Financial instruments - derivative instruments (Details) - USD ($) $ in Millions	Aug. 31, 2022	Aug. 31, 2021
Foreign currency forwards | Derivatives designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 448	$ 575
Fair value, assets	$ 19	$ 7
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
Foreign currency forwards | Derivatives designated as hedges: | Other non-current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 3	$ 6
Fair value, assets	$ 0	$ 0
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other non-current assets	Other non-current assets
Foreign currency forwards | Derivatives designated as hedges: | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities		$ 23
Fair value, liabilities		$ 1
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Other non-current liabilities
Foreign currency forwards | Derivatives designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 221	$ 31
Fair value, liabilities	$ 1	$ 1
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Foreign currency forwards | Derivatives not designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 2,874	$ 3,636
Fair value, assets	$ 49	$ 38
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
Foreign currency forwards | Derivatives not designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 1,098	$ 808
Fair value, liabilities	$ 6	$ 3
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Cross currency interest rate swaps | Derivatives designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 150
Fair value, assets	$ 12
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets
Cross currency interest rate swaps | Derivatives designated as hedges: | Other non-current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 750	$ 155
Fair value, assets	$ 83	$ 1
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other non-current assets	Other non-current assets
Cross currency interest rate swaps | Derivatives designated as hedges: | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities		$ 801
Fair value, liabilities		$ 23
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Other non-current liabilities
Cross currency interest rate swaps | Derivatives designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities		$ 109
Fair value, liabilities		$ 9
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Accrued expenses and other liabilities
Total return swap | Derivatives not designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, liabilities		$ 224
Fair value, liabilities		$ 2
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other current assets
Total return swap | Derivatives not designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 183	$ 37
Fair value, liabilities	$ 6	$ 0
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities