Derivative Financial Instruments - Fair Value of Open Foreign Currency Exchange Contracts (Detail) - Foreign Exchange Contracts [Member] - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Derivatives, Fair Value [Line Items]
Net fair value	$ 29,780	$ (6,380)
Prepaid Expenses and Other Current Assets [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	31,524	3,264
Prepaid Expenses and Other Current Assets [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	11,898	2,674
Other Noncurrent Assets [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	2,987
Other Noncurrent Assets [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	1,236
Accrued Expenses and Other Current Liabilities [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability	(6,235)	(4,093)
Accrued Expenses and Other Current Liabilities [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability	(7,407)	(12,212)
Other Noncurrent Liabilities [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability	0	(236)
Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Net fair value	25,289	1,922
Non Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Net fair value	$ 4,491	$ (8,302)

Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

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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.

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