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
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
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-Section 50
-Paragraph 1A
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A

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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

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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
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Section 45
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- Definition

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

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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		6 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Sep. 30, 2023
Derivatives, Fair Value [Line Items]
Deferred (losses) gains on derivative financial instruments	$ 0	$ (4)	$ (1)	$ (5)
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)	7
Foreign Exchange Contract \| Other Income (Expense)
Derivatives, Fair Value [Line Items]
Unrealized foreign exchange forward contract gain (loss)			0	4
Realized foreign exchange forward contract loss			(1)	$ 2
Sale
Derivatives, Fair Value [Line Items]
Outstanding hedge contracts	326		326
Purchase
Derivatives, Fair Value [Line Items]
Outstanding hedge contracts	$ 192		$ 192