exchange forward contract loss			1	6
Unrealized foreign exchange forward contract gain (loss)			1	$ (1)
Sale
Derivatives, Fair Value [Line Items]
Outstanding hedge contracts	175		175
Purchase
Derivatives, Fair Value [Line Items]
Outstanding hedge contracts	$ 108		$ 108