Fair value measurements - Fair Value Roll Forward (Details) - Derivative Financial Instruments, Liabilities - USD ($) $ in Millions	12 Months Ended
Aug. 31, 2024	Aug. 31, 2023
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	$ (2,548)	$ 0
VPF derivative additions	(424)	(2,568)
Unrealized (losses) gains recorded in Other income, net	(946)	19
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	$ (3,919)	$ (2,548)

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of transfers of financial instrument classified as a liability into level 3 of the fair value hierarchy.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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