Fair value measurements (Details) - USD ($) $ in Millions	Nov. 30, 2018	Aug. 31, 2018
Assets [Abstract]
Money market funds	$ 398	$ 227
Available-for-sale investments	0	1
Level 1
Assets [Abstract]
Money market funds	398	227
Available-for-sale investments	0	1
Level 2
Assets [Abstract]
Money market funds	0	0
Available-for-sale investments	0	0
Level 3
Assets [Abstract]
Money market funds	0	0
Available-for-sale investments	0	0
Foreign currency forwards
Assets [Abstract]
Derivative asset	65	52
Liabilities [Abstract]
Derivative liability	5	4
Foreign currency forwards \| Level 1
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Foreign currency forwards \| Level 2
Assets [Abstract]
Derivative asset	65	52
Liabilities [Abstract]
Derivative liability	5	4
Foreign currency forwards \| Level 3
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Cross currency interest rate swaps
Assets [Abstract]
Derivative asset	3
Cross currency interest rate swaps \| Level 1
Assets [Abstract]
Derivative asset	0
Cross currency interest rate swaps \| Level 2
Assets [Abstract]
Derivative asset	3
Cross currency interest rate swaps \| Level 3
Assets [Abstract]
Derivative asset	0
Interest rate swaps
Liabilities [Abstract]
Derivative liability	2	1
Interest rate swaps \| Level 1
Liabilities [Abstract]
Derivative liability	0	0
Interest rate swaps \| Level 2
Liabilities [Abstract]
Derivative liability	2	1
Interest rate swaps \| Level 3
Liabilities [Abstract]
Derivative liability	$ 0	$ 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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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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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No definition available.

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

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