Fair value measurements (Details) - USD ($) $ in Millions	Feb. 28, 2022	Aug. 31, 2021
Recurring
Assets [Abstract]
Money market funds		$ 634
Investments in debt securities	$ 20	663
Investments in equity securities	1	2
Recurring \| Level 1
Assets [Abstract]
Money market funds		634
Investments in debt securities	0	0
Investments in equity securities	1	2
Recurring \| Level 2
Assets [Abstract]
Money market funds		0
Investments in debt securities	0	0
Investments in equity securities	0	0
Recurring \| Level 3
Assets [Abstract]
Money market funds		0
Investments in debt securities	20	663
Investments in equity securities	0	0
Recurring \| Foreign currency forwards
Assets [Abstract]
Derivative asset	12	46
Liabilities [Abstract]
Derivative liability	23	5
Recurring \| Foreign currency forwards \| Level 1
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring \| Foreign currency forwards \| Level 2
Assets [Abstract]
Derivative asset	12	46
Liabilities [Abstract]
Derivative liability	23	5
Recurring \| Foreign currency forwards \| Level 3
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring \| Cross currency interest rate swaps
Assets [Abstract]
Derivative asset	1	1
Liabilities [Abstract]
Derivative liability	25	32
Recurring \| Cross currency interest rate swaps \| Level 1
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring \| Cross currency interest rate swaps \| Level 2
Assets [Abstract]
Derivative asset	1	1
Liabilities [Abstract]
Derivative liability	25	32
Recurring \| Cross currency interest rate swaps \| Level 3
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring \| Total return swap
Assets [Abstract]
Derivative asset		2
Liabilities [Abstract]
Derivative liability	1
Recurring \| Total return swap \| Level 1
Assets [Abstract]
Derivative asset		0
Liabilities [Abstract]
Derivative liability	0
Recurring \| Total return swap \| Level 2
Assets [Abstract]
Derivative asset		2
Liabilities [Abstract]
Derivative liability	1
Recurring \| Total return swap \| Level 3
Assets [Abstract]
Derivative asset		$ 0
Liabilities [Abstract]
Derivative liability	0
Carrying Value
Liabilities [Abstract]
Fair value of long-term notes outstanding	8,500
Estimate of Fair Value Measurement
Liabilities [Abstract]
Carrying value of long-term notes outstanding	$ 8,800

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Fair value, after the effects of master netting arrangements, of a 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. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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