Fair value measurements (Details) - USD ($) $ in Millions	Aug. 31, 2021	Aug. 31, 2020
Liabilities [Abstract]
Carrying value of long-term notes outstanding	$ 9,018
Carrying Value
Liabilities [Abstract]
Carrying value of long-term notes outstanding	8,900
Estimate of Fair Value Measurement
Liabilities [Abstract]
Fair value of long-term notes outstanding	9,800
Recurring
Assets [Abstract]
Money market funds	634	$ 6
Investment in equity securities	2	1
Investments in debt securities	663
Recurring \| Level 1
Assets [Abstract]
Money market funds	634	6
Investment in equity securities	2	1
Investments in debt securities	0
Recurring \| Level 2
Assets [Abstract]
Money market funds	0	0
Investment in equity securities	0	0
Investments in debt securities	0
Recurring \| Level 3
Assets [Abstract]
Money market funds	0	0
Investment in equity securities	0	0
Investments in debt securities	663
Recurring \| Foreign currency forwards
Assets [Abstract]
Derivative asset	46	20
Liabilities [Abstract]
Derivative liability	5	80
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	46	20
Liabilities [Abstract]
Derivative liability	5	80
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	16
Liabilities [Abstract]
Derivative liability	32	16
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	16
Liabilities [Abstract]
Derivative liability	32	16
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
Recurring \| Interest rate swaps
Liabilities [Abstract]
Derivative liability		10
Recurring \| Interest rate swaps \| Level 1
Liabilities [Abstract]
Derivative liability		0
Recurring \| Interest rate swaps \| Level 2
Liabilities [Abstract]
Derivative liability		10
Recurring \| Interest rate swaps \| Level 3
Liabilities [Abstract]
Derivative liability		$ 0

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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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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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